Roll FFMpeg for M26. Fix ffmpeg float audio decoding.

media/filters/ffmpeg_audio_decoder.cc

Index: media/filters/ffmpeg_audio_decoder.cc
diff --git a/media/filters/ffmpeg_audio_decoder.cc b/media/filters/ffmpeg_audio_decoder.cc
index 5384d63c48874a70c01b8c00aece2eebe5392d5b..de674cb65c277f2d0b7f108ce8be814306de93d4 100644
--- a/media/filters/ffmpeg_audio_decoder.cc
+++ b/media/filters/ffmpeg_audio_decoder.cc
@@ -8,6 +8,7 @@
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/message_loop_proxy.h"
+#include "media/base/audio_bus.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/audio_timestamp_helper.h"
 #include "media/base/data_buffer.h"
@@ -290,6 +291,22 @@ bool FFmpegAudioDecoder::ConfigureDecoder() {
     return false;
   }
 
+  // Some codecs will only output float data, so we need to convert to integer
+  // before returning the decoded buffer.
+  if (codec_context_->sample_fmt == AV_SAMPLE_FMT_FLTP ||
+      codec_context_->sample_fmt == AV_SAMPLE_FMT_FLT) {
+    DCHECK_EQ(static_cast<size_t>(config.bits_per_channel() / 8),

[DaleCurtis, 2012/12/13 02:39:38]

Fails since MediaSource configures S16 in the decoder config. I could have it
specify float, but that means MediaSource has to know about ffmpeg internals.
Instead I've chosen to adjust the decoded_audio_size as necessary.

+              sizeof(float));
+
+    // Preallocate the AudioBus for float conversions.  We can treat interleaved
+    // float data as a single planar channel since our output is expected in an
+    // interleaved format anyways.
+    int channels = codec_context_->channels;
+    if (codec_context_->sample_fmt == AV_SAMPLE_FMT_FLT)
+      channels = 1;
+    converter_bus_ = AudioBus::CreateWrapper(channels);
+  }
+
   // Success!
   av_frame_ = avcodec_alloc_frame();
   bits_per_channel_ = config.bits_per_channel();
@@ -374,7 +391,6 @@ void FFmpegAudioDecoder::RunDecodeLoop(
       }
     }
 
-    const uint8* decoded_audio_data = NULL;
     int decoded_audio_size = 0;
     if (frame_decoded) {
       int output_sample_rate = av_frame_->sample_rate;
@@ -388,24 +404,57 @@ void FFmpegAudioDecoder::RunDecodeLoop(
         break;
       }
 
-      decoded_audio_data = av_frame_->data[0];
       decoded_audio_size = av_samples_get_buffer_size(
           NULL, codec_context_->channels, av_frame_->nb_samples,
           codec_context_->sample_fmt, 1);
     }
 
-    scoped_refptr<DataBuffer> output;
-
+    int start_sample = 0;
     if (decoded_audio_size > 0 && output_bytes_to_drop_ > 0) {
+      DCHECK_EQ(decoded_audio_size % bytes_per_frame_, 0)
+          << "Decoder didn't output full frames";
+
       int dropped_size = std::min(decoded_audio_size, output_bytes_to_drop_);
-      decoded_audio_data += dropped_size;
+      start_sample = dropped_size / bytes_per_frame_;
       decoded_audio_size -= dropped_size;
       output_bytes_to_drop_ -= dropped_size;
     }
 
+    scoped_refptr<DataBuffer> output;
     if (decoded_audio_size > 0) {
-      // Copy the audio samples into an output buffer.
-      output = new DataBuffer(decoded_audio_data, decoded_audio_size);
+      DCHECK_EQ(decoded_audio_size % bytes_per_frame_, 0)
+          << "Decoder didn't output full frames";
+
+      // Convert float data using an AudioBus.
+      if (converter_bus_) {
+        // Setup the AudioBus as a wrapper of the AVFrame data and then use
+        // AudioBus::ToInterleaved() to convert the data as necessary.
+        int skip_frames = start_sample;
+        int total_frames = av_frame_->nb_samples - start_sample;
+        if (codec_context_->sample_fmt == AV_SAMPLE_FMT_FLT) {
+          DCHECK_EQ(converter_bus_->channels(), 1);
+          total_frames *= codec_context_->channels;
+          skip_frames *= codec_context_->channels;
+        }
+        converter_bus_->set_frames(total_frames);
+        DCHECK_EQ(decoded_audio_size,
+                  converter_bus_->frames() * bytes_per_frame_);
+
+        for (int i = 0; i < converter_bus_->channels(); ++i) {
+          converter_bus_->SetChannelData(i, reinterpret_cast<float*>(
+              av_frame_->extended_data[i]) + skip_frames);
+        }
+
+        output = new DataBuffer(decoded_audio_size);
+        output->SetDataSize(decoded_audio_size);
+        converter_bus_->ToInterleaved(
+            converter_bus_->frames(), bits_per_channel_ / 8,
+            output->GetWritableData());
+      } else {
+        output = new DataBuffer(
+            av_frame_->extended_data[0] + start_sample * bytes_per_frame_,
+            decoded_audio_size);
+      }
       output->SetTimestamp(output_timestamp_helper_->GetTimestamp());
       output->SetDuration(
           output_timestamp_helper_->GetDuration(decoded_audio_size));