gstreamer/gst-libs/gst/pbutils/missing-plugins.c
Tim-Philipp Müller 883dc41848 pbutils: fix installer detail string version number
Should still be '1.0' not '1.1'. Fixs pbutils unit test.
2012-10-25 14:41:22 +01:00

799 lines
25 KiB
C

/* GStreamer base utils library missing plugins support
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
*
* 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:gstpbutilsmissingplugins
* @short_description: Create, recognise and parse missing-plugins messages
*
* <refsect2>
* <para>
* Functions to create, recognise and parse missing-plugins messages for
* applications and elements.
* </para>
* <para>
* Missing-plugin messages are posted on the bus by elements like decodebin
* or playbin if they can't find an appropriate source element or decoder
* element. The application can use these messages for two things:
* <itemizedlist>
* <listitem><para>
* concise error/problem reporting to the user mentioning what exactly
* is missing, see gst_missing_plugin_message_get_description()
* </para></listitem>
* <listitem><para>
* initiate installation of missing plugins, see
* gst_missing_plugin_message_get_installer_detail() and
* gst_install_plugins_async()
* </para></listitem>
* </itemizedlist>
* </para>
* <para>
* Applications may also create missing-plugin messages themselves to install
* required elements that are missing, using the install mechanism mentioned
* above.
* </para>
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h> /* getpid on UNIX */
#endif
#ifdef HAVE_PROCESS_H
# include <process.h> /* getpid on win32 */
#endif
#include "gst/gst-i18n-plugin.h"
#include "pbutils.h"
#include "pbutils-private.h"
#include <string.h>
#define GST_DETAIL_STRING_MARKER "gstreamer"
typedef enum
{
GST_MISSING_TYPE_UNKNOWN = 0,
GST_MISSING_TYPE_URISOURCE,
GST_MISSING_TYPE_URISINK,
GST_MISSING_TYPE_ELEMENT,
GST_MISSING_TYPE_DECODER,
GST_MISSING_TYPE_ENCODER
} GstMissingType;
static const struct
{
GstMissingType type;
const gchar type_string[12];
} missing_type_mapping[] = {
{
GST_MISSING_TYPE_URISOURCE, "urisource"}, {
GST_MISSING_TYPE_URISINK, "urisink"}, {
GST_MISSING_TYPE_ELEMENT, "element"}, {
GST_MISSING_TYPE_DECODER, "decoder"}, {
GST_MISSING_TYPE_ENCODER, "encoder"}
};
static GstMissingType
missing_structure_get_type (const GstStructure * s)
{
const gchar *type;
guint i;
type = gst_structure_get_string (s, "type");
g_return_val_if_fail (type != NULL, GST_MISSING_TYPE_UNKNOWN);
for (i = 0; i < G_N_ELEMENTS (missing_type_mapping); ++i) {
if (strcmp (missing_type_mapping[i].type_string, type) == 0)
return missing_type_mapping[i].type;
}
return GST_MISSING_TYPE_UNKNOWN;
}
GstCaps *
copy_and_clean_caps (const GstCaps * caps)
{
GstStructure *s;
GstCaps *ret;
ret = gst_caps_copy (caps);
/* make caps easier to interpret, remove common fields that are likely
* to be irrelevant for determining the right plugin (ie. mostly fields
* where template caps usually have the standard MIN - MAX range as value) */
s = gst_caps_get_structure (ret, 0);
gst_structure_remove_field (s, "codec_data");
gst_structure_remove_field (s, "palette_data");
gst_structure_remove_field (s, "pixel-aspect-ratio");
gst_structure_remove_field (s, "framerate");
gst_structure_remove_field (s, "leaf_size");
gst_structure_remove_field (s, "packet_size");
gst_structure_remove_field (s, "block_align");
gst_structure_remove_field (s, "metadata-interval"); /* icy caps */
/* decoders/encoders almost always handle the usual width/height/channel/rate
* range (and if we don't remove this then the app will have a much harder
* time blacklisting formats it has unsuccessfully tried to install before) */
gst_structure_remove_field (s, "width");
gst_structure_remove_field (s, "depth");
gst_structure_remove_field (s, "height");
gst_structure_remove_field (s, "channels");
gst_structure_remove_field (s, "rate");
/* rtp fields */
gst_structure_remove_field (s, "config");
gst_structure_remove_field (s, "clock-rate");
gst_structure_remove_field (s, "clock-base");
gst_structure_remove_field (s, "maxps");
gst_structure_remove_field (s, "seqnum-base");
gst_structure_remove_field (s, "npt-start");
gst_structure_remove_field (s, "npt-stop");
gst_structure_remove_field (s, "play-speed");
gst_structure_remove_field (s, "play-scale");
gst_structure_remove_field (s, "dynamic_range");
return ret;
}
/**
* gst_missing_uri_source_message_new:
* @element: the #GstElement posting the message
* @protocol: the URI protocol the missing source needs to implement,
* e.g. "http" or "mms"
*
* Creates a missing-plugin message for @element to notify the application
* that a source element for a particular URI protocol is missing. This
* function is mainly for use in plugins.
