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gstreamer/gst/gstutils.c
Tim-Philipp Müller ae0d1ee4a9 gst/gstutils.c: Docs enhancement: make it crystal clear what the gst_pad_add_*_probe() callbacks should look like. 
Original commit message from CVS:
* gst/gstutils.c:
Docs enhancement: make it crystal clear what the
gst_pad_add_*_probe() callbacks should look like.
2006-02-24 16:54:27 +00:00

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2002 Thomas Vander Stichele <thomas@apestaart.org>
*
* gstutils.c: Utility functions: gtk_get_property stuff, etc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstutils
* @short_description: Various utility functions
*
* When defining own plugins, use the GST_BOILERPLATE ease gobject creation.
*/
#include <stdio.h>
#include <string.h>
#include "gst_private.h"
#include "gstghostpad.h"
#include "gstutils.h"
#include "gstinfo.h"
#include "gstparse.h"
#include "gst-i18n-lib.h"
/**
* gst_util_dump_mem:
* @mem: a pointer to the memory to dump
* @size: the size of the memory block to dump
*
* Dumps the memory block into a hex representation. Useful for debugging.
*/
void
gst_util_dump_mem (const guchar * mem, guint size)
{
guint i, j;
GString *string = g_string_sized_new (50);
GString *chars = g_string_sized_new (18);
i = j = 0;
while (i < size) {
if (g_ascii_isprint (mem[i]))
g_string_append_printf (chars, "%c", mem[i]);
else
g_string_append_printf (chars, ".");
g_string_append_printf (string, "%02x ", mem[i]);
j++;
i++;
if (j == 16 || i == size) {
g_print ("%08x (%p): %-48.48s %-16.16s\n", i - j, mem + i - j,
string->str, chars->str);
g_string_set_size (string, 0);
g_string_set_size (chars, 0);
j = 0;
}
}
g_string_free (string, TRUE);
g_string_free (chars, TRUE);
}
/**
* gst_util_set_value_from_string:
* @value: the value to set
* @value_str: the string to get the value from
*
* Converts the string to the type of the value and
* sets the value with it.
*/
void
gst_util_set_value_from_string (GValue * value, const gchar * value_str)
{
gint sscanf_ret;
g_return_if_fail (value != NULL);
g_return_if_fail (value_str != NULL);
GST_CAT_DEBUG (GST_CAT_PARAMS, "parsing '%s' to type %s", value_str,
g_type_name (G_VALUE_TYPE (value)));
switch (G_VALUE_TYPE (value)) {
case G_TYPE_STRING:
g_value_set_string (value, g_strdup (value_str));
break;
case G_TYPE_ENUM:
case G_TYPE_INT:{
gint i;
sscanf_ret = sscanf (value_str, "%d", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_int (value, i);
break;
}
case G_TYPE_UINT:{
guint i;
sscanf_ret = sscanf (value_str, "%u", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_uint (value, i);
break;
}
case G_TYPE_LONG:{
glong i;
sscanf_ret = sscanf (value_str, "%ld", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_long (value, i);
break;
}
case G_TYPE_ULONG:{
gulong i;
sscanf_ret = sscanf (value_str, "%lu", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_ulong (value, i);
break;
}
case G_TYPE_BOOLEAN:{
gboolean i = FALSE;
if (!g_ascii_strncasecmp ("true", value_str, 4))
i = TRUE;
g_value_set_boolean (value, i);
break;
}
case G_TYPE_CHAR:{
gchar i;
sscanf_ret = sscanf (value_str, "%c", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_char (value, i);
break;
}
case G_TYPE_UCHAR:{
guchar i;
sscanf_ret = sscanf (value_str, "%c", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_uchar (value, i);
break;
}
case G_TYPE_FLOAT:{
gfloat i;
sscanf_ret = sscanf (value_str, "%f", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_float (value, i);
break;
}
case G_TYPE_DOUBLE:{
gfloat i;
sscanf_ret = sscanf (value_str, "%g", &i);
g_return_if_fail (sscanf_ret == 1);
g_value_set_double (value, (gdouble) i);
break;
}
default:
break;
}
}
/**
* gst_util_set_object_arg:
* @object: the object to set the argument of
* @name: the name of the argument to set
* @value: the string value to set
*
* Convertes the string value to the type of the objects argument and
* sets the argument with it.
*/
void
gst_util_set_object_arg (GObject * object, const gchar * name,
const gchar * value)
{
gboolean sscanf_ret;
if (name && value) {
GParamSpec *paramspec;
paramspec =
g_object_class_find_property (G_OBJECT_GET_CLASS (object), name);
if (!paramspec) {
return;
}
GST_DEBUG ("paramspec->flags is %d, paramspec->value_type is %d",
paramspec->flags, (gint) paramspec->value_type);
if (paramspec->flags & G_PARAM_WRITABLE) {
switch (paramspec->value_type) {
case G_TYPE_STRING:
g_object_set (G_OBJECT (object), name, value, NULL);
break;
case G_TYPE_ENUM:
case G_TYPE_INT:{
gint i;
sscanf_ret = sscanf (value, "%d", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_UINT:{
guint i;
sscanf_ret = sscanf (value, "%u", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_LONG:{
glong i;
sscanf_ret = sscanf (value, "%ld", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_ULONG:{
gulong i;
sscanf_ret = sscanf (value, "%lu", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_BOOLEAN:{
gboolean i = FALSE;
if (!g_ascii_strncasecmp ("true", value, 4))
i = TRUE;
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_CHAR:{
gchar i;
sscanf_ret = sscanf (value, "%c", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_UCHAR:{
guchar i;
sscanf_ret = sscanf (value, "%c", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_FLOAT:{
gfloat i;
sscanf_ret = sscanf (value, "%f", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
break;
}
case G_TYPE_DOUBLE:{
gfloat i;
sscanf_ret = sscanf (value, "%g", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, (gdouble) i, NULL);
break;
}
default:
if (G_IS_PARAM_SPEC_ENUM (paramspec)) {
gint i;
sscanf_ret = sscanf (value, "%d", &i);
g_return_if_fail (sscanf_ret == 1);
g_object_set (G_OBJECT (object), name, i, NULL);
}
break;
}
}
}
}
/* work around error C2520: conversion from unsigned __int64 to double
* not implemented, use signed __int64
*
* These are implemented as functions because on some platforms a 64bit int to
* double conversion is not defined/implemented.
*/
gdouble
gst_util_guint64_to_gdouble (guint64 value)
{
if (value & G_GINT64_CONSTANT (0x8000000000000000))
return (gdouble) ((gint64) value) + (gdouble) 18446744073709551616.;
else
return (gdouble) ((gint64) value);
}
guint64
gst_util_gdouble_to_guint64 (gdouble value)
{
if (value < (gdouble) 9223372036854775808.) /* 1 << 63 */
return ((guint64) ((gint64) value));
value -= (gdouble) 18446744073709551616.;
return ((guint64) ((gint64) value));
}
/* convenience struct for getting high and low uint32 parts of
* a guint64 */
typedef union
{
guint64 ll;
struct
{
#if G_BYTE_ORDER == G_BIG_ENDIAN
guint32 high, low;
#else
guint32 low, high;
#endif
} l;
} GstUInt64;
/* based on Hacker's Delight p152 */
static guint64
gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
{
GstUInt64 q1, q0, rhat;
GstUInt64 v, cmp1, cmp2;
guint s;
v.ll = denom;
/* count number of leading zeroes, we know they must be in the high
* part of denom since denom > G_MAXUINT32. */
s = v.l.high | (v.l.high >> 1);
s |= (s >> 2);
s |= (s >> 4);
s |= (s >> 8);
s = ~(s | (s >> 16));
s = s - ((s >> 1) & 0x55555555);
s = (s & 0x33333333) + ((s >> 2) & 0x33333333);
s = (s + (s >> 4)) & 0x0f0f0f0f;
s += (s >> 8);
s = (s + (s >> 16)) & 0x3f;
if (s > 0) {
/* normalize divisor and dividend */
v.ll <<= s;
c1.ll = (c1.ll << s) | (c0.l.high >> (32 - s));
c0.ll <<= s;
}
q1.ll = c1.ll / v.l.high;
rhat.ll = c1.ll - q1.ll * v.l.high;
cmp1.l.high = rhat.l.low;
cmp1.l.low = c0.l.high;
cmp2.ll = q1.ll * v.l.low;
while (q1.l.high || cmp2.ll > cmp1.ll) {
q1.ll--;
rhat.ll += v.l.high;
if (rhat.l.high)
break;
cmp1.l.high = rhat.l.low;
cmp2.ll -= v.l.low;
}
c1.l.high = c1.l.low;
c1.l.low = c0.l.high;
c1.ll -= q1.ll * v.ll;
q0.ll = c1.ll / v.l.high;
rhat.ll = c1.ll - q0.ll * v.l.high;
cmp1.l.high = rhat.l.low;
cmp1.l.low = c0.l.low;
cmp2.ll = q0.ll * v.l.low;
while (q0.l.high || cmp2.ll > cmp1.ll) {
q0.ll--;
rhat.ll += v.l.high;
if (rhat.l.high)
break;
cmp1.l.high = rhat.l.low;
cmp2.ll -= v.l.low;
}
q0.l.high += q1.l.low;
return q0.ll;
}
static guint64
gst_util_uint64_scale_int64 (guint64 val, guint64 num, guint64 denom)
{
GstUInt64 a0, a1, b0, b1, c0, ct, c1, result;
GstUInt64 v, n;
/* prepare input */
v.ll = val;
n.ll = num;
/* do 128 bits multiply
* nh nl
* * vh vl
* ----------
* a0 = vl * nl
* a1 = vl * nh
* b0 = vh * nl
* b1 = + vh * nh
* -------------------
* c1,c0
*/
a0.ll = (guint64) v.l.low * n.l.low;
a1.ll = (guint64) v.l.low * n.l.high;
b0.ll = (guint64) v.l.high * n.l.low;
b1.ll = (guint64) v.l.high * n.l.high;
/* and sum together with carry into 128 bits c1, c0 */
c0.l.low = a0.l.low;
ct.ll = (guint64) a0.l.high + a1.l.low + b0.l.low;
c0.l.high = ct.l.low;
c1.ll = (guint64) a1.l.high + b0.l.high + ct.l.high + b1.ll;
/* if high bits bigger than denom, we overflow */
if (c1.ll >= denom)
goto overflow;
/* shortcut for division by 1, c1.ll should be 0 because of the
* overflow check above. */
if (denom == 1)
return c0.ll;
/* and 128/64 bits division, result fits 64 bits */
if (denom <= G_MAXUINT32) {
guint32 den = (guint32) denom;
/* easy case, (c1,c0)128/(den)32 division */
c1.l.high %= den;
c1.l.high = c1.ll % den;
c1.l.low = c0.l.high;
c0.l.high = c1.ll % den;
result.l.high = c1.ll / den;
result.l.low = c0.ll / den;
} else {
result.ll = gst_util_div128_64 (c1, c0, denom);
}
return result.ll;
overflow:
{
return G_MAXUINT64;
}
}
/**
* gst_util_uint64_scale:
* @val: the number to scale
* @num: the numerator of the scale ratio
* @denom: the denominator of the scale ratio
*
* Scale @val by @num / @denom, trying to avoid overflows.
