Implement WebKitClientImpl::loadAudioResource() to decode in-memory audio fil...

media/audio/audio_util.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.

[scherkus (not reviewing), 2010/12/11 02:31:12]

copyright year

[Chris Rogers, 2010/12/13 20:25:27]

Done.

 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_AUDIO_AUDIO_UTIL_H_
 #define MEDIA_AUDIO_AUDIO_UTIL_H_
 
 #include "base/basictypes.h"
+#include "media/ffmpeg/ffmpeg_common.h"
 
 namespace media {
 
 // For all audio functions 3 audio formats are supported:
 // 8 bits unsigned 0 to 255.
 // 16 bit signed (little endian).
 // 32 bit signed (little endian)
 
 // AdjustVolume() does a software volume adjustment of a sample buffer.
 // The samples are multiplied by the volume, which should range from
@@ skipping 23 matching lines @@
 // since clamping is performed a value of more than 1 is allowed to increase
 // volume.
 // The buffer is modified in-place to avoid memory management, as this
 // function may be called in performance critical code.
 bool FoldChannels(void* buf,
                   size_t buflen,
                   int channels,
                   int bytes_per_sample,
                   float volume);
 
+// DeinterleaveAudioChannel() takes interleaved audio buffer |source|
+// of the given |sample_fmt| and |number_of_channels| and extracts
+// |number_of_frames| data for the given |channel_index| and
+// puts it in the floating point |destination|.
+// It returns |true| on success, or |false| if the |sample_fmt| is
+// not recognized.
+bool DeinterleaveAudioChannel(void* source,
+                              float* destination,
+                              AVSampleFormat sample_fmt,

[scherkus (not reviewing), 2010/12/11 02:31:12]

similar to the other functions you should remove the dependency on FFmpeg types
and instead use "int bytes_per_sample" where:
  1 == 8 bits
  2 == 16 bit signed (little endian)
  4 == 32 bit signed (little endian)

Refer to the comment at the top of the file where it says these functions must
support these audio formats

[Chris Rogers, 2010/12/13 20:25:27]

Done.

+                              size_t number_of_channels,

[scherkus (not reviewing), 2010/12/11 02:31:12]

for the sake of API consistency I'd recommend we rename this "int channels"

same goes with channel_index and number_of_frames... just go with int

unsigned/size_t tends to propagate throughout the code (like const!) and isn't
needed in most cases

[Chris Rogers, 2010/12/13 20:25:27]

Done.

+                              unsigned channel_index,
+                              unsigned number_of_frames);
+
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_UTIL_H_