Transcoder: Improve video transcoding with audio passthrough performance
MediaSampleWriter was stalling the video transcoding when processing
chunks of audio samples at a time. Since the underlying muxer
buffers ~1 sec worth of data and interleaves tracks anyway the
sample writer now prioritizes pulling samples from the track that is
farthest behind while making sure the tracks are kept reasonably
in sync, i.e. max ~1 second divergence.
This change also raises the priority of the video transcoding thread
since that will be the bottleneck when audio is pased through.
Test: Unit tests
Fixes: 160268606
Change-Id: I004583b2a31a57882ea543072be321f9f1347508
diff --git a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
index 65dcad3..d2a7154 100644
--- a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
+++ b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
@@ -19,6 +19,7 @@
#include <android-base/logging.h>
#include <media/VideoTrackTranscoder.h>
+#include <utils/AndroidThreads.h>
namespace android {
@@ -437,6 +438,8 @@
}
media_status_t VideoTrackTranscoder::runTranscodeLoop() {
+ androidSetThreadPriority(0 /* tid (0 = current) */, ANDROID_PRIORITY_VIDEO);
+
// Push start decoder and encoder as two messages, so that these are subject to the
// stop request as well. If the job is cancelled (or paused) immediately after start,
// we don't need to waste time start then stop the codecs.