*
* This function can potentially be very slow if denom > G_MAXUINT32.
*
* Returns: @val * @num / @denom, trying to avoid overflows.
*/
guint64
gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom)
{
g_return_val_if_fail (denom != 0, G_MAXUINT64);
if (num == 0)
return 0;
if (num == 1 && denom == 1)
return val;
/* if the denom is high, we need to do a 64 muldiv */
if (denom > G_MAXINT32)
goto do_int64;
/* if num and denom are low we can do a 32 bit muldiv */
if (num <= G_MAXINT32)
goto do_int32;
/* val and num are high, we need 64 muldiv */
if (val > G_MAXINT32)
goto do_int64;
/* val is low and num is high, we can swap them and do 32 muldiv */
return gst_util_uint64_scale_int (num, (gint) val, (gint) denom);
do_int32:
return gst_util_uint64_scale_int (val, (gint) num, (gint) denom);
do_int64:
/* to the more heavy implementations... */
return gst_util_uint64_scale_int64 (val, num, denom);
}
/**
* gst_util_uint64_scale_int:
* @val: guint64 (such as a #GstClockTime) to scale.
* @num: numerator of the scale factor.
* @denom: denominator of the scale factor.
*
* Scale a guint64 by a factor expressed as a fraction (num/denom), avoiding
* overflows and loss of precision.
*
* @num and @denom must be positive integers. @denom cannot be 0.
*
* Returns: @val * @num / @denom, avoiding overflow and loss of precision
*/
guint64
gst_util_uint64_scale_int (guint64 val, gint num, gint denom)
{
GstUInt64 result;
GstUInt64 low, high;
g_return_val_if_fail (denom > 0, G_MAXUINT64);
g_return_val_if_fail (num >= 0, G_MAXUINT64);
if (num == 0)
return 0;
if (num == 1 && denom == 1)
return val;
if (val <= G_MAXUINT32)
/* simple case */
return val * num / denom;
/* do 96 bits mult/div */
low.ll = val;
result.ll = ((guint64) low.l.low) * num;
high.ll = ((guint64) low.l.high) * num + (result.l.high);
low.ll = high.ll / denom;
result.l.high = high.ll % denom;
result.ll /= denom;
/* avoid overflow */
if (low.ll + result.l.high > G_MAXUINT32)
goto overflow;
result.l.high += low.l.low;
return result.ll;
overflow:
{
return G_MAXUINT64;
}
}
/* -----------------------------------------------------
*
* The following code will be moved out of the main
* gstreamer library someday.
*/
#include "gstpad.h"
static void
string_append_indent (GString * str, gint count)
{
gint xx;
for (xx = 0; xx < count; xx++)
g_string_append_c (str, ' ');
}
/**
* gst_print_pad_caps:
* @buf: the buffer to print the caps in
* @indent: initial indentation
* @pad: the pad to print the caps from
*
* Write the pad capabilities in a human readable format into
* the given GString.
*/
void
gst_print_pad_caps (GString * buf, gint indent, GstPad * pad)
{
GstCaps *caps;
caps = pad->caps;
if (!caps) {
string_append_indent (buf, indent);
g_string_printf (buf, "%s:%s has no capabilities",
GST_DEBUG_PAD_NAME (pad));
} else {
char *s;
s = gst_caps_to_string (caps);
g_string_append (buf, s);
g_free (s);
}
}
/**
* gst_print_element_args:
* @buf: the buffer to print the args in
* @indent: initial indentation
* @element: the element to print the args of
*
* Print the element argument in a human readable format in the given
* GString.
*/
void
gst_print_element_args (GString * buf, gint indent, GstElement * element)
{
guint width;
GValue value = { 0, }; /* the important thing is that value.type = 0 */
gchar *str = NULL;
GParamSpec *spec, **specs, **walk;
specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (element), NULL);
width = 0;
for (walk = specs; *walk; walk++) {
spec = *walk;
if (width < strlen (spec->name))
width = strlen (spec->name);
}
for (walk = specs; *walk; walk++) {
spec = *walk;
if (spec->flags & G_PARAM_READABLE) {
g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (spec));
g_object_get_property (G_OBJECT (element), spec->name, &value);
str = g_strdup_value_contents (&value);
g_value_unset (&value);
} else {
str = g_strdup ("Parameter not readable.");
}
string_append_indent (buf, indent);
g_string_append (buf, spec->name);
string_append_indent (buf, 2 + width - strlen (spec->name));
g_string_append (buf, str);
g_string_append_c (buf, '\n');
g_free (str);
}
g_free (specs);
}
/**
* gst_element_create_all_pads:
* @element: a #GstElement to create pads for
*
* Creates a pad for each pad template that is always available.
* This function is only useful during object intialization of
* subclasses of #GstElement.
*/
void
gst_element_create_all_pads (GstElement * element)
{
GList *padlist;
/* FIXME: lock element */
padlist =
gst_element_class_get_pad_template_list (GST_ELEMENT_CLASS
(G_OBJECT_GET_CLASS (element)));
while (padlist) {
GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
if (padtempl->presence == GST_PAD_ALWAYS) {
GstPad *pad;
pad = gst_pad_new_from_template (padtempl, padtempl->name_template);
gst_element_add_pad (element, pad);
}
padlist = padlist->next;
}
}
/**
* gst_element_get_compatible_pad_template:
* @element: a #GstElement to get a compatible pad template for.
* @compattempl: the #GstPadTemplate to find a compatible template for.
*
* Retrieves a pad template from @element that is compatible with @compattempl.
* Pads from compatible templates can be linked together.
*
* Returns: a compatible #GstPadTemplate, or NULL if none was found. No
* unreferencing is necessary.
*/
GstPadTemplate *
gst_element_get_compatible_pad_template (GstElement * element,
GstPadTemplate * compattempl)
{
GstPadTemplate *newtempl = NULL;
GList *padlist;
GstElementClass *class;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (compattempl != NULL, NULL);
class = GST_ELEMENT_GET_CLASS (element);
padlist = gst_element_class_get_pad_template_list (class);
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"Looking for a suitable pad template in %s out of %d templates...",
GST_ELEMENT_NAME (element), g_list_length (padlist));
while (padlist) {
GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
GstCaps *intersection;
/* Ignore name
* Ignore presence
* Check direction (must be opposite)
* Check caps
*/
GST_CAT_LOG (GST_CAT_CAPS,
"checking pad template %s", padtempl->name_template);
if (padtempl->direction != compattempl->direction) {
GST_CAT_DEBUG (GST_CAT_CAPS,
"compatible direction: found %s pad template \"%s\"",
padtempl->direction == GST_PAD_SRC ? "src" : "sink",
padtempl->name_template);
GST_CAT_DEBUG (GST_CAT_CAPS,
"intersecting %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (compattempl));
GST_CAT_DEBUG (GST_CAT_CAPS,
"..and %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (padtempl));
intersection = gst_caps_intersect (GST_PAD_TEMPLATE_CAPS (compattempl),
GST_PAD_TEMPLATE_CAPS (padtempl));
GST_CAT_DEBUG (GST_CAT_CAPS, "caps are %scompatible %" GST_PTR_FORMAT,
(intersection ? "" : "not "), intersection);
if (!gst_caps_is_empty (intersection))
newtempl = padtempl;
gst_caps_unref (intersection);
if (newtempl)
break;
}
padlist = g_list_next (padlist);
}
if (newtempl)
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"Returning new pad template %p", newtempl);
else
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "No compatible pad template found");
return newtempl;
}
static GstPad *
gst_element_request_pad (GstElement * element, GstPadTemplate * templ,
const gchar * name)
{
GstPad *newpad = NULL;
GstElementClass *oclass;
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->request_new_pad)
newpad = (oclass->request_new_pad) (element, templ, name);
if (newpad)
gst_object_ref (newpad);
return newpad;
}
/**
* gst_element_get_pad_from_template:
* @element: a #GstElement.
* @templ: a #GstPadTemplate belonging to @element.
*
* Gets a pad from @element described by @templ. If the presence of @templ is
* #GST_PAD_REQUEST, requests a new pad. Can return %NULL for #GST_PAD_SOMETIMES
* templates.
