Use cached Key frames to avoid browser seek

media/base/android/media_decoder_job.cc

Index: media/base/android/media_decoder_job.cc
diff --git a/media/base/android/media_decoder_job.cc b/media/base/android/media_decoder_job.cc
index 41b74a08e5100dc69147db854f4c987d5157911e..90094439605c4380a35021bf59ab8daa763c06ce 100644
--- a/media/base/android/media_decoder_job.cc
+++ b/media/base/android/media_decoder_job.cc
@@ -110,7 +110,7 @@ void MediaDecoderJob::Prefetch(const base::Closure& prefetch_cb) {
   RequestData(prefetch_cb);
 }
 
-bool MediaDecoderJob::Decode(
+MediaDecoderJob::MediaDecoderJobStatus MediaDecoderJob::Decode(
     base::TimeTicks start_time_ticks,
     base::TimeDelta start_presentation_timestamp,
     const DecoderCallback& callback) {
@@ -120,10 +120,11 @@ bool MediaDecoderJob::Decode(
   if (!media_codec_bridge_ || need_to_reconfig_decoder_job_) {
     if (drain_decoder_)
       OnDecoderDrained();
-    need_to_reconfig_decoder_job_ = !CreateMediaCodecBridge();
+    MediaDecoderJobStatus status = CreateMediaCodecBridge();
+    need_to_reconfig_decoder_job_ = (status != STATUS_SUCCESS);
     skip_eos_enqueue_ = true;
     if (need_to_reconfig_decoder_job_)
-      return false;
+      return status;
   }
 
   decode_cb_ = callback;
@@ -133,11 +134,11 @@ bool MediaDecoderJob::Decode(
                            base::Unretained(this),
                            start_time_ticks,
                            start_presentation_timestamp));
-    return true;
+    return STATUS_SUCCESS;
   }
 
   DecodeCurrentAccessUnit(start_time_ticks, start_presentation_timestamp);
-  return true;
+  return STATUS_SUCCESS;
 }
 
 void MediaDecoderJob::StopDecode() {
@@ -205,6 +206,32 @@ base::android::ScopedJavaLocalRef<jobject> MediaDecoderJob::GetMediaCrypto() {
   return media_crypto;
 }
 
+bool MediaDecoderJob::SetCurrentFrameToPreviouslyCachedKeyFrame() {
+  const std::vector<AccessUnit>& access_units =
+      received_data_[current_demuxer_data_index_].access_units;
+  // If the current data chunk is empty, the player must be in an initial or
+  // seek state. The next access unit will always be a key frame.
+  if (access_units.size() == 0)
+    return true;
+
+  // Find key frame in all the access units the decoder have decoded,
+  // or is about to decode.
+  int i = std::min(access_unit_index_[current_demuxer_data_index_],
+                   access_units.size() - 1);
+  for (; i >= 0; --i) {
+    // Config change is always the last access unit, and it always come with
+    // a key frame afterwards.
+    if (access_units[i].status == DemuxerStream::kConfigChanged)
+      return true;
+    if (access_units[i].is_key_frame) {
+      access_unit_index_[current_demuxer_data_index_] = i;
+      return true;
+    }
+  }
+  return false;
+}
+
+
 void MediaDecoderJob::Release() {
   DCHECK(ui_task_runner_->BelongsToCurrentThread());
   DVLOG(1) << __FUNCTION__;
@@ -518,11 +545,8 @@ void MediaDecoderJob::OnDecodeCompleted(
     case MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER:
     case MEDIA_CODEC_OUTPUT_FORMAT_CHANGED:
     case MEDIA_CODEC_OUTPUT_END_OF_STREAM:
-      if (!input_eos_encountered_) {
-        CurrentDataConsumed(
-            CurrentAccessUnit().status == DemuxerStream::kConfigChanged);
+      if (!input_eos_encountered_)
         access_unit_index_[current_demuxer_data_index_]++;
-      }
       break;
 
     case MEDIA_CODEC_DEQUEUE_INPUT_AGAIN_LATER:
@@ -589,7 +613,7 @@ void MediaDecoderJob::RequestCurrentChunkIfEmpty() {
 
   // Requests new data if the the last access unit of the next chunk is not EOS.
   current_demuxer_data_index_ = inactive_demuxer_data_index();
-  const AccessUnit last_access_unit =
+  const AccessUnit& last_access_unit =
       received_data_[current_demuxer_data_index_].access_units.back();
   if (!last_access_unit.is_end_of_stream &&
       last_access_unit.status != DemuxerStream::kAborted) {
@@ -616,26 +640,26 @@ void MediaDecoderJob::OnDecoderDrained() {
   // Increase the access unit index so that the new decoder will not handle
   // the config change again.
   access_unit_index_[current_demuxer_data_index_]++;
-  CurrentDataConsumed(true);
 }
 
-bool MediaDecoderJob::CreateMediaCodecBridge() {
+MediaDecoderJob::MediaDecoderJobStatus
+    MediaDecoderJob::CreateMediaCodecBridge() {
   DVLOG(1) << __FUNCTION__;
   DCHECK(ui_task_runner_->BelongsToCurrentThread());
   DCHECK(decode_cb_.is_null());
 
   if (!HasStream()) {
     ReleaseMediaCodecBridge();
-    return false;
+    return STATUS_FAILURE;
   }
 
   // Create |media_codec_bridge_| only if config changes.
   if (media_codec_bridge_ && !need_to_reconfig_decoder_job_)
-    return true;
+    return STATUS_SUCCESS;
 
   base::android::ScopedJavaLocalRef<jobject> media_crypto = GetMediaCrypto();
   if (is_content_encrypted_ && media_crypto.is_null())
-    return false;
+    return STATUS_FAILURE;
 
   ReleaseMediaCodecBridge();
   DVLOG(1) << __FUNCTION__ << " : creating new media codec bridge";