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
diff --git a/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp b/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp
index 46f3e9b..0a41b00 100644
--- a/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/MediaSampleWriterTests.cpp
@@ -179,8 +179,6 @@
 
 class TestCallbacks : public MediaSampleWriter::CallbackInterface {
 public:
-    TestCallbacks(bool expectSuccess = true) : mExpectSuccess(expectSuccess) {}
-
     bool hasFinished() {
         std::unique_lock<std::mutex> lock(mMutex);
         return mFinished;
@@ -191,12 +189,15 @@
                             media_status_t status) override {
         std::unique_lock<std::mutex> lock(mMutex);
         EXPECT_FALSE(mFinished);
-        if (mExpectSuccess) {
-            EXPECT_EQ(status, AMEDIA_OK);
-        } else {
-            EXPECT_NE(status, AMEDIA_OK);
-        }
         mFinished = true;
+        mStatus = status;
+        mCondition.notify_all();
+    }
+
+    virtual void onStopped(const MediaSampleWriter* writer __unused) {
+        std::unique_lock<std::mutex> lock(mMutex);
+        EXPECT_FALSE(mFinished);
+        mStopped = true;
         mCondition.notify_all();
     }
 
@@ -213,18 +214,20 @@
 
     void waitForWritingFinished() {
         std::unique_lock<std::mutex> lock(mMutex);
-        while (!mFinished) {
+        while (!mFinished && !mStopped) {
             mCondition.wait(lock);
         }
     }
 
     uint32_t getProgressUpdateCount() const { return mProgressUpdateCount; }
+    bool wasStopped() const { return mStopped; }
 
 private:
     std::mutex mMutex;
     std::condition_variable mCondition;
     bool mFinished = false;
-    bool mExpectSuccess;
+    bool mStopped = false;
+    media_status_t mStatus = AMEDIA_OK;
     int32_t mLastProgress = -1;
     uint32_t mProgressUpdateCount = 0;
 };
@@ -316,8 +319,7 @@
 TEST_F(MediaSampleWriterTests, TestDoubleStartStop) {
     std::shared_ptr<MediaSampleWriter> writer = MediaSampleWriter::Create();
 
-    std::shared_ptr<TestCallbacks> callbacks =
-            std::make_shared<TestCallbacks>(false /* expectSuccess */);
+    std::shared_ptr<TestCallbacks> callbacks = std::make_shared<TestCallbacks>();
     EXPECT_TRUE(writer->init(mTestMuxer, callbacks));
 
     const TestMediaSource& mediaSource = getMediaSource();
@@ -327,9 +329,10 @@
     ASSERT_TRUE(writer->start());
     EXPECT_FALSE(writer->start());
 
-    EXPECT_TRUE(writer->stop());
-    EXPECT_TRUE(callbacks->hasFinished());
-    EXPECT_FALSE(writer->stop());
+    writer->stop();
+    writer->stop();
+    callbacks->waitForWritingFinished();
+    EXPECT_TRUE(callbacks->wasStopped());
 }
 
 TEST_F(MediaSampleWriterTests, TestStopWithoutStart) {
@@ -340,7 +343,7 @@
     EXPECT_NE(writer->addTrack(mediaSource.mTrackFormats[0]), nullptr);
     EXPECT_EQ(mTestMuxer->popEvent(), TestMuxer::AddTrack(mediaSource.mTrackFormats[0].get()));
 
-    EXPECT_FALSE(writer->stop());
+    writer->stop();
     EXPECT_EQ(mTestMuxer->popEvent(), TestMuxer::NoEvent);
 }
 
@@ -468,7 +471,6 @@
     }
 
     EXPECT_EQ(mTestMuxer->popEvent(), TestMuxer::Stop());
-    EXPECT_TRUE(writer->stop());
     EXPECT_TRUE(mTestCallbacks->hasFinished());
 }
 
@@ -541,7 +543,6 @@
 
     // Wait for writer.
     mTestCallbacks->waitForWritingFinished();
-    EXPECT_TRUE(writer->stop());
 
     // Compare output file with source.
     mediaSource.reset();
diff --git a/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp
index 83f0a4a..21f0b86 100644
--- a/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp
@@ -61,13 +61,10 @@
         }
         ASSERT_NE(mTranscoder, nullptr);
 
-        initSampleReader();
+        initSampleReader("/data/local/tmp/TranscodingTestAssets/cubicle_avc_480x240_aac_24KHz.mp4");
     }
 
-    void initSampleReader() {
-        const char* sourcePath =
-                "/data/local/tmp/TranscodingTestAssets/cubicle_avc_480x240_aac_24KHz.mp4";
-
+    void initSampleReader(const char* sourcePath) {
         const int sourceFd = open(sourcePath, O_RDONLY);
         ASSERT_GT(sourceFd, 0);
 
