gstreamer/plugins/elements/gstfdsrc.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2005 Philippe Khalaf <burger@speedy.org>
*
* gstfdsrc.c:
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gst/gst_private.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdlib.h>
#include <errno.h>
#include "gstfdsrc.h"
/* the select call is also performed on the control sockets, that way
* we can send special commands to unblock the select call */
#define CONTROL_STOP 'S' /* stop the select call */
#define CONTROL_SOCKETS(src) src->control_sock
#define WRITE_SOCKET(src) src->control_sock[1]
#define READ_SOCKET(src) src->control_sock[0]
#define SEND_COMMAND(src, command) \
G_STMT_START { \
unsigned char c; c = command; \
write (WRITE_SOCKET(src), &c, 1); \
} G_STMT_END
#define READ_COMMAND(src, command, res) \
G_STMT_START { \
res = read(READ_SOCKET(src), &command, 1); \
} G_STMT_END
#define DEFAULT_BLOCKSIZE 4096
static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
GST_DEBUG_CATEGORY_STATIC (gst_fdsrc_debug);
#define GST_CAT_DEFAULT gst_fdsrc_debug
static GstElementDetails gst_fdsrc_details = GST_ELEMENT_DETAILS ("Disk Source",
"Source/File",
"Synchronous read from a file",
"Erik Walthinsen <omega@cse.ogi.edu>");
enum
{
PROP_0,
PROP_FD,
};
#define _do_init(bla) \
GST_DEBUG_CATEGORY_INIT (gst_fdsrc_debug, "fdsrc", 0, "fdsrc element");
GST_BOILERPLATE_FULL (GstFdSrc, gst_fdsrc, GstElement, GST_TYPE_PUSH_SRC,
_do_init);
static void gst_fdsrc_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_fdsrc_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean gst_fdsrc_start (GstBaseSrc * bsrc);
static gboolean gst_fdsrc_stop (GstBaseSrc * bsrc);
static gboolean gst_fdsrc_unlock (GstBaseSrc * bsrc);
static GstFlowReturn gst_fdsrc_create (GstPushSrc * psrc, GstBuffer ** outbuf);
static void
gst_fdsrc_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&srctemplate));
gst_element_class_set_details (gstelement_class, &gst_fdsrc_details);
}
static void
gst_fdsrc_class_init (GstFdSrcClass * klass)
{
GObjectClass *gobject_class;
GstBaseSrcClass *gstbasesrc_class;
GstElementClass *gstelement_class;
GstPushSrcClass *gstpush_src_class;
gobject_class = G_OBJECT_CLASS (klass);
gstelement_class = GST_ELEMENT_CLASS (klass);
gstbasesrc_class = (GstBaseSrcClass *) klass;
gstpush_src_class = (GstPushSrcClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_PUSH_SRC);
gobject_class->set_property = gst_fdsrc_set_property;
gobject_class->get_property = gst_fdsrc_get_property;
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FD,
g_param_spec_int ("fd", "fd", "An open file descriptor to read from",
0, G_MAXINT, 0, G_PARAM_READWRITE));
gstbasesrc_class->start = gst_fdsrc_start;
gstbasesrc_class->stop = gst_fdsrc_stop;
gstbasesrc_class->unlock = gst_fdsrc_unlock;
gstpush_src_class->create = gst_fdsrc_create;
}
static void
check/elements/identity.c: Make the error a little clearer when the test fails because identity made a copy of the bu... Original commit message from CVS: * check/elements/identity.c: (GST_START_TEST): Make the error a little clearer when the test fails because identity made a copy of the buffer. * docs/gst/gstreamer-sections.txt: New symbols in gstbasetransform.h * gst/base/gstbasetransform.c: (gst_base_transform_class_init), (gst_base_transform_init), (gst_base_transform_transform_size), (gst_base_transform_configure_caps), (gst_base_transform_setcaps), (gst_base_transform_default_prepare_buf), (gst_base_transform_get_unit_size), (gst_base_transform_buffer_alloc), (gst_base_transform_handle_buffer), (gst_base_transform_chain), (gst_base_transform_change_state), (gst_base_transform_set_passthrough), (gst_base_transform_set_in_place), (gst_base_transform_is_in_place): * gst/base/gstbasetransform.h: Change BaseTransform to separate in_place operate from same_caps output. in_place implies that the element can perform the transform on incoming buffers in-place, even if the caps on the output are different. Sub-class elements can now implement special buffer allocation methods for outgoing buffers if they wish to. Big documentation addition. * gst/elements/gstcapsfilter.c: (gst_capsfilter_transform_ip): * gst/elements/gstelements.c: Changes for basetransform modifications. * gst/elements/Makefile.am: * gst/elements/gstfdsrc.c: (gst_fdsrc_init), (gst_fdsrc_create): Compile fix. Extra debug output.