*
* Returns: the #GstPad, or NULL if one could not be found or created.
*/
static GstPad *
gst_element_get_pad_from_template (GstElement * element, GstPadTemplate * templ)
{
GstPad *ret = NULL;
GstPadPresence presence;
/* If this function is ever exported, we need check the validity of `element'
* and `templ', and to make sure the template actually belongs to the
* element. */
presence = GST_PAD_TEMPLATE_PRESENCE (templ);
switch (presence) {
case GST_PAD_ALWAYS:
case GST_PAD_SOMETIMES:
ret = gst_element_get_static_pad (element, templ->name_template);
if (!ret && presence == GST_PAD_ALWAYS)
g_warning
("Element %s has an ALWAYS template %s, but no pad of the same name",
GST_OBJECT_NAME (element), templ->name_template);
break;
case GST_PAD_REQUEST:
ret = gst_element_request_pad (element, templ, NULL);
break;
}
return ret;
}
/**
* gst_element_request_compatible_pad:
* @element: a #GstElement.
* @templ: the #GstPadTemplate to which the new pad should be able to link.
*
* Requests a pad from @element. The returned pad should be unlinked and
* compatible with @templ. Might return an existing pad, or request a new one.
*
* Returns: a #GstPad, or %NULL if one could not be found or created.
*/
GstPad *
gst_element_request_compatible_pad (GstElement * element,
GstPadTemplate * templ)
{
GstPadTemplate *templ_new;
GstPad *pad = NULL;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
/* FIXME: should really loop through the templates, testing each for
* compatibility and pad availability. */
templ_new = gst_element_get_compatible_pad_template (element, templ);
if (templ_new)
pad = gst_element_get_pad_from_template (element, templ_new);
/* This can happen for non-request pads. No need to unref. */
if (pad && GST_PAD_PEER (pad))
pad = NULL;
return pad;
}
/**
* gst_element_get_compatible_pad:
* @element: a #GstElement in which the pad should be found.
* @pad: the #GstPad to find a compatible one for.
* @caps: the #GstCaps to use as a filter.
*
* Looks for an unlinked pad to which the given pad can link. It is not
* guaranteed that linking the pads will work, though it should work in most
* cases.
*
* Returns: the #GstPad to which a link can be made, or %NULL if one cannot be
* found.
*/
GstPad *
gst_element_get_compatible_pad (GstElement * element, GstPad * pad,
const GstCaps * caps)
{
GstIterator *pads;
GstPadTemplate *templ;
GstCaps *templcaps;
GstPad *foundpad = NULL;
gboolean done;
/* FIXME check for caps compatibility */
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"finding pad in %s compatible with %s:%s",
GST_ELEMENT_NAME (element), GST_DEBUG_PAD_NAME (pad));
g_return_val_if_fail (GST_PAD_PEER (pad) == NULL, NULL);
done = FALSE;
/* try to get an existing unlinked pad */
pads = gst_element_iterate_pads (element);
while (!done) {
gpointer padptr;
switch (gst_iterator_next (pads, &padptr)) {
case GST_ITERATOR_OK:
{
GstPad *peer;
GstPad *current;
current = GST_PAD (padptr);
GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
GST_DEBUG_PAD_NAME (current));
peer = gst_pad_get_peer (current);
if (peer == NULL && gst_pad_can_link (pad, current)) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"found existing unlinked pad %s:%s",
GST_DEBUG_PAD_NAME (current));
gst_iterator_free (pads);
return current;
} else {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unreffing pads");
gst_object_unref (current);
if (peer)
gst_object_unref (peer);
}
break;
}
case GST_ITERATOR_DONE:
done = TRUE;
break;
case GST_ITERATOR_RESYNC:
gst_iterator_resync (pads);
break;
case GST_ITERATOR_ERROR:
g_assert_not_reached ();
break;
}
}
gst_iterator_free (pads);
/* try to create a new one */
/* requesting is a little crazy, we need a template. Let's create one */
templcaps = gst_pad_get_caps (pad);
templ = gst_pad_template_new ((gchar *) GST_PAD_NAME (pad),
GST_PAD_DIRECTION (pad), GST_PAD_ALWAYS, templcaps);
foundpad = gst_element_request_compatible_pad (element, templ);
gst_object_unref (templ);
if (foundpad) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"found existing request pad %s:%s", GST_DEBUG_PAD_NAME (foundpad));
return foundpad;
}
GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element,
"Could not find a compatible pad to link to %s:%s",
GST_DEBUG_PAD_NAME (pad));
return NULL;
}
/**
* gst_element_state_get_name:
* @state: a #GstState to get the name of.
*
* Gets a string representing the given state.
*
* Returns: a string with the name of the state.
*/
const gchar *
gst_element_state_get_name (GstState state)
{
switch (state) {
#ifdef GST_DEBUG_COLOR
case GST_STATE_VOID_PENDING:
return "VOID_PENDING";
break;
case GST_STATE_NULL:
return "\033[01;34mNULL\033[00m";
break;
case GST_STATE_READY:
return "\033[01;31mREADY\033[00m";
break;
case GST_STATE_PLAYING:
return "\033[01;32mPLAYING\033[00m";
break;
case GST_STATE_PAUSED:
return "\033[01;33mPAUSED\033[00m";
break;
default:
/* This is a memory leak */
return g_strdup_printf ("\033[01;35;41mUNKNOWN!\033[00m(%d)", state);
#else
case GST_STATE_VOID_PENDING:
return "VOID_PENDING";
break;
case GST_STATE_NULL:
return "NULL";
break;
case GST_STATE_READY:
return "READY";
break;
case GST_STATE_PLAYING:
return "PLAYING";
break;
case GST_STATE_PAUSED:
return "PAUSED";
break;
default:
/* This is a memory leak */
return g_strdup_printf ("UNKNOWN!(%d)", state);
#endif
}
return "";
}
/**
* gst_element_factory_can_src_caps :
* @factory: factory to query
* @caps: the caps to check
*
* Checks if the factory can source the given capability.
*
* Returns: true if it can src the capabilities
*/
gboolean
gst_element_factory_can_src_caps (GstElementFactory * factory,
const GstCaps * caps)
{
GList *templates;
g_return_val_if_fail (factory != NULL, FALSE);
g_return_val_if_fail (caps != NULL, FALSE);
templates = factory->staticpadtemplates;
while (templates) {
GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
if (template->direction == GST_PAD_SRC) {
if (gst_caps_is_always_compatible (gst_static_caps_get (&template->
static_caps), caps))
return TRUE;
}
templates = g_list_next (templates);
}
return FALSE;
}
/**
* gst_element_factory_can_sink_caps :
* @factory: factory to query
* @caps: the caps to check
*
* Checks if the factory can sink the given capability.
*
* Returns: true if it can sink the capabilities
*/
gboolean
gst_element_factory_can_sink_caps (GstElementFactory * factory,
const GstCaps * caps)
{
GList *templates;
g_return_val_if_fail (factory != NULL, FALSE);
g_return_val_if_fail (caps != NULL, FALSE);
templates = factory->staticpadtemplates;
while (templates) {
GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
if (template->direction == GST_PAD_SINK) {
if (gst_caps_is_always_compatible (caps,
gst_static_caps_get (&template->static_caps)))
return TRUE;
}
templates = g_list_next (templates);
}
return FALSE;
}
/* if return val is true, *direct_child is a caller-owned ref on the direct
* child of ancestor that is part of object's ancestry */
static gboolean
object_has_ancestor (GstObject * object, GstObject * ancestor,
GstObject ** direct_child)
{
GstObject *child, *parent;
if (direct_child)
*direct_child = NULL;
child = gst_object_ref (object);
parent = gst_object_get_parent (object);
while (parent) {
if (ancestor == parent) {
if (direct_child)
*direct_child = child;
else
gst_object_unref (child);
gst_object_unref (parent);
return TRUE;
}
gst_object_unref (child);
child = parent;
parent = gst_object_get_parent (parent);
}
gst_object_unref (child);
return FALSE;
}
/* caller owns return */
static GstObject *
find_common_root (GstObject * o1, GstObject * o2)
{
GstObject *top = o1;
GstObject *kid1, *kid2;
GstObject *root = NULL;
while (GST_OBJECT_PARENT (top))
top = GST_OBJECT_PARENT (top);
/* the itsy-bitsy spider... */
if (!object_has_ancestor (o2, top, &kid2))
return NULL;
root = gst_object_ref (top);
while (TRUE) {
if (!object_has_ancestor (o1, kid2, &kid1)) {
gst_object_unref (kid2);
return root;
}
root = kid2;
if (!object_has_ancestor (o2, kid1, &kid2)) {
gst_object_unref (kid1);
return root;
}
root = kid1;
}
}
/* caller does not own return */
static GstPad *
ghost_up (GstElement * e, GstPad * pad)
{
static gint ghost_pad_index = 0;
GstPad *gpad;
gchar *name;
GstObject *parent = GST_OBJECT_PARENT (e);
name = g_strdup_printf ("ghost%d", ghost_pad_index++);
gpad = gst_ghost_pad_new (name, pad);
g_free (name);
if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
g_warning ("Pad named %s already exists in element %s\n",
GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
gst_object_unref ((GstObject *) gpad);
return NULL;
}
return gpad;
}
static void
remove_pad (gpointer ppad, gpointer unused)
{
GstPad *pad = ppad;
if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
g_warning ("Couldn't remove pad %s from element %s",
GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
}
static gboolean
prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
GSList ** pads_created)
{
GstObject *root;
GstObject *e1, *e2;
GSList *pads_created_local = NULL;
g_assert (pads_created);
e1 = GST_OBJECT_PARENT (*src);
e2 = GST_OBJECT_PARENT (*sink);
if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
return TRUE;
}
GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
/* we need to setup some ghost pads */
root = find_common_root (e1, e2);
if (!root) {
g_warning
("Trying to connect elements that don't share a common ancestor: %s and %s\n",
GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2));
return FALSE;
}
while (GST_OBJECT_PARENT (e1) != root) {
*src = ghost_up ((GstElement *) e1, *src);
if (!*src)
goto cleanup_fail;
e1 = GST_OBJECT_PARENT (*src);
pads_created_local = g_slist_prepend (pads_created_local, *src);
}
while (GST_OBJECT_PARENT (e2) != root) {
*sink = ghost_up ((GstElement *) e2, *sink);
if (!*sink)
goto cleanup_fail;
e2 = GST_OBJECT_PARENT (*sink);
pads_created_local = g_slist_prepend (pads_created_local, *sink);
}
gst_object_unref (root);
*pads_created = g_slist_concat (*pads_created, pads_created_local);
return TRUE;
cleanup_fail:
gst_object_unref (root);
g_slist_foreach (pads_created_local, remove_pad, NULL);
g_slist_free (pads_created_local);
return FALSE;
}
static gboolean
pad_link_maybe_ghosting (GstPad * src, GstPad * sink)
{
GSList *pads_created = NULL;
gboolean ret;
if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
ret = FALSE;
} else {
ret = (gst_pad_link (src, sink) == GST_PAD_LINK_OK);
}
if (!ret) {
g_slist_foreach (pads_created, remove_pad, NULL);
}
g_slist_free (pads_created);
return ret;
}
/**
* gst_element_link_pads:
* @src: a #GstElement containing the source pad.
