Don't try to decode more than one EOS at a time.

media/base/video_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_BASE_VIDEO_DECODER_H_
 #define MEDIA_BASE_VIDEO_DECODER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/media_export.h"
@@ skipping 51 matching lines @@
 
   // Requests a |buffer| to be decoded. The status of the decoder and decoded
   // frame are returned via the provided callback. Some decoders may allow
   // decoding multiple buffers in parallel. Callers should call
   // GetMaxDecodeRequests() to get number of buffers that may be decoded in
   // parallel. Decoder must call |decode_cb| in the same order in which Decode()
   // is called.
   //
   // Implementations guarantee that the callback will not be called from within
   // this method and that |decode_cb| will not be blocked on the following
-  // Decode() calls (i.e. |decode_cb| will be called even Decode() is never
+  // Decode() calls (i.e. |decode_cb| will be called even if Decode() is never
   // called again).
   //
   // After decoding is finished the decoder calls |output_cb| specified in
   // Initialize() for each decoded frame. |output_cb| may be called before or
   // after |decode_cb|.
   //
   // If |buffer| is an EOS buffer then the decoder must be flushed, i.e.
   // |output_cb| must be called for each frame pending in the queue and
-  // |decode_cb| must be called after that.
+  // |decode_cb| must be called after that. Callers will not call Decode()
+  // again until after the flush completes.
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const DecodeCB& decode_cb) = 0;
 
   // Resets decoder state. All pending Decode() requests will be finished or
   // aborted before |closure| is called.
   // Note: No VideoDecoder calls should be made before |closure| is executed.
   virtual void Reset(const base::Closure& closure) = 0;
 
   // Returns true if the decoder needs bitstream conversion before decoding.
   virtual bool NeedsBitstreamConversion() const;
 
   // Returns true if the decoder currently has the ability to decode and return
   // a VideoFrame. Most implementations can allocate a new VideoFrame and hence
   // this will always return true. Override and return false for decoders that
   // use a fixed set of VideoFrames for decoding.
   virtual bool CanReadWithoutStalling() const;
 
   // Returns maximum number of parallel decode requests.
   virtual int GetMaxDecodeRequests() const;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(VideoDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_DECODER_H_