*
* Returns: (transfer full): a new #GstMessage, or NULL on error
*/
GstMessage *
gst_missing_uri_source_message_new (GstElement * element,
const gchar * protocol)
{
GstStructure *s;
gchar *description;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (protocol != NULL, NULL);
description = gst_pb_utils_get_source_description (protocol);
s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,
"urisource", "detail", G_TYPE_STRING, protocol, "name", G_TYPE_STRING,
description, NULL);
g_free (description);
return gst_message_new_element (GST_OBJECT_CAST (element), s);
}
/**
* gst_missing_uri_sink_message_new:
* @element: the #GstElement posting the message
* @protocol: the URI protocol the missing sink needs to implement,
* e.g. "http" or "smb"
*
* Creates a missing-plugin message for @element to notify the application
* that a sink element for a particular URI protocol is missing. This
* function is mainly for use in plugins.
*
* Returns: (transfer full): a new #GstMessage, or NULL on error
*/
GstMessage *
gst_missing_uri_sink_message_new (GstElement * element, const gchar * protocol)
{
GstStructure *s;
gchar *description;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (protocol != NULL, NULL);
description = gst_pb_utils_get_sink_description (protocol);
s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,
"urisink", "detail", G_TYPE_STRING, protocol, "name", G_TYPE_STRING,
description, NULL);
g_free (description);
return gst_message_new_element (GST_OBJECT_CAST (element), s);
}
/**
* gst_missing_element_message_new:
* @element: the #GstElement posting the message
* @factory_name: the name of the missing element (element factory),
* e.g. "videoscale" or "cdparanoiasrc"
*
* Creates a missing-plugin message for @element to notify the application
* that a certain required element is missing. This function is mainly for
* use in plugins.
*
* Returns: (transfer full): a new #GstMessage, or NULL on error
*/
GstMessage *
gst_missing_element_message_new (GstElement * element,
const gchar * factory_name)
{
GstStructure *s;
gchar *description;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (factory_name != NULL, NULL);
description = gst_pb_utils_get_element_description (factory_name);
s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,
"element", "detail", G_TYPE_STRING, factory_name, "name", G_TYPE_STRING,
description, NULL);
g_free (description);
return gst_message_new_element (GST_OBJECT_CAST (element), s);
}
/**
* gst_missing_decoder_message_new:
* @element: the #GstElement posting the message
* @decode_caps: the (fixed) caps for which a decoder element is needed
*
* Creates a missing-plugin message for @element to notify the application
* that a decoder element for a particular set of (fixed) caps is missing.
* This function is mainly for use in plugins.
