/* must be called with the lock */
static void
do_set_flushing (GstBufferPool * pool, gboolean flushing)
{
GstBufferPoolPrivate *priv = pool->priv;
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
if (GST_BUFFER_POOL_IS_FLUSHING (pool) == flushing)
return;
if (flushing) {
g_atomic_int_set (&pool->flushing, 1);
gst_poll_write_control (priv->poll);
if (pclass->flush_start)
pclass->flush_start (pool);
} else {
if (pclass->flush_stop)
pclass->flush_stop (pool);
gst_poll_read_control (priv->poll);
g_atomic_int_set (&pool->flushing, 0);
}
}
static inline void
dec_outstanding (GstBufferPool * pool)
{
if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
/* all buffers are returned to the pool, see if we need to free them */
if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
/* take the lock so that set_active is not run concurrently */
GST_BUFFER_POOL_LOCK (pool);
/* recheck the flushing state in the lock, the pool could have been
* set to active again */
if (GST_BUFFER_POOL_IS_FLUSHING (pool))
do_stop (pool);
GST_BUFFER_POOL_UNLOCK (pool);
}
}
}
static GstFlowReturn
default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstFlowReturn result;
GstBufferPoolPrivate *priv = pool->priv;
while (TRUE) {
if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
goto flushing;
/* try to get a buffer from the queue */
*buffer = gst_atomic_queue_pop (priv->queue);
if (G_LIKELY (*buffer)) {
gst_poll_read_control (priv->poll);
result = GST_FLOW_OK;
GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
break;
}
/* no buffer, try to allocate some more */
GST_LOG_OBJECT (pool, "no buffer, trying to allocate");
result = do_alloc_buffer (pool, buffer, NULL);
if (G_LIKELY (result == GST_FLOW_OK))
/* we have a buffer, return it */
break;
if (G_UNLIKELY (result != GST_FLOW_EOS))
/* something went wrong, return error */
break;
/* check if we need to wait */
if (params && (params->flags & GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT)) {
GST_LOG_OBJECT (pool, "no more buffers");
break;
}
/* now we release the control socket, we wait for a buffer release or
* flushing */
gst_poll_read_control (pool->priv->poll);
GST_LOG_OBJECT (pool, "waiting for free buffers or flushing");
gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE);
gst_poll_write_control (pool->priv->poll);
}
return result;
/* ERRORS */
flushing:
{
GST_DEBUG_OBJECT (pool, "we are flushing");
return GST_FLOW_FLUSHING;
}
}
static inline void
dec_outstanding (GstBufferPool * pool)
{
if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
/* all buffers are returned to the pool, see if we need to free them */
if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
/* take the lock so that set_active is not run concurrently */
GST_BUFFER_POOL_LOCK (pool);
/* now that we have the lock, check if we have been de-activated with
* outstanding buffers */
if (!pool->priv->active)
do_stop (pool);
GST_BUFFER_POOL_UNLOCK (pool);
}
}
}
static GstFlowReturn gst_imx_v4l2_buffer_pool_acquire_buffer(GstBufferPool *bpool, GstBuffer **buffer, G_GNUC_UNUSED GstBufferPoolAcquireParams *params)
{
GstImxV4l2BufferPool *pool = GST_IMX_V4L2_BUFFER_POOL(bpool);
struct v4l2_buffer vbuffer;
GstBuffer *buf;
GstImxV4l2Meta *meta;
if (GST_BUFFER_POOL_IS_FLUSHING(bpool))
return GST_FLOW_FLUSHING;
memset(&vbuffer, 0, sizeof(vbuffer));
vbuffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
vbuffer.memory = V4L2_MEMORY_MMAP;
if (ioctl(GST_IMX_FD_OBJECT_GET_FD(pool->fd_obj_v4l), VIDIOC_DQBUF, &vbuffer) < 0)
{
GST_ERROR_OBJECT(pool, "VIDIOC_DQBUF failed: %s", g_strerror(errno));
return GST_FLOW_ERROR;
}
buf = pool->buffers[vbuffer.index];
GST_DEBUG_OBJECT(pool, "dqbuf %u %p", vbuffer.index, (gpointer)buf);
pool->buffers[vbuffer.index] = NULL;
g_assert(buf);
meta = GST_IMX_V4L2_META_GET(buf);
g_assert(meta);
gst_buffer_remove_all_memory(buf);
gst_buffer_append_memory(buf,
gst_memory_new_wrapped(0,
meta->mem, meta->vbuffer.length, 0,
vbuffer.bytesused, NULL, NULL));
GST_BUFFER_TIMESTAMP(buf) = GST_TIMEVAL_TO_TIME(vbuffer.timestamp);
*buffer = buf;
return GST_FLOW_OK;
}
/* must be called with the lock */
static void
do_set_flushing (GstBufferPool * pool, gboolean flushing)
{
GstBufferPoolPrivate *priv = pool->priv;
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
if (GST_BUFFER_POOL_IS_FLUSHING (pool) == flushing)
return;
if (flushing) {
g_atomic_int_set (&pool->flushing, 1);
/* Write the flush token to wake up any waiters */
gst_poll_write_control (priv->poll);
if (pclass->flush_start)
pclass->flush_start (pool);
} else {
if (pclass->flush_stop)
pclass->flush_stop (pool);
while (!gst_poll_read_control (priv->poll)) {
if (errno == EWOULDBLOCK) {