2005-09-09 17:42:20 +00:00
gst_fdsrc_init (GstFdSrc * fdsrc, GstFdSrcClass * klass)
{
/* TODO set live only if it's actually a live source (check
* for seekable fd) */
gst_base_src_set_live (GST_BASE_SRC (fdsrc), TRUE);
fdsrc->fd = 0;
fdsrc->curoffset = 0;
}
static gboolean
gst_fdsrc_start (GstBaseSrc * bsrc)
{
GstFdSrc *src = GST_FDSRC (bsrc);
gint control_sock[2];
src->curoffset = 0;
if (socketpair (PF_UNIX, SOCK_STREAM, 0, control_sock) < 0)
goto socket_pair;
READ_SOCKET (src) = control_sock[0];
WRITE_SOCKET (src) = control_sock[1];
fcntl (READ_SOCKET (src), F_SETFL, O_NONBLOCK);
fcntl (WRITE_SOCKET (src), F_SETFL, O_NONBLOCK);
return TRUE;
/* ERRORS */
socket_pair:
{
GST_ELEMENT_ERROR (src, RESOURCE, OPEN_READ_WRITE, (NULL),
GST_ERROR_SYSTEM);
return FALSE;
}
}
static gboolean
gst_fdsrc_stop (GstBaseSrc * bsrc)
{
GstFdSrc *src = GST_FDSRC (bsrc);
close (READ_SOCKET (src));
close (WRITE_SOCKET (src));
return TRUE;
}
static gboolean
gst_fdsrc_unlock (GstBaseSrc * bsrc)
{
GstFdSrc *src = GST_FDSRC (bsrc);
SEND_COMMAND (src, CONTROL_STOP);
return TRUE;
}
static void
gst_fdsrc_set_property (GObject * object, guint prop_id, const GValue * value,
GParamSpec * pspec)
{
GstFdSrc *src = GST_FDSRC (object);
switch (prop_id) {
case PROP_FD:
src->fd = g_value_get_int (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_fdsrc_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstFdSrc *src = GST_FDSRC (object);
switch (prop_id) {
case PROP_FD:
g_value_set_int (value, src->fd);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstFlowReturn
gst_fdsrc_create (GstPushSrc * psrc, GstBuffer ** outbuf)
{
Changed the way things are scheduled, especially sources. A Src used to have a push() function, and optionally a pus... Original commit message from CVS: Changed the way things are scheduled, especially sources. A Src used to have a push() function, and optionally a pushregion() to deal with async reads, etc. That whole thing has gone away, in favor of providing a pull() function for the output (Src) pad instead, ala chain functions. This makes constructing cothreaded schedules out of non-loop elements somewhat easier. Basically there was always a question as to which pad was being dealt with. In the pullregion case, cothread-specific data was used to try to pass the region struct to the right place, which is a slow hack. And in general, the push function severely limited the kind of tricks that could be played when there's more than one output pad, such as a multi-out file reader with async capabilities on each pad independently. This changes the way cothread scheduling occurs. Instead of the hack to deal with Src's by calling their push() function (or optionally the pushregion(), in certain cases), we now are working towards a general mechanism where pads are the only thing that are dealt with directly. An optimization was made in the process of doing this: the loopfunction actually run as the outer [stack] frame of the cothread is now set more intelligently in create_plan() based on what kind of element it is. We now have: loopfunc_wrapper: used for loop-based elements, it simply calls the loopfunc in a loop, paying attention to COTHREAD_STOPPING (see below). It currently does other, soon to be depracated, stuff. pullsrc_wrapper: wraps a Src that's not loop-based (since your options are now loop- or pull-based) There will be a couple more to deal with other cases, such as Connections and chain-based elements. The general idea is that it's a lot more efficient to make the decisions once in create_plan than to keep doing this huge if/else chain in the wrapper. Just choose the right wrapper up front. It'll be most apparent performance-wise in the case of whichever element context is switched to first for each iteration, since the whole wrapper setup is done for every iteration. The tricky part is that there is now a bit of overloading of the function pointers in a pad. The current meanings (possibly to change a bit more soon) are: chainfunc: as always, chainfunc pointer is mirrored between peer pads (this may change, and the chain func may end up in pushfunc) pushfunc: SrcPad: gst_pad_pushfunc_proxy, cothread_switch to peer SinkPad: none (may take over chainfunc, see below) pullfunc: SrcPad: Src or Connection's function to construct buffers SinkPad: gst_pad_pullfunc_proxy, cothread_switch to peer There are a number of issues remaining with the scheduling, not the least of which is the fact that Connections are still dealt with the old way, with _push() functions and such. I'm trying to figure out a way to unify the system so it makes sense. Following the scheduling system is hard enough, trying to change it is murder. Another useful scheduling addition, mentioned above, is COTHREAD_STOPPING. It's an element