* @srcpadname: the name of the #GstPad in source element or NULL for any pad.
* @dest: the #GstElement containing the destination pad.
* @destpadname: the name of the #GstPad in destination element,
* or NULL for any pad.
*
* Links the two named pads of the source and destination elements.
* Side effect is that if one of the pads has no parent, it becomes a
* child of the parent of the other element. If they have different
* parents, the link fails.
*
* Returns: TRUE if the pads could be linked, FALSE otherwise.
*/
gboolean
gst_element_link_pads (GstElement * src, const gchar * srcpadname,
GstElement * dest, const gchar * destpadname)
{
const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
GstPad *srcpad, *destpad;
GstPadTemplate *srctempl, *desttempl;
GstElementClass *srcclass, *destclass;
/* checks */
g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
srcclass = GST_ELEMENT_GET_CLASS (src);
destclass = GST_ELEMENT_GET_CLASS (dest);
GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
"trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
destpadname ? destpadname : "(any)");
/* get a src pad */
if (srcpadname) {
/* name specified, look it up */
srcpad = gst_element_get_pad (src, srcpadname);
if (!srcpad) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
GST_ELEMENT_NAME (src), srcpadname);
return FALSE;
} else {
if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
GST_DEBUG_PAD_NAME (srcpad));
gst_object_unref (srcpad);
return FALSE;
}
if (GST_PAD_PEER (srcpad) != NULL) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is already linked",
GST_DEBUG_PAD_NAME (srcpad));
gst_object_unref (srcpad);
return FALSE;
}
}
srcpads = NULL;
} else {
/* no name given, get the first available pad */
GST_OBJECT_LOCK (src);
srcpads = GST_ELEMENT_PADS (src);
srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
if (srcpad)
gst_object_ref (srcpad);
GST_OBJECT_UNLOCK (src);
}
/* get a destination pad */
if (destpadname) {
/* name specified, look it up */
destpad = gst_element_get_pad (dest, destpadname);
if (!destpad) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
GST_ELEMENT_NAME (dest), destpadname);
return FALSE;
} else {
if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
GST_DEBUG_PAD_NAME (destpad));
gst_object_unref (destpad);
return FALSE;
}
if (GST_PAD_PEER (destpad) != NULL) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is already linked",
GST_DEBUG_PAD_NAME (destpad));
gst_object_unref (destpad);
return FALSE;
}
}
destpads = NULL;
} else {
/* no name given, get the first available pad */
GST_OBJECT_LOCK (dest);
destpads = GST_ELEMENT_PADS (dest);
destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
if (destpad)
gst_object_ref (destpad);
GST_OBJECT_UNLOCK (dest);
}
if (srcpadname && destpadname) {
gboolean result;
/* two explicitly specified pads */
result = pad_link_maybe_ghosting (srcpad, destpad);
gst_object_unref (srcpad);
gst_object_unref (destpad);
return result;
}
if (srcpad) {
/* loop through the allowed pads in the source, trying to find a
* compatible destination pad */
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"looping through allowed src and dest pads");
do {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
GST_DEBUG_PAD_NAME (srcpad));
if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
(GST_PAD_PEER (srcpad) == NULL)) {
GstPad *temp;
if (destpadname) {
temp = destpad;
gst_object_ref (temp);
} else {
temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
}
if (temp && pad_link_maybe_ghosting (srcpad, temp)) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
if (destpad)
gst_object_unref (destpad);
gst_object_unref (srcpad);
gst_object_unref (temp);
return TRUE;
}
if (temp) {
gst_object_unref (temp);
}
}
/* find a better way for this mess */
if (srcpads) {
srcpads = g_list_next (srcpads);
if (srcpads) {
gst_object_unref (srcpad);
srcpad = GST_PAD_CAST (srcpads->data);
gst_object_ref (srcpad);
}
}
} while (srcpads);
}
if (srcpadname) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
if (srcpad)
gst_object_unref (srcpad);
srcpad = NULL;
if (destpad)
gst_object_unref (destpad);
destpad = NULL;
} else {
if (srcpad)
gst_object_unref (srcpad);
srcpad = NULL;
}
if (destpad) {
/* loop through the existing pads in the destination */
do {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
GST_DEBUG_PAD_NAME (destpad));
if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
(GST_PAD_PEER (destpad) == NULL)) {
GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
if (temp && pad_link_maybe_ghosting (temp, destpad)) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
gst_object_unref (temp);
gst_object_unref (destpad);
if (srcpad)
gst_object_unref (srcpad);
return TRUE;
}
if (temp) {
gst_object_unref (temp);
}
}
if (destpads) {
destpads = g_list_next (destpads);
if (destpads) {
gst_object_unref (destpad);
destpad = GST_PAD_CAST (destpads->data);
gst_object_ref (destpad);
}
}
} while (destpads);
}
if (destpadname) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
gst_object_unref (destpad);
if (srcpad)
gst_object_unref (srcpad);
return FALSE;
} else {
if (srcpad)
gst_object_unref (srcpad);
srcpad = NULL;
if (destpad)
gst_object_unref (destpad);
destpad = NULL;
}
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"we might have request pads on both sides, checking...");
srctempls = gst_element_class_get_pad_template_list (srcclass);
desttempls = gst_element_class_get_pad_template_list (destclass);
if (srctempls && desttempls) {
while (srctempls) {
srctempl = (GstPadTemplate *) srctempls->data;
if (srctempl->presence == GST_PAD_REQUEST) {
for (l = desttempls; l; l = l->next) {
desttempl = (GstPadTemplate *) l->data;
if (desttempl->presence == GST_PAD_REQUEST &&
desttempl->direction != srctempl->direction) {
if (gst_caps_is_always_compatible (gst_pad_template_get_caps
(srctempl), gst_pad_template_get_caps (desttempl))) {
srcpad =
gst_element_get_request_pad (src, srctempl->name_template);
destpad =
gst_element_get_request_pad (dest, desttempl->name_template);
if (pad_link_maybe_ghosting (srcpad, destpad)) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"linked pad %s:%s to pad %s:%s",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
gst_object_unref (srcpad);
gst_object_unref (destpad);
return TRUE;
}
/* it failed, so we release the request pads */
gst_element_release_request_pad (src, srcpad);
gst_element_release_request_pad (dest, destpad);
}
}
}
}
srctempls = srctempls->next;
}
}
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
return FALSE;
}
/**
* gst_element_link_pads_filtered:
* @src: a #GstElement containing the source pad.
* @srcpadname: the name of the #GstPad in source element or NULL for any pad.
* @dest: the #GstElement containing the destination pad.
* @destpadname: the name of the #GstPad in destination element or NULL for any pad.
* @filter: the #GstCaps to filter the link, or #NULL for no filter.
*
* Links the two named pads of the source and destination elements. Side effect
* is that if one of the pads has no parent, it becomes a child of the parent of
* the other element. If they have different parents, the link fails. If @caps
* is not #NULL, makes sure that the caps of the link is a subset of @caps.
*
* Returns: TRUE if the pads could be linked, FALSE otherwise.
*/
gboolean
gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
GstElement * dest, const gchar * destpadname, GstCaps * filter)
{
/* checks */
g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
if (filter) {
GstElement *capsfilter;
GstObject *parent;
GstState state, pending;
capsfilter = gst_element_factory_make ("capsfilter", NULL);
if (!capsfilter) {
GST_ERROR ("Could not make a capsfilter");
return FALSE;
}
parent = gst_object_get_parent (GST_OBJECT (src));
g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
GST_ERROR ("Could not add capsfilter");
gst_object_unref (capsfilter);
gst_object_unref (parent);
return FALSE;
}
if (pending != GST_STATE_VOID_PENDING)
state = pending;
gst_element_set_state (capsfilter, state);
gst_object_unref (parent);
g_object_set (capsfilter, "caps", filter, NULL);
if (gst_element_link_pads (src, srcpadname, capsfilter, "sink")
&& gst_element_link_pads (capsfilter, "src", dest, destpadname)) {
return TRUE;
} else {
GST_INFO ("Could not link elements");
gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
/* will unref and unlink as appropriate */
return FALSE;
}
} else {
return gst_element_link_pads (src, srcpadname, dest, destpadname);
}
}
/**
* gst_element_link:
* @src: a #GstElement containing the source pad.
