commit fdb3e3399e5a2d6f4a91ef272125b7e0bc792d1d
author Linus Nilsson <lnilsson@google.com> Fri Sep 18 17:11:41 2020 -0700
committer Linus Nilsson <lnilsson@google.com> Mon Nov 23 14:17:04 2020 -0800
tree f5beb45ec337e25b5349622be4c72b58edb5ca12
parent f674100ba8a40ff989573d5826fe645a6c8894a0

Transcoder: Add support for pausing transcoding on a sync frame.

- Added support for stopping transcoders on a sync frame.
- Refactored MediaTrackTranscoders and MediaSampleWriter to stop()
asynchronously.
- Fixed callback and error handling logic in MediaTranscoder.
- Added tests for pause and stopping on sync frame.

Bug: 162886306
Test: Unit tests.

Change-Id: If689a10dfee198c674c4c13b865a7c56a901e075

media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp

diff --git a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
index 4cf54f1..08ae9aa 100644
--- a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
+++ b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
@@ -156,11 +156,7 @@
                 static_cast<VideoTrackTranscoder::CodecWrapper*>(userdata);
         if (auto transcoder = wrapper->getTranscoder()) {
             transcoder->mCodecMessageQueue.push(
-                    [transcoder, error] {
-                        transcoder->mStatus = error;
-                        transcoder->mStopRequested = true;
-                    },
-                    true);
+                    [transcoder, error] { transcoder->mStatus = error; }, true);
         }
     }
 };
@@ -404,6 +400,8 @@
         sample->info.presentationTimeUs = bufferInfo.presentationTimeUs;
 
         onOutputSampleAvailable(sample);
+
+        mLastSampleWasSync = sample->info.flags & SAMPLE_FLAG_SYNC_SAMPLE;
     } else if (bufferIndex == AMEDIACODEC_INFO_OUTPUT_FORMAT_CHANGED) {
         AMediaFormat* newFormat = AMediaCodec_getOutputFormat(mEncoder->getCodec());
         LOG(DEBUG) << "Encoder output format changed: " << AMediaFormat_toString(newFormat);
@@ -483,7 +481,7 @@
     notifyTrackFormatAvailable();
 }
 
-media_status_t VideoTrackTranscoder::runTranscodeLoop() {
+media_status_t VideoTrackTranscoder::runTranscodeLoop(bool* stopped) {
     androidSetThreadPriority(0 /* tid (0 = current) */, ANDROID_PRIORITY_VIDEO);
 
     // Push start decoder and encoder as two messages, so that these are subject to the
@@ -507,25 +505,31 @@
     });
 
     // Process codec events until EOS is reached, transcoding is stopped or an error occurs.
-    while (!mStopRequested && !mEosFromEncoder && mStatus == AMEDIA_OK) {
+    while (mStopRequest != STOP_NOW && !mEosFromEncoder && mStatus == AMEDIA_OK) {
         std::function<void()> message = mCodecMessageQueue.pop();
         message();
+
+        if (mStopRequest == STOP_ON_SYNC && mLastSampleWasSync) {
+            break;
+        }
     }
 
     mCodecMessageQueue.abort();
     AMediaCodec_stop(mDecoder);
 
-    // Return error if transcoding was stopped before it finished.
-    if (mStopRequested && !mEosFromEncoder && mStatus == AMEDIA_OK) {
-        mStatus = AMEDIA_ERROR_UNKNOWN;  // TODO: Define custom error codes?
+    // Signal if transcoding was stopped before it finished.
+    if (mStopRequest != NONE && !mEosFromEncoder && mStatus == AMEDIA_OK) {
+        *stopped = true;
     }
 
     return mStatus;
 }
 
 void VideoTrackTranscoder::abortTranscodeLoop() {
-    // Push abort message to the front of the codec event queue.
-    mCodecMessageQueue.push([this] { mStopRequested = true; }, true /* front */);
+    if (mStopRequest == STOP_NOW) {
+        // Wake up transcoder thread.
+        mCodecMessageQueue.push([] {}, true /* front */);
+    }
 }
 
 std::shared_ptr<AMediaFormat> VideoTrackTranscoder::getOutputFormat() const {