Moved codec-specific audio packet splitting into decoders.

webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.h"
 
 #include "webrtc/base/checks.h"
+#include "webrtc/modules/audio_coding/codecs/split_by_samples.h"
 #include "webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.h"
 
 namespace webrtc {
 
 AudioDecoderPcm16B::AudioDecoderPcm16B(int sample_rate_hz, size_t num_channels)
     : sample_rate_hz_(sample_rate_hz), num_channels_(num_channels) {
   RTC_DCHECK(sample_rate_hz == 8000 || sample_rate_hz == 16000 ||
              sample_rate_hz == 32000 || sample_rate_hz == 48000)
       << "Unsupported sample rate " << sample_rate_hz;
   RTC_DCHECK_GE(num_channels, 1u);
@@ skipping 13 matching lines @@
                                        size_t encoded_len,
                                        int sample_rate_hz,
                                        int16_t* decoded,
                                        SpeechType* speech_type) {
   RTC_DCHECK_EQ(sample_rate_hz_, sample_rate_hz);
   size_t ret = WebRtcPcm16b_Decode(encoded, encoded_len, decoded);
   *speech_type = ConvertSpeechType(1);
   return static_cast<int>(ret);
 }
 
+std::vector<AudioDecoder::PacketSplit> AudioDecoderPcm16B::SplitPacket(
+    rtc::ArrayView<const uint8_t> payload) const {
+  // TODO(ossu): Investigate if we can ever get 44.1KHz audio here, in which

[hlundin-webrtc, 2016/09/09 12:52:52]

Short answer: no. If codecs should be allowed to return something else than {8,
16, 32, 48} kHz, we've got plenty of bigger fish to fry. But hey, feel free to
add that CheckedDivExact.

Nit: kHz with small 'k'.

[kwiberg-webrtc, 2016/09/12 02:11:01]

Also, space between the number and the unit. But I guess it doesn't matter since
this comment is going away...

[ossu, 2016/09/12 11:26:37]

The comment is only here for this to get caught in the review, so no, it doesn't
really matter. I'll put the CheckedDivExact in and annotate why. And then I'll
make sure I spell 44.1 kHz correctly. :)

[kwiberg-webrtc, 2016/09/13 12:23:37]

Well, if you didn't want pedantic complaints about your spelling, you asked the
wrong two people to review. :-)

[ossu, 2016/09/13 14:25:55]

Acknowledged.

[hlundin-webrtc, 2016/09/15 08:49:14]

:)

+  //             case rounding will break. Consider replacing with
+  //             CheckedDivExact to catch that happening.
+  return internal::SplitBySamples(payload,
+                                  sample_rate_hz_ * 2 * num_channels_ / 1000,
+                                  sample_rate_hz_ / 1000);
+}
+
 int AudioDecoderPcm16B::PacketDuration(const uint8_t* encoded,
                                        size_t encoded_len) const {
   // Two encoded byte per sample per channel.
   return static_cast<int>(encoded_len / (2 * Channels()));
 }
 
 }  // namespace webrtc