* @dest: the #GstElement containing the destination pad.
*
* Links @src to @dest. The link must be from source to
* destination; the other direction will not be tried. The function looks for
* existing pads that aren't linked yet. It will request new pads if necessary.
* If multiple links are possible, only one is established.
*
* Returns: TRUE if the elements could be linked, FALSE otherwise.
*/
gboolean
gst_element_link (GstElement * src, GstElement * dest)
{
return gst_element_link_pads_filtered (src, NULL, dest, NULL, NULL);
}
/**
* gst_element_link_many:
* @element_1: the first #GstElement in the link chain.
* @element_2: the second #GstElement in the link chain.
* @...: the NULL-terminated list of elements to link in order.
*
* Chain together a series of elements. Uses gst_element_link().
*
* Returns: TRUE on success, FALSE otherwise.
*/
gboolean
gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
{
va_list args;
g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
va_start (args, element_2);
while (element_2) {
if (!gst_element_link (element_1, element_2))
return FALSE;
element_1 = element_2;
element_2 = va_arg (args, GstElement *);
}
va_end (args);
return TRUE;
}
/**
* gst_element_link_filtered:
* @src: a #GstElement containing the source pad.
* @dest: the #GstElement containing the destination pad.
* @filter: the #GstCaps to filter the link, or #NULL for no filter.
*
* Links @src to @dest using the given caps as filtercaps.
* The link must be from source to
* destination; the other direction will not be tried. The function looks for
* existing pads that aren't linked yet. It will request new pads if necessary.
* If multiple links are possible, only one is established.
*
* Returns: TRUE if the pads could be linked, FALSE otherwise.
*/
gboolean
gst_element_link_filtered (GstElement * src, GstElement * dest,
GstCaps * filter)
{
return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
}
/**
* gst_element_unlink_pads:
* @src: a #GstElement containing the source pad.
* @srcpadname: the name of the #GstPad in source element.
* @dest: a #GstElement containing the destination pad.
* @destpadname: the name of the #GstPad in destination element.
*
* Unlinks the two named pads of the source and destination elements.
*/
void
gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
GstElement * dest, const gchar * destpadname)
{
GstPad *srcpad, *destpad;
g_return_if_fail (src != NULL);
g_return_if_fail (GST_IS_ELEMENT (src));
g_return_if_fail (srcpadname != NULL);
g_return_if_fail (dest != NULL);
g_return_if_fail (GST_IS_ELEMENT (dest));
g_return_if_fail (destpadname != NULL);
/* obtain the pads requested */
srcpad = gst_element_get_pad (src, srcpadname);
if (srcpad == NULL) {
GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
return;
}
destpad = gst_element_get_pad (dest, destpadname);
if (destpad == NULL) {
GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
destpadname);
gst_object_unref (srcpad);
return;
}
/* we're satisified they can be unlinked, let's do it */
gst_pad_unlink (srcpad, destpad);
gst_object_unref (srcpad);
gst_object_unref (destpad);
}
/**
* gst_element_unlink_many:
* @element_1: the first #GstElement in the link chain.
* @element_2: the second #GstElement in the link chain.
* @...: the NULL-terminated list of elements to unlink in order.
*
* Unlinks a series of elements. Uses gst_element_unlink().
*/
void
gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
{
va_list args;
g_return_if_fail (element_1 != NULL && element_2 != NULL);
g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
va_start (args, element_2);
while (element_2) {
gst_element_unlink (element_1, element_2);
element_1 = element_2;
element_2 = va_arg (args, GstElement *);
}
va_end (args);
}
/**
* gst_element_unlink:
* @src: the source #GstElement to unlink.
* @dest: the sink #GstElement to unlink.
*
* Unlinks all source pads of the source element with all sink pads
* of the sink element to which they are linked.
*/
void
gst_element_unlink (GstElement * src, GstElement * dest)
{
GstIterator *pads;
gboolean done = FALSE;
g_return_if_fail (GST_IS_ELEMENT (src));
g_return_if_fail (GST_IS_ELEMENT (dest));
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
pads = gst_element_iterate_pads (src);
while (!done) {
gpointer data;
switch (gst_iterator_next (pads, &data)) {
case GST_ITERATOR_OK:
{
GstPad *pad = GST_PAD_CAST (data);
if (GST_PAD_IS_SRC (pad)) {
GstPad *peerpad = gst_pad_get_peer (pad);
/* see if the pad is connected and is really a pad
* of dest */
if (peerpad) {
GstElement *peerelem;
peerelem = gst_pad_get_parent_element (peerpad);
if (peerelem == dest) {
gst_pad_unlink (pad, peerpad);
}
if (peerelem)
gst_object_unref (peerelem);
gst_object_unref (peerpad);
}
}
gst_object_unref (pad);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (pads);
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
}
}
/**
* gst_element_query_position:
* @element: a #GstElement to invoke the position query on.
* @format: a pointer to the #GstFormat asked for.
* On return contains the #GstFormat used.
* @cur: A location in which to store the current position, or NULL.
*
* Queries an element for the stream position.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_element_query_position (GstElement * element, GstFormat * format,
gint64 * cur)
{
GstQuery *query;
gboolean ret;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (format != NULL, FALSE);
query = gst_query_new_position (*format);
ret = gst_element_query (element, query);
if (ret)
gst_query_parse_position (query, format, cur);
gst_query_unref (query);
return ret;
}
/**
* gst_element_query_duration:
* @element: a #GstElement to invoke the duration query on.
* @format: a pointer to the #GstFormat asked for.
* On return contains the #GstFormat used.
* @duration: A location in which to store the total duration, or NULL.
*
* Queries an element for the total stream duration.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_element_query_duration (GstElement * element, GstFormat * format,
gint64 * duration)
{
GstQuery *query;
gboolean ret;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (format != NULL, FALSE);
query = gst_query_new_duration (*format);
ret = gst_element_query (element, query);
if (ret)
gst_query_parse_duration (query, format, duration);
gst_query_unref (query);
return ret;
}
/**
* gst_element_query_convert:
* @element: a #GstElement to invoke the convert query on.
* @src_format: a #GstFormat to convert from.
* @src_val: a value to convert.
* @dest_format: a pointer to the #GstFormat to convert to.
* @dest_val: a pointer to the result.
*
* Queries an element to convert @src_val in @src_format to @dest_format.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_element_query_convert (GstElement * element, GstFormat src_format,
gint64 src_val, GstFormat * dest_format, gint64 * dest_val)
{
GstQuery *query;
gboolean ret;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (dest_format != NULL, FALSE);
g_return_val_if_fail (dest_val != NULL, FALSE);
if (*dest_format == src_format) {
*dest_val = src_val;
return TRUE;
}
query = gst_query_new_convert (src_format, src_val, *dest_format);
ret = gst_element_query (element, query);
if (ret)
gst_query_parse_convert (query, NULL, NULL, dest_format, dest_val);
gst_query_unref (query);
return ret;
}
/**
* gst_pad_can_link:
* @srcpad: the source #GstPad to link.
* @sinkpad: the sink #GstPad to link.
*
* Checks if the source pad and the sink pad can be linked.
* Both @srcpad and @sinkpad must be unlinked.
*
* Returns: TRUE if the pads can be linked, FALSE otherwise.
*/
gboolean
gst_pad_can_link (GstPad * srcpad, GstPad * sinkpad)
{
/* FIXME This function is gross. It's almost a direct copy of
* gst_pad_link_filtered(). Any decent programmer would attempt
* to merge the two functions, which I will do some day. --ds
*/
/* generic checks */
g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
/* FIXME: shouldn't we convert this to g_return_val_if_fail? */
if (GST_PAD_PEER (srcpad) != NULL) {
GST_CAT_INFO (GST_CAT_PADS, "Source pad %s:%s has a peer, failed",
GST_DEBUG_PAD_NAME (srcpad));
return FALSE;
}
if (GST_PAD_PEER (sinkpad) != NULL) {
GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has a peer, failed",
GST_DEBUG_PAD_NAME (sinkpad));
return FALSE;
}
if (!GST_PAD_IS_SRC (srcpad)) {
GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s is not source pad, failed",
GST_DEBUG_PAD_NAME (srcpad));
return FALSE;
}
if (!GST_PAD_IS_SINK (sinkpad)) {
GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s is not sink pad, failed",
GST_DEBUG_PAD_NAME (sinkpad));
return FALSE;
}
if (GST_PAD_PARENT (srcpad) == NULL) {
GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s has no parent, failed",
GST_DEBUG_PAD_NAME (srcpad));
return FALSE;
}
if (GST_PAD_PARENT (sinkpad) == NULL) {
GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has no parent, failed",
GST_DEBUG_PAD_NAME (srcpad));
return FALSE;
}
return TRUE;
}
/**
* gst_pad_use_fixed_caps:
* @pad: the pad to use
*
* A helper function you can use that sets the
* @gst_pad_get_fixed_caps_func as the getcaps function for the
* pad. This way the function will always return the negotiated caps
* or in case the pad is not negotiated, the padtemplate caps.
*
* Use this function on a pad that, once _set_caps() has been called
* on it, cannot be renegotiated to something else.
*/
void
gst_pad_use_fixed_caps (GstPad * pad)
{
gst_pad_set_getcaps_function (pad, gst_pad_get_fixed_caps_func);
}
/**
* gst_pad_get_fixed_caps_func:
* @pad: the pad to use
*
* A helper function you can use as a GetCaps function that
* will return the currently negotiated caps or the padtemplate
* when NULL.
*
* Returns: The currently negotiated caps or the padtemplate.
