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gstreamer/subprojects/gst-plugins-good/sys/v4l2/gstv4l2bufferpool.c
Hou Qi 61820ed0dc v4l2bufferpool: Fix race condition between qbuf and pool streamoff 
There is a chance that pool->buffers[index] sets BUFFER_STATE_QUEUED, but
it has not been queued yet which makes pool->buffers[index] still NULL.
At this time, if pool_streamff release all buffers with BUFFER_STATE_QUEUED
state regardless of whether the buffer is NULL or not, it will cause segfault.

To fix this, also check buffer when streamoff release buffer.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1948>
2022-03-14 00:57:24 +00:00

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/* GStreamer
*
* Copyright (C) 2001-2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
* 2006 Edgard Lima <edgard.lima@gmail.com>
* 2009 Texas Instruments, Inc - http://www.ti.com/
*
* gstv4l2bufferpool.c V4L2 buffer pool class
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifndef _GNU_SOURCE
# define _GNU_SOURCE /* O_CLOEXEC */
#endif
#include <fcntl.h>
#include <sys/mman.h>
#include <string.h>
#include <unistd.h>
#include "gst/video/video.h"
#include "gst/video/gstvideometa.h"
#include "gst/video/gstvideopool.h"
#include "gst/allocators/gstdmabuf.h"
#include <gstv4l2bufferpool.h>
#include "gstv4l2object.h"
#include "gst/gst-i18n-plugin.h"
#include <gst/glib-compat-private.h>
GST_DEBUG_CATEGORY_STATIC (v4l2bufferpool_debug);
GST_DEBUG_CATEGORY_STATIC (CAT_PERFORMANCE);
#define GST_CAT_DEFAULT v4l2bufferpool_debug
#define GST_V4L2_IMPORT_QUARK gst_v4l2_buffer_pool_import_quark ()
/*
* GstV4l2BufferPool:
*/
#define gst_v4l2_buffer_pool_parent_class parent_class
G_DEFINE_TYPE (GstV4l2BufferPool, gst_v4l2_buffer_pool, GST_TYPE_BUFFER_POOL);
enum _GstV4l2BufferPoolAcquireFlags
{
GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_RESURRECT =
GST_BUFFER_POOL_ACQUIRE_FLAG_LAST,
GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_LAST
};
/* Buffer state flags */
enum _GstV4l2BufferState
{
/* Buffer is free (either on the GstBufferPool free queue, or no GstBuffer has
* been allocated yet) */
BUFFER_STATE_FREE = 0,
/* Buffer had outstanding external users */
BUFFER_STATE_OUTSTANDING = 1,
/* Buffer is on one of the kernel queues */
BUFFER_STATE_QUEUED = 2,
};
static void gst_v4l2_buffer_pool_complete_release_buffer (GstBufferPool * bpool,
GstBuffer * buffer, gboolean queued);
static gboolean
gst_v4l2_is_buffer_valid (GstBuffer * buffer, GstV4l2MemoryGroup ** out_group)
{
GstMemory *mem = gst_buffer_peek_memory (buffer, 0);
gboolean valid = FALSE;
if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY))
goto done;
if (gst_is_dmabuf_memory (mem))
mem = gst_mini_object_get_qdata (GST_MINI_OBJECT (mem),
GST_V4L2_MEMORY_QUARK);
if (mem && gst_is_v4l2_memory (mem)) {
GstV4l2Memory *vmem = (GstV4l2Memory *) mem;
GstV4l2MemoryGroup *group = vmem->group;
gint i;
if (group->n_mem != gst_buffer_n_memory (buffer))
goto done;
for (i = 0; i < group->n_mem; i++) {
if (group->mem[i] != gst_buffer_peek_memory (buffer, i))
goto done;
if (!gst_memory_is_writable (group->mem[i]))
goto done;
}
valid = TRUE;
if (out_group)
*out_group = group;
}
done:
return valid;
}
static GstFlowReturn
gst_v4l2_buffer_pool_copy_buffer (GstV4l2BufferPool * pool, GstBuffer * dest,
GstBuffer * src)
{
const GstVideoFormatInfo *finfo = pool->caps_info.finfo;
GST_LOG_OBJECT (pool, "copying buffer");
if (finfo && (finfo->format != GST_VIDEO_FORMAT_UNKNOWN &&
finfo->format != GST_VIDEO_FORMAT_ENCODED)) {
GstVideoFrame src_frame, dest_frame;
GST_DEBUG_OBJECT (pool, "copy video frame");
/* we have raw video, use videoframe copy to get strides right */
if (!gst_video_frame_map (&src_frame, &pool->caps_info, src, GST_MAP_READ))
goto invalid_buffer;
if (!gst_video_frame_map (&dest_frame, &pool->caps_info, dest,
GST_MAP_WRITE)) {
gst_video_frame_unmap (&src_frame);
goto invalid_buffer;
}
gst_video_frame_copy (&dest_frame, &src_frame);
gst_video_frame_unmap (&src_frame);
gst_video_frame_unmap (&dest_frame);
} else {
GstMapInfo map;
GST_DEBUG_OBJECT (pool, "copy raw bytes");
if (!gst_buffer_map (src, &map, GST_MAP_READ))
goto invalid_buffer;
gst_buffer_fill (dest, 0, map.data, gst_buffer_get_size (src));
gst_buffer_unmap (src, &map);
gst_buffer_resize (dest, 0, gst_buffer_get_size (src));
}
gst_buffer_copy_into (dest, src,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
GST_CAT_LOG_OBJECT (CAT_PERFORMANCE, pool, "slow copy into buffer %p", dest);
return GST_FLOW_OK;
invalid_buffer:
{
GST_ERROR_OBJECT (pool, "could not map buffer");
return GST_FLOW_ERROR;
}
}
struct UserPtrData
{
GstBuffer *buffer;
gboolean is_frame;
GstVideoFrame frame;
GstMapInfo map;
};
static GQuark
gst_v4l2_buffer_pool_import_quark (void)
{
static GQuark quark = 0;
if (quark == 0)
quark = g_quark_from_string ("GstV4l2BufferPoolUsePtrData");
return quark;
}
static void
_unmap_userptr_frame (struct UserPtrData *data)
{
if (data->is_frame)
gst_video_frame_unmap (&data->frame);
else
gst_buffer_unmap (data->buffer, &data->map);
if (data->buffer)
gst_buffer_unref (data->buffer);
g_slice_free (struct UserPtrData, data);
}
static GstFlowReturn
gst_v4l2_buffer_pool_import_userptr (GstV4l2BufferPool * pool,
GstBuffer * dest, GstBuffer * src)
{
GstFlowReturn ret = GST_FLOW_OK;
GstV4l2MemoryGroup *group = NULL;
GstMapFlags flags;
const GstVideoFormatInfo *finfo = pool->caps_info.finfo;
struct UserPtrData *data = NULL;
GST_LOG_OBJECT (pool, "importing userptr");
/* get the group */
if (!gst_v4l2_is_buffer_valid (dest, &group))
goto not_our_buffer;
if (V4L2_TYPE_IS_OUTPUT (pool->obj->type))
flags = GST_MAP_READ;
else
flags = GST_MAP_WRITE;
data = g_slice_new0 (struct UserPtrData);
if (finfo && (finfo->format != GST_VIDEO_FORMAT_UNKNOWN &&
finfo->format != GST_VIDEO_FORMAT_ENCODED)) {
gsize size[GST_VIDEO_MAX_PLANES] = { 0, };
gint i;
data->is_frame = TRUE;
if (!gst_video_frame_map (&data->frame, &pool->caps_info, src, flags))
goto invalid_buffer;
for (i = 0; i < GST_VIDEO_FORMAT_INFO_N_PLANES (finfo); i++) {
if (GST_VIDEO_FORMAT_INFO_IS_TILED (finfo)) {
gint tinfo = GST_VIDEO_FRAME_PLANE_STRIDE (&data->frame, i);
gint pstride;
guint pheight;
pstride = GST_VIDEO_TILE_X_TILES (tinfo) <<
GST_VIDEO_FORMAT_INFO_TILE_WS (finfo);
pheight = GST_VIDEO_TILE_Y_TILES (tinfo) <<
GST_VIDEO_FORMAT_INFO_TILE_HS (finfo);
size[i] = pstride * pheight;
} else {
size[i] = GST_VIDEO_FRAME_PLANE_STRIDE (&data->frame, i) *
GST_VIDEO_FRAME_COMP_HEIGHT (&data->frame, i);
}
}
/* In the single planar API, planes must be contiguous in memory and
* therefore they must have expected size. ie: no padding.
