No EOS frame in {Audio|Video}Decoder::OutputCB.

media/filters/ffmpeg_audio_decoder.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
 #define MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
 
 #include <list>
 
 #include "base/callback.h"
@@ skipping 27 matching lines @@
   // AudioDecoder implementation.
   virtual void Initialize(const AudioDecoderConfig& config,
                           const PipelineStatusCB& status_cb,
                           const OutputCB& output_cb) OVERRIDE;
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const DecodeCB& decode_cb) OVERRIDE;
   virtual void Reset(const base::Closure& closure) OVERRIDE;
   virtual void Stop() OVERRIDE;
 
  private:
+  // There are four states the decoder can be in:
+  //
+  // - kUninitialized: The decoder is not initialized.
+  // - kNormal: This is the normal state. The decoder is idle and ready to
+  //            decode input buffers, or is decoding an input buffer.
+  // - kDecodeFinished: EOS buffer received, codec flushed and decode finished.
+  //                    No further Decode() call should be made.
+  // - kError: Unexpected error happened.
+  //
+  // These are the possible state transitions.
+  //
+  // kUninitialized -> kNormal:
+  //     The decoder is successfully initialized and is ready to decode buffers.
+  // kNormal -> kDecodeFinished:
+  //     When buffer->end_of_stream() is true and avcodec_decode_audio4()
+  //     returns 0 data.
+  // kNormal -> kError:
+  //     A decoding error occurs and decoding needs to stop.
+  // (any state) -> kNormal:
+  //     Any time Reset() is called.
   enum DecoderState {
     kUninitialized,
     kNormal,
     kDecodeFinished,
     kError
   };
 
   // Reset decoder and call |reset_cb_|.
   void DoReset();
 
   // Handles decoding an unencrypted encoded buffer.
   void DecodeBuffer(const scoped_refptr<DecoderBuffer>& buffer,
                     const DecodeCB& decode_cb);
-  bool FFmpegDecode(const scoped_refptr<DecoderBuffer>& buffer);
+  bool FFmpegDecode(const scoped_refptr<DecoderBuffer>& buffer,
+                    bool* has_produced_frame);
 
   // Handles (re-)initializing the decoder with a (new) config.
   // Returns true if initialization was successful.
   bool ConfigureDecoder();
 
   // Releases resources associated with |codec_context_| and |av_frame_|
   // and resets them to NULL.
   void ReleaseFFmpegResources();
   void ResetTimestampState();
 
@@ skipping 15 matching lines @@
   scoped_ptr<AudioDiscardHelper> discard_helper_;
 
   LogCB log_cb_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(FFmpegAudioDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_