commit 6233fed6f67703460d4bd0b025bacc03513f1284
author Linus Nilsson <lnilsson@google.com> Thu Aug 13 15:15:14 2020 -0700
committer Linus Nilsson <lnilsson@google.com> Tue Aug 25 16:47:59 2020 -0700
tree abee276ae4e2063782144adfc36c96a37576cafd
parent 615364792b6fe07869c685e4bccbf7837e1ba97b

Transcoder: Improve AV transcoding speed by enforcing sequential sample access.

MediaSampleReader was bottlenecking the transcoding pipeline due to
non-sequential sample access. This commit adds an option to the sample
reader to enforce sequential sample access by blocking reads until
the underlying extractor advances to that specific track.
Follow-up: b/165374867 Make MediaSampleWriter robust against buffering track transcoders

Fixes: 160268606
Test: Transcoder unit tests, and benchmark tests.
Change-Id: Id2a363d06df927ea3e547462c52803594e0511e1

media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp

diff --git a/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
index b432553..e809cbd 100644
--- a/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
@@ -97,6 +97,7 @@
     std::shared_ptr<TestCallback> callback = std::make_shared<TestCallback>();
     auto transcoder = VideoTrackTranscoder::create(callback);
 
+    EXPECT_EQ(mMediaSampleReader->selectTrack(mTrackIndex), AMEDIA_OK);
     EXPECT_EQ(transcoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
               AMEDIA_OK);
     ASSERT_TRUE(transcoder->start());
@@ -152,6 +153,11 @@
             mSourceFormat.get(), false /* includeBitrate*/);
     EXPECT_NE(destFormat, nullptr);
 
+    EXPECT_EQ(mMediaSampleReader->selectTrack(mTrackIndex), AMEDIA_OK);
+
+    int32_t srcBitrate;
+    EXPECT_EQ(mMediaSampleReader->getEstimatedBitrateForTrack(mTrackIndex, &srcBitrate), AMEDIA_OK);
+
     ASSERT_EQ(transcoder->configure(mMediaSampleReader, mTrackIndex, destFormat), AMEDIA_OK);
     ASSERT_TRUE(transcoder->start());
 
@@ -166,9 +172,6 @@
     int32_t outBitrate;
     EXPECT_TRUE(AMediaFormat_getInt32(outputFormat.get(), AMEDIAFORMAT_KEY_BIT_RATE, &outBitrate));
 
-    int32_t srcBitrate;
-    EXPECT_EQ(mMediaSampleReader->getEstimatedBitrateForTrack(mTrackIndex, &srcBitrate), AMEDIA_OK);
-
     EXPECT_EQ(srcBitrate, outBitrate);
 }
 
@@ -206,6 +209,7 @@
     auto callback = std::make_shared<TestCallback>();
     auto transcoder = VideoTrackTranscoder::create(callback);
 
+    EXPECT_EQ(mMediaSampleReader->selectTrack(mTrackIndex), AMEDIA_OK);
     EXPECT_EQ(transcoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
               AMEDIA_OK);
     ASSERT_TRUE(transcoder->start());
@@ -214,7 +218,7 @@
     std::vector<std::shared_ptr<MediaSample>> samples;
     std::thread sampleConsumerThread([&outputQueue, &samples, &semaphore] {
         std::shared_ptr<MediaSample> sample;
-        while (samples.size() < 10 && !outputQueue->dequeue(&sample)) {
+        while (samples.size() < 4 && !outputQueue->dequeue(&sample)) {
             ASSERT_NE(sample, nullptr);
             samples.push_back(sample);