* To check these conditions, we check that plane 'i' start address
* + plane 'i' size equals to plane 'i+1' start address */
if (!V4L2_TYPE_IS_MULTIPLANAR (pool->obj->type)) {
for (i = 0; i < (GST_VIDEO_FORMAT_INFO_N_PLANES (finfo) - 1); i++) {
const struct v4l2_pix_format *pix_fmt = &pool->obj->format.fmt.pix;
gpointer tmp;
gint estride = gst_v4l2_object_extrapolate_stride (finfo, i,
pix_fmt->bytesperline);
guint eheight = GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (finfo, i,
pix_fmt->height);
tmp = ((guint8 *) data->frame.data[i]) + estride * eheight;
if (tmp != data->frame.data[i + 1])
goto non_contiguous_mem;
}
}
if (!gst_v4l2_allocator_import_userptr (pool->vallocator, group,
data->frame.info.size, finfo->n_planes, data->frame.data, size))
goto import_failed;
} else {
gpointer ptr[1];
gsize size[1];
data->is_frame = FALSE;
if (!gst_buffer_map (src, &data->map, flags))
goto invalid_buffer;
ptr[0] = data->map.data;
size[0] = data->map.size;
if (!gst_v4l2_allocator_import_userptr (pool->vallocator, group,
data->map.size, 1, ptr, size))
goto import_failed;
}
data->buffer = gst_buffer_ref (src);
gst_mini_object_set_qdata (GST_MINI_OBJECT (dest), GST_V4L2_IMPORT_QUARK,
data, (GDestroyNotify) _unmap_userptr_frame);
gst_buffer_copy_into (dest, src,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
return ret;
not_our_buffer:
{
GST_ERROR_OBJECT (pool, "destination buffer invalid or not from our pool");
return GST_FLOW_ERROR;
}
invalid_buffer:
{
GST_ERROR_OBJECT (pool, "could not map buffer");
g_slice_free (struct UserPtrData, data);
return GST_FLOW_ERROR;
}
non_contiguous_mem:
{
GST_ERROR_OBJECT (pool, "memory is not contiguous or plane size mismatch");
_unmap_userptr_frame (data);
return GST_FLOW_ERROR;
}
import_failed:
{
GST_ERROR_OBJECT (pool, "failed to import data");
_unmap_userptr_frame (data);
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_import_dmabuf (GstV4l2BufferPool * pool,
GstBuffer * dest, GstBuffer * src)
{
GstV4l2MemoryGroup *group = NULL;
GstMemory *dma_mem[GST_VIDEO_MAX_PLANES] = { 0 };
guint n_mem = gst_buffer_n_memory (src);
gint i;
GST_LOG_OBJECT (pool, "importing dmabuf");
if (!gst_v4l2_is_buffer_valid (dest, &group))
goto not_our_buffer;
if (n_mem > GST_VIDEO_MAX_PLANES)
goto too_many_mems;
for (i = 0; i < n_mem; i++)
dma_mem[i] = gst_buffer_peek_memory (src, i);
if (!gst_v4l2_allocator_import_dmabuf (pool->vallocator, group, n_mem,
dma_mem))
goto import_failed;
gst_mini_object_set_qdata (GST_MINI_OBJECT (dest), GST_V4L2_IMPORT_QUARK,
gst_buffer_ref (src), (GDestroyNotify) gst_buffer_unref);
gst_buffer_copy_into (dest, src,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
return GST_FLOW_OK;
not_our_buffer:
{
GST_ERROR_OBJECT (pool, "destination buffer invalid or not from our pool");
return GST_FLOW_ERROR;
}
too_many_mems:
{
GST_ERROR_OBJECT (pool, "could not map buffer");
return GST_FLOW_ERROR;
}
import_failed:
{
GST_ERROR_OBJECT (pool, "failed to import dmabuf");
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_prepare_buffer (GstV4l2BufferPool * pool,
GstBuffer * dest, GstBuffer * src)
{
GstFlowReturn ret = GST_FLOW_OK;
gboolean own_src = FALSE;
if (src == NULL) {
if (pool->other_pool == NULL) {
GST_ERROR_OBJECT (pool, "can't prepare buffer, source buffer missing");
return GST_FLOW_ERROR;
}
ret = gst_buffer_pool_acquire_buffer (pool->other_pool, &src, NULL);
if (ret != GST_FLOW_OK) {
GST_ERROR_OBJECT (pool, "failed to acquire buffer from downstream pool");
goto done;
}
own_src = TRUE;
}
switch (pool->obj->mode) {
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_DMABUF:
ret = gst_v4l2_buffer_pool_copy_buffer (pool, dest, src);
break;
case GST_V4L2_IO_USERPTR:
ret = gst_v4l2_buffer_pool_import_userptr (pool, dest, src);
break;
case GST_V4L2_IO_DMABUF_IMPORT:
ret = gst_v4l2_buffer_pool_import_dmabuf (pool, dest, src);
break;
default:
break;
}
if (own_src)
gst_buffer_unref (src);
done:
return ret;
}
static GstFlowReturn
gst_v4l2_buffer_pool_alloc_buffer (GstBufferPool * bpool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstV4l2MemoryGroup *group = NULL;
GstBuffer *newbuf = NULL;
GstV4l2Object *obj;
GstVideoInfo *info;
obj = pool->obj;
info = &obj->info;
switch (obj->mode) {
case GST_V4L2_IO_RW:
newbuf =
gst_buffer_new_allocate (pool->allocator, pool->size, &pool->params);
break;
case GST_V4L2_IO_MMAP:
group = gst_v4l2_allocator_alloc_mmap (pool->vallocator);
break;
case GST_V4L2_IO_DMABUF:
group = gst_v4l2_allocator_alloc_dmabuf (pool->vallocator,
pool->allocator);
break;
case GST_V4L2_IO_USERPTR:
group = gst_v4l2_allocator_alloc_userptr (pool->vallocator);
break;
case GST_V4L2_IO_DMABUF_IMPORT:
group = gst_v4l2_allocator_alloc_dmabufin (pool->vallocator);
break;
default:
newbuf = NULL;
g_assert_not_reached ();
break;
}
if (group != NULL) {
gint i;
newbuf = gst_buffer_new ();
for (i = 0; i < group->n_mem; i++)
gst_buffer_append_memory (newbuf, group->mem[i]);
if (g_atomic_int_get (&pool->buffer_state[group->buffer.index])) {
GST_WARNING_OBJECT (pool, "newly allocated buffer %u is not free",
group->buffer.index);
}
} else if (newbuf == NULL) {
goto allocation_failed;
}
/* add metadata to raw video buffers */
if (pool->add_videometa) {
GstVideoMeta *videometa =
gst_buffer_add_video_meta_full (newbuf, GST_VIDEO_FRAME_FLAG_NONE,
GST_VIDEO_INFO_FORMAT (info), GST_VIDEO_INFO_WIDTH (info),
GST_VIDEO_INFO_HEIGHT (info), GST_VIDEO_INFO_N_PLANES (info),
info->offset, info->stride);
if (videometa)
gst_video_meta_set_alignment (videometa, obj->align);
}
*buffer = newbuf;
return GST_FLOW_OK;
/* ERRORS */
allocation_failed:
{
GST_ERROR_OBJECT (pool, "failed to allocate buffer");
return GST_FLOW_ERROR;
}
}
static gboolean
gst_v4l2_buffer_pool_set_config (GstBufferPool * bpool, GstStructure * config)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstV4l2Object *obj = pool->obj;
GstCaps *caps;
guint size, min_buffers, max_buffers;
GstAllocator *allocator;
GstAllocationParams params;
gboolean can_allocate = FALSE;
gboolean updated = FALSE;
gboolean ret;
pool->add_videometa =
gst_buffer_pool_config_has_option (config,
GST_BUFFER_POOL_OPTION_VIDEO_META);
/* parse the config and keep around */
if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers,
&max_buffers))
goto wrong_config;
if (!gst_buffer_pool_config_get_allocator (config, &allocator, &params))
goto wrong_config;
GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config);
if (pool->allocator)
gst_object_unref (pool->allocator);
pool->allocator = NULL;
switch (obj->mode) {
case GST_V4L2_IO_DMABUF:
pool->allocator = gst_dmabuf_allocator_new ();
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP);
break;
case GST_V4L2_IO_MMAP:
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP);
break;
case GST_V4L2_IO_USERPTR:
can_allocate =
GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, USERPTR);
break;
case GST_V4L2_IO_DMABUF_IMPORT:
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, DMABUF);
break;
case GST_V4L2_IO_RW:
if (allocator)
pool->allocator = g_object_ref (allocator);
pool->params = params;
/* No need to change the configuration */
goto done;
break;
default:
g_assert_not_reached ();
break;
}
/* libv4l2 conversion code does not handle CREATE_BUFS, and may lead to
* instability and crash, disable it for now */
if (can_allocate && obj->fmtdesc->flags & V4L2_FMT_FLAG_EMULATED) {
GST_WARNING_OBJECT (pool,
"libv4l2 converter detected, disabling CREATE_BUFS");
can_allocate = FALSE;
GST_OBJECT_FLAG_UNSET (pool->vallocator,
