Hi,
On 05/18/2018 02:50 PM, Frediano Ziglio wrote:
Hi,
On 04/19/2018 03:28 PM, Frediano Ziglio wrote:
display_queue is queued with decoded frames ready to be displayed.
However current code can insert a timeout before displaying and
removing the queued frames. As the frames are not compressed the
usage of memory by this queue can became in some cases quite
huge (in the order of different gigabytes).
To prevent this do not queue all the frames but just one and count the
pending frames.
This way GStreamer will stop queuing after a while.
Signed-off-by: Frediano Ziglio <fziglio@xxxxxxxxxx>
---
src/channel-display-gst.c | 76
+++++++++++++++++++++++++++++------------------
1 file changed, 47 insertions(+), 29 deletions(-)
diff --git a/src/channel-display-gst.c b/src/channel-display-gst.c
index 0d7aabb..7ba8cd0 100644
--- a/src/channel-display-gst.c
+++ b/src/channel-display-gst.c
@@ -29,6 +29,8 @@
#include <gst/video/gstvideometa.h>
+typedef struct SpiceGstFrame SpiceGstFrame;
+
/* GStreamer decoder implementation */
typedef struct SpiceGstDecoder {
@@ -47,8 +49,9 @@ typedef struct SpiceGstDecoder {
GMutex queues_mutex;
GQueue *decoding_queue;
- GQueue *display_queue;
+ SpiceGstFrame *display_frame;
guint timer_id;
+ guint pending_samples;
} SpiceGstDecoder;
#define VALID_VIDEO_CODEC_TYPE(codec) \
@@ -74,11 +77,11 @@ typedef enum {
/* ---------- SpiceGstFrame ---------- */
-typedef struct SpiceGstFrame {
+struct SpiceGstFrame {
GstClockTime timestamp;
SpiceFrame *frame;
GstSample *sample;
-} SpiceGstFrame;
+};
static SpiceGstFrame *create_gst_frame(GstBuffer *buffer, SpiceFrame
*frame)
{
@@ -102,6 +105,7 @@ static void free_gst_frame(SpiceGstFrame *gstframe)
/* ---------- GStreamer pipeline ---------- */
static void schedule_frame(SpiceGstDecoder *decoder);
+static void fetch_pending_sample(SpiceGstDecoder *decoder);
static int spice_gst_buffer_get_stride(GstBuffer *buffer)
{
@@ -122,7 +126,8 @@ static gboolean display_frame(gpointer video_decoder)
g_mutex_lock(&decoder->queues_mutex);
decoder->timer_id = 0;
- gstframe = g_queue_pop_head(decoder->display_queue);
+ gstframe = decoder->display_frame;
+ decoder->display_frame = NULL;
g_mutex_unlock(&decoder->queues_mutex);
/* If the queue is empty we don't even need to reschedule */
g_return_val_if_fail(gstframe, G_SOURCE_REMOVE);
@@ -168,7 +173,12 @@ static void schedule_frame(SpiceGstDecoder *decoder)
g_mutex_lock(&decoder->queues_mutex);
while (!decoder->timer_id) {
- SpiceGstFrame *gstframe =
g_queue_peek_head(decoder->display_queue);
+ while (decoder->display_frame == NULL && decoder->pending_samples)
{
+ decoder->pending_samples--;
+ fetch_pending_sample(decoder);
Maybe pending_samples--; should be done after making sure a pulling\fetching
of a sample was completed successfully.
If there are pending samples fetch_pending_sample is supposed to get a
sample anyway. Not sure what could have been so wrong that gstreamer
told us "there is a sample" but there is not... "ghost" sample?
I'm not sure it could happen but i was wondering if there is a chance to
wrongly count EOS (in the middle of a stream?) or state change (iirc
those can also release the gst_app_sink_pull_sample blocking.. the
latter is async event)
+ }
+
+ SpiceGstFrame *gstframe = decoder->display_frame;
if (!gstframe) {
break;
}
@@ -176,7 +186,7 @@ static void schedule_frame(SpiceGstDecoder *decoder)
if (spice_mmtime_diff(now, gstframe->frame->mm_time) < 0) {
decoder->timer_id = g_timeout_add(gstframe->frame->mm_time -
now,
display_frame, decoder);
- } else if (g_queue_get_length(decoder->display_queue) == 1) {
+ } else if (decoder->display_frame && !decoder->pending_samples) {
/* Still attempt to display the least out of date frame so
the
* video is not completely frozen for an extended period of
time.
*/
Is this comment still true? if there's no pending samples this
is the only frame available (which is probably also out of date)
I suppose can still happen if we just got last frame from queue after
rendering another.
@@ -186,7 +196,7 @@ static void schedule_frame(SpiceGstDecoder *decoder)
__FUNCTION__, now - gstframe->frame->mm_time,
gstframe->frame->mm_time, now);
stream_dropped_frame_on_playback(decoder->base.stream);
- g_queue_pop_head(decoder->display_queue);
+ decoder->display_frame = NULL;
free_gst_frame(gstframe);
}
}
@@ -194,22 +204,11 @@ static void schedule_frame(SpiceGstDecoder *decoder)
g_mutex_unlock(&decoder->queues_mutex);
}
-/* GStreamer thread
- *
- * We cannot use GStreamer's signals because they are not always run in
- * the main context. So use a callback (lower overhead) and have it pull
- * the sample to avoid a race with free_pipeline(). This means queuing the
- * decoded frames outside GStreamer. So while we're at it, also schedule
- * the frame display ourselves in schedule_frame().