@@ -157,16 +154,23 @@
     ASSERT_TRUE(mTranscoder->start());
     drainOutputSamples();
     EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
-    EXPECT_TRUE(mTranscoder->stop());
+    EXPECT_TRUE(mCallback->transcodingFinished());
     EXPECT_TRUE(mGotEndOfStream);
 }
 
 TEST_P(MediaTrackTranscoderTests, StopNormalOperation) {
     LOG(DEBUG) << "Testing StopNormalOperation";
+
+    // Use a longer test asset to make sure that transcoding can be stopped.
+    initSampleReader("/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4");
+
     EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
               AMEDIA_OK);
     EXPECT_TRUE(mTranscoder->start());
-    EXPECT_TRUE(mTranscoder->stop());
+    mCallback->waitUntilTrackFormatAvailable();
+    mTranscoder->stop();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
+    EXPECT_TRUE(mCallback->transcodingWasStopped());
 }
 
 TEST_P(MediaTrackTranscoderTests, StartWithoutConfigure) {
@@ -178,17 +182,23 @@
     LOG(DEBUG) << "Testing StopWithoutStart";
     EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
               AMEDIA_OK);
-    EXPECT_FALSE(mTranscoder->stop());
+    mTranscoder->stop();
 }
 
 TEST_P(MediaTrackTranscoderTests, DoubleStartStop) {
     LOG(DEBUG) << "Testing DoubleStartStop";
+
+    // Use a longer test asset to make sure that transcoding can be stopped.
+    initSampleReader("/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4");
+
     EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
               AMEDIA_OK);
     EXPECT_TRUE(mTranscoder->start());
     EXPECT_FALSE(mTranscoder->start());
-    EXPECT_TRUE(mTranscoder->stop());
-    EXPECT_FALSE(mTranscoder->stop());
+    mTranscoder->stop();
+    mTranscoder->stop();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
+    EXPECT_TRUE(mCallback->transcodingWasStopped());
 }
 
 TEST_P(MediaTrackTranscoderTests, DoubleConfigure) {
@@ -212,7 +222,8 @@
     EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
               AMEDIA_OK);
     EXPECT_TRUE(mTranscoder->start());
-    EXPECT_TRUE(mTranscoder->stop());
+    mTranscoder->stop();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
     EXPECT_FALSE(mTranscoder->start());
 }
 
@@ -223,7 +234,7 @@
     ASSERT_TRUE(mTranscoder->start());
     drainOutputSamples();
     EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
-    EXPECT_TRUE(mTranscoder->stop());
+    mTranscoder->stop();
     EXPECT_FALSE(mTranscoder->start());
     EXPECT_TRUE(mGotEndOfStream);
 }
@@ -235,7 +246,7 @@
     ASSERT_TRUE(mTranscoder->start());
     drainOutputSamples(1 /* numSamplesToSave */);
     EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
-    EXPECT_TRUE(mTranscoder->stop());
+    mTranscoder->stop();
     EXPECT_TRUE(mGotEndOfStream);
 
     mTranscoder.reset();
@@ -251,7 +262,8 @@
     ASSERT_TRUE(mTranscoder->start());
     drainOutputSamples(1 /* numSamplesToSave */);
     mSamplesSavedSemaphore.wait();
-    EXPECT_TRUE(mTranscoder->stop());
+    mTranscoder->stop();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
 
     std::this_thread::sleep_for(std::chrono::milliseconds(20));
     mSavedSamples.clear();
@@ -272,6 +284,44 @@
               AMEDIA_OK);
 }
 
+TEST_P(MediaTrackTranscoderTests, StopOnSync) {
+    LOG(DEBUG) << "Testing StopOnSync";
+
+    // Use a longer test asset to make sure there is a GOP to finish.
+    initSampleReader("/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4");
+
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+
+    bool lastSampleWasEos = false;
+    bool lastRealSampleWasSync = false;
+    OneShotSemaphore samplesReceivedSemaphore;
+    uint32_t sampleCount = 0;
+
+    mTranscoder->setSampleConsumer([&](const std::shared_ptr<MediaSample>& sample) {
+        ASSERT_NE(sample, nullptr);
+
+        if ((lastSampleWasEos = sample->info.flags & SAMPLE_FLAG_END_OF_STREAM)) {
+            samplesReceivedSemaphore.signal();
+            return;
+        }
+        lastRealSampleWasSync = sample->info.flags & SAMPLE_FLAG_SYNC_SAMPLE;
+
+        if (++sampleCount >= 10) {  // Wait for a few samples before stopping.
+            samplesReceivedSemaphore.signal();
+        }
+    });
+
+    ASSERT_TRUE(mTranscoder->start());
+    samplesReceivedSemaphore.wait();
+    mTranscoder->stop(true /* stopOnSync */);
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
+
+    EXPECT_TRUE(lastSampleWasEos);
+    EXPECT_TRUE(lastRealSampleWasSync);
+    EXPECT_TRUE(mCallback->transcodingWasStopped());
+}
+
 };  // namespace android
 