*/
GstCaps *
gst_pad_get_fixed_caps_func (GstPad * pad)
{
GstCaps *result;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
if (GST_PAD_CAPS (pad)) {
result = GST_PAD_CAPS (pad);
GST_CAT_DEBUG (GST_CAT_CAPS,
"using pad caps %p %" GST_PTR_FORMAT, result, result);
result = gst_caps_ref (result);
goto done;
}
if (GST_PAD_PAD_TEMPLATE (pad)) {
GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
result = GST_PAD_TEMPLATE_CAPS (templ);
GST_CAT_DEBUG (GST_CAT_CAPS,
"using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
result);
result = gst_caps_ref (result);
goto done;
}
GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
result = gst_caps_new_empty ();
done:
return result;
}
/**
* gst_pad_get_parent_element:
* @pad: a pad
*
* Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
* its parent is not an element, return NULL.
*
* Returns: The parent of the pad. The caller has a reference on the parent, so
* unref when you're finished with it.
*
* MT safe.
*/
GstElement *
gst_pad_get_parent_element (GstPad * pad)
{
GstObject *p;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
p = gst_object_get_parent (GST_OBJECT_CAST (pad));
if (p && !GST_IS_ELEMENT (p)) {
gst_object_unref (p);
p = NULL;
}
return GST_ELEMENT_CAST (p);
}
/**
* gst_object_default_error:
* @source: the #GstObject that initiated the error.
* @error: the GError.
* @debug: an additional debug information string, or NULL.
*
* A default error function.
*
* The default handler will simply print the error string using g_print.
*/
void
gst_object_default_error (GstObject * source, GError * error, gchar * debug)
{
gchar *name = gst_object_get_path_string (source);
g_print (_("ERROR: from element %s: %s\n"), name, error->message);
if (debug)
g_print (_("Additional debug info:\n%s\n"), debug);
g_free (name);
}
/**
* gst_bin_add_many:
* @bin: a #GstBin
* @element_1: the #GstElement element to add to the bin
* @...: additional elements to add to the bin
*
* Adds a NULL-terminated list of elements to a bin. This function is
* equivalent to calling gst_bin_add() for each member of the list.
*/
void
gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
{
va_list args;
g_return_if_fail (GST_IS_BIN (bin));
g_return_if_fail (GST_IS_ELEMENT (element_1));
va_start (args, element_1);
while (element_1) {
gst_bin_add (bin, element_1);
element_1 = va_arg (args, GstElement *);
}
va_end (args);
}
/**
* gst_bin_remove_many:
* @bin: a #GstBin
* @element_1: the first #GstElement to remove from the bin
* @...: NULL-terminated list of elements to remove from the bin
*
* Remove a list of elements from a bin. This function is equivalent
* to calling gst_bin_remove() with each member of the list.
*/
void
gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
{
va_list args;
g_return_if_fail (GST_IS_BIN (bin));
g_return_if_fail (GST_IS_ELEMENT (element_1));
va_start (args, element_1);
while (element_1) {
gst_bin_remove (bin, element_1);
element_1 = va_arg (args, GstElement *);
}
va_end (args);
}
static void
gst_element_populate_std_props (GObjectClass * klass, const gchar * prop_name,
guint arg_id, GParamFlags flags)
{
GQuark prop_id = g_quark_from_string (prop_name);
GParamSpec *pspec;
static GQuark fd_id = 0;
static GQuark blocksize_id;
static GQuark bytesperread_id;
static GQuark dump_id;
static GQuark filesize_id;
static GQuark mmapsize_id;
static GQuark location_id;
static GQuark offset_id;
static GQuark silent_id;
static GQuark touch_id;
if (!fd_id) {
fd_id = g_quark_from_static_string ("fd");
blocksize_id = g_quark_from_static_string ("blocksize");
bytesperread_id = g_quark_from_static_string ("bytesperread");
dump_id = g_quark_from_static_string ("dump");
filesize_id = g_quark_from_static_string ("filesize");
mmapsize_id = g_quark_from_static_string ("mmapsize");
location_id = g_quark_from_static_string ("location");
offset_id = g_quark_from_static_string ("offset");
silent_id = g_quark_from_static_string ("silent");
touch_id = g_quark_from_static_string ("touch");
}
if (prop_id == fd_id) {
pspec = g_param_spec_int ("fd", "File-descriptor",
"File-descriptor for the file being read", 0, G_MAXINT, 0, flags);
} else if (prop_id == blocksize_id) {
pspec = g_param_spec_ulong ("blocksize", "Block Size",
"Block size to read per buffer", 0, G_MAXULONG, 4096, flags);
} else if (prop_id == bytesperread_id) {
pspec = g_param_spec_int ("bytesperread", "Bytes per read",
"Number of bytes to read per buffer", G_MININT, G_MAXINT, 0, flags);
} else if (prop_id == dump_id) {
pspec = g_param_spec_boolean ("dump", "Dump",
"Dump bytes to stdout", FALSE, flags);
} else if (prop_id == filesize_id) {
pspec = g_param_spec_int64 ("filesize", "File Size",
"Size of the file being read", 0, G_MAXINT64, 0, flags);
} else if (prop_id == mmapsize_id) {
pspec = g_param_spec_ulong ("mmapsize", "mmap() Block Size",
"Size in bytes of mmap()d regions", 0, G_MAXULONG, 4 * 1048576, flags);
} else if (prop_id == location_id) {
pspec = g_param_spec_string ("location", "File Location",
"Location of the file to read", NULL, flags);
} else if (prop_id == offset_id) {
pspec = g_param_spec_int64 ("offset", "File Offset",
"Byte offset of current read pointer", 0, G_MAXINT64, 0, flags);
} else if (prop_id == silent_id) {
pspec = g_param_spec_boolean ("silent", "Silent", "Don't produce events",
FALSE, flags);
} else if (prop_id == touch_id) {
pspec = g_param_spec_boolean ("touch", "Touch read data",
"Touch data to force disk read before " "push ()", TRUE, flags);
} else {
g_warning ("Unknown - 'standard' property '%s' id %d from klass %s",
prop_name, arg_id, g_type_name (G_OBJECT_CLASS_TYPE (klass)));
pspec = NULL;
}
if (pspec) {
g_object_class_install_property (klass, arg_id, pspec);
}
}
/**
* gst_element_class_install_std_props:
* @klass: the #GstElementClass to add the properties to.
* @first_name: the name of the first property.
* in a NULL terminated
* @...: the id and flags of the first property, followed by
* further 'name', 'id', 'flags' triplets and terminated by NULL.
*
* Adds a list of standardized properties with types to the @klass.
* the id is for the property switch in your get_prop method, and
* the flags determine readability / writeability.
**/
void
gst_element_class_install_std_props (GstElementClass * klass,
const gchar * first_name, ...)
{
const char *name;
va_list args;
g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
va_start (args, first_name);
name = first_name;
while (name) {
int arg_id = va_arg (args, int);
int flags = va_arg (args, int);
gst_element_populate_std_props ((GObjectClass *) klass, name, arg_id,
flags);
name = va_arg (args, char *);
}
va_end (args);
}
/**
* gst_buffer_merge:
* @buf1: the first source #GstBuffer to merge.
* @buf2: the second source #GstBuffer to merge.
*
* Create a new buffer that is the concatenation of the two source
* buffers. The original source buffers will not be modified or
* unref'd. Make sure you unref the source buffers if they are not used
* anymore afterwards.
*
* If the buffers point to contiguous areas of memory, the buffer
* is created without copying the data.
*
* Returns: the new #GstBuffer which is the concatenation of the source buffers.
*/
GstBuffer *
gst_buffer_merge (GstBuffer * buf1, GstBuffer * buf2)
{
GstBuffer *result;
/* we're just a specific case of the more general gst_buffer_span() */
result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
return result;
}
/**
* gst_buffer_join:
* @buf1: the first source #GstBuffer.
* @buf2: the second source #GstBuffer.
*
* Create a new buffer that is the concatenation of the two source
* buffers, and unrefs the original source buffers.
*
* If the buffers point to contiguous areas of memory, the buffer
* is created without copying the data.
*
* Returns: the new #GstBuffer which is the concatenation of the source buffers.
*/
GstBuffer *
gst_buffer_join (GstBuffer * buf1, GstBuffer * buf2)
{
GstBuffer *result;
result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
gst_buffer_unref (buf1);
gst_buffer_unref (buf2);
return result;
}
/**
* gst_buffer_stamp:
* @dest: buffer to stamp
* @src: buffer to stamp from
*
* Copies additional information (the timestamp, duration, and offset start
* and end) from one buffer to the other.
*
* This function does not copy any buffer flags or caps.
*/
void
gst_buffer_stamp (GstBuffer * dest, const GstBuffer * src)
{
g_return_if_fail (dest != NULL);
g_return_if_fail (src != NULL);
GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
}
static gboolean
intersect_caps_func (GstPad * pad, GValue * ret, GstPad * orig)
{
if (pad != orig) {
GstCaps *peercaps, *existing;
existing = g_value_get_pointer (ret);
peercaps = gst_pad_peer_get_caps (pad);
if (peercaps == NULL)
peercaps = gst_caps_new_any ();
g_value_set_pointer (ret, gst_caps_intersect (existing, peercaps));
gst_caps_unref (existing);
gst_caps_unref (peercaps);
}
gst_object_unref (pad);
return TRUE;
}
/**
* gst_pad_proxy_getcaps:
* @pad: a #GstPad to proxy.
*
* Calls gst_pad_get_allowed_caps() for every other pad belonging to the
* same element as @pad, and returns the intersection of the results.
*
* This function is useful as a default getcaps function for an element
* that can handle any stream format, but requires all its pads to have
* the same caps. Two such elements are tee and aggregator.
*
* Returns: the intersection of the other pads' allowed caps.
