gstreamer/sys/v4l2/v4l2src_calls.c
Stefan Kost 21a8cb1e06 v4l2src: don't deref NULL
Error out when the pool gets shutdown.
2010-01-25 17:23:43 +02:00

433 lines
12 KiB
C

/* GStreamer
*
* Copyright (C) 2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
* 2006 Edgard Lima <edgard.lima@indt.org.br>
*
* v4l2src.c - system calls
*
* 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 <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <string.h>
#include <errno.h>
#include "v4l2src_calls.h"
#include <sys/time.h>
#include <unistd.h>
#ifdef __sun
/* Needed on older Solaris Nevada builds (72 at least) */
#include <stropts.h>
#include <sys/ioccom.h>
#endif
#include "gstv4l2tuner.h"
#include "gstv4l2bufferpool.h"
#include "gst/gst-i18n-plugin.h"
GST_DEBUG_CATEGORY_EXTERN (v4l2src_debug);
#define GST_CAT_DEFAULT v4l2src_debug
GST_DEBUG_CATEGORY_EXTERN (GST_CAT_PERFORMANCE);
/* lalala... */
#define GST_V4L2_SET_ACTIVE(element) (element)->buffer = GINT_TO_POINTER (-1)
#define GST_V4L2_SET_INACTIVE(element) (element)->buffer = NULL
/* On some systems MAP_FAILED seems to be missing */
#ifndef MAP_FAILED
#define MAP_FAILED ((caddr_t) -1)
#endif
/* Local functions */
static gboolean
gst_v4l2src_buffer_pool_activate (GstV4l2BufferPool * pool,
GstV4l2Src * v4l2src)
{
GstV4l2Buffer *buf;
while ((buf = gst_v4l2_buffer_pool_get (pool)) != NULL)
if (!gst_v4l2_buffer_pool_qbuf (pool, buf))
goto queue_failed;
return TRUE;
/* ERRORS */
queue_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("Could not enqueue buffers in device '%s'."),
v4l2src->v4l2object->videodev),
("enqueing buffer %d/%d failed: %s",
buf->vbuffer.index, v4l2src->num_buffers, g_strerror (errno)));
return FALSE;
}
}
/******************************************************
* gst_v4l2src_grab_frame ():
* grab a frame for capturing
* return value: GST_FLOW_OK, GST_FLOW_WRONG_STATE or GST_FLOW_ERROR
******************************************************/
GstFlowReturn
gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf)
{
#define NUM_TRIALS 50
GstV4l2Object *v4l2object;
GstV4l2BufferPool *pool;
gint32 trials = NUM_TRIALS;
GstBuffer *pool_buffer;
gboolean need_copy;
gint ret;
v4l2object = v4l2src->v4l2object;
pool = v4l2src->pool;
if (!pool)
goto no_buffer_pool;
GST_DEBUG_OBJECT (v4l2src, "grab frame");
for (;;) {
if (v4l2object->can_poll_device) {
ret = gst_poll_wait (v4l2object->poll, GST_CLOCK_TIME_NONE);
if (G_UNLIKELY (ret < 0)) {
if (errno == EBUSY)
goto stopped;
if (errno == ENXIO) {
GST_DEBUG_OBJECT (v4l2src,
"v4l2 device doesn't support polling. Disabling");
v4l2object->can_poll_device = FALSE;
} else {
if (errno != EAGAIN && errno != EINTR)
goto select_error;
}
}
}
pool_buffer = GST_BUFFER (gst_v4l2_buffer_pool_dqbuf (pool));
if (pool_buffer)
break;
GST_WARNING_OBJECT (pool->v4l2elem, "trials=%d", trials);
/* if the sync() got interrupted, we can retry */
switch (errno) {
case EINVAL:
case ENOMEM:
/* fatal */
return GST_FLOW_ERROR;
case EAGAIN:
case EIO:
case EINTR:
default:
/* try again, until too many trials */
break;
}
/* check nr. of attempts to capture */
if (--trials == -1) {
goto too_many_trials;
}
}
/* if we are handing out the last buffer in the pool, we need to make a
* copy and bring the buffer back in the pool. */
need_copy = v4l2src->always_copy
|| !gst_v4l2_buffer_pool_available_buffers (pool);
if (G_UNLIKELY (need_copy)) {
if (!v4l2src->always_copy) {
GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, v4l2src,