 using namespace android;
diff --git a/media/libmediatranscoding/transcoder/tests/MediaTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/MediaTranscoderTests.cpp
index 1bf2d8c..2487e08 100644
--- a/media/libmediatranscoding/transcoder/tests/MediaTranscoderTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/MediaTranscoderTests.cpp
@@ -99,11 +99,11 @@
         }
     }
     media_status_t mStatus = AMEDIA_OK;
+    bool mFinished = false;
 
 private:
     std::mutex mMutex;
     std::condition_variable mCondition;
-    bool mFinished = false;
     bool mProgressMade = false;
 };
 
@@ -145,6 +145,8 @@
         kRunToCompletion,
         kCancelAfterProgress,
         kCancelAfterStart,
+        kPauseAfterProgress,
+        kPauseAfterStart,
     } TranscodeExecutionControl;
 
     using FormatConfigurationCallback = std::function<AMediaFormat*(AMediaFormat*)>;
@@ -181,7 +183,10 @@
 
         media_status_t startStatus = transcoder->start();
         EXPECT_EQ(startStatus, AMEDIA_OK);
+
         if (startStatus == AMEDIA_OK) {
+            std::shared_ptr<ndk::ScopedAParcel> pausedState;
+
             switch (executionControl) {
             case kCancelAfterProgress:
                 mCallbacks->waitForProgressMade();
@@ -189,6 +194,12 @@
             case kCancelAfterStart:
                 transcoder->cancel();
                 break;
+            case kPauseAfterProgress:
+                mCallbacks->waitForProgressMade();
+                FALLTHROUGH_INTENDED;
+            case kPauseAfterStart:
+                transcoder->pause(&pausedState);
+                break;
             case kRunToCompletion:
             default:
                 mCallbacks->waitForTranscodingFinished();
@@ -360,9 +371,10 @@
     const char* srcPath = "/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4";
     const char* destPath = "/data/local/tmp/MediaTranscoder_Cancel.MP4";
 
-    for (int i = 0; i < 32; ++i) {
+    for (int i = 0; i < 20; ++i) {
         EXPECT_EQ(transcodeHelper(srcPath, destPath, getAVCVideoFormat, kCancelAfterProgress),
                   AMEDIA_OK);
+        EXPECT_FALSE(mCallbacks->mFinished);
         mCallbacks = std::make_shared<TestCallbacks>();
     }
 }
@@ -371,9 +383,34 @@
     const char* srcPath = "/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4";
     const char* destPath = "/data/local/tmp/MediaTranscoder_Cancel.MP4";
 
-    for (int i = 0; i < 32; ++i) {
+    for (int i = 0; i < 20; ++i) {
         EXPECT_EQ(transcodeHelper(srcPath, destPath, getAVCVideoFormat, kCancelAfterStart),
                   AMEDIA_OK);
+        EXPECT_FALSE(mCallbacks->mFinished);
+        mCallbacks = std::make_shared<TestCallbacks>();
+    }
+}
+
+TEST_F(MediaTranscoderTests, TestPauseAfterProgress) {
+    const char* srcPath = "/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4";
+    const char* destPath = "/data/local/tmp/MediaTranscoder_Pause.MP4";
+
+    for (int i = 0; i < 20; ++i) {
+        EXPECT_EQ(transcodeHelper(srcPath, destPath, getAVCVideoFormat, kPauseAfterProgress),
+                  AMEDIA_OK);
+        EXPECT_FALSE(mCallbacks->mFinished);
+        mCallbacks = std::make_shared<TestCallbacks>();
+    }
+}
+
+TEST_F(MediaTranscoderTests, TestPauseAfterStart) {
+    const char* srcPath = "/data/local/tmp/TranscodingTestAssets/longtest_15s.mp4";
+    const char* destPath = "/data/local/tmp/MediaTranscoder_Pause.MP4";
+
+    for (int i = 0; i < 20; ++i) {
+        EXPECT_EQ(transcodeHelper(srcPath, destPath, getAVCVideoFormat, kPauseAfterStart),
+                  AMEDIA_OK);
+        EXPECT_FALSE(mCallbacks->mFinished);
         mCallbacks = std::make_shared<TestCallbacks>();
     }
 }
diff --git a/media/libmediatranscoding/transcoder/tests/PassthroughTrackTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/PassthroughTrackTranscoderTests.cpp
index 9713e17..5071efd 100644
--- a/media/libmediatranscoding/transcoder/tests/PassthroughTrackTranscoderTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/PassthroughTrackTranscoderTests.cpp
@@ -183,7 +183,6 @@
 
     callback->waitUntilFinished();
     EXPECT_EQ(sampleCount, sampleChecksums.size());
-    EXPECT_TRUE(transcoder.stop());
 }
 
