Fix an issue that audio and video may run out of sync

media/base/android/media_source_player.cc

Index: media/base/android/media_source_player.cc
diff --git a/media/base/android/media_source_player.cc b/media/base/android/media_source_player.cc
index e52d0e49fc2e651e0d6352b391a96432fc8cb6bc..fa1095f9a7f8f595703ca55eb15c0c61ea49d51d 100644
--- a/media/base/android/media_source_player.cc
+++ b/media/base/android/media_source_player.cc
@@ -316,9 +316,11 @@ void MediaSourcePlayer::OnDemuxerConfigsAvailable(
   is_audio_encrypted_ = configs.is_audio_encrypted;
   audio_extra_data_ = configs.audio_extra_data;
   if (HasAudio()) {
-    DCHECK_GT(num_channels_, 0);
-    audio_timestamp_helper_.reset(new AudioTimestampHelper(sampling_rate_));
-    audio_timestamp_helper_->SetBaseTimestamp(GetCurrentTime());
+    if (reconfig_audio_decoder_ || !audio_decoder_job_) {
+      DCHECK_GT(num_channels_, 0);
+      audio_timestamp_helper_.reset(new AudioTimestampHelper(sampling_rate_));
+      audio_timestamp_helper_->SetBaseTimestamp(GetCurrentTime());
+    }
   } else {
     audio_timestamp_helper_.reset();
   }
@@ -471,16 +473,25 @@ void MediaSourcePlayer::OnDemuxerSeekDone(
 }
 
 void MediaSourcePlayer::UpdateTimestamps(
-    base::TimeDelta presentation_timestamp, size_t audio_output_bytes) {
-  base::TimeDelta new_max_time = presentation_timestamp;
-
+    base::TimeDelta presentation_timestamp, size_t audio_output_bytes,
+    int64 audio_head_position, base::TimeTicks audio_render_time) {
   if (audio_output_bytes > 0) {
     audio_timestamp_helper_->AddFrames(
         audio_output_bytes / (kBytesPerAudioOutputSample * num_channels_));
-    new_max_time = audio_timestamp_helper_->GetTimestamp();
+    int64 frames_to_play =
+        audio_timestamp_helper_->frame_count() - audio_head_position;
+    DCHECK(frames_to_play >= 0);

[wolenetz, 2014/04/01 18:15:47]

nit: lint: "Consider using DCHECK_GE instead of DCHECK(a >= b)"

[qinmin, 2014/04/01 20:42:34]

Done.

+    base::TimeDelta new_max_time = audio_timestamp_helper_->GetTimestamp();
+    base::TimeDelta current_presentation_timestamp =
+        base::TimeTicks::Now() - audio_render_time + new_max_time -
+        audio_timestamp_helper_->GetFrameDuration(frames_to_play);
+    if (current_presentation_timestamp >= new_max_time)
+      current_presentation_timestamp = new_max_time;
+    clock_.SetTime(current_presentation_timestamp, new_max_time);
+  } else {
+    clock_.SetMaxTime(presentation_timestamp);
   }
 
-  clock_.SetMaxTime(new_max_time);
   manager()->OnTimeUpdate(player_id(), GetCurrentTime());
 }
 
@@ -581,7 +592,8 @@ void MediaSourcePlayer::ProcessPendingEvents() {
 
 void MediaSourcePlayer::MediaDecoderCallback(
     bool is_audio, MediaCodecStatus status,
-    base::TimeDelta presentation_timestamp, size_t audio_output_bytes) {
+    base::TimeDelta presentation_timestamp, size_t audio_output_bytes,
+    int64 audio_head_position, base::TimeTicks audio_render_time) {
   DVLOG(1) << __FUNCTION__ << ": " << is_audio << ", " << status;
 
   // TODO(xhwang): Drop IntToString() when http://crbug.com/303899 is fixed.
@@ -625,6 +637,13 @@ void MediaSourcePlayer::MediaDecoderCallback(
     return;
   }
 
+  if (status == MEDIA_CODEC_OK && is_clock_manager &&
+      presentation_timestamp != kNoTimestamp()) {
+    UpdateTimestamps(
+        presentation_timestamp, audio_output_bytes, audio_head_position,
+        audio_render_time);
+  }
+
   if (status == MEDIA_CODEC_OUTPUT_END_OF_STREAM)
     PlaybackCompleted(is_audio);
 
@@ -636,11 +655,6 @@ void MediaSourcePlayer::MediaDecoderCallback(
   if (status == MEDIA_CODEC_OUTPUT_END_OF_STREAM)
     return;
 
-  if (status == MEDIA_CODEC_OK && is_clock_manager &&
-      presentation_timestamp != kNoTimestamp()) {
-    UpdateTimestamps(presentation_timestamp, audio_output_bytes);
-  }
-
   if (!playing_) {
     if (is_clock_manager)
       clock_.Pause();