/* This should not really happen unless flushing and unflushing
* happens on different threads. Let's wait a bit to get back flush
* token from the thread that was setting it to flushing */
g_thread_yield ();
continue;
} else {
/* Critical error but GstPoll already complained */
break;
}
}
g_atomic_int_set (&pool->flushing, 0);
}
}
static GstFlowReturn
gst_v4l2_buffer_pool_acquire_buffer (GstBufferPool * bpool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstFlowReturn ret;
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool);
GstV4l2Object *obj = pool->obj;
GST_DEBUG_OBJECT (pool, "acquire");
if (GST_BUFFER_POOL_IS_FLUSHING (bpool))
goto flushing;
switch (obj->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
/* 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 = GST_BUFFER_POOL_CLASS (parent_class)->acquire_buffer (bpool,
buffer, params);
break;
case GST_V4L2_IO_MMAP:
/* 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);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto done;
/* start copying buffers when we are running low on buffers */
if (pool->num_queued < pool->copy_threshold) {
GstBuffer *copy;
/* copy the memory */
copy = gst_buffer_copy (*buffer);
GST_LOG_OBJECT (pool, "copy buffer %p->%p", *buffer, copy);
/* and requeue so that we can continue capturing */
ret = gst_v4l2_buffer_pool_qbuf (pool, *buffer);
*buffer = copy;
}
break;
case GST_V4L2_IO_USERPTR:
default:
g_assert_not_reached ();
break;
}
break;
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
/* playback, This function should return an empty buffer */
switch (obj->mode) {
case GST_V4L2_IO_RW:
/* get an empty buffer */
ret = GST_BUFFER_POOL_CLASS (parent_class)->acquire_buffer (bpool,
buffer, params);
break;
case GST_V4L2_IO_MMAP:
/* get a free unqueued buffer */
ret = GST_BUFFER_POOL_CLASS (parent_class)->acquire_buffer (bpool,
buffer, params);
break;
case GST_V4L2_IO_USERPTR:
default:
g_assert_not_reached ();
break;
}
break;
default:
g_assert_not_reached ();
break;
}
done:
return ret;
/* ERRORS */
flushing:
{
GST_DEBUG_OBJECT (pool, "We are flushing");
return GST_FLOW_FLUSHING;
}
}
/**
* 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;
}
}
static GstFlowReturn
default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstFlowReturn result;
GstBufferPoolPrivate *priv = pool->priv;
while (TRUE) {
if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
goto flushing;
/* try to get a buffer from the queue */
*buffer = gst_atomic_queue_pop (priv->queue);
if (G_LIKELY (*buffer)) {
while (!gst_poll_read_control (priv->poll)) {
if (errno == EWOULDBLOCK) {
/* We put the buffer into the queue but did not finish writing control
* yet, let's wait a bit and retry */
g_thread_yield ();
continue;
} else {
/* Critical error but GstPoll already complained */
break;
}
}
result = GST_FLOW_OK;
GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
break;
}
/* no buffer, try to allocate some more */
GST_LOG_OBJECT (pool, "no buffer, trying to allocate");
result = do_alloc_buffer (pool, buffer, params);
if (G_LIKELY (result == GST_FLOW_OK))
/* we have a buffer, return it */
break;
if (G_UNLIKELY (result != GST_FLOW_EOS))
/* something went wrong, return error */
break;
/* check if we need to wait */
if (params && (params->flags & GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT)) {
GST_LOG_OBJECT (pool, "no more buffers");
break;
}
/* now we release the control socket, we wait for a buffer release or
* flushing */
if (!gst_poll_read_control (pool->priv->poll)) {
if (errno == EWOULDBLOCK) {
/* This means that we have two threads trying to allocate buffers
* already, and the other one already got the wait token. This
* means that we only have to wait for the poll now and not write the
* token afterwards: we will be woken up once the other thread is
* woken up and that one will write the wait token it removed */
GST_LOG_OBJECT (pool, "waiting for free buffers or flushing");
gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE);
} else {
/* This is a critical error, GstPoll already gave a warning */
result = GST_FLOW_ERROR;
break;
}
} else {
/* We're the first thread waiting, we got the wait token and have to
* write it again later
* OR
* We're a second thread and just consumed the flush token and block all
* other threads, in which case we must not wait and give it back
* immediately */
if (!GST_BUFFER_POOL_IS_FLUSHING (pool)) {
GST_LOG_OBJECT (pool, "waiting for free buffers or flushing");
gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE);
}
gst_poll_write_control (pool->priv->poll);
}
}
return result;
/* ERRORS */
flushing:
{
GST_DEBUG_OBJECT (pool, "we are flushing");
return GST_FLOW_FLUSHING;
}
}
