guint
gst_v4l2_allocator_start (GstV4l2Allocator * allocator, guint32 count,
guint32 memory)
{
struct v4l2_requestbuffers breq = { count, allocator->type, memory };
gboolean can_allocate;
gint i;
g_return_val_if_fail (count != 0, 0);
GST_OBJECT_LOCK (allocator);
if (g_atomic_int_get (&allocator->active))
goto already_active;
if (v4l2_ioctl (allocator->video_fd, VIDIOC_REQBUFS, &breq) < 0)
goto reqbufs_failed;
if (breq.count < 1)
goto out_of_memory;
switch (memory) {
case V4L2_MEMORY_MMAP:
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (allocator, MMAP);
break;
case V4L2_MEMORY_USERPTR:
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (allocator, USERPTR);
break;
case V4L2_MEMORY_DMABUF:
can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (allocator, DMABUF);
break;
default:
can_allocate = FALSE;
break;
}
GST_DEBUG_OBJECT (allocator, "allocated %u %s buffers out of %u requested",
breq.count, memory_type_to_str (memory), count);
allocator->can_allocate = can_allocate;
allocator->count = breq.count;
allocator->memory = memory;
/* Create memory groups */
for (i = 0; i < allocator->count; i++) {
allocator->groups[i] = gst_v4l2_memory_group_new (allocator, i);
if (allocator->groups[i] == NULL)
goto error;
gst_atomic_queue_push (allocator->free_queue, allocator->groups[i]);
}
g_atomic_int_set (&allocator->active, TRUE);
done:
GST_OBJECT_UNLOCK (allocator);
return breq.count;
already_active:
{
GST_ERROR_OBJECT (allocator, "allocator already active");
goto error;
}
reqbufs_failed:
{
GST_ERROR_OBJECT (allocator,
"error requesting %d buffers: %s", count, g_strerror (errno));
goto error;
}
out_of_memory:
{
GST_ERROR_OBJECT (allocator, "Not enough memory to allocate buffers");
goto error;
}
error:
{
breq.count = 0;
goto done;
}
}
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, ¶ms))
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:
pool->allocator = g_object_ref (allocator);
pool->params = params;
/* No need to change the configuration */
goto done;
break;
default:
g_assert_not_reached ();
break;
}
if (min_buffers < GST_V4L2_MIN_BUFFERS) {
updated = TRUE;
min_buffers = GST_V4L2_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);
}
if (updated)
gst_buffer_pool_config_set_params (config, caps, 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 recommand to return FALSE */
return !updated && ret;
/* ERRORS */
wrong_config:
{
GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
return FALSE;
}
}
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;
GST_DEBUG_OBJECT (pool, "activating pool");
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->min_buffers);
switch (obj->mode) {
case GST_V4L2_IO_RW:
can_allocate = TRUE;
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);
if (count < GST_V4L2_MIN_BUFFERS) {
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) everytime configure is
* called. */
if (count != min_buffers) {
GST_WARNING_OBJECT (pool, "using %u buffers instead of %u",
count, min_buffers);
min_buffers = count;
copy_threshold = min_latency;
/* The initial minimum could be provide either by GstBufferPool or
* driver needs. */
min_buffers = count;
}
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);
/* 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);
/* 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 < 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);
if (pool->other_pool)
if (!gst_buffer_pool_set_active (pool->other_pool, TRUE))
goto other_pool_failed;
/* now, allocate the buffers: */
if (!pclass->start (bpool))
goto start_failed;
if (!V4L2_TYPE_IS_OUTPUT (obj->type))
pool->group_released_handler =
g_signal_connect_swapped (pool->vallocator, "group-released",
G_CALLBACK (gst_v4l2_buffer_pool_group_released), pool);
return TRUE;
/* 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);
gst_structure_free (config);
return FALSE;
}
start_failed:
{
GST_ERROR_OBJECT (pool, "failed to start streaming");
return FALSE;
}
other_pool_failed:
{
GST_ERROR_OBJECT (pool, "failed to active the other pool %"
GST_PTR_FORMAT, pool->other_pool);
return FALSE;
}
}
/**
* gst_v4l2_buffer_pool_process:
* @bpool: a #GstBufferPool
* @buf: a #GstBuffer, maybe be replaced
*
* 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.
*
* Returns: %GST_FLOW_OK on success.
*/
GstFlowReturn
gst_v4l2_buffer_pool_process (GstV4l2BufferPool * pool, GstBuffer ** buf)
{
GstFlowReturn ret = GST_FLOW_OK;
GstBufferPool *bpool = GST_BUFFER_POOL_CAST (pool);
GstV4l2Object *obj = pool->obj;
GST_DEBUG_OBJECT (pool, "process buffer %p", buf);
g_return_val_if_fail (gst_buffer_pool_is_active (bpool), GST_FLOW_ERROR);
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) {
if (gst_buffer_get_size (*buf) == 0)
goto eos;
/* start copying buffers when we are running low on buffers */
if (g_atomic_int_get (&pool->num_queued) < pool->copy_threshold) {
GstBuffer *copy;
if (GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP)) {
if (gst_buffer_pool_acquire_buffer (bpool, ©,
NULL) == GST_FLOW_OK) {
gst_v4l2_buffer_pool_release_buffer (bpool, copy);
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;
}
/* 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)) != 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_release_buffer (bpool, tmp);
goto eos;
}
ret = gst_v4l2_buffer_pool_copy_buffer (pool, *buf, tmp);
/* an queue the buffer again after the copy */
gst_v4l2_buffer_pool_release_buffer (bpool, tmp);
if (ret != GST_FLOW_OK)
goto copy_failed;
break;
}
case GST_V4L2_IO_USERPTR:
{
struct UserPtrData *data;
/* Replace our buffer with downstream allocated buffer */
data = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf),
GST_V4L2_IMPORT_QUARK);
gst_buffer_replace (buf, data->buffer);
_unmap_userptr_frame (data);
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_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;
GstV4l2MemoryGroup *group;
gint index;
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);
index = group->buffer.index;
if (pool->buffers[index] != NULL) {
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, ¶ms);
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;
}
}
if ((ret = gst_v4l2_buffer_pool_qbuf (pool, to_queue)) != 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 taken the ref of the to_queue buffer but we are no 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;
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;
}
if (g_atomic_int_get (&pool->num_queued) >= pool->min_latency) {
GstBuffer *out;
/* 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, &out);
if (ret == GST_FLOW_OK)
/* release the rendered buffer back into the pool. This wakes up any
* thread waiting for a buffer in _acquire(). */
gst_buffer_unref (out);
}
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;
}
eos:
{
GST_DEBUG_OBJECT (pool, "end of stream reached");
return GST_FLOW_EOS;
}
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;
}
}
