mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-07-11 09:06:05 +00:00
Code Issues 1 Projects Releases Wiki Activity

qtdemux: Add a minimum buffer size for raw audio to not output one buffer per frame

Browse source 
Outputting 48000 buffers per second is not a good idea performance-wise.
If a container sample is less than 1024 raw audio frames, combine
multiple samples to get at least 1024 raw audio samples as long as
they're stored contiguous in the file.

For the other direction, if a container sample contains more than 4096
samples there is already code for splitting them up.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=692750
This commit is contained in:
Sebastian Dröge 2020-01-13 11:55:42 +02:00 committed by Sebastian Dröge
parent 1471100f37
commit be1c97d3c9
1 changed files with 59 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

64
gst/isomp4/qtdemux.c
View file

@ -322,6 +322,8 @@ struct _QtDemuxStream
* streams which have got exceedingly big
* sample size (such as 24s of raw audio).
* Only used when max_buffer_size is non-NULL */
guint32 min_buffer_size; /* Minimum allowed size for output buffers.
* Currently only set for raw audio streams*/
guint32 max_buffer_size; /* Maximum allowed size for output buffers.
* Currently only set for raw audio streams*/
@ -6314,6 +6316,7 @@ gst_qtdemux_loop_state_movie (GstQTDemux * qtdemux)
GstClockTime duration = 0;
gboolean keyframe = FALSE;
guint sample_size = 0;
guint num_samples = 1;
gboolean empty = 0;
guint size;
gint i;
@ -6457,14 +6460,58 @@ gst_qtdemux_loop_state_movie (GstQTDemux * qtdemux)
if (G_UNLIKELY (GST_PAD_LAST_FLOW_RETURN (stream->pad) == GST_FLOW_EOS))
goto next;
if (stream->max_buffer_size == 0 || sample_size <= stream->max_buffer_size) {
size = sample_size;
} else {
if (stream->max_buffer_size != 0 && sample_size > stream->max_buffer_size) {
GST_DEBUG_OBJECT (qtdemux,
"size %d larger than stream max_buffer_size %d, trimming",
sample_size, stream->max_buffer_size);
size =
MIN (sample_size - stream->offset_in_sample, stream->max_buffer_size);
} else if (stream->min_buffer_size != 0 && stream->offset_in_sample == 0
&& sample_size < stream->min_buffer_size) {
guint start_sample_index = stream->sample_index;
guint accumulated_size = sample_size;
guint64 expected_next_offset = offset + sample_size;
GST_DEBUG_OBJECT (qtdemux,
"size %d smaller than stream min_buffer_size %d, combining with the next",
sample_size, stream->min_buffer_size);
while (stream->sample_index < stream->to_sample
&& stream->sample_index + 1 < stream->n_samples) {
const QtDemuxSample *next_sample;
/* Increment temporarily */
stream->sample_index++;
/* Failed to parse sample so let's go back to the previous one that was
* still successful */
if (!qtdemux_parse_samples (qtdemux, stream, stream->sample_index)) {
stream->sample_index--;
break;
}
next_sample = &stream->samples[stream->sample_index];
/* Not contiguous with the previous sample so let's go back to the
* previous one that was still successful */
if (next_sample->offset != expected_next_offset) {
stream->sample_index--;
break;
}
accumulated_size += next_sample->size;
expected_next_offset += next_sample->size;
if (accumulated_size >= stream->min_buffer_size)
break;
}
num_samples = stream->sample_index + 1 - start_sample_index;
stream->sample_index = start_sample_index;
GST_DEBUG_OBJECT (qtdemux, "Pulling %u samples of size %u at once",
num_samples, accumulated_size);
size = accumulated_size;
} else {
size = sample_size;
}
if (qtdemux->cenc_aux_info_offset > 0) {
@ -6506,6 +6553,7 @@ gst_qtdemux_loop_state_movie (GstQTDemux * qtdemux)
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto beach;
/* Update for both splitting and combining of samples */
if (size != sample_size) {
pts += gst_util_uint64_scale_int (GST_SECOND,
stream->offset_in_sample / CUR_STREAM (stream)->bytes_per_frame,
@ -6522,7 +6570,7 @@ gst_qtdemux_loop_state_movie (GstQTDemux * qtdemux)
ret = gst_qtdemux_decorate_and_push_buffer (qtdemux, stream, buf,
dts, pts, duration, keyframe, min_time, offset);
if (size != sample_size) {
if (size < sample_size) {
QtDemuxSample *sample = &stream->samples[stream->sample_index];
QtDemuxSegment *segment = &stream->segments[stream->segment_index];
@ -6540,6 +6588,10 @@ gst_qtdemux_loop_state_movie (GstQTDemux * qtdemux)
* decode the first sample of the segment. */
stream->time_position = segment->time;
}
} else if (size > sample_size) {
/* Increase to the last sample we already pulled so that advancing
* below brings us to the next sample we need to pull */
stream->sample_index += num_samples - 1;
}
/* combine flows */
@ -15490,8 +15542,10 @@ qtdemux_audio_caps (GstQTDemux * qtdemux, QtDemuxStream * stream,
name = gst_structure_get_name (s);
if (g_str_has_prefix (name, "audio/x-raw")) {
stream->need_clip = TRUE;
stream->min_buffer_size = 1024 * entry->bytes_per_frame;
stream->max_buffer_size = 4096 * entry->bytes_per_frame;
GST_DEBUG ("setting max buffer size to %d", stream->max_buffer_size);
GST_DEBUG ("setting min/max buffer sizes to %d/%d", stream->min_buffer_size,
stream->max_buffer_size);
}
return caps;
}