media/formats/webm/webm_audio_client.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/formats/webm/webm_audio_client.h"
   6
   7 #include "media/base/audio_decoder_config.h"
   8 #include "media/base/channel_layout.h"
   9 #include "media/formats/webm/webm_constants.h"
  10
  11 namespace media {
  12
  13 WebMAudioClient::WebMAudioClient(const LogCB& log_cb)
  14     : log_cb_(log_cb) {
  15   Reset();
  16 }
  17
  18 WebMAudioClient::~WebMAudioClient() {
  19 }
  20
  21 void WebMAudioClient::Reset() {
  22   channels_ = -1;
  23   samples_per_second_ = -1;
  24   output_samples_per_second_ = -1;
  25 }
  26
  27 bool WebMAudioClient::InitializeConfig(
  28     const std::string& codec_id, const std::vector<uint8>& codec_private,
  29     int64 seek_preroll, int64 codec_delay, bool is_encrypted,
  30     AudioDecoderConfig* config) {
  31   DCHECK(config);
  32   SampleFormat sample_format = kSampleFormatPlanarF32;
  33
  34   AudioCodec audio_codec = kUnknownAudioCodec;
  35   if (codec_id == "A_VORBIS") {
  36     audio_codec = kCodecVorbis;
  37   } else if (codec_id == "A_OPUS") {
  38     audio_codec = kCodecOpus;
  39   } else {
  40     MEDIA_LOG(log_cb_) << "Unsupported audio codec_id " << codec_id;
  41     return false;
  42   }
  43
  44   if (samples_per_second_ <= 0)
  45     return false;
  46
  47   // Set channel layout default if a Channels element was not present.
  48   if (channels_ == -1)
  49     channels_ = 1;
  50
  51   ChannelLayout channel_layout =  GuessChannelLayout(channels_);
  52
  53   if (channel_layout == CHANNEL_LAYOUT_UNSUPPORTED) {
  54     MEDIA_LOG(log_cb_) << "Unsupported channel count " << channels_;
  55     return false;
  56   }
  57
  58   int samples_per_second = samples_per_second_;
  59   if (output_samples_per_second_ > 0)
  60     samples_per_second = output_samples_per_second_;
  61
  62   // Always use 48kHz for OPUS.  See the "Input Sample Rate" section of the
  63   // spec: http://tools.ietf.org/html/draft-terriberry-oggopus-01#page-11
  64   if (audio_codec == kCodecOpus) {
  65     samples_per_second = 48000;
  66     sample_format = kSampleFormatF32;
  67   }
  68
  69   const uint8* extra_data = NULL;
  70   size_t extra_data_size = 0;
  71   if (codec_private.size() > 0) {
  72     extra_data = &codec_private[0];
  73     extra_data_size = codec_private.size();
  74   }
  75
  76   // Convert |codec_delay| from nanoseconds into frames.
  77   int codec_delay_in_frames = 0;
  78   if (codec_delay != -1) {
  79     codec_delay_in_frames =
  80         0.5 +
  81         samples_per_second * (static_cast<double>(codec_delay) /
  82                               base::Time::kNanosecondsPerSecond);
  83   }
  84
  85   config->Initialize(
  86       audio_codec,
  87       sample_format,
  88       channel_layout,
  89       samples_per_second,
  90       extra_data,
  91       extra_data_size,
  92       is_encrypted,
  93       true,
  94       base::TimeDelta::FromMicroseconds(
  95           (seek_preroll != -1 ? seek_preroll : 0) / 1000),
  96       codec_delay_in_frames);
  97   return config->IsValidConfig();
  98 }
  99
 100 bool WebMAudioClient::OnUInt(int id, int64 val) {
 101   if (id == kWebMIdChannels) {
 102     if (channels_ != -1) {
 103       MEDIA_LOG(log_cb_) << "Multiple values for id " << std::hex << id
 104                          << " specified. (" << channels_ << " and " << val
 105                          << ")";
 106       return false;
 107     }
 108
 109     channels_ = val;
 110   }
 111   return true;
 112 }
 113
 114 bool WebMAudioClient::OnFloat(int id, double val) {
 115   double* dst = NULL;
 116
 117   switch (id) {
 118     case kWebMIdSamplingFrequency:
 119       dst = &samples_per_second_;
 120       break;
 121     case kWebMIdOutputSamplingFrequency:
 122       dst = &output_samples_per_second_;
 123       break;
 124     default:
 125       return true;
 126   }
 127
 128   if (val <= 0)
 129     return false;
 130
 131   if (*dst != -1) {
 132     MEDIA_LOG(log_cb_) << "Multiple values for id " << std::hex << id
 133                        << " specified (" << *dst << " and " << val << ")";
 134     return false;
 135   }
 136
 137   *dst = val;
 138   return true;
 139 }
 140
 141 }  // namespace media