GST_V4L2_ALLOCATOR_FLAG_MMAP_CREATE_BUFS
| GST_V4L2_ALLOCATOR_FLAG_USERPTR_CREATE_BUFS
| GST_V4L2_ALLOCATOR_FLAG_DMABUF_CREATE_BUFS);
}
if (min_buffers < GST_V4L2_MIN_BUFFERS (obj)) {
updated = TRUE;
min_buffers = GST_V4L2_MIN_BUFFERS (obj);
GST_INFO_OBJECT (pool, "increasing minimum buffers to %u", min_buffers);
}
/* respect driver requirements */
if (min_buffers < obj->min_buffers) {
updated = TRUE;
min_buffers = obj->min_buffers;
GST_INFO_OBJECT (pool, "increasing minimum buffers to %u", min_buffers);
}
if (max_buffers > VIDEO_MAX_FRAME || max_buffers == 0) {
updated = TRUE;
max_buffers = VIDEO_MAX_FRAME;
GST_INFO_OBJECT (pool, "reducing maximum buffers to %u", max_buffers);
}
if (min_buffers > max_buffers) {
updated = TRUE;
min_buffers = max_buffers;
GST_INFO_OBJECT (pool, "reducing minimum buffers to %u", min_buffers);
} else if (min_buffers != max_buffers) {
if (!can_allocate) {
updated = TRUE;
max_buffers = min_buffers;
GST_INFO_OBJECT (pool, "can't allocate, setting maximum to minimum");
}
}
if (!pool->add_videometa && obj->need_video_meta) {
GST_INFO_OBJECT (pool, "adding needed video meta");
updated = TRUE;
gst_buffer_pool_config_add_option (config,
GST_BUFFER_POOL_OPTION_VIDEO_META);
}
/* Always update the config to ensure the configured size matches */
gst_buffer_pool_config_set_params (config, caps, obj->info.size, min_buffers,
max_buffers);
/* keep a GstVideoInfo with defaults for the when we need to copy */
gst_video_info_from_caps (&pool->caps_info, caps);
done:
ret = GST_BUFFER_POOL_CLASS (parent_class)->set_config (bpool, config);
/* If anything was changed documentation recommend to return FALSE */
return !updated && ret;
/* ERRORS */
wrong_config:
{
GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
return FALSE;
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_resurrect_buffer (GstV4l2BufferPool * pool)
{
GstBufferPoolAcquireParams params = { 0 };
GstBuffer *buffer = NULL;
GstFlowReturn ret;
GST_DEBUG_OBJECT (pool, "A buffer was lost, reallocating it");
/* block recursive calls to this function */
g_signal_handler_block (pool->vallocator, pool->group_released_handler);
params.flags =
(GstBufferPoolAcquireFlags) GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_RESURRECT |
GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT;
ret =
gst_buffer_pool_acquire_buffer (GST_BUFFER_POOL (pool), &buffer, &params);
if (ret == GST_FLOW_OK)
gst_buffer_unref (buffer);
g_signal_handler_unblock (pool->vallocator, pool->group_released_handler);
return ret;
}
static gboolean
gst_v4l2_buffer_pool_streamon (GstV4l2BufferPool * pool)
{
GstV4l2Object *obj = pool->obj;
if (pool->streaming)
return TRUE;
switch (obj->mode) {
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_DMABUF_IMPORT:
if (!V4L2_TYPE_IS_OUTPUT (pool->obj->type)) {
guint num_queued;
guint i, n = 0;
num_queued = g_atomic_int_get (&pool->num_queued);
if (num_queued < pool->num_allocated)
n = pool->num_allocated - num_queued;
/* For captures, we need to enqueue buffers before we start streaming,
* so the driver don't underflow immediately. As we have put then back
* into the base class queue, resurrect them, then releasing will queue
* them back. */
for (i = 0; i < n; i++)
gst_v4l2_buffer_pool_resurrect_buffer (pool);
}
if (obj->ioctl (pool->video_fd, VIDIOC_STREAMON, &obj->type) < 0)
goto streamon_failed;
pool->streaming = TRUE;
GST_DEBUG_OBJECT (pool, "Started streaming");
break;
default:
break;
}
return TRUE;
streamon_failed:
{
GST_ERROR_OBJECT (pool, "error with STREAMON %d (%s)", errno,
g_strerror (errno));
return FALSE;
}
}
/* Call with streamlock held, or when streaming threads are down */
static void
gst_v4l2_buffer_pool_streamoff (GstV4l2BufferPool * pool)
{
GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class);
GstV4l2Object *obj = pool->obj;
gint i;
if (!pool->streaming)
return;
switch (obj->mode) {
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_DMABUF_IMPORT:
if (obj->ioctl (pool->video_fd, VIDIOC_STREAMOFF, &obj->type) < 0)
GST_WARNING_OBJECT (pool, "STREAMOFF failed with errno %d (%s)",
errno, g_strerror (errno));
pool->streaming = FALSE;
GST_DEBUG_OBJECT (pool, "Stopped streaming");
if (pool->vallocator)
gst_v4l2_allocator_flush (pool->vallocator);
break;
default:
break;
}
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
gint old_buffer_state =
g_atomic_int_and (&pool->buffer_state[i], ~BUFFER_STATE_QUEUED);
if ((old_buffer_state & BUFFER_STATE_QUEUED) && pool->buffers[i]) {
GstBuffer *buffer = pool->buffers[i];
GstBufferPool *bpool = GST_BUFFER_POOL (pool);
pool->buffers[i] = NULL;
if (!(old_buffer_state & BUFFER_STATE_OUTSTANDING)) {
if (V4L2_TYPE_IS_OUTPUT (pool->obj->type))
gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer, FALSE);
else /* Don't re-enqueue capture buffer on stop */
pclass->release_buffer (bpool, buffer);
}
g_atomic_int_add (&pool->num_queued, -1);
}
}
}
static gboolean
gst_v4l2_buffer_pool_start (GstBufferPool * bpool)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class);
GstV4l2Object *obj = pool->obj;
GstStructure *config;
GstCaps *caps;
guint size, min_buffers, max_buffers;
guint max_latency, min_latency, copy_threshold = 0;
gboolean can_allocate = FALSE, ret = TRUE;
GST_DEBUG_OBJECT (pool, "activating pool");
if (pool->other_pool) {
GstBuffer *buffer;
if (!gst_buffer_pool_set_active (pool->other_pool, TRUE))
goto other_pool_failed;
if (gst_buffer_pool_acquire_buffer (pool->other_pool, &buffer, NULL) !=
GST_FLOW_OK)
goto other_pool_failed;
if (!gst_v4l2_object_try_import (obj, buffer)) {
gst_buffer_unref (buffer);
goto cannot_import;
}
gst_buffer_unref (buffer);
}
config = gst_buffer_pool_get_config (bpool);
if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers,
&max_buffers))
goto wrong_config;
min_latency = MAX (GST_V4L2_MIN_BUFFERS (obj), obj->min_buffers);
switch (obj->mode) {
case GST_V4L2_IO_RW:
can_allocate = TRUE;
#ifdef HAVE_LIBV4L2
/* This workaround a unfixable bug in libv4l2 when RW is emulated on top
* of MMAP. In this case, the first read initialize the queues, but the
* poll before that will always fail. Doing an empty read, forces the
* queue to be initialized now. We only do this if we have a streaming
* driver. */
if (obj->device_caps & V4L2_CAP_STREAMING)
obj->read (obj->video_fd, NULL, 0);
#endif
break;
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_MMAP:
{
guint count;
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP);
/* first, lets request buffers, and see how many we can get: */
GST_DEBUG_OBJECT (pool, "requesting %d MMAP buffers", min_buffers);
count = gst_v4l2_allocator_start (pool->vallocator, min_buffers,
V4L2_MEMORY_MMAP);
pool->num_allocated = count;
if (count < GST_V4L2_MIN_BUFFERS (obj)) {
min_buffers = count;
goto no_buffers;
}
/* V4L2 buffer pool are often very limited in the amount of buffers it
* can offer. The copy_threshold will workaround this limitation by
* falling back to copy if the pipeline needed more buffers. This also
* prevent having to do REQBUFS(N)/REQBUFS(0) every time configure is
* called. */
if (count != min_buffers || pool->enable_copy_threshold) {
GST_WARNING_OBJECT (pool,
"Uncertain or not enough buffers, enabling copy threshold");
min_buffers = count;
copy_threshold = min_latency;
}
break;
}
case GST_V4L2_IO_USERPTR:
{
guint count;
can_allocate =
GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, USERPTR);
GST_DEBUG_OBJECT (pool, "requesting %d USERPTR buffers", min_buffers);
