Fix MediaSource code so it can handle HE-AAC content that uses implicit signalling.

media/mp4/aac.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_MP4_AAC_H_
 #define MEDIA_MP4_AAC_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 14 matching lines @@
  public:
   AAC();
   ~AAC();
 
   // Parse the AAC config from the raw binary data embedded in esds box.
   // The function will parse the data and get the ElementaryStreamDescriptor,
   // then it will parse the ElementaryStreamDescriptor to get audio stream
   // configurations.
   bool Parse(const std::vector<uint8>& data);
 
-  uint32 frequency() const;
+  // Gets the output sample rate for the AAC stream.
+  // |sbr_in_mimetype| should be set to true if the SBR mode is
+  //  signalled in the mimetype. (ie mp4a.40.5 in the codecs parameter).

[vrk (LEFT CHROMIUM), 2012/07/20 23:08:48]

nit: extra space "//  "

[acolwell GONE FROM CHROMIUM, 2012/07/20 23:20:05]

Done.

+  // Returns the samples_per_second value that should used in an
+  //  AudioDecoderConfig.

[vrk (LEFT CHROMIUM), 2012/07/20 23:08:48]

nit: extra space "//  "

[acolwell GONE FROM CHROMIUM, 2012/07/20 23:20:05]

Done.

+  int GetOutputSamplesPerSecond(bool sbr_in_mimetype) const;
   ChannelLayout channel_layout() const;
 
   // This function converts a raw AAC frame into an AAC frame with an ADTS
   // header. On success, the function returns true and stores the converted data
   // in the buffer. The function returns false on failure and leaves the buffer
   // unchanged.
   bool ConvertEsdsToADTS(std::vector<uint8>* buffer) const;
 
  private:
   bool SkipDecoderGASpecificConfig(BitReader* bit_reader) const;
   bool SkipErrorSpecificConfig() const;
   bool SkipGASpecificConfig(BitReader* bit_reader) const;
 
   // The following variables store the AAC specific configuration information
   // that are used to generate the ADTS header.
   uint8 profile_;
   uint8 frequency_index_;
   uint8 channel_config_;
 
   // The following variables store audio configuration information that
   // can be used by Chromium. They are based on the AAC specific
   // configuration but can be overridden by extensions in elementary
   // stream descriptor.
-  uint32 frequency_;
+  int frequency_;
+  int extension_frequency_;
   ChannelLayout channel_layout_;
 };
 
 }  // namespace mp4
 
 }  // namespace media
 
 #endif  // MEDIA_MP4_AAC_H_