flag that's used to signal whatever code is running in cothread context that it should be finishing up and exiting soon. An example of this is in plugins/cobin/spindentity.c. All the loops should now be composed of do/while loops, rather than while(1) loops: do { buf = gst_pad_pull(spindentity->sinkpad); gst_pad_push(spindentity->srcpad,buf); } while (!GST_ELEMENT_IS_COTHREAD_STOPPING(element)); The reason for this is that COTHREAD_STOPPING may be set before the above loop ever gets started. It wouldn't do for the body of the loop to never once get called, that would simply stall the pipeline. Note that only the core library code is ever responsible for setting and unsetting this flag. All elements have to do is respond to it by cleanly exiting the loop and the function holding it. This is needed primarily to allow iterations to occur properly. Basically, there's a single entry point in the cothread scheduling loop, gst_bin_iterate_func() simply switches to this cothread. If the element in this context is allowed to loop infinitely, nothing would even switch back to the context from which the iterate() was originally called. This is a bit of a problem. The solution is for there to be an implicit switch back to the originating context. Now, even I'm not sure exactly how this works, but if the cothread that's switched to actually returns, execution returns back to the calling context, i.e. iterate_func(). COTHREAD_STOPPING is therefore set just before switching into this (currently randomly chosen) context, on the assumption that it will return promptly after finishing its duties. The burden of clearing the flag falls to the various wrapper functions provided by the Bin code, thus element writers don't have to worry about doing that at all (and simply shouldn't). Related changes: All the sources in elements/ have been changed to reflect the new system. FIXMEs: 1) gstpipeline.c calls gst_src_push at some point, dunno why, it's commented out now. 2) any other sources, including vcdsrc, dvdsrc, and v4lsrc will break badly and need to be modified to work as pull-based sources.
2000-12-04 10:52:30 +00:00
GstFdSrc *src;
GstBuffer *buf;
glong readbytes;
guint blocksize;
#ifndef HAVE_WIN32
fd_set readfds;
gint retval;
#endif
src = GST_FDSRC (psrc);
#ifndef HAVE_WIN32
FD_ZERO (&readfds);
FD_SET (src->fd, &readfds);
FD_SET (READ_SOCKET (src), &readfds);
do {
retval = select (FD_SETSIZE, &readfds, NULL, NULL, NULL);
} while ((retval == -1 && errno == EINTR));
if (retval == -1)
goto select_error;
if (FD_ISSET (READ_SOCKET (src), &readfds)) {
/* read all stop commands */
while (TRUE) {
gchar command;
int res;
READ_COMMAND (src, command, res);
if (res < 0) {
GST_LOG_OBJECT (src, "no more commands");
/* no more commands */
break;
}
}
goto stopped;
}
#endif
blocksize = GST_BASE_SRC (src)->blocksize;
/* create the buffer */
buf = gst_buffer_new_and_alloc (blocksize);
do {
readbytes = read (src->fd, GST_BUFFER_DATA (buf), blocksize);
} while (readbytes == -1 && errno == EINTR); /* retry if interrupted */
if (readbytes < 0)
goto read_error;
if (readbytes == 0)
goto eos;
GST_BUFFER_OFFSET (buf) = src->curoffset;
GST_BUFFER_SIZE (buf) = readbytes;
GST_BUFFER_TIMESTAMP (buf) = GST_CLOCK_TIME_NONE;
src->curoffset += readbytes;
check/elements/identity.c: Make the error a little clearer when the test fails because identity made a copy of the bu... Original commit message from CVS: * check/elements/identity.c: (GST_START_TEST): Make the error a little clearer when the test fails because identity made a copy of the buffer. * docs/gst/gstreamer-sections.txt: New symbols in gstbasetransform.h * gst/base/gstbasetransform.c: (gst_base_transform_class_init), (gst_base_transform_init), (gst_base_transform_transform_size), (gst_base_transform_configure_caps), (gst_base_transform_setcaps), (gst_base_transform_default_prepare_buf), (gst_base_transform_get_unit_size), (gst_base_transform_buffer_alloc), (gst_base_transform_handle_buffer), (gst_base_transform_chain), (gst_base_transform_change_state), (gst_base_transform_set_passthrough), (gst_base_transform_set_in_place), (gst_base_transform_is_in_place): * gst/base/gstbasetransform.h: Change BaseTransform to separate in_place operate from same_caps output. in_place implies that the element can perform the transform on incoming buffers in-place, even if the caps on the output are different. Sub-class elements can now implement special buffer allocation methods for outgoing buffers if they wish to. Big documentation addition. * gst/elements/gstcapsfilter.c: (gst_capsfilter_transform_ip): * gst/elements/gstelements.c: Changes for basetransform modifications. * gst/elements/Makefile.am: * gst/elements/gstfdsrc.c: (gst_fdsrc_init), (gst_fdsrc_create): Compile fix. Extra debug output.