count = gst_v4l2_allocator_start (pool->vallocator, min_buffers,
V4L2_MEMORY_USERPTR);
pool->num_allocated = count;
/* There is no rational to not get what we asked */
if (count < min_buffers) {
min_buffers = count;
goto no_buffers;
}
min_buffers = count;
break;
}
case GST_V4L2_IO_DMABUF_IMPORT:
{
guint count;
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, DMABUF);
GST_DEBUG_OBJECT (pool, "requesting %d DMABUF buffers", min_buffers);
count = gst_v4l2_allocator_start (pool->vallocator, min_buffers,
V4L2_MEMORY_DMABUF);
pool->num_allocated = count;
/* There is no rational to not get what we asked */
if (count < min_buffers) {
min_buffers = count;
goto no_buffers;
}
min_buffers = count;
break;
}
default:
min_buffers = 0;
copy_threshold = 0;
g_assert_not_reached ();
break;
}
if (can_allocate)
max_latency = max_buffers;
else
max_latency = min_buffers;
pool->size = size;
pool->copy_threshold = copy_threshold;
pool->max_latency = max_latency;
pool->min_latency = min_latency;
pool->num_queued = 0;
if (max_buffers != 0 && max_buffers < min_buffers)
max_buffers = min_buffers;
gst_buffer_pool_config_set_params (config, caps, size, min_buffers,
max_buffers);
pclass->set_config (bpool, config);
gst_structure_free (config);
/* now, allocate the buffers: */
if (!pclass->start (bpool))
goto start_failed;
if (!V4L2_TYPE_IS_OUTPUT (obj->type)) {
if (g_atomic_int_get (&pool->num_queued) < pool->num_allocated)
goto queue_failed;
pool->group_released_handler =
g_signal_connect_swapped (pool->vallocator, "group-released",
G_CALLBACK (gst_v4l2_buffer_pool_resurrect_buffer), pool);
ret = gst_v4l2_buffer_pool_streamon (pool);
}
return ret;
/* ERRORS */
wrong_config:
{
GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
gst_structure_free (config);
return FALSE;
}
no_buffers:
{
GST_ERROR_OBJECT (pool,
"we received %d buffer from device '%s', we want at least %d",
min_buffers, obj->videodev, GST_V4L2_MIN_BUFFERS (obj));
gst_structure_free (config);
return FALSE;
}
start_failed:
{
GST_ERROR_OBJECT (pool, "allocate failed");
return FALSE;
}
other_pool_failed:
{
GST_ERROR_OBJECT (pool, "failed to activate the other pool %"
GST_PTR_FORMAT, pool->other_pool);
return FALSE;
}
queue_failed:
{
GST_ERROR_OBJECT (pool, "failed to queue buffers into the capture queue");
return FALSE;
}
cannot_import:
{
GST_ERROR_OBJECT (pool, "cannot import buffers from downstream pool");
return FALSE;
}
}
static gboolean
gst_v4l2_buffer_pool_vallocator_stop (GstV4l2BufferPool * pool)
{
GstV4l2Return vret;
if (!pool->vallocator)
return TRUE;
vret = gst_v4l2_allocator_stop (pool->vallocator);
if (vret == GST_V4L2_BUSY)
GST_WARNING_OBJECT (pool, "some buffers are still outstanding");
return (vret == GST_V4L2_OK);
}
static gboolean
gst_v4l2_buffer_pool_stop (GstBufferPool * bpool)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
gboolean ret;
GST_DEBUG_OBJECT (pool, "stopping pool");
if (pool->group_released_handler > 0) {
g_signal_handler_disconnect (pool->vallocator,
pool->group_released_handler);
pool->group_released_handler = 0;
}
if (pool->other_pool) {
gst_buffer_pool_set_active (pool->other_pool, FALSE);
gst_object_unref (pool->other_pool);
pool->other_pool = NULL;
}
if (!pool->orphaned)
gst_v4l2_buffer_pool_streamoff (pool);
ret = GST_BUFFER_POOL_CLASS (parent_class)->stop (bpool);
if (ret)
ret = gst_v4l2_buffer_pool_vallocator_stop (pool);
return ret;
}
gboolean
gst_v4l2_buffer_pool_orphan (GstBufferPool ** bpool)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (*bpool);
gboolean ret;
g_return_val_if_fail (pool->orphaned == FALSE, FALSE);
if (!GST_V4L2_ALLOCATOR_CAN_ORPHAN_BUFS (pool->vallocator))
return FALSE;
if (g_getenv ("GST_V4L2_FORCE_DRAIN"))
return FALSE;
GST_DEBUG_OBJECT (pool, "orphaning pool");
gst_buffer_pool_set_active (*bpool, FALSE);
/* We lock to prevent racing with a return buffer in QBuf, and has a
* workaround of not being able to use the pool hidden activation lock. */
GST_OBJECT_LOCK (pool);
gst_v4l2_buffer_pool_streamoff (pool);
ret = gst_v4l2_allocator_orphan (pool->vallocator);
if (ret)
pool->orphaned = TRUE;
GST_OBJECT_UNLOCK (pool);
if (ret) {
gst_object_unref (*bpool);
*bpool = NULL;
}
return ret;
}
static void
gst_v4l2_buffer_pool_flush_start (GstBufferPool * bpool)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GST_DEBUG_OBJECT (pool, "start flushing");
gst_poll_set_flushing (pool->poll, TRUE);
GST_OBJECT_LOCK (pool);
pool->empty = FALSE;
g_cond_broadcast (&pool->empty_cond);
GST_OBJECT_UNLOCK (pool);
if (pool->other_pool && gst_buffer_pool_is_active (pool->other_pool))
gst_buffer_pool_set_flushing (pool->other_pool, TRUE);
}
static void
gst_v4l2_buffer_pool_flush_stop (GstBufferPool * bpool)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GST_DEBUG_OBJECT (pool, "stop flushing");
if (pool->other_pool && gst_buffer_pool_is_active (pool->other_pool))
gst_buffer_pool_set_flushing (pool->other_pool, FALSE);
gst_poll_set_flushing (pool->poll, FALSE);
}
static GstFlowReturn
gst_v4l2_buffer_pool_poll (GstV4l2BufferPool * pool, gboolean wait)
{
gint ret;
GstClockTime timeout;
if (wait)
timeout = GST_CLOCK_TIME_NONE;
else
timeout = 0;
/* In RW mode there is no queue, hence no need to wait while the queue is
* empty */
if (pool->obj->mode != GST_V4L2_IO_RW) {
GST_OBJECT_LOCK (pool);
if (!wait && pool->empty) {
GST_OBJECT_UNLOCK (pool);
goto no_buffers;
}
while (pool->empty)
g_cond_wait (&pool->empty_cond, GST_OBJECT_GET_LOCK (pool));
GST_OBJECT_UNLOCK (pool);
}
if (!pool->can_poll_device) {
if (wait)
goto done;
else
goto no_buffers;
}
GST_LOG_OBJECT (pool, "polling device");
again:
ret = gst_poll_wait (pool->poll, timeout);
if (G_UNLIKELY (ret < 0)) {
switch (errno) {
case EBUSY:
goto stopped;
case EAGAIN:
case EINTR:
goto again;
case ENXIO:
GST_WARNING_OBJECT (pool,
"v4l2 device doesn't support polling. Disabling"
" using libv4l2 in this case may cause deadlocks");
pool->can_poll_device = FALSE;
goto done;
default:
goto select_error;
}
}
if (gst_poll_fd_has_error (pool->poll, &pool->pollfd))
goto select_error;
/* PRI is used to signal that events are available */
if (gst_poll_fd_has_pri (pool->poll, &pool->pollfd)) {
struct v4l2_event event = { 0, };
if (!gst_v4l2_dequeue_event (pool->obj, &event))
goto dqevent_failed;
if (event.type != V4L2_EVENT_SOURCE_CHANGE) {
GST_INFO_OBJECT (pool, "Received unhandled event, ignoring.");
goto again;
}
if ((event.u.src_change.changes & V4L2_EVENT_SRC_CH_RESOLUTION) == 0) {
GST_DEBUG_OBJECT (pool,
"Received non-resolution source-change, ignoring.");
goto again;
}
return GST_V4L2_FLOW_RESOLUTION_CHANGE;
}
if (ret == 0)
goto no_buffers;
done:
return GST_FLOW_OK;
/* ERRORS */
stopped:
{
GST_DEBUG_OBJECT (pool, "stop called");
return GST_FLOW_FLUSHING;
}
select_error:
{
GST_ELEMENT_ERROR (pool->obj->element, RESOURCE, READ, (NULL),
("poll error %d: %s (%d)", ret, g_strerror (errno), errno));
return GST_FLOW_ERROR;
}
no_buffers:
{
return GST_V4L2_FLOW_LAST_BUFFER;
}
dqevent_failed:
{
GST_ELEMENT_ERROR (pool->obj->element, RESOURCE, READ, (NULL),
("dqevent error: %s (%d)", g_strerror (errno), errno));
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_qbuf (GstV4l2BufferPool * pool, GstBuffer * buf,
GstV4l2MemoryGroup * group, guint32 * frame_number)
{
const GstV4l2Object *obj = pool->obj;
gint old_buffer_state;
gint index;
index = group->buffer.index;
old_buffer_state =
g_atomic_int_or (&pool->buffer_state[index], BUFFER_STATE_QUEUED);
if (old_buffer_state & BUFFER_STATE_QUEUED)
goto already_queued;