*
* Returns: (transfer full): a new #GstMessage, or NULL on error
*/
GstMessage *
gst_missing_decoder_message_new (GstElement * element,
const GstCaps * decode_caps)
{
GstStructure *s;
GstCaps *caps;
gchar *description;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (decode_caps != NULL, NULL);
g_return_val_if_fail (GST_IS_CAPS (decode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_any (decode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_empty (decode_caps), NULL);
g_return_val_if_fail (gst_caps_is_fixed (decode_caps), NULL);
description = gst_pb_utils_get_decoder_description (decode_caps);
caps = copy_and_clean_caps (decode_caps);
s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,
"decoder", "detail", GST_TYPE_CAPS, caps, "name", G_TYPE_STRING,
description, NULL);
gst_caps_unref (caps);
g_free (description);
return gst_message_new_element (GST_OBJECT_CAST (element), s);
}
/**
* gst_missing_encoder_message_new:
* @element: the #GstElement posting the message
* @encode_caps: the (fixed) caps for which an encoder element is needed
*
* Creates a missing-plugin message for @element to notify the application
* that an encoder element for a particular set of (fixed) caps is missing.
* This function is mainly for use in plugins.
*
* Returns: (transfer full): a new #GstMessage, or NULL on error
*/
GstMessage *
gst_missing_encoder_message_new (GstElement * element,
const GstCaps * encode_caps)
{
GstStructure *s;
GstCaps *caps;
gchar *description;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (encode_caps != NULL, NULL);
g_return_val_if_fail (GST_IS_CAPS (encode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_any (encode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_empty (encode_caps), NULL);
g_return_val_if_fail (gst_caps_is_fixed (encode_caps), NULL);
description = gst_pb_utils_get_encoder_description (encode_caps);
caps = copy_and_clean_caps (encode_caps);
s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,
"encoder", "detail", GST_TYPE_CAPS, caps, "name", G_TYPE_STRING,
description, NULL);
gst_caps_unref (caps);
g_free (description);
return gst_message_new_element (GST_OBJECT_CAST (element), s);
}
static gboolean
missing_structure_get_string_detail (const GstStructure * s, gchar ** p_detail)
{
const gchar *detail;
GType detail_type;
*p_detail = NULL;
detail_type = gst_structure_get_field_type (s, "detail");
if (!g_type_is_a (detail_type, G_TYPE_STRING)) {
GST_WARNING ("expected 'detail' field to be of G_TYPE_STRING");
return FALSE;
}
detail = gst_structure_get_string (s, "detail");
if (detail == NULL || *detail == '\0') {
GST_WARNING ("empty 'detail' field");
return FALSE;
}
*p_detail = g_strdup (detail);
return TRUE;
}
static gboolean
missing_structure_get_caps_detail (const GstStructure * s, GstCaps ** p_caps)
{
const GstCaps *caps;
const GValue *val;
GType detail_type;
*p_caps = NULL;
detail_type = gst_structure_get_field_type (s, "detail");
if (!g_type_is_a (detail_type, GST_TYPE_CAPS)) {
GST_WARNING ("expected 'detail' field to be of GST_TYPE_CAPS");
return FALSE;
}
val = gst_structure_get_value (s, "detail");
caps = gst_value_get_caps (val);
if (gst_caps_is_empty (caps) || gst_caps_is_any (caps)) {
GST_WARNING ("EMPTY or ANY caps not allowed");
return FALSE;
}
*p_caps = gst_caps_copy (caps);
return TRUE;
}
/**
* gst_missing_plugin_message_get_installer_detail:
* @msg: a missing-plugin #GstMessage of type #GST_MESSAGE_ELEMENT
*
* Returns an opaque string containing all the details about the missing
* element to be passed to an external installer called via
* gst_install_plugins_async() or gst_install_plugins_sync().
*
* This function is mainly for applications that call external plugin
* installation mechanisms using one of the two above-mentioned functions.
*
* Returns: a newly-allocated detail string, or NULL on error. Free string
* with g_free() when not needed any longer.