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GST_DEBUG_OBJECT (psrc, "Read buffer of size %u.", readbytes);
/* we're done, return the buffer */
*outbuf = buf;
return GST_FLOW_OK;
/* ERRORS */
#ifndef HAVE_WIN32
select_error:
{
GST_ELEMENT_ERROR (src, RESOURCE, READ, (NULL),
("select on file descriptor: %s.", g_strerror (errno)));
GST_DEBUG_OBJECT (psrc, "Error during select");
return GST_FLOW_ERROR;
}
stopped:
{
GST_DEBUG_OBJECT (psrc, "Select stopped");
return GST_FLOW_WRONG_STATE;
}
#endif
eos:
{
check/elements/identity.c: Make the error a little clearer when the test fails because identity made a copy of the bu... Original commit message from CVS: * check/elements/identity.c: (GST_START_TEST): Make the error a little clearer when the test fails because identity made a copy of the buffer. * docs/gst/gstreamer-sections.txt: New symbols in gstbasetransform.h * gst/base/gstbasetransform.c: (gst_base_transform_class_init), (gst_base_transform_init), (gst_base_transform_transform_size), (gst_base_transform_configure_caps), (gst_base_transform_setcaps), (gst_base_transform_default_prepare_buf), (gst_base_transform_get_unit_size), (gst_base_transform_buffer_alloc), (gst_base_transform_handle_buffer), (gst_base_transform_chain), (gst_base_transform_change_state), (gst_base_transform_set_passthrough), (gst_base_transform_set_in_place), (gst_base_transform_is_in_place): * gst/base/gstbasetransform.h: Change BaseTransform to separate in_place operate from same_caps output. in_place implies that the element can perform the transform on incoming buffers in-place, even if the caps on the output are different. Sub-class elements can now implement special buffer allocation methods for outgoing buffers if they wish to. Big documentation addition. * gst/elements/gstcapsfilter.c: (gst_capsfilter_transform_ip): * gst/elements/gstelements.c: Changes for basetransform modifications. * gst/elements/Makefile.am: * gst/elements/gstfdsrc.c: (gst_fdsrc_init), (gst_fdsrc_create): Compile fix. Extra debug output.
2005-09-09 17:42:20 +00:00
GST_DEBUG_OBJECT (psrc, "Read 0 bytes. EOS.");
gst_buffer_unref (buf);
return GST_FLOW_UNEXPECTED;
}
read_error:
{
GST_ELEMENT_ERROR (src, RESOURCE, READ, (NULL),
("read on file descriptor: %s.", g_strerror (errno)));
check/elements/identity.c: Make the error a little clearer when the test fails because identity made a copy of the bu... Original commit message from CVS: * check/elements/identity.c: (GST_START_TEST): Make the error a little clearer when the test fails because identity made a copy of the buffer. * docs/gst/gstreamer-sections.txt: New symbols in gstbasetransform.h * gst/base/gstbasetransform.c: (gst_base_transform_class_init), (gst_base_transform_init), (gst_base_transform_transform_size), (gst_base_transform_configure_caps), (gst_base_transform_setcaps), (gst_base_transform_default_prepare_buf), (gst_base_transform_get_unit_size), (gst_base_transform_buffer_alloc), (gst_base_transform_handle_buffer), (gst_base_transform_chain), (gst_base_transform_change_state), (gst_base_transform_set_passthrough), (gst_base_transform_set_in_place), (gst_base_transform_is_in_place): * gst/base/gstbasetransform.h: Change BaseTransform to separate in_place operate from same_caps output. in_place implies that the element can perform the transform on incoming buffers in-place, even if the caps on the output are different. Sub-class elements can now implement special buffer allocation methods for outgoing buffers if they wish to. Big documentation addition. * gst/elements/gstcapsfilter.c: (gst_capsfilter_transform_ip): * gst/elements/gstelements.c: Changes for basetransform modifications. * gst/elements/Makefile.am: * gst/elements/gstfdsrc.c: (gst_fdsrc_init), (gst_fdsrc_create): Compile fix. Extra debug output.
2005-09-09 17:42:20 +00:00
GST_DEBUG_OBJECT (psrc, "Error reading from fd");
gst_buffer_unref (buf);
return GST_FLOW_ERROR;
}
}