GST_LOG_OBJECT (pool, "queuing buffer %i, previous-state = %i", index,
old_buffer_state);
if (V4L2_TYPE_IS_OUTPUT (obj->type)) {
enum v4l2_field field;
/* Buffer field is the same as the one defined in format */
if (V4L2_TYPE_IS_MULTIPLANAR (obj->type))
field = obj->format.fmt.pix_mp.field;
else
field = obj->format.fmt.pix.field;
group->buffer.field = field;
}
if (frame_number) {
group->buffer.timestamp.tv_sec = *frame_number;
group->buffer.timestamp.tv_usec = 0;
} else {
if (GST_BUFFER_TIMESTAMP_IS_VALID (buf)) {
GstClockTime timestamp = GST_BUFFER_TIMESTAMP (buf);
GST_TIME_TO_TIMEVAL (timestamp, group->buffer.timestamp);
} else {
group->buffer.timestamp.tv_sec = -1;
group->buffer.timestamp.tv_usec = -1;
}
}
GST_OBJECT_LOCK (pool);
/* If the pool was orphaned, don't try to queue any returned buffers.
* This is done with the objet lock in order to synchronize with
* orphaning. */
if (pool->orphaned)
goto was_orphaned;
g_atomic_int_inc (&pool->num_queued);
pool->buffers[index] = buf;
if (!gst_v4l2_allocator_qbuf (pool->vallocator, group))
goto queue_failed;
pool->empty = FALSE;
g_cond_signal (&pool->empty_cond);
GST_OBJECT_UNLOCK (pool);
return GST_FLOW_OK;
already_queued:
{
GST_ERROR_OBJECT (pool, "the buffer %i was already queued", index);
return GST_FLOW_ERROR;
}
was_orphaned:
{
GST_DEBUG_OBJECT (pool, "pool was orphaned, not queuing back buffer.");
GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_TAG_MEMORY);
g_atomic_int_and (&pool->buffer_state[index], ~BUFFER_STATE_QUEUED);
GST_OBJECT_UNLOCK (pool);
return GST_FLOW_FLUSHING;
}
queue_failed:
{
GST_ERROR_OBJECT (pool, "could not queue a buffer %i", index);
/* Mark broken buffer to the allocator */
GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_TAG_MEMORY);
g_atomic_int_add (&pool->num_queued, -1);
pool->buffers[index] = NULL;
g_atomic_int_and (&pool->buffer_state[index], ~BUFFER_STATE_QUEUED);
GST_OBJECT_UNLOCK (pool);
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_dqbuf (GstV4l2BufferPool * pool, GstBuffer ** buffer,
gboolean * outstanding, gboolean wait)
{
GstFlowReturn res;
GstBuffer *outbuf = NULL;
GstV4l2Object *obj = pool->obj;
GstClockTime timestamp;
GstV4l2MemoryGroup *group;
GstVideoMeta *vmeta;
gsize size;
gint i;
gint old_buffer_state;
if ((res = gst_v4l2_buffer_pool_poll (pool, wait)) < GST_FLOW_OK)
goto poll_failed;
if (res == GST_V4L2_FLOW_LAST_BUFFER) {
GST_LOG_OBJECT (pool, "nothing to dequeue");
goto done;
}
if (res == GST_V4L2_FLOW_RESOLUTION_CHANGE) {
GST_INFO_OBJECT (pool, "Resolution change detected.");
goto done;
}
GST_LOG_OBJECT (pool, "dequeueing a buffer");
res = gst_v4l2_allocator_dqbuf (pool->vallocator, &group);
if (res == GST_FLOW_EOS)
goto eos;
if (res != GST_FLOW_OK)
goto dqbuf_failed;
old_buffer_state =
g_atomic_int_and (&pool->buffer_state[group->buffer.index],
~BUFFER_STATE_QUEUED);
if (!(old_buffer_state & BUFFER_STATE_QUEUED))
goto no_buffer;
if (outstanding) {
*outstanding = (old_buffer_state & BUFFER_STATE_OUTSTANDING) != 0;
} else if (old_buffer_state & BUFFER_STATE_OUTSTANDING) {
GST_WARNING_OBJECT (pool, "unexpected outstanding buffer %u",
group->buffer.index);
}
outbuf = pool->buffers[group->buffer.index];
if (outbuf == NULL)
goto no_buffer;
pool->buffers[group->buffer.index] = NULL;
if (g_atomic_int_dec_and_test (&pool->num_queued)) {
GST_OBJECT_LOCK (pool);
pool->empty = TRUE;
GST_OBJECT_UNLOCK (pool);
}
timestamp = GST_TIMEVAL_TO_TIME (group->buffer.timestamp);
size = 0;
vmeta = gst_buffer_get_video_meta (outbuf);
for (i = 0; i < group->n_mem; i++) {
GST_LOG_OBJECT (pool,
"dequeued buffer %p seq:%d (ix=%d), mem %p used %d, plane=%d, flags %08x, ts %"
GST_TIME_FORMAT ", pool-queued=%d, buffer=%p, previous-state=%i",
outbuf, group->buffer.sequence, group->buffer.index, group->mem[i],
group->planes[i].bytesused, i, group->buffer.flags,
GST_TIME_ARGS (timestamp), pool->num_queued, outbuf, old_buffer_state);
if (vmeta) {
vmeta->offset[i] = size;
size += gst_memory_get_sizes (group->mem[i], NULL, NULL);
}
}
/* Ignore timestamp and field for OUTPUT device */
if (V4L2_TYPE_IS_OUTPUT (obj->type))
goto done;
/* Check for driver bug in reporting feild */
if (group->buffer.field == V4L2_FIELD_ANY) {
/* Only warn once to avoid the spamming */
#ifndef GST_DISABLE_GST_DEBUG
if (!pool->has_warned_on_buggy_field) {
pool->has_warned_on_buggy_field = TRUE;
GST_WARNING_OBJECT (pool,
"Driver should never set v4l2_buffer.field to ANY");
}
#endif
/* Use the value from the format (works for UVC bug) */
group->buffer.field = obj->format.fmt.pix.field;
/* If driver also has buggy S_FMT, assume progressive */
if (group->buffer.field == V4L2_FIELD_ANY) {
#ifndef GST_DISABLE_GST_DEBUG
if (!pool->has_warned_on_buggy_field) {
pool->has_warned_on_buggy_field = TRUE;
GST_WARNING_OBJECT (pool,
"Driver should never set v4l2_format.pix.field to ANY");
}
#endif
group->buffer.field = V4L2_FIELD_NONE;
}
}
/* set top/bottom field first if v4l2_buffer has the information */
switch (group->buffer.field) {
case V4L2_FIELD_NONE:
GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF);
break;
case V4L2_FIELD_TOP:
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_TOP_FIELD);
break;
case V4L2_FIELD_BOTTOM:
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_BOTTOM_FIELD);
break;
case V4L2_FIELD_INTERLACED_TB:
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF);
break;
case V4L2_FIELD_INTERLACED_BT:
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF);
break;
case V4L2_FIELD_INTERLACED:
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
if (obj->tv_norm == V4L2_STD_NTSC_M ||
obj->tv_norm == V4L2_STD_NTSC_M_JP ||
obj->tv_norm == V4L2_STD_NTSC_M_KR) {
GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF);
} else {
GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF);
}
break;
default:
GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED);
GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF);
GST_FIXME_OBJECT (pool,
"Unhandled enum v4l2_field %d - treating as progressive",
group->buffer.field);
break;
}
if (GST_VIDEO_INFO_FORMAT (&obj->info) == GST_VIDEO_FORMAT_ENCODED) {
if ((group->buffer.flags & V4L2_BUF_FLAG_KEYFRAME) ||
GST_V4L2_PIXELFORMAT (obj) == V4L2_PIX_FMT_MJPEG ||
GST_V4L2_PIXELFORMAT (obj) == V4L2_PIX_FMT_JPEG ||
GST_V4L2_PIXELFORMAT (obj) == V4L2_PIX_FMT_PJPG)
GST_BUFFER_FLAG_UNSET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
else
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
}
if (group->buffer.flags & V4L2_BUF_FLAG_ERROR)
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_CORRUPTED);
GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
GST_BUFFER_OFFSET (outbuf) = group->buffer.sequence;
GST_BUFFER_OFFSET_END (outbuf) = group->buffer.sequence + 1;
done:
*buffer = outbuf;
return res;
/* ERRORS */
poll_failed:
{
GST_DEBUG_OBJECT (pool, "poll error %s", gst_flow_get_name (res));
return res;
}
eos:
{
return GST_FLOW_EOS;
}
dqbuf_failed:
{
return GST_FLOW_ERROR;
}
no_buffer:
{
GST_ERROR_OBJECT (pool, "No free buffer found in the pool at index %d.",
group->buffer.index);
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_acquire_buffer (GstBufferPool * bpool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstFlowReturn ret;
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class);
GstV4l2Object *obj = pool->obj;
GST_DEBUG_OBJECT (pool, "acquire");
/* If this is being called to resurrect a lost buffer */
if (params && params->flags & GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_RESURRECT) {
