Mpeg2 TS parser: Es parsing using an ES byte queue.

media/formats/mp2t/es_parser_adts.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/formats/mp2t/es_parser_adts.h"
 
 #include <list>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 100 matching lines @@
   DCHECK_EQ(adts_frame.queue_offset, es_queue_->head());
   es_queue_->Pop(adts_frame.size);
 }
 
 EsParserAdts::EsParserAdts(
     const NewAudioConfigCB& new_audio_config_cb,
     const EmitBufferCB& emit_buffer_cb,
     bool sbr_in_mimetype)
   : new_audio_config_cb_(new_audio_config_cb),
     emit_buffer_cb_(emit_buffer_cb),
-    sbr_in_mimetype_(sbr_in_mimetype),
-    es_queue_(new media::OffsetByteQueue()) {
+    sbr_in_mimetype_(sbr_in_mimetype) {
 }
 
 EsParserAdts::~EsParserAdts() {
 }
 
-bool EsParserAdts::Parse(const uint8* buf, int size,
-                         base::TimeDelta pts,
-                         DecodeTimestamp dts) {
-  // The incoming PTS applies to the access unit that comes just after
-  // the beginning of |buf|.
-  if (pts != kNoTimestamp())
-    pts_list_.push_back(EsPts(es_queue_->tail(), pts));
-
-  // Copy the input data to the ES buffer.
-  es_queue_->Push(buf, size);
-
+bool EsParserAdts::ParseFromEsQueue() {
   // Look for every ADTS frame in the ES buffer.
   AdtsFrame adts_frame;
   while (LookForAdtsFrame(&adts_frame)) {
     // Update the audio configuration if needed.
     DCHECK_GE(adts_frame.size, kADTSHeaderMinSize);
     if (!UpdateAudioConfiguration(adts_frame.data))
       return false;
 
     // Get the PTS & the duration of this access unit.
-    while (!pts_list_.empty() &&
-           pts_list_.front().first <= adts_frame.queue_offset) {
-      audio_timestamp_helper_->SetBaseTimestamp(pts_list_.front().second);
-      pts_list_.pop_front();
-    }
+    TimingDesc current_timing_desc =
+        GetTimingDescriptor(adts_frame.queue_offset);
+    if (current_timing_desc.pts != kNoTimestamp())
+      audio_timestamp_helper_->SetBaseTimestamp(current_timing_desc.pts);
 
     if (audio_timestamp_helper_->base_timestamp() == kNoTimestamp()) {
       DVLOG(1) << "Audio frame with unknown timestamp";
       return false;
     }
     base::TimeDelta current_pts = audio_timestamp_helper_->GetTimestamp();
     base::TimeDelta frame_duration =
         audio_timestamp_helper_->GetFrameDuration(kSamplesPerAACFrame);
 
     // Emit an audio frame.
@@ skipping 18 matching lines @@
     SkipAdtsFrame(adts_frame);
   }
 
   return true;
 }
 
 void EsParserAdts::Flush() {
 }
 
 void EsParserAdts::Reset() {
-  es_queue_.reset(new media::OffsetByteQueue());
-  pts_list_.clear();
+  EsParser::Reset();

[wolenetz, 2014/08/26 23:01:44]

This seems fragile to require overriding method to remember to call the
overridden member. Suggestion: Make the existing EsParser::Reset() be
non-virtual and have it first call an abstract method, like "ResetInternal()"
that each concrete EsParser implementation overrides with their custom reset
logic. (Kind of like how you've refactored Parse into super::Parse() and
child::ParseFromEsQueue().)

[damienv1, 2014/08/27 16:23:43]

Done.

   last_audio_decoder_config_ = AudioDecoderConfig();
 }
 
 bool EsParserAdts::UpdateAudioConfiguration(const uint8* adts_header) {
   size_t frequency_index = ExtractAdtsFrequencyIndex(adts_header);
   if (frequency_index >= kADTSFrequencyTableSize) {
     // Frequency index 13 & 14 are reserved
     // while 15 means that the frequency is explicitly written
     // (not supported).
     return false;
@@ skipping 60 matching lines @@
     // Audio config notification.
     last_audio_decoder_config_ = audio_decoder_config;
     new_audio_config_cb_.Run(audio_decoder_config);
   }
 
   return true;
 }
 
 }  // namespace mp2t
 }  // namespace media