*/
GstCaps *
gst_pad_proxy_getcaps (GstPad * pad)
{
GstElement *element;
GstCaps *caps, *intersected;
GstIterator *iter;
GstIteratorResult res;
GValue ret = { 0, };
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_DEBUG ("proxying getcaps for %s:%s", GST_DEBUG_PAD_NAME (pad));
element = gst_pad_get_parent_element (pad);
if (element == NULL)
return NULL;
iter = gst_element_iterate_pads (element);
g_value_init (&ret, G_TYPE_POINTER);
g_value_set_pointer (&ret, gst_caps_new_any ());
res = gst_iterator_fold (iter, (GstIteratorFoldFunction) intersect_caps_func,
&ret, pad);
gst_iterator_free (iter);
if (res != GST_ITERATOR_DONE)
goto pads_changed;
gst_object_unref (element);
caps = g_value_get_pointer (&ret);
g_value_unset (&ret);
intersected = gst_caps_intersect (caps, gst_pad_get_pad_template_caps (pad));
gst_caps_unref (caps);
return intersected;
/* ERRORS */
pads_changed:
{
g_warning ("Pad list changed during capsnego for element %s",
GST_ELEMENT_NAME (element));
gst_object_unref (element);
return NULL;
}
}
typedef struct
{
GstPad *orig;
GstCaps *caps;
} LinkData;
static gboolean
link_fold_func (GstPad * pad, GValue * ret, LinkData * data)
{
gboolean success = TRUE;
if (pad != data->orig) {
success = gst_pad_set_caps (pad, data->caps);
g_value_set_boolean (ret, success);
}
gst_object_unref (pad);
return success;
}
/**
* gst_pad_proxy_setcaps
* @pad: a #GstPad to proxy from
* @caps: the #GstCaps to link with
*
* Calls gst_pad_set_caps() for every other pad belonging to the
* same element as @pad. If gst_pad_set_caps() fails on any pad,
* the proxy setcaps fails. May be used only during negotiation.
*
* Returns: TRUE if sucessful
*/
gboolean
gst_pad_proxy_setcaps (GstPad * pad, GstCaps * caps)
{
GstElement *element;
GstIterator *iter;
GstIteratorResult res;
GValue ret = { 0, };
LinkData data;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (caps != NULL, FALSE);
GST_DEBUG ("proxying pad link for %s:%s", GST_DEBUG_PAD_NAME (pad));
element = gst_pad_get_parent_element (pad);
if (element == NULL)
return FALSE;
iter = gst_element_iterate_pads (element);
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, TRUE);
data.orig = pad;
data.caps = caps;
res = gst_iterator_fold (iter, (GstIteratorFoldFunction) link_fold_func,
&ret, &data);
gst_iterator_free (iter);
if (res != GST_ITERATOR_DONE)
goto pads_changed;
gst_object_unref (element);
/* ok not to unset the gvalue */
return g_value_get_boolean (&ret);
/* ERRORS */
pads_changed:
{
g_warning ("Pad list changed during proxy_pad_link for element %s",
GST_ELEMENT_NAME (element));
gst_object_unref (element);
return FALSE;
}
}
/**
* gst_pad_query_position:
* @pad: a #GstPad to invoke the position query on.
* @format: a pointer to the #GstFormat asked for.
* On return contains the #GstFormat used.
* @cur: A location in which to store the current position, or NULL.
*
* Queries a pad for the stream position.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_pad_query_position (GstPad * pad, GstFormat * format, gint64 * cur)
{
GstQuery *query;
gboolean ret;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (format != NULL, FALSE);
query = gst_query_new_position (*format);
ret = gst_pad_query (pad, query);
if (ret)
gst_query_parse_position (query, format, cur);
gst_query_unref (query);
return ret;
}
/**
* gst_pad_query_duration:
* @pad: a #GstPad to invoke the duration query on.
* @format: a pointer to the #GstFormat asked for.
* On return contains the #GstFormat used.
* @duration: A location in which to store the total duration, or NULL.
*
* Queries a pad for the total stream duration.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_pad_query_duration (GstPad * pad, GstFormat * format, gint64 * duration)
{
GstQuery *query;
gboolean ret;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (format != NULL, FALSE);
query = gst_query_new_duration (*format);
ret = gst_pad_query (pad, query);
if (ret)
gst_query_parse_duration (query, format, duration);
gst_query_unref (query);
return ret;
}
/**
* gst_pad_query_convert:
* @pad: a #GstPad to invoke the convert query on.
* @src_format: a #GstFormat to convert from.
* @src_val: a value to convert.
* @dest_format: a pointer to the #GstFormat to convert to.
* @dest_val: a pointer to the result.
*
* Queries a pad to convert @src_val in @src_format to @dest_format.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
GstFormat * dest_format, gint64 * dest_val)
{
GstQuery *query;
gboolean ret;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (src_val >= 0, FALSE);
g_return_val_if_fail (dest_format != NULL, FALSE);
g_return_val_if_fail (dest_val != NULL, FALSE);
if (*dest_format == src_format) {
*dest_val = src_val;
return TRUE;
}
query = gst_query_new_convert (src_format, src_val, *dest_format);
ret = gst_pad_query (pad, query);
if (ret)
gst_query_parse_convert (query, NULL, NULL, dest_format, dest_val);
gst_query_unref (query);
return ret;
}
/**
* gst_atomic_int_set:
* @atomic_int: pointer to an atomic integer
* @value: value to set
*
* Unconditionally sets the atomic integer to @value.
*/
void
gst_atomic_int_set (gint * atomic_int, gint value)
{
int ignore;
*atomic_int = value;
/* read acts as a memory barrier */
ignore = g_atomic_int_get (atomic_int);
}
/**
* gst_pad_add_data_probe:
* @pad: pad to add the data probe handler to
* @handler: function to call when data is passed over pad
* @data: data to pass along with the handler
*
* Adds a "data probe" to a pad. This function will be called whenever data
* passes through a pad. In this case data means both events and buffers. The
* probe will be called with the data as an argument, meaning @handler should
* have the same callback signature as the 'have-data' signal of #GstPad.
* Note that the data will have a reference count greater than 1, so it will
* be immutable -- you must not change it.
*
* For source pads, the probe will be called after the blocking function, if any
* (see gst_pad_set_blocked_async()), but before looking up the peer to chain
* to. For sink pads, the probe function will be called before configuring the
* sink with new caps, if any, and before calling the pad's chain function.
*
* Your data probe should return TRUE to let the data continue to flow, or FALSE
* to drop it. Dropping data is rarely useful, but occasionally comes in handy
* with events.
*
* Although probes are implemented internally by connecting @handler to the
* have-data signal on the pad, if you want to remove a probe it is insufficient
* to only call g_signal_handler_disconnect on the returned handler id. To
* remove a probe, use the appropriate function, such as
* gst_pad_remove_data_probe().
*
* Returns: The handler id.
*/
gulong
gst_pad_add_data_probe (GstPad * pad, GCallback handler, gpointer data)
{
gulong sigid;
gboolean was_ghost = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), 0);
g_return_val_if_fail (handler != NULL, 0);
if (GST_IS_GHOST_PAD (pad)) {
pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
if (!pad) {
return 0;
}
was_ghost = TRUE;
}
GST_OBJECT_LOCK (pad);
sigid = g_signal_connect (pad, "have-data", handler, data);
GST_PAD_DO_EVENT_SIGNALS (pad)++;
GST_PAD_DO_BUFFER_SIGNALS (pad)++;
GST_DEBUG ("adding data probe to pad %s:%s, now %d data, %d event probes",
GST_DEBUG_PAD_NAME (pad),
GST_PAD_DO_BUFFER_SIGNALS (pad), GST_PAD_DO_EVENT_SIGNALS (pad));
GST_OBJECT_UNLOCK (pad);
if (was_ghost) {
gst_object_unref (pad);
}
return sigid;
}
/**
* gst_pad_add_event_probe:
* @pad: pad to add the event probe handler to
* @handler: function to call when data is passed over pad
* @data: data to pass along with the handler
*
* Adds a probe that will be called for all events passing through a pad. See
* gst_pad_add_data_probe() for more information.
*
* Returns: The handler id
*/
gulong
gst_pad_add_event_probe (GstPad * pad, GCallback handler, gpointer data)
{
gulong sigid;
gboolean was_ghost = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), 0);
g_return_val_if_fail (handler != NULL, 0);
if (GST_IS_GHOST_PAD (pad)) {
pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
if (!pad) {
return 0;
}
was_ghost = TRUE;
}
GST_OBJECT_LOCK (pad);
sigid = g_signal_connect (pad, "have-data::event", handler, data);
GST_PAD_DO_EVENT_SIGNALS (pad)++;
GST_DEBUG ("adding event probe to pad %s:%s, now %d probes",
GST_DEBUG_PAD_NAME (pad), GST_PAD_DO_EVENT_SIGNALS (pad));
GST_OBJECT_UNLOCK (pad);
if (was_ghost) {
gst_object_unref (pad);
}
return sigid;
}
/**
* gst_pad_add_buffer_probe:
* @pad: pad to add the buffer probe handler to
* @handler: function to call when data is passed over pad
* @data: data to pass along with the handler
*
* Adds a probe that will be called for all buffers passing through a pad. See
* gst_pad_add_data_probe() for more information.