"running out of buffers, making a copy to reuse current one");
}
*buf = gst_buffer_copy (pool_buffer);
GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
/* this will requeue */
gst_buffer_unref (pool_buffer);
} else {
*buf = pool_buffer;
}
/* we set the buffer metadata in gst_v4l2src_create() */
return GST_FLOW_OK;
/* ERRORS */
no_buffer_pool:
{
GST_DEBUG ("no buffer pool");
return GST_FLOW_WRONG_STATE;
}
select_error:
{
GST_ELEMENT_ERROR (pool->v4l2elem, RESOURCE, READ, (NULL),
("select error %d: %s (%d)", ret, g_strerror (errno), errno));
return GST_FLOW_ERROR;
}
stopped:
{
GST_DEBUG ("stop called");
return GST_FLOW_WRONG_STATE;
}
too_many_trials:
{
GST_ELEMENT_ERROR (pool->v4l2elem, RESOURCE, FAILED,
(_("Failed trying to get video frames from device '%s'."),
v4l2object->videodev),
(_("Failed after %d tries. device %s. system error: %s"),
NUM_TRIALS, v4l2object->videodev, g_strerror (errno)));
return GST_FLOW_ERROR;
}
}
/* Note about fraction simplification
* n1/d1 == n2/d2 is also written as n1 == ( n2 * d1 ) / d2
*/
#define fractions_are_equal(n1,d1,n2,d2) ((n1) == gst_util_uint64_scale_int((n2), (d1), (d2)))
/******************************************************
* gst_v4l2src_set_capture():
* set capture parameters
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_set_capture (GstV4l2Src * v4l2src, guint32 pixelformat,
guint32 width, guint32 height, guint fps_n, guint fps_d)
{
gint fd = v4l2src->v4l2object->video_fd;
struct v4l2_streamparm stream;
if (pixelformat == GST_MAKE_FOURCC ('M', 'P', 'E', 'G'))
return TRUE;
if (!gst_v4l2_object_set_format (v4l2src->v4l2object, pixelformat, width,
height)) {
/* error already reported */
return FALSE;
}
/* Is there a reason we require the caller to always specify a framerate? */
GST_LOG_OBJECT (v4l2src, "Desired framerate: %u/%u", fps_n, fps_d);
memset (&stream, 0x00, sizeof (struct v4l2_streamparm));
stream.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (v4l2_ioctl (fd, VIDIOC_G_PARM, &stream) < 0) {
GST_ELEMENT_WARNING (v4l2src, RESOURCE, SETTINGS,
(_("Could not get parameters on device '%s'"),
v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
goto done;
}
/* Note: V4L2 provides the frame interval, we have the frame rate */
if (fractions_are_equal (stream.parm.capture.timeperframe.numerator,
stream.parm.capture.timeperframe.denominator, fps_d, fps_n)) {
GST_LOG_OBJECT (v4l2src, "Desired framerate already set");
v4l2src->fps_n = fps_n;
v4l2src->fps_d = fps_d;
goto done;
}
/* We want to change the frame rate, so check whether we can. Some cheap USB
* cameras don't have the capability */
if ((stream.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) == 0) {
GST_DEBUG_OBJECT (v4l2src, "Not setting framerate (not supported)");
goto done;
}
GST_LOG_OBJECT (v4l2src, "Setting framerate to %u/%u", fps_n, fps_d);
/* Note: V4L2 wants the frame interval, we have the frame rate */
stream.parm.capture.timeperframe.numerator = fps_d;
stream.parm.capture.timeperframe.denominator = fps_n;
/* some cheap USB cam's won't accept any change */
if (v4l2_ioctl (fd, VIDIOC_S_PARM, &stream) < 0) {
GST_ELEMENT_WARNING (v4l2src, RESOURCE, SETTINGS,
(_("Video input device did not accept new frame rate setting.")),
GST_ERROR_SYSTEM);
goto done;
}
v4l2src->fps_n = fps_n;
v4l2src->fps_d = fps_d;
GST_INFO_OBJECT (v4l2src, "Set framerate to %u/%u", fps_n, fps_d);
done:
return TRUE;
}
/******************************************************
* gst_v4l2src_capture_init():