ret = pclass->acquire_buffer (bpool, buffer, params);
goto done;
}
switch (obj->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
/* capture, This function should return a buffer with new captured data */
switch (obj->mode) {
case GST_V4L2_IO_RW:
{
/* take empty buffer from the pool */
ret = pclass->acquire_buffer (bpool, buffer, params);
break;
}
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF_IMPORT:
{
/* just dequeue a buffer, we basically use the queue of v4l2 as the
* storage for our buffers. This function does poll first so we can
* interrupt it fine. */
ret = gst_v4l2_buffer_pool_dqbuf (pool, buffer, NULL, TRUE);
break;
}
default:
ret = GST_FLOW_ERROR;
g_assert_not_reached ();
break;
}
break;
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
/* playback, This function should return an empty buffer */
switch (obj->mode) {
case GST_V4L2_IO_RW:
/* get an empty buffer */
ret = pclass->acquire_buffer (bpool, buffer, params);
break;
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF_IMPORT:
/* get a free unqueued buffer */
ret = pclass->acquire_buffer (bpool, buffer, params);
break;
default:
ret = GST_FLOW_ERROR;
g_assert_not_reached ();
break;
}
break;
default:
ret = GST_FLOW_ERROR;
g_assert_not_reached ();
break;
}
done:
/* Mark buffer as outstanding */
if (ret == GST_FLOW_OK) {
GstV4l2MemoryGroup *group;
if (gst_v4l2_is_buffer_valid (*buffer, &group)) {
GST_LOG_OBJECT (pool, "mark buffer %u outstanding", group->buffer.index);
g_atomic_int_or (&pool->buffer_state[group->buffer.index],
BUFFER_STATE_OUTSTANDING);
}
}
return ret;
}
/*
* Completes a release buffer operation
*
* Before calling this function:
* - The buffer state (if applicable) must have already been updated.
* - The buffer must not be outstanding.
* - The "queued" argument contains whether the buffer is currently queued.
*/
static void
gst_v4l2_buffer_pool_complete_release_buffer (GstBufferPool * bpool,
GstBuffer * buffer, gboolean queued)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class);
GstV4l2Object *obj = pool->obj;
GST_DEBUG_OBJECT (pool, "complete release buffer %p (queued = %s)", buffer,
queued ? "yes" : "no");
switch (obj->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
/* capture, put the buffer back in the queue so that we can refill it
* later. */
if (queued) {
GST_WARNING_OBJECT (pool,
"capture buffer %p was release while still queued", buffer);
}
switch (obj->mode) {
case GST_V4L2_IO_RW:
/* release back in the pool */
pclass->release_buffer (bpool, buffer);
break;
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF_IMPORT:
{
GstV4l2MemoryGroup *group;
if (gst_v4l2_is_buffer_valid (buffer, &group)) {
GstFlowReturn ret = GST_FLOW_OK;
gst_v4l2_allocator_reset_group (pool->vallocator, group);
/* queue back in the device */
if (pool->other_pool)
ret = gst_v4l2_buffer_pool_prepare_buffer (pool, buffer, NULL);
if (ret != GST_FLOW_OK ||
gst_v4l2_buffer_pool_qbuf (pool, buffer, group,
NULL) != GST_FLOW_OK)
pclass->release_buffer (bpool, buffer);
} else {
/* Simply release invalid/modified buffer, the allocator will
* give it back later */
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
pclass->release_buffer (bpool, buffer);
}
break;
}
default:
g_assert_not_reached ();
break;
}
break;
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
switch (obj->mode) {
case GST_V4L2_IO_RW:
/* release back in the pool */
pclass->release_buffer (bpool, buffer);
break;
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF_IMPORT:
{
GstV4l2MemoryGroup *group;
guint index;
if (!gst_v4l2_is_buffer_valid (buffer, &group)) {
/* Simply release invalid/modified buffer, the allocator will
* give it back later */
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
pclass->release_buffer (bpool, buffer);
break;
}
index = group->buffer.index;
if (!queued) {
GST_LOG_OBJECT (pool, "buffer %u not queued, putting on free list",
index);
/* Remove qdata, this will unmap any map data in userptr */
gst_mini_object_set_qdata (GST_MINI_OBJECT (buffer),
GST_V4L2_IMPORT_QUARK, NULL, NULL);
/* reset to default size */
gst_v4l2_allocator_reset_group (pool->vallocator, group);
/* playback, put the buffer back in the queue to refill later. */
pclass->release_buffer (bpool, buffer);
} else {
/* the buffer is queued in the device but maybe not played yet. We just
* leave it there and not make it available for future calls to acquire
* for now. The buffer will be dequeued and reused later. */
GST_LOG_OBJECT (pool, "buffer %u is queued", index);
}
break;
}
default:
g_assert_not_reached ();
break;
}
break;
default:
g_assert_not_reached ();
break;
}
}
static void
gst_v4l2_buffer_pool_release_buffer (GstBufferPool * bpool, GstBuffer * buffer)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstV4l2MemoryGroup *group;
gboolean queued = FALSE;
if (gst_v4l2_is_buffer_valid (buffer, &group)) {
gint old_buffer_state =
g_atomic_int_and (&pool->buffer_state[group->buffer.index],
~BUFFER_STATE_OUTSTANDING);
queued = (old_buffer_state & BUFFER_STATE_QUEUED) != 0;
GST_LOG_OBJECT (pool, "mark buffer %u not outstanding",
group->buffer.index);
}
gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer, queued);
}
static void
gst_v4l2_buffer_pool_dispose (GObject * object)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (object);
if (pool->vallocator)
gst_object_unref (pool->vallocator);
pool->vallocator = NULL;
if (pool->allocator)
gst_object_unref (pool->allocator);
pool->allocator = NULL;
if (pool->other_pool)
gst_object_unref (pool->other_pool);
pool->other_pool = NULL;
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_v4l2_buffer_pool_finalize (GObject * object)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (object);
if (pool->video_fd >= 0)
pool->obj->close (pool->video_fd);
gst_poll_free (pool->poll);
/* This can't be done in dispose method because we must not set pointer
* to NULL as it is part of the v4l2object and dispose could be called
* multiple times */
gst_object_unref (pool->obj->element);
g_cond_clear (&pool->empty_cond);
/* FIXME have we done enough here ? */
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_v4l2_buffer_pool_init (GstV4l2BufferPool * pool)
{
pool->poll = gst_poll_new (TRUE);
pool->can_poll_device = TRUE;
g_cond_init (&pool->empty_cond);
pool->empty = TRUE;
pool->orphaned = FALSE;
for (gint i = 0; i < VIDEO_MAX_FRAME; i++)
g_atomic_int_set (&pool->buffer_state[i], BUFFER_STATE_FREE);
}
static void
gst_v4l2_buffer_pool_class_init (GstV4l2BufferPoolClass * klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GstBufferPoolClass *bufferpool_class = GST_BUFFER_POOL_CLASS (klass);
object_class->dispose = gst_v4l2_buffer_pool_dispose;
object_class->finalize = gst_v4l2_buffer_pool_finalize;
bufferpool_class->start = gst_v4l2_buffer_pool_start;
bufferpool_class->stop = gst_v4l2_buffer_pool_stop;
bufferpool_class->set_config = gst_v4l2_buffer_pool_set_config;
bufferpool_class->alloc_buffer = gst_v4l2_buffer_pool_alloc_buffer;
bufferpool_class->acquire_buffer = gst_v4l2_buffer_pool_acquire_buffer;
bufferpool_class->release_buffer = gst_v4l2_buffer_pool_release_buffer;
bufferpool_class->flush_start = gst_v4l2_buffer_pool_flush_start;
bufferpool_class->flush_stop = gst_v4l2_buffer_pool_flush_stop;
GST_DEBUG_CATEGORY_INIT (v4l2bufferpool_debug, "v4l2bufferpool", 0,
"V4L2 Buffer Pool");
GST_DEBUG_CATEGORY_GET (CAT_PERFORMANCE, "GST_PERFORMANCE");
}
/**
* gst_v4l2_buffer_pool_new:
* @obj: the v4l2 object owning the pool
*
* Construct a new buffer pool.
