media/audio/cras/cras_input.cc

   1 // Copyright (c) 2012 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/audio/cras/cras_input.h"
   6
   7 #include <math.h>
   8
   9 #include "base/basictypes.h"
  10 #include "base/logging.h"
  11 #include "base/time/time.h"
  12 #include "media/audio/audio_manager.h"
  13 #include "media/audio/cras/audio_manager_cras.h"
  14
  15 namespace media {
  16
  17 CrasInputStream::CrasInputStream(const AudioParameters& params,
  18                                  AudioManagerCras* manager,
  19                                  const std::string& device_id)
  20     : audio_manager_(manager),
  21       bytes_per_frame_(0),
  22       callback_(NULL),
  23       client_(NULL),
  24       params_(params),
  25       started_(false),
  26       stream_id_(0),
  27       stream_direction_(device_id == AudioManagerBase::kLoopbackInputDeviceId ?
  28                             CRAS_STREAM_POST_MIX_PRE_DSP : CRAS_STREAM_INPUT) {
  29   DCHECK(audio_manager_);
  30   audio_bus_ = AudioBus::Create(params_);
  31 }
  32
  33 CrasInputStream::~CrasInputStream() {
  34   DCHECK(!client_);
  35 }
  36
  37 bool CrasInputStream::Open() {
  38   if (client_) {
  39     NOTREACHED() << "CrasInputStream already open";
  40     return false;  // Already open.
  41   }
  42
  43   // Sanity check input values.
  44   if (params_.sample_rate() <= 0) {
  45     DLOG(WARNING) << "Unsupported audio frequency.";
  46     return false;
  47   }
  48
  49   if (AudioParameters::AUDIO_PCM_LINEAR != params_.format() &&
  50       AudioParameters::AUDIO_PCM_LOW_LATENCY != params_.format()) {
  51     DLOG(WARNING) << "Unsupported audio format.";
  52     return false;
  53   }
  54
  55   snd_pcm_format_t pcm_format =
  56       AudioManagerCras::BitsToFormat(params_.bits_per_sample());
  57   if (pcm_format == SND_PCM_FORMAT_UNKNOWN) {
  58     DLOG(WARNING) << "Unsupported bits/sample: " << params_.bits_per_sample();
  59     return false;
  60   }
  61
  62   // Create the client and connect to the CRAS server.
  63   if (cras_client_create(&client_) < 0) {
  64     DLOG(WARNING) << "Couldn't create CRAS client.\n";
  65     client_ = NULL;
  66     return false;
  67   }
  68
  69   if (cras_client_connect(client_)) {
  70     DLOG(WARNING) << "Couldn't connect CRAS client.\n";
  71     cras_client_destroy(client_);
  72     client_ = NULL;
  73     return false;
  74   }
  75
  76   // Then start running the client.
  77   if (cras_client_run_thread(client_)) {
  78     DLOG(WARNING) << "Couldn't run CRAS client.\n";
  79     cras_client_destroy(client_);
  80     client_ = NULL;
  81     return false;
  82   }
  83
  84   return true;
  85 }
  86
  87 void CrasInputStream::Close() {
  88   Stop();
  89
  90   if (client_) {
  91     cras_client_stop(client_);
  92     cras_client_destroy(client_);
  93     client_ = NULL;
  94   }
  95
  96   // Signal to the manager that we're closed and can be removed.
  97   // Should be last call in the method as it deletes "this".
  98   audio_manager_->ReleaseInputStream(this);
  99 }
 100
 101 void CrasInputStream::Start(AudioInputCallback* callback) {
 102   DCHECK(client_);
 103   DCHECK(callback);
 104
 105   // Channel map to CRAS_CHANNEL, values in the same order of
 106   // corresponding source in Chromium defined Channels.