* initialize the capture system
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_init (GstV4l2Src * v4l2src, GstCaps * caps)
{
GST_DEBUG_OBJECT (v4l2src, "initializing the capture system");
GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
GST_V4L2_CHECK_NOT_ACTIVE (v4l2src->v4l2object);
if (v4l2src->v4l2object->vcap.capabilities & V4L2_CAP_STREAMING) {
/* Map the buffers */
GST_LOG_OBJECT (v4l2src, "initiating buffer pool");
if (!(v4l2src->pool = gst_v4l2_buffer_pool_new (GST_ELEMENT (v4l2src),
v4l2src->v4l2object->video_fd,
v4l2src->num_buffers, caps, TRUE, V4L2_BUF_TYPE_VIDEO_CAPTURE)))
goto buffer_pool_new_failed;
GST_INFO_OBJECT (v4l2src, "capturing buffers via mmap()");
v4l2src->use_mmap = TRUE;
if (v4l2src->num_buffers != v4l2src->pool->buffer_count) {
v4l2src->num_buffers = v4l2src->pool->buffer_count;
g_object_notify (G_OBJECT (v4l2src), "queue-size");
}
} else if (v4l2src->v4l2object->vcap.capabilities & V4L2_CAP_READWRITE) {
GST_INFO_OBJECT (v4l2src, "capturing buffers via read()");
v4l2src->use_mmap = FALSE;
v4l2src->pool = NULL;
} else {
goto no_supported_capture_method;
}
GST_V4L2_SET_ACTIVE (v4l2src->v4l2object);
return TRUE;
/* ERRORS */
buffer_pool_new_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("Could not map buffers from device '%s'"),
v4l2src->v4l2object->videodev),
("Failed to create buffer pool: %s", g_strerror (errno)));
return FALSE;
}
no_supported_capture_method:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("The driver of device '%s' does not support any known capture "
"method."), v4l2src->v4l2object->videodev), (NULL));
return FALSE;
}
}
/******************************************************
* gst_v4l2src_capture_start():
* start streaming capture
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_start (GstV4l2Src * v4l2src)
{
GST_DEBUG_OBJECT (v4l2src, "starting the capturing");
//GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
GST_V4L2_CHECK_ACTIVE (v4l2src->v4l2object);
v4l2src->quit = FALSE;
if (v4l2src->use_mmap) {
if (!gst_v4l2src_buffer_pool_activate (v4l2src->pool, v4l2src)) {
return FALSE;
}
if (!gst_v4l2_object_start_streaming (v4l2src->v4l2object)) {
return FALSE;
}
}
v4l2src->is_capturing = TRUE;
return TRUE;
}
/******************************************************
* gst_v4l2src_capture_stop():
* stop streaming capture
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_stop (GstV4l2Src * v4l2src)
{
GST_DEBUG_OBJECT (v4l2src, "stopping capturing");
if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
goto done;
}
if (!GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
goto done;
}
if (v4l2src->use_mmap) {
/* we actually need to sync on all queued buffers but not
* on the non-queued ones */
if (!gst_v4l2_object_stop_streaming (v4l2src->v4l2object)) {
return FALSE;
}
}
done:
/* make an optional pending wait stop */
v4l2src->quit = TRUE;
v4l2src->is_capturing = FALSE;
return TRUE;
}
/******************************************************
* gst_v4l2src_capture_deinit():
* deinitialize the capture system
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_deinit (GstV4l2Src * v4l2src)
{
GST_DEBUG_OBJECT (v4l2src, "deinitting capture system");
if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
return TRUE;
}
if (!GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
return TRUE;
}
if (v4l2src->pool) {
gst_v4l2_buffer_pool_destroy (v4l2src->pool);
v4l2src->pool = NULL;
}
GST_V4L2_SET_INACTIVE (v4l2src->v4l2object);
return TRUE;
}