*/
gchar *
gst_missing_plugin_message_get_installer_detail (GstMessage * msg)
{
GstMissingType missing_type;
const gchar *progname;
const gchar *type;
GString *str = NULL;
gchar *detail = NULL;
gchar *desc;
const GstStructure *structure;
g_return_val_if_fail (gst_is_missing_plugin_message (msg), NULL);
structure = gst_message_get_structure (msg);
GST_LOG ("Parsing missing-plugin message: %" GST_PTR_FORMAT, structure);
missing_type = missing_structure_get_type (structure);
if (missing_type == GST_MISSING_TYPE_UNKNOWN) {
GST_WARNING ("couldn't parse 'type' field");
goto error;
}
type = gst_structure_get_string (structure, "type");
g_assert (type != NULL); /* validity already checked above */
/* FIXME: use gst_installer_detail_new() here too */
str = g_string_new (GST_DETAIL_STRING_MARKER "|");
g_string_append_printf (str, "%s|", GST_API_VERSION);
progname = (const gchar *) g_get_prgname ();
if (progname) {
g_string_append_printf (str, "%s|", progname);
} else {
g_string_append_printf (str, "pid/%lu|", (gulong) getpid ());
}
desc = gst_missing_plugin_message_get_description (msg);
if (desc) {
g_strdelimit (desc, "|", '#');
g_string_append_printf (str, "%s|", desc);
g_free (desc);
} else {
g_string_append (str, "|");
}
switch (missing_type) {
case GST_MISSING_TYPE_URISOURCE:
case GST_MISSING_TYPE_URISINK:
case GST_MISSING_TYPE_ELEMENT:
if (!missing_structure_get_string_detail (structure, &detail))
goto error;
break;
case GST_MISSING_TYPE_DECODER:
case GST_MISSING_TYPE_ENCODER:{
GstCaps *caps = NULL;
if (!missing_structure_get_caps_detail (structure, &caps))
goto error;
detail = gst_caps_to_string (caps);
gst_caps_unref (caps);
break;
}
default:
g_return_val_if_reached (NULL);
}
g_string_append_printf (str, "%s-%s", type, detail);
g_free (detail);
return g_string_free (str, FALSE);
/* ERRORS */
error:
{
GST_WARNING ("Failed to parse missing-plugin msg: %" GST_PTR_FORMAT, msg);
if (str)
g_string_free (str, TRUE);
return NULL;
}
}
/**
* gst_missing_plugin_message_get_description:
* @msg: a missing-plugin #GstMessage of type #GST_MESSAGE_ELEMENT
*
* Returns a localised string describing the missing feature, for use in
* error dialogs and the like. Should never return NULL unless @msg is not
* a valid missing-plugin message.
*
* This function is mainly for applications that need a human-readable string
* describing a missing plugin, given a previously collected missing-plugin
* message
*
* Returns: a newly-allocated description string, or NULL on error. Free
* string with g_free() when not needed any longer.
*/
gchar *
gst_missing_plugin_message_get_description (GstMessage * msg)
{
GstMissingType missing_type;
const gchar *desc;
gchar *ret = NULL;
const GstStructure *structure;
g_return_val_if_fail (gst_is_missing_plugin_message (msg), NULL);
structure = gst_message_get_structure (msg);
GST_LOG ("Parsing missing-plugin message: %" GST_PTR_FORMAT, structure);
desc = gst_structure_get_string (structure, "name");
if (desc != NULL && *desc != '\0') {
ret = g_strdup (desc);
goto done;
}
/* fallback #1 */
missing_type = missing_structure_get_type (structure);
switch (missing_type) {
case GST_MISSING_TYPE_URISOURCE:
case GST_MISSING_TYPE_URISINK:
case GST_MISSING_TYPE_ELEMENT:{
gchar *detail = NULL;
if (missing_structure_get_string_detail (structure, &detail)) {
if (missing_type == GST_MISSING_TYPE_URISOURCE)
ret = gst_pb_utils_get_source_description (detail);
else if (missing_type == GST_MISSING_TYPE_URISINK)
ret = gst_pb_utils_get_sink_description (detail);
else
ret = gst_pb_utils_get_sink_description (detail);
g_free (detail);
}
break;
}
case GST_MISSING_TYPE_DECODER:
case GST_MISSING_TYPE_ENCODER:{
GstCaps *caps = NULL;