*
* Returns: the new pool, use gst_object_unref() to free resources
*/
GstBufferPool *
gst_v4l2_buffer_pool_new (GstV4l2Object * obj, GstCaps * caps)
{
GstV4l2BufferPool *pool;
GstStructure *config;
gchar *name, *parent_name;
gint fd;
fd = obj->dup (obj->video_fd);
if (fd < 0)
goto dup_failed;
/* setting a significant unique name */
parent_name = gst_object_get_name (GST_OBJECT (obj->element));
name = g_strdup_printf ("%s:pool%u:%s",
parent_name, obj->pool_seq++,
V4L2_TYPE_IS_OUTPUT (obj->type) ? "sink" : "src");
g_free (parent_name);
pool = (GstV4l2BufferPool *) g_object_new (GST_TYPE_V4L2_BUFFER_POOL,
"name", name, NULL);
g_object_ref_sink (pool);
g_free (name);
gst_poll_fd_init (&pool->pollfd);
pool->pollfd.fd = fd;
gst_poll_add_fd (pool->poll, &pool->pollfd);
if (V4L2_TYPE_IS_OUTPUT (obj->type))
gst_poll_fd_ctl_write (pool->poll, &pool->pollfd, TRUE);
else
gst_poll_fd_ctl_read (pool->poll, &pool->pollfd, TRUE);
pool->video_fd = fd;
pool->obj = obj;
pool->can_poll_device = TRUE;
pool->vallocator = gst_v4l2_allocator_new (GST_OBJECT (pool), obj);
if (pool->vallocator == NULL)
goto allocator_failed;
gst_object_ref (obj->element);
config = gst_buffer_pool_get_config (GST_BUFFER_POOL_CAST (pool));
gst_buffer_pool_config_set_params (config, caps, obj->info.size, 0, 0);
/* This will simply set a default config, but will not configure the pool
* because min and max are not valid */
gst_buffer_pool_set_config (GST_BUFFER_POOL_CAST (pool), config);
return GST_BUFFER_POOL (pool);
/* ERRORS */
dup_failed:
{
GST_ERROR ("failed to dup fd %d (%s)", errno, g_strerror (errno));
return NULL;
}
allocator_failed:
{
GST_ERROR_OBJECT (pool, "Failed to create V4L2 allocator");
gst_object_unref (pool);
return NULL;
}
}
static GstFlowReturn
gst_v4l2_do_read (GstV4l2BufferPool * pool, GstBuffer * buf)
{
GstFlowReturn res;
GstV4l2Object *obj = pool->obj;
gint amount;
GstMapInfo map;
gint toread;
toread = obj->info.size;
GST_LOG_OBJECT (pool, "reading %d bytes into buffer %p", toread, buf);
gst_buffer_map (buf, &map, GST_MAP_WRITE);
do {
if ((res = gst_v4l2_buffer_pool_poll (pool, TRUE)) != GST_FLOW_OK)
goto poll_error;
amount = obj->read (obj->video_fd, map.data, toread);
if (amount == toread) {
break;
} else if (amount == -1) {
if (errno == EAGAIN || errno == EINTR) {
continue;
} else
goto read_error;
} else {
/* short reads can happen if a signal interrupts the read */
continue;
}
} while (TRUE);
GST_LOG_OBJECT (pool, "read %d bytes", amount);
gst_buffer_unmap (buf, &map);
gst_buffer_resize (buf, 0, amount);
return GST_FLOW_OK;
/* ERRORS */
poll_error:
{
GST_DEBUG ("poll error %s", gst_flow_get_name (res));
goto cleanup;
}
read_error:
{
GST_ELEMENT_ERROR (obj->element, RESOURCE, READ,
(_("Error reading %d bytes from device '%s'."),
toread, obj->videodev), GST_ERROR_SYSTEM);
res = GST_FLOW_ERROR;
goto cleanup;
}
cleanup:
{
gst_buffer_unmap (buf, &map);
gst_buffer_resize (buf, 0, 0);
return res;
}
}
/**
* gst_v4l2_buffer_pool_process:
* @bpool: a #GstBufferPool
* @buf: a #GstBuffer, maybe be replaced
* @frame_number: 32 bit frame number or %NULL
*
* Process @buf in @bpool. For capture devices, this functions fills @buf with
* data from the device. For output devices, this functions send the contents of
* @buf to the device for playback.
*
* If non-%NULL and an output device, @frame_number is stored inside the timestamp for output devices and read
* back from the timestamp for capture devices.
*
* Returns: %GST_FLOW_OK on success.
*/
GstFlowReturn
gst_v4l2_buffer_pool_process (GstV4l2BufferPool * pool, GstBuffer ** buf,
guint32 * frame_number)
{
GstFlowReturn ret = GST_FLOW_OK;
GstBufferPool *bpool = GST_BUFFER_POOL_CAST (pool);
GstV4l2Object *obj = pool->obj;
GST_DEBUG_OBJECT (pool, "process buffer %p", buf);
if (GST_BUFFER_POOL_IS_FLUSHING (pool))
return GST_FLOW_FLUSHING;
switch (obj->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
/* capture */
switch (obj->mode) {
case GST_V4L2_IO_RW:
/* capture into the buffer */
ret = gst_v4l2_do_read (pool, *buf);
break;
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_DMABUF:
{
GstBuffer *tmp;
if ((*buf)->pool == bpool) {
guint num_queued;
gsize size = gst_buffer_get_size (*buf);
/* Legacy M2M devices return empty buffer when drained */
if (size == 0 && GST_V4L2_IS_M2M (obj->device_caps))
goto eos;
if (GST_VIDEO_INFO_FORMAT (&pool->caps_info) !=
GST_VIDEO_FORMAT_ENCODED && size < pool->size)
goto buffer_truncated;
num_queued = g_atomic_int_get (&pool->num_queued);
GST_TRACE_OBJECT (pool, "Only %i buffer left in the capture queue.",
num_queued);
/* If we have no more buffer, and can allocate it time to do so */
if (num_queued == 0) {
if (GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP)) {
ret = gst_v4l2_buffer_pool_resurrect_buffer (pool);
if (ret == GST_FLOW_OK)
goto done;
}
}
/* start copying buffers when we are running low on buffers */
if (num_queued < pool->copy_threshold) {
GstBuffer *copy;
if (GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP)) {
ret = gst_v4l2_buffer_pool_resurrect_buffer (pool);
if (ret == GST_FLOW_OK)
goto done;
}
/* copy the buffer */
copy = gst_buffer_copy_region (*buf,
GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP, 0, -1);
GST_LOG_OBJECT (pool, "copy buffer %p->%p", *buf, copy);
/* and requeue so that we can continue capturing */
gst_buffer_unref (*buf);
*buf = copy;
}
ret = GST_FLOW_OK;
/* nothing, data was inside the buffer when we did _acquire() */
goto done;
}
/* buffer not from our pool, grab a frame and copy it into the target */
if ((ret = gst_v4l2_buffer_pool_dqbuf (pool, &tmp, NULL, TRUE))
!= GST_FLOW_OK)
goto done;
/* An empty buffer on capture indicates the end of stream */
if (gst_buffer_get_size (tmp) == 0) {
gst_v4l2_buffer_pool_complete_release_buffer (bpool, tmp, FALSE);
/* Legacy M2M devices return empty buffer when drained */
if (GST_V4L2_IS_M2M (obj->device_caps))
goto eos;
}
ret = gst_v4l2_buffer_pool_copy_buffer (pool, *buf, tmp);
/* an queue the buffer again after the copy */
gst_v4l2_buffer_pool_complete_release_buffer (bpool, tmp, FALSE);
if (ret != GST_FLOW_OK)
goto copy_failed;
break;
}
case GST_V4L2_IO_USERPTR:
{
struct UserPtrData *data;
GstBuffer *tmp;
/* Replace our buffer with downstream allocated buffer */
data = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf),
GST_V4L2_IMPORT_QUARK);
tmp = gst_buffer_ref (data->buffer);
_unmap_userptr_frame (data);