 /** Class for testing PassthroughTrackTranscoder's built in buffer pool. */
diff --git a/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h b/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h
index 8d05353..a782f71 100644
--- a/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h
+++ b/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h
@@ -33,20 +33,14 @@
             AMediaFormat* sourceFormat, bool includeBitrate = true) {
         // Default video destination format setup.
         static constexpr float kFrameRate = 30.0f;
-        static constexpr float kIFrameInterval = 30.0f;
         static constexpr int32_t kBitRate = 2 * 1000 * 1000;
-        static constexpr int32_t kColorFormatSurface = 0x7f000789;
 
         AMediaFormat* destinationFormat = AMediaFormat_new();
         AMediaFormat_copy(destinationFormat, sourceFormat);
         AMediaFormat_setFloat(destinationFormat, AMEDIAFORMAT_KEY_FRAME_RATE, kFrameRate);
-        AMediaFormat_setFloat(destinationFormat, AMEDIAFORMAT_KEY_I_FRAME_INTERVAL,
-                              kIFrameInterval);
         if (includeBitrate) {
             AMediaFormat_setInt32(destinationFormat, AMEDIAFORMAT_KEY_BIT_RATE, kBitRate);
         }
-        AMediaFormat_setInt32(destinationFormat, AMEDIAFORMAT_KEY_COLOR_FORMAT,
-                              kColorFormatSurface);
 
         return std::shared_ptr<AMediaFormat>(destinationFormat, &AMediaFormat_delete);
     }
@@ -70,6 +64,13 @@
         mTranscodingFinishedCondition.notify_all();
     }
 
+    virtual void onTrackStopped(const MediaTrackTranscoder* transcoder __unused) override {
+        std::unique_lock<std::mutex> lock(mMutex);
+        mTranscodingFinished = true;
+        mTranscodingStopped = true;
+        mTranscodingFinishedCondition.notify_all();
+    }
+
     void onTrackError(const MediaTrackTranscoder* transcoder __unused, media_status_t status) {
         std::unique_lock<std::mutex> lock(mMutex);
         mTranscodingFinished = true;
@@ -93,12 +94,18 @@
         }
     }
 
+    bool transcodingWasStopped() const { return mTranscodingFinished && mTranscodingStopped; }
+    bool transcodingFinished() const {
+        return mTranscodingFinished && !mTranscodingStopped && mStatus == AMEDIA_OK;
+    }
+
 private:
     media_status_t mStatus = AMEDIA_OK;
     std::mutex mMutex;
     std::condition_variable mTranscodingFinishedCondition;
     std::condition_variable mTrackFormatAvailableCondition;
     bool mTranscodingFinished = false;
+    bool mTranscodingStopped = false;
     bool mTrackFormatAvailable = false;
 };
 
diff --git a/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
index 1b5bd13..4ede97f 100644
--- a/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
+++ b/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
@@ -135,7 +135,6 @@
     });
 
     EXPECT_EQ(callback->waitUntilFinished(), AMEDIA_OK);
-    EXPECT_TRUE(transcoder->stop());
 }
 
 TEST_F(VideoTrackTranscoderTests, PreserveBitrate) {
@@ -160,7 +159,8 @@
     auto outputFormat = transcoder->getOutputFormat();
     ASSERT_NE(outputFormat, nullptr);
 
-    ASSERT_TRUE(transcoder->stop());
+    transcoder->stop();
+    EXPECT_EQ(callback->waitUntilFinished(), AMEDIA_OK);
 
     int32_t outBitrate;
     EXPECT_TRUE(AMediaFormat_getInt32(outputFormat.get(), AMEDIAFORMAT_KEY_BIT_RATE, &outBitrate));
@@ -205,7 +205,8 @@
     // Wait for the encoder to output samples before stopping and releasing the transcoder.
     semaphore.wait();
 
-    EXPECT_TRUE(transcoder->stop());
+    transcoder->stop();
+    EXPECT_EQ(callback->waitUntilFinished(), AMEDIA_OK);
     transcoder.reset();
 
     // Return buffers to the codec so that it can resume processing, but keep one buffer to avoid