if (missing_structure_get_caps_detail (structure, &caps)) {
if (missing_type == GST_MISSING_TYPE_DECODER)
ret = gst_pb_utils_get_decoder_description (caps);
else
ret = gst_pb_utils_get_encoder_description (caps);
gst_caps_unref (caps);
}
break;
}
default:
break;
}
if (ret)
goto done;
/* fallback #2 */
switch (missing_type) {
case GST_MISSING_TYPE_URISOURCE:
desc = _("Unknown source element");
break;
case GST_MISSING_TYPE_URISINK:
desc = _("Unknown sink element");
break;
case GST_MISSING_TYPE_ELEMENT:
desc = _("Unknown element");
break;
case GST_MISSING_TYPE_DECODER:
desc = _("Unknown decoder element");
break;
case GST_MISSING_TYPE_ENCODER:
desc = _("Unknown encoder element");
break;
default:
/* we should really never get here, but we better still return
* something if we do */
desc = _("Plugin or element of unknown type");
break;
}
ret = g_strdup (desc);
done:
GST_LOG ("returning '%s'", ret);
return ret;
}
/**
* gst_is_missing_plugin_message:
* @msg: a #GstMessage
*
* Checks whether @msg is a missing plugins message.
*
* Returns: %TRUE if @msg is a missing-plugins message, otherwise %FALSE.
*/
gboolean
gst_is_missing_plugin_message (GstMessage * msg)
{
const GstStructure *structure;
g_return_val_if_fail (msg != NULL, FALSE);
g_return_val_if_fail (GST_IS_MESSAGE (msg), FALSE);
structure = gst_message_get_structure (msg);
if (GST_MESSAGE_TYPE (msg) != GST_MESSAGE_ELEMENT || structure == NULL)
return FALSE;
return gst_structure_has_name (structure, "missing-plugin");
}
/* takes ownership of the description */
static gchar *
gst_installer_detail_new (gchar * description, const gchar * type,
const gchar * detail)
{
const gchar *progname;
GString *s;
s = g_string_new (GST_DETAIL_STRING_MARKER "|");
g_string_append_printf (s, "%s|", GST_API_VERSION);
progname = (const gchar *) g_get_prgname ();
if (progname) {
g_string_append_printf (s, "%s|", progname);
} else {
g_string_append_printf (s, "pid/%lu|", (gulong) getpid ());
}
if (description) {
g_strdelimit (description, "|", '#');
g_string_append_printf (s, "%s|", description);
g_free (description);
} else {
g_string_append (s, "|");
}
g_string_append_printf (s, "%s-%s", type, detail);
return g_string_free (s, FALSE);
}
/**
* gst_missing_uri_source_installer_detail_new:
* @protocol: the URI protocol the missing source needs to implement,
* e.g. "http" or "mms"
*
* Returns an opaque string containing all the details about the missing
* element to be passed to an external installer called via
* gst_install_plugins_async() or gst_install_plugins_sync().
*
* This function is mainly for applications that call external plugin
* installation mechanisms using one of the two above-mentioned functions in
* the case where the application knows exactly what kind of plugin it is
* missing.
*
* Returns: a newly-allocated detail string, or NULL on error. Free string
* with g_free() when not needed any longer.
*/
gchar *
gst_missing_uri_source_installer_detail_new (const gchar * protocol)
{
gchar *desc;
g_return_val_if_fail (protocol != NULL, NULL);
desc = gst_pb_utils_get_source_description (protocol);
return gst_installer_detail_new (desc, "urisource", protocol);
}
/**
* gst_missing_uri_sink_installer_detail_new:
* @protocol: the URI protocol the missing source needs to implement,
* e.g. "http" or "mms"
*
* Returns an opaque string containing all the details about the missing
* element to be passed to an external installer called via
* gst_install_plugins_async() or gst_install_plugins_sync().
*
* This function is mainly for applications that call external plugin
* installation mechanisms using one of the two above-mentioned functions in
* the case where the application knows exactly what kind of plugin it is
* missing.