/* Now tmp is writable, copy the flags and timestamp */
gst_buffer_copy_into (tmp, *buf,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
gst_buffer_replace (buf, tmp);
gst_buffer_unref (tmp);
break;
}
case GST_V4L2_IO_DMABUF_IMPORT:
{
GstBuffer *tmp;
/* Replace our buffer with downstream allocated buffer */
tmp = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf),
GST_V4L2_IMPORT_QUARK);
gst_buffer_copy_into (tmp, *buf,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
gst_buffer_replace (buf, tmp);
gst_buffer_unref (tmp);
break;
}
default:
g_assert_not_reached ();
break;
}
break;
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
/* playback */
switch (obj->mode) {
case GST_V4L2_IO_RW:
/* FIXME, do write() */
GST_WARNING_OBJECT (pool, "implement write()");
break;
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF_IMPORT:
case GST_V4L2_IO_DMABUF:
case GST_V4L2_IO_MMAP:
{
GstBuffer *to_queue = NULL;
GstBuffer *buffer;
GstV4l2MemoryGroup *group;
gint index;
gboolean outstanding;
if ((*buf)->pool != bpool)
goto copying;
if (!gst_v4l2_is_buffer_valid (*buf, &group))
goto copying;
index = group->buffer.index;
GST_LOG_OBJECT (pool, "processing buffer %i from our pool", index);
if (g_atomic_int_get (&pool->buffer_state[index]) &
BUFFER_STATE_QUEUED) {
GST_LOG_OBJECT (pool, "buffer %i already queued, copying", index);
goto copying;
}
/* we can queue directly */
to_queue = gst_buffer_ref (*buf);
copying:
if (to_queue == NULL) {
GstBufferPoolAcquireParams params = { 0 };
GST_LOG_OBJECT (pool, "alloc buffer from our pool");
/* this can return EOS if all buffers are outstanding which would
* be strange because we would expect the upstream element to have
* allocated them and returned to us.. */
params.flags = GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT;
ret = gst_buffer_pool_acquire_buffer (bpool, &to_queue, &params);
if (ret != GST_FLOW_OK)
goto acquire_failed;
ret = gst_v4l2_buffer_pool_prepare_buffer (pool, to_queue, *buf);
if (ret != GST_FLOW_OK) {
gst_buffer_unref (to_queue);
goto prepare_failed;
}
/* retrieve the group */
gst_v4l2_is_buffer_valid (to_queue, &group);
}
if ((ret =
gst_v4l2_buffer_pool_qbuf (pool, to_queue, group,
frame_number))
!= GST_FLOW_OK)
goto queue_failed;
/* if we are not streaming yet (this is the first buffer, start
* streaming now */
if (!gst_v4l2_buffer_pool_streamon (pool)) {
/* don't check return value because qbuf would have failed */
gst_v4l2_is_buffer_valid (to_queue, &group);
/* qbuf has stored to_queue buffer but we are not in
* streaming state, so the flush logic won't be performed.
* To avoid leaks, flush the allocator and restore the queued
* buffer as non-queued */
gst_v4l2_allocator_flush (pool->vallocator);
pool->buffers[group->buffer.index] = NULL;
g_atomic_int_and (&pool->buffer_state[group->buffer.index],
~BUFFER_STATE_QUEUED);
gst_mini_object_set_qdata (GST_MINI_OBJECT (to_queue),
GST_V4L2_IMPORT_QUARK, NULL, NULL);
gst_buffer_unref (to_queue);
g_atomic_int_add (&pool->num_queued, -1);
goto start_failed;
}
/* Remove our ref, we will still hold this buffer in acquire as needed,
* otherwise the pool will think it is outstanding and will refuse to stop. */
gst_buffer_unref (to_queue);
/* release as many buffer as possible */
while (gst_v4l2_buffer_pool_dqbuf (pool, &buffer, &outstanding,
FALSE) == GST_FLOW_OK) {
if (!outstanding)
gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer,
FALSE);
}
if (g_atomic_int_get (&pool->num_queued) >= pool->min_latency) {
/* all buffers are queued, try to dequeue one and release it back
* into the pool so that _acquire can get to it again. */
ret =
gst_v4l2_buffer_pool_dqbuf (pool, &buffer, &outstanding, TRUE);
if (ret == GST_FLOW_OK && !outstanding)
/* release the rendered buffer back into the pool. This wakes up any
* thread waiting for a buffer in _acquire(). */
gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer,
FALSE);
}
break;
}
default:
g_assert_not_reached ();
break;
}
break;
default:
g_assert_not_reached ();
break;
}
done:
return ret;
/* ERRORS */
copy_failed:
{
GST_ERROR_OBJECT (pool, "failed to copy buffer");
return ret;
}
buffer_truncated:
{
GST_WARNING_OBJECT (pool,
"Dropping truncated buffer, this is likely a driver bug.");
gst_buffer_unref (*buf);
*buf = NULL;
return GST_V4L2_FLOW_CORRUPTED_BUFFER;
}
eos:
{
GST_DEBUG_OBJECT (pool, "end of stream reached");
gst_buffer_unref (*buf);
*buf = NULL;
return GST_V4L2_FLOW_LAST_BUFFER;
}
acquire_failed:
{
if (ret == GST_FLOW_FLUSHING)
GST_DEBUG_OBJECT (pool, "flushing");
else
GST_WARNING_OBJECT (pool, "failed to acquire a buffer: %s",
gst_flow_get_name (ret));
return ret;
}
prepare_failed:
{
GST_ERROR_OBJECT (pool, "failed to prepare data");
return ret;
}
queue_failed:
{
GST_ERROR_OBJECT (pool, "failed to queue buffer");
return ret;
}
start_failed:
{
GST_ERROR_OBJECT (pool, "failed to start streaming");
return GST_FLOW_ERROR;
}
}
void
gst_v4l2_buffer_pool_set_other_pool (GstV4l2BufferPool * pool,
GstBufferPool * other_pool)
{
g_return_if_fail (!gst_buffer_pool_is_active (GST_BUFFER_POOL (pool)));
if (pool->other_pool)
gst_object_unref (pool->other_pool);
pool->other_pool = gst_object_ref (other_pool);
}
void
gst_v4l2_buffer_pool_copy_at_threshold (GstV4l2BufferPool * pool, gboolean copy)
{
GST_OBJECT_LOCK (pool);
pool->enable_copy_threshold = copy;
GST_OBJECT_UNLOCK (pool);
}
gboolean
gst_v4l2_buffer_pool_flush (GstBufferPool * bpool)
{
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
gboolean ret = TRUE;
gst_v4l2_buffer_pool_streamoff (pool);
if (!V4L2_TYPE_IS_OUTPUT (pool->obj->type))
ret = gst_v4l2_buffer_pool_streamon (pool);
return ret;
}
/**
* gst_v4l2_buffer_pool_enable_resolution_change:
* @pool: a #GstBufferPool
*
* When this is called, the pool will subscribe to the
* %V4L2_EVENT_SOURCE_CHANGE. Upon receiving this event, it will notify
* the element acquiring buffer with the special flow return
* %GST_V4L2_FLOW_RESOLUTION_CHANGE.
*/
void
gst_v4l2_buffer_pool_enable_resolution_change (GstV4l2BufferPool * pool)
{
guint32 input_id = 0;
g_return_if_fail (!gst_buffer_pool_is_active (GST_BUFFER_POOL (pool)));
/* Make sure we subscribe for the current input */
gst_v4l2_get_input (pool->obj, &input_id);
if (gst_v4l2_subscribe_event (pool->obj, V4L2_EVENT_SOURCE_CHANGE, input_id))
gst_poll_fd_ctl_pri (pool->poll, &pool->pollfd, TRUE);
}
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