*
* Returns: The handler id
*/
gulong
gst_pad_add_buffer_probe (GstPad * pad, GCallback handler, gpointer data)
{
gulong sigid;
gboolean was_ghost = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), 0);
g_return_val_if_fail (handler != NULL, 0);
if (GST_IS_GHOST_PAD (pad)) {
pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
if (!pad) {
return 0;
}
was_ghost = TRUE;
}
GST_OBJECT_LOCK (pad);
sigid = g_signal_connect (pad, "have-data::buffer", handler, data);
GST_PAD_DO_BUFFER_SIGNALS (pad)++;
GST_DEBUG ("adding buffer probe to pad %s:%s, now %d probes",
GST_DEBUG_PAD_NAME (pad), GST_PAD_DO_BUFFER_SIGNALS (pad));
GST_OBJECT_UNLOCK (pad);
if (was_ghost) {
gst_object_unref (pad);
}
return sigid;
}
/**
* gst_pad_remove_data_probe:
* @pad: pad to remove the data probe handler from
* @handler_id: handler id returned from gst_pad_add_data_probe
*
* Removes a data probe from @pad.
*/
void
gst_pad_remove_data_probe (GstPad * pad, guint handler_id)
{
gboolean was_ghost = FALSE;
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (handler_id > 0);
if (GST_IS_GHOST_PAD (pad)) {
pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
if (!pad) {
return;
}
was_ghost = TRUE;
}
GST_OBJECT_LOCK (pad);
g_signal_handler_disconnect (pad, handler_id);
GST_PAD_DO_BUFFER_SIGNALS (pad)--;
GST_PAD_DO_EVENT_SIGNALS (pad)--;
GST_DEBUG
("removed data probe from pad %s:%s, now %d event, %d buffer probes",
GST_DEBUG_PAD_NAME (pad), GST_PAD_DO_EVENT_SIGNALS (pad),
GST_PAD_DO_BUFFER_SIGNALS (pad));
GST_OBJECT_UNLOCK (pad);
if (was_ghost) {
gst_object_unref (pad);
}
}
/**
* gst_pad_remove_event_probe:
* @pad: pad to remove the event probe handler from
* @handler_id: handler id returned from gst_pad_add_event_probe
*
* Removes an event probe from @pad.
*/
void
gst_pad_remove_event_probe (GstPad * pad, guint handler_id)
{
gboolean was_ghost = FALSE;
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (handler_id > 0);
if (GST_IS_GHOST_PAD (pad)) {
pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
if (!pad) {
return;
}
was_ghost = TRUE;
}
GST_OBJECT_LOCK (pad);
g_signal_handler_disconnect (pad, handler_id);
GST_PAD_DO_EVENT_SIGNALS (pad)--;
GST_DEBUG ("removed event probe from pad %s:%s, now %d event probes",
GST_DEBUG_PAD_NAME (pad), GST_PAD_DO_EVENT_SIGNALS (pad));
GST_OBJECT_UNLOCK (pad);
if (was_ghost) {
gst_object_unref (pad);
}
}
/**
* gst_pad_remove_buffer_probe:
* @pad: pad to remove the buffer probe handler from
* @handler_id: handler id returned from gst_pad_add_buffer_probe
*
* Removes a buffer probe from @pad.
*/
void
gst_pad_remove_buffer_probe (GstPad * pad, guint handler_id)
{
gboolean was_ghost = FALSE;
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (handler_id > 0);
if (GST_IS_GHOST_PAD (pad)) {
pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
if (!pad) {
return;
}
was_ghost = TRUE;
}
GST_OBJECT_LOCK (pad);
g_signal_handler_disconnect (pad, handler_id);
GST_PAD_DO_BUFFER_SIGNALS (pad)--;
GST_DEBUG ("removed buffer probe from pad %s:%s, now %d buffer probes",
GST_DEBUG_PAD_NAME (pad), GST_PAD_DO_BUFFER_SIGNALS (pad));
GST_OBJECT_UNLOCK (pad);
if (was_ghost) {
gst_object_unref (pad);
}
}
/**
* gst_element_found_tags_for_pad:
* @element: element for which to post taglist to bus.
* @pad: pad on which to push tag-event.
* @list: the taglist to post on the bus and create event from.
*
* Posts a message to the bus that new tags were found and pushes the
* tags as event. Takes ownership of the @list.
*
* This is a utility method for elements. Applications should use the
* #GstTagSetter interface.
*/
void
gst_element_found_tags_for_pad (GstElement * element,
GstPad * pad, GstTagList * list)
{
g_return_if_fail (element != NULL);
g_return_if_fail (pad != NULL);
g_return_if_fail (list != NULL);
gst_pad_push_event (pad, gst_event_new_tag (gst_tag_list_copy (list)));
gst_element_post_message (element,
gst_message_new_tag (GST_OBJECT (element), list));
}
static void
push_and_ref (GstPad * pad, GstEvent * event)
{
gst_pad_push_event (pad, gst_event_ref (event));
}
/**
* gst_element_found_tags:
* @element: element for which we found the tags.
* @list: list of tags.
*
* Posts a message to the bus that new tags were found, and pushes an event
* to all sourcepads. Takes ownership of the @list.
*
* This is a utility method for elements. Applications should use the
* #GstTagSetter interface.
*/
void
gst_element_found_tags (GstElement * element, GstTagList * list)
{
GstIterator *iter;
GstEvent *event;
g_return_if_fail (element != NULL);
g_return_if_fail (list != NULL);
iter = gst_element_iterate_src_pads (element);
event = gst_event_new_tag (gst_tag_list_copy (list));
gst_iterator_foreach (iter, (GFunc) push_and_ref, event);
gst_iterator_free (iter);
gst_event_unref (event);
gst_element_post_message (element,
gst_message_new_tag (GST_OBJECT (element), list));
}
static GstPad *
element_find_unconnected_pad (GstElement * element, GstPadDirection direction)
{
GstIterator *iter;
GstPad *unconnected_pad = NULL;
gboolean done;
switch (direction) {
case GST_PAD_SRC:
iter = gst_element_iterate_src_pads (element);
break;
case GST_PAD_SINK:
iter = gst_element_iterate_sink_pads (element);
break;
default:
g_assert_not_reached ();
}
done = FALSE;
while (!done) {
gpointer pad;
switch (gst_iterator_next (iter, &pad)) {
case GST_ITERATOR_OK:{
GstPad *peer;
GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
GST_DEBUG_PAD_NAME (pad));
peer = gst_pad_get_peer (GST_PAD (pad));
if (peer == NULL) {
unconnected_pad = pad;
done = TRUE;
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"found existing unlinked pad %s:%s",
GST_DEBUG_PAD_NAME (unconnected_pad));
} else {
gst_object_unref (pad);
gst_object_unref (peer);
}
break;
}
case GST_ITERATOR_DONE:
done = TRUE;
break;
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
case GST_ITERATOR_ERROR:
g_return_val_if_reached (NULL);
break;
}
}
gst_iterator_free (iter);
return unconnected_pad;
}
/**
* gst_bin_find_unconnected_pad:
* @bin: bin in which to look for elements with unconnected pads
* @direction: whether to look for an unconnected source or sink pad
*
* Recursively looks for elements with an unconnected pad of the given
* direction within the specified bin and returns an unconnected pad
* if one is found, or NULL otherwise. If a pad is found, the caller
* owns a reference to it and should use gst_object_unref() on the
* pad when it is not needed any longer.
*
* Returns: unconnected pad of the given direction, or NULL.
*
* Since: 0.10.3
*/
GstPad *
gst_bin_find_unconnected_pad (GstBin * bin, GstPadDirection direction)
{
GstIterator *iter;
gboolean done;
GstPad *pad = NULL;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
done = FALSE;
iter = gst_bin_iterate_recurse (bin);
while (!done) {
gpointer element;
switch (gst_iterator_next (iter, &element)) {
case GST_ITERATOR_OK:
pad = element_find_unconnected_pad (GST_ELEMENT (element), direction);
gst_object_unref (element);
if (pad != NULL)
done = TRUE;
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
case GST_ITERATOR_ERROR:
g_return_val_if_reached (NULL);
break;
}
}
gst_iterator_free (iter);
return pad;
}
#ifndef GST_DISABLE_PARSE
/**
* gst_parse_bin_from_description:
* @bin_description: command line describing the bin
* @ghost_unconnected_pads: whether to automatically create ghost pads
* for unconnected source or sink pads within
* the bin
* @err: where to store the error message in case of an error, or NULL
*
* This is a convenience wrapper around gst_parse_launch() to create a
* #GstBin from a gst-launch-style pipeline description. See
* gst_parse_launch() and the gst-launch man page for details about the
* syntax. Ghost pads on the bin for unconnected source or sink pads
* within the bin can automatically be created (but only a maximum of
* one ghost pad for each direction will be created; if you expect
* multiple unconnected source pads or multiple unconnected sink pads
* and want them all ghosted, you will have to create the ghost pads
* yourself).
*
* Returns: a newly-created bin, or NULL if an error occurred.
*
* Since: 0.10.3
*/
GstElement *
gst_parse_bin_from_description (const gchar * bin_description,
gboolean ghost_unconnected_pads, GError ** err)
{
GstPad *pad = NULL;
GstBin *bin;
gchar *desc;
g_return_val_if_fail (bin_description != NULL, NULL);
g_return_val_if_fail (err == NULL || *err == NULL, NULL);
GST_DEBUG ("Making bin from description '%s'", bin_description);
/* parse the pipeline to a bin */
desc = g_strdup_printf ("bin.( %s )", bin_description);
bin = (GstBin *) gst_parse_launch (desc, err);
g_free (desc);
if (bin == NULL || (err && *err != NULL)) {
if (bin)
gst_object_unref (bin);
return NULL;
}
/* find pads and ghost them if necessary */
if (ghost_unconnected_pads) {
if ((pad = gst_bin_find_unconnected_pad (bin, GST_PAD_SRC))) {
gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
gst_object_unref (pad);
}
if ((pad = gst_bin_find_unconnected_pad (bin, GST_PAD_SINK))) {
gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
gst_object_unref (pad);
}
}
return GST_ELEMENT (bin);
}
#endif
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