*
* Returns: a newly-allocated detail string, or NULL on error. Free string
* with g_free() when not needed any longer.
*/
gchar *
gst_missing_uri_sink_installer_detail_new (const gchar * protocol)
{
gchar *desc;
g_return_val_if_fail (protocol != NULL, NULL);
desc = gst_pb_utils_get_sink_description (protocol);
return gst_installer_detail_new (desc, "urisink", protocol);
}
/**
* gst_missing_element_installer_detail_new:
* @factory_name: the name of the missing element (element factory),
* e.g. "videoscale" or "cdparanoiasrc"
*
* Returns an opaque string containing all the details about the missing
* element to be passed to an external installer called via
* gst_install_plugins_async() or gst_install_plugins_sync().
*
* This function is mainly for applications that call external plugin
* installation mechanisms using one of the two above-mentioned functions in
* the case where the application knows exactly what kind of plugin it is
* missing.
*
* Returns: a newly-allocated detail string, or NULL on error. Free string
* with g_free() when not needed any longer.
*/
gchar *
gst_missing_element_installer_detail_new (const gchar * factory_name)
{
gchar *desc;
g_return_val_if_fail (factory_name != NULL, NULL);
desc = gst_pb_utils_get_element_description (factory_name);
return gst_installer_detail_new (desc, "element", factory_name);
}
/**
* gst_missing_decoder_installer_detail_new:
* @decode_caps: the (fixed) caps for which a decoder element is needed
*
* Returns an opaque string containing all the details about the missing
* element to be passed to an external installer called via
* gst_install_plugins_async() or gst_install_plugins_sync().
*
* This function is mainly for applications that call external plugin
* installation mechanisms using one of the two above-mentioned functions in
* the case where the application knows exactly what kind of plugin it is
* missing.
*
* Returns: a newly-allocated detail string, or NULL on error. Free string
* with g_free() when not needed any longer.
*/
gchar *
gst_missing_decoder_installer_detail_new (const GstCaps * decode_caps)
{
GstCaps *caps;
gchar *detail_str, *caps_str, *desc;
g_return_val_if_fail (decode_caps != NULL, NULL);
g_return_val_if_fail (GST_IS_CAPS (decode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_any (decode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_empty (decode_caps), NULL);
g_return_val_if_fail (gst_caps_is_fixed (decode_caps), NULL);
desc = gst_pb_utils_get_decoder_description (decode_caps);
caps = copy_and_clean_caps (decode_caps);
caps_str = gst_caps_to_string (caps);
detail_str = gst_installer_detail_new (desc, "decoder", caps_str);
g_free (caps_str);
gst_caps_unref (caps);
return detail_str;
}
/**
* gst_missing_encoder_installer_detail_new:
* @encode_caps: the (fixed) caps for which an encoder element is needed
*
* Returns an opaque string containing all the details about the missing
* element to be passed to an external installer called via
* gst_install_plugins_async() or gst_install_plugins_sync().
*
* This function is mainly for applications that call external plugin
* installation mechanisms using one of the two above-mentioned functions in
* the case where the application knows exactly what kind of plugin it is
* missing.
*
* Returns: a newly-allocated detail string, or NULL on error. Free string
* with g_free() when not needed any longer.
*/
gchar *
gst_missing_encoder_installer_detail_new (const GstCaps * encode_caps)
{
GstCaps *caps;
gchar *detail_str, *caps_str, *desc;
g_return_val_if_fail (encode_caps != NULL, NULL);
g_return_val_if_fail (GST_IS_CAPS (encode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_any (encode_caps), NULL);
g_return_val_if_fail (!gst_caps_is_empty (encode_caps), NULL);
g_return_val_if_fail (gst_caps_is_fixed (encode_caps), NULL);
desc = gst_pb_utils_get_encoder_description (encode_caps);
caps = copy_and_clean_caps (encode_caps);
caps_str = gst_caps_to_string (caps);
detail_str = gst_installer_detail_new (desc, "encoder", caps_str);
g_free (caps_str);
gst_caps_unref (caps);
return detail_str;
}