- */
-static GstFlowReturn new_sample(GstAppSink *gstappsink, gpointer
video_decoder)
+static void fetch_pending_sample(SpiceGstDecoder *decoder)
{
- SpiceGstDecoder *decoder = video_decoder;
-
GstSample *sample = gst_app_sink_pull_sample(decoder->appsink);
if (sample) {
GstBuffer *buffer = gst_sample_get_buffer(sample);
- g_mutex_lock(&decoder->queues_mutex);
/* gst_app_sink_pull_sample() sometimes returns the same buffer
twice
* or buffers that have a modified, and thus unrecognizable, PTS.
@@ -225,7 +224,7 @@ static GstFlowReturn new_sample(GstAppSink *gstappsink,
gpointer video_decoder)
if (gstframe->timestamp == GST_BUFFER_PTS(buffer)) {
/* The frame is now ready for display */
gstframe->sample = sample;
- g_queue_push_tail(decoder->display_queue, gstframe);
+ decoder->display_frame = gstframe;
/* Now that we know there is a match, remove it and the
older
* frames from the decoding queue.
@@ -248,12 +247,33 @@ static GstFlowReturn new_sample(GstAppSink
*gstappsink, gpointer video_decoder)
spice_warning("got an unexpected decoded buffer!");
gst_sample_unref(sample);
}
-
- g_mutex_unlock(&decoder->queues_mutex);
- schedule_frame(decoder);
} else {
spice_warning("GStreamer error: could not pull sample");
}
+}
+
+/* GStreamer thread
+ *
+ * We cannot use GStreamer's signals because they are not always run in
+ * the main context. So use a callback (lower overhead) and have it pull
+ * the sample to avoid a race with free_pipeline(). This means queuing the
+ * decoded frames outside GStreamer. So while we're at it, also schedule
+ * the frame display ourselves in schedule_frame().
+ */
+static GstFlowReturn new_sample(GstAppSink *gstappsink, gpointer
video_decoder)
+{
+ SpiceGstDecoder *decoder = video_decoder;
+
+ g_mutex_lock(&decoder->queues_mutex);
+ decoder->pending_samples++;
+ if (decoder->timer_id && decoder->display_frame) {
+ g_mutex_unlock(&decoder->queues_mutex);
+ return GST_FLOW_OK;
Should it return GST_FLOW_OK also when the new sample is not being pulled?
(although i assume it's fine)
Looking at the enumeration looks like any other option will disable
the pipeline.
I have to try but I think would be a good idea to call gst_app_sink_set_max_buffers
limiting the gstreamer queue to... I would say 2 (at the end would be 3 considering
we retrieve a sample as soon as possible).
I think this patch reduce the display queue we build after gstreamer (AppSink)
but the queue maybe moved just on the step before.
Yes, if pulling rate is not fast enough the gstreamer's queue will grow.
but i'm not sure what will happen if we will limit the sink's queue, will
it throw frames or it will signal the pipeline to slow down (and than
queuing may move to an earlier step)
Snir.
+ }
+ g_mutex_unlock(&decoder->queues_mutex);
+
+ schedule_frame(decoder);
+
return GST_FLOW_OK;
}
@@ -474,10 +494,9 @@ static void spice_gst_decoder_destroy(VideoDecoder
*video_decoder)
free_gst_frame(gstframe);
}
g_queue_free(decoder->decoding_queue);
- while ((gstframe = g_queue_pop_head(decoder->display_queue))) {
- free_gst_frame(gstframe);
+ if (decoder->display_frame) {
+ free_gst_frame(decoder->display_frame);
}
- g_queue_free(decoder->display_queue);
g_free(decoder);
@@ -503,11 +522,11 @@ static void spice_gst_decoder_destroy(VideoDecoder
*video_decoder)
* the decoding queue using the GStreamer timestamp information to
deal with
* dropped frames. The SpiceGstFrame is popped from the
decoding_queue.
* 6) new_sample() then attaches the decompressed frame to the
SpiceGstFrame,
- * pushes it to the display_queue and calls schedule_frame().
+ * set into display_frame and calls schedule_frame().
* 7) schedule_frame() then uses gstframe->frame->mm_time to arrange for
* display_frame() to be called, in the main thread, at the right time
for
* the next frame.
- * 8) display_frame() pops the first SpiceGstFrame from the display_queue
and
+ * 8) display_frame() use SpiceGstFrame from display_frame and
* calls stream_display_frame().
* 9) display_frame() then frees the SpiceGstFrame, which frees the
SpiceFrame
* and decompressed frame with it.
@@ -609,7 +628,6 @@ VideoDecoder* create_gstreamer_decoder(int codec_type,
display_stream *stream)
decoder->base.stream = stream;
g_mutex_init(&decoder->queues_mutex);
decoder->decoding_queue = g_queue_new();
- decoder->display_queue = g_queue_new();
if (!create_pipeline(decoder)) {
decoder->base.destroy((VideoDecoder*)decoder);
Looks good!! tried it and seems to work well (i haven't re-based) i
really prefer
it like that- avoiding the display queue.
I want to believe the different pipelines playbin may build in other
cases will also
behave nicely :| , anyway i'd say these patches should go upstream.
About next patch I was thinking that even better instead of having a
fixed size limit and pushing buffers another idea would be to instead
handle need-data signal (either with signals or callbacks).
64MB can be really large causing big delays.
Frediano
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