 107   static const int kChannelMap[] = {
 108     CRAS_CH_FL,
 109     CRAS_CH_FR,
 110     CRAS_CH_FC,
 111     CRAS_CH_LFE,
 112     CRAS_CH_RL,
 113     CRAS_CH_RR,
 114     CRAS_CH_FLC,
 115     CRAS_CH_FRC,
 116     CRAS_CH_RC,
 117     CRAS_CH_SL,
 118     CRAS_CH_SR
 119   };
 120   COMPILE_ASSERT(arraysize(kChannelMap) == CHANNELS_MAX + 1,
 121                  channel_map_size_do_not_match);
 122
 123   // If already playing, stop before re-starting.
 124   if (started_)
 125     return;
 126
 127   StartAgc();
 128
 129   callback_ = callback;
 130
 131   // Prepare |audio_format| and |stream_params| for the stream we
 132   // will create.
 133   cras_audio_format* audio_format = cras_audio_format_create(
 134       AudioManagerCras::BitsToFormat(params_.bits_per_sample()),
 135       params_.sample_rate(),
 136       params_.channels());
 137   if (!audio_format) {
 138     DLOG(WARNING) << "Error setting up audio parameters.";
 139     callback_->OnError(this);
 140     callback_ = NULL;
 141     return;
 142   }
 143
 144   // Initialize channel layout to all -1 to indicate that none of
 145   // the channels is set in the layout.
 146   int8 layout[CRAS_CH_MAX];
 147   for (size_t i = 0; i < arraysize(layout); ++i)
 148     layout[i] = -1;
 149
 150   // Converts to CRAS defined channels. ChannelOrder will return -1
 151   // for channels that are not present in params_.channel_layout().
 152   for (size_t i = 0; i < arraysize(kChannelMap); ++i) {
 153     layout[kChannelMap[i]] = ChannelOrder(params_.channel_layout(),
 154                                           static_cast<Channels>(i));
 155   }
 156   if (cras_audio_format_set_channel_layout(audio_format, layout) != 0) {
 157     DLOG(WARNING) << "Error setting channel layout.";
 158     callback->OnError(this);
 159     return;
 160   }
 161
 162   unsigned int frames_per_packet = params_.frames_per_buffer();
 163   cras_stream_params* stream_params = cras_client_stream_params_create(
 164       stream_direction_,
 165       frames_per_packet,  // Total latency.
 166       frames_per_packet,  // Call back when this many ready.
 167       frames_per_packet,  // Minimum Callback level ignored for capture streams.
 168       CRAS_STREAM_TYPE_DEFAULT,
 169       0,  // Unused flags.
 170       this,
 171       CrasInputStream::SamplesReady,
 172       CrasInputStream::StreamError,
 173       audio_format);
 174   if (!stream_params) {
 175     DLOG(WARNING) << "Error setting up stream parameters.";
 176     callback_->OnError(this);
 177     callback_ = NULL;
 178     cras_audio_format_destroy(audio_format);
 179     return;
 180   }
 181
 182   // Before starting the stream, save the number of bytes in a frame for use in
 183   // the callback.
 184   bytes_per_frame_ = cras_client_format_bytes_per_frame(audio_format);
 185
 186   // Adding the stream will start the audio callbacks.
 187   if (cras_client_add_stream(client_, &stream_id_, stream_params)) {
 188     DLOG(WARNING) << "Failed to add the stream.";
 189     callback_->OnError(this);
 190     callback_ = NULL;
 191   }
 192
 193   // Done with config params.
 194   cras_audio_format_destroy(audio_format);
 195   cras_client_stream_params_destroy(stream_params);
 196
 197   started_ = true;
 198 }
 199
 200 void CrasInputStream::Stop() {
 201   DCHECK(client_);
 202
 203   if (!callback_ || !started_)
 204     return;
 205
 206   StopAgc();
 207
 208   // Removing the stream from the client stops audio.
 209   cras_client_rm_stream(client_, stream_id_);
 210
 211   started_ = false;
 212   callback_ = NULL;
 213 }
 214
 215 // Static callback asking for samples.  Run on high priority thread.
 216 int CrasInputStream::SamplesReady(cras_client* client,
 217                                   cras_stream_id_t stream_id,
 218                                   uint8* samples,
 219                                   size_t frames,
 220                                   const timespec* sample_ts,
 221                                   void* arg) {
 222   CrasInputStream* me = static_cast<CrasInputStream*>(arg);
 223   me->ReadAudio(frames, samples, sample_ts);
 224   return frames;
 225 }
 226
 227 // Static callback for stream errors.
 228 int CrasInputStream::StreamError(cras_client* client,
 229                                  cras_stream_id_t stream_id,
 230                                  int err,
 231                                  void* arg) {
 232   CrasInputStream* me = static_cast<CrasInputStream*>(arg);
 233   me->NotifyStreamError(err);
 234   return 0;
 235 }
 236
 237 void CrasInputStream::ReadAudio(size_t frames,
 238                                 uint8* buffer,
 239                                 const timespec* sample_ts) {
 240   DCHECK(callback_);
 241
 242   timespec latency_ts = {0, 0};
 243
 244   // Determine latency and pass that on to the sink.  sample_ts is the wall time
 245   // indicating when the first sample in the buffer was captured.  Convert that
 246   // to latency in bytes.
 247   cras_client_calc_capture_latency(sample_ts, &latency_ts);
 248   double latency_usec =
 249       latency_ts.tv_sec * base::Time::kMicrosecondsPerSecond +
 250       latency_ts.tv_nsec / base::Time::kNanosecondsPerMicrosecond;
 251   double frames_latency =
 252       latency_usec * params_.sample_rate() / base::Time::kMicrosecondsPerSecond;
 253   unsigned int bytes_latency =
 254       static_cast<unsigned int>(frames_latency * bytes_per_frame_);
 255
 256   // Update the AGC volume level once every second. Note that, |volume| is
 257   // also updated each time SetVolume() is called through IPC by the
 258   // render-side AGC.
 259   double normalized_volume = 0.0;
 260   GetAgcVolume(&normalized_volume);
 261
 262   audio_bus_->FromInterleaved(
 263       buffer, audio_bus_->frames(), params_.bits_per_sample() / 8);
 264   callback_->OnData(this, audio_bus_.get(), bytes_latency, normalized_volume);
 265 }
 266
 267 void CrasInputStream::NotifyStreamError(int err) {
 268   if (callback_)
 269     callback_->OnError(this);
 270 }
 271
 272 double CrasInputStream::GetMaxVolume() {
 273   DCHECK(client_);
 274
 275   // Capture gain is returned as dB * 100 (150 => 1.5dBFS).  Convert the dB
 276   // value to a ratio before returning.
 277   double dB = cras_client_get_system_max_capture_gain(client_) / 100.0;
 278   return GetVolumeRatioFromDecibels(dB);
 279 }
 280
 281 void CrasInputStream::SetVolume(double volume) {
 282   DCHECK(client_);
 283
 284   // Convert from the passed volume ratio, to dB * 100.
 285   double dB = GetDecibelsFromVolumeRatio(volume);
 286   cras_client_set_system_capture_gain(client_, static_cast<long>(dB * 100.0));
 287
 288   // Update the AGC volume level based on the last setting above. Note that,
 289   // the volume-level resolution is not infinite and it is therefore not
 290   // possible to assume that the volume provided as input parameter can be
 291   // used directly. Instead, a new query to the audio hardware is required.
 292   // This method does nothing if AGC is disabled.
 293   UpdateAgcVolume();
 294 }
 295
 296 double CrasInputStream::GetVolume() {
 297   if (!client_)
 298     return 0.0;
 299
 300   long dB = cras_client_get_system_capture_gain(client_) / 100.0;
 301   return GetVolumeRatioFromDecibels(dB);
 302 }
 303
 304 bool CrasInputStream::IsMuted() {
 305   return false;
 306 }
 307
 308 double CrasInputStream::GetVolumeRatioFromDecibels(double dB) const {
 309   return pow(10, dB / 20.0);
 310 }
 311
 312 double CrasInputStream::GetDecibelsFromVolumeRatio(double volume_ratio) const {
 313   return 20 * log10(volume_ratio);
 314 }
 315
 316 }  // namespace media