cras_input.cc revision 6d86b77056ed63eb6871182f42a9fd5f07550f90 
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
15namespace media {
16
17CrasInputStream::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
33CrasInputStream::~CrasInputStream() {
34  DCHECK(!client_);
35}
36
37bool 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
87void 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
101void CrasInputStream::Start(AudioInputCallback* callback) {
102  DCHECK(client_);
103  DCHECK(callback);
104
105  // If already playing, stop before re-starting.
106  if (started_)
107    return;
108
109  StartAgc();
110
111  callback_ = callback;
112
113  // Prepare |audio_format| and |stream_params| for the stream we
114  // will create.
115  cras_audio_format* audio_format = cras_audio_format_create(
116      AudioManagerCras::BitsToFormat(params_.bits_per_sample()),
117      params_.sample_rate(),
118      params_.channels());
119  if (!audio_format) {
120    DLOG(WARNING) << "Error setting up audio parameters.";
121    callback_->OnError(this);
122    callback_ = NULL;
123    return;
124  }
125
126  unsigned int frames_per_packet = params_.frames_per_buffer();
127  cras_stream_params* stream_params = cras_client_stream_params_create(
128      stream_direction_,
129      frames_per_packet,  // Total latency.
130      frames_per_packet,  // Call back when this many ready.
131      frames_per_packet,  // Minimum Callback level ignored for capture streams.
132      CRAS_STREAM_TYPE_DEFAULT,
133      0,  // Unused flags.
134      this,
135      CrasInputStream::SamplesReady,
136      CrasInputStream::StreamError,
137      audio_format);
138  if (!stream_params) {
139    DLOG(WARNING) << "Error setting up stream parameters.";
140    callback_->OnError(this);
141    callback_ = NULL;
142    cras_audio_format_destroy(audio_format);
143    return;
144  }
145
146  // Before starting the stream, save the number of bytes in a frame for use in
147  // the callback.
148  bytes_per_frame_ = cras_client_format_bytes_per_frame(audio_format);
149
150  // Adding the stream will start the audio callbacks.
151  if (cras_client_add_stream(client_, &stream_id_, stream_params)) {
152    DLOG(WARNING) << "Failed to add the stream.";
153    callback_->OnError(this);
154    callback_ = NULL;
155  }
156
157  // Done with config params.
158  cras_audio_format_destroy(audio_format);
159  cras_client_stream_params_destroy(stream_params);
160
161  started_ = true;
162}
163
164void CrasInputStream::Stop() {
165  DCHECK(client_);
166
167  if (!callback_ || !started_)
168    return;
169
170  StopAgc();
171
172  // Removing the stream from the client stops audio.
173  cras_client_rm_stream(client_, stream_id_);
174
175  started_ = false;
176  callback_ = NULL;
177}
178
179// Static callback asking for samples.  Run on high priority thread.
180int CrasInputStream::SamplesReady(cras_client* client,
181                                  cras_stream_id_t stream_id,
182                                  uint8* samples,
183                                  size_t frames,
184                                  const timespec* sample_ts,
185                                  void* arg) {
186  CrasInputStream* me = static_cast<CrasInputStream*>(arg);
187  me->ReadAudio(frames, samples, sample_ts);
188  return frames;
189}
190
191// Static callback for stream errors.
192int CrasInputStream::StreamError(cras_client* client,
193                                 cras_stream_id_t stream_id,
194                                 int err,
195                                 void* arg) {
196  CrasInputStream* me = static_cast<CrasInputStream*>(arg);
197  me->NotifyStreamError(err);
198  return 0;
199}
200
201void CrasInputStream::ReadAudio(size_t frames,
202                                uint8* buffer,
203                                const timespec* sample_ts) {
204  DCHECK(callback_);
205
206  timespec latency_ts = {0, 0};
207
208  // Determine latency and pass that on to the sink.  sample_ts is the wall time
209  // indicating when the first sample in the buffer was captured.  Convert that
210  // to latency in bytes.
211  cras_client_calc_capture_latency(sample_ts, &latency_ts);
212  double latency_usec =
213      latency_ts.tv_sec * base::Time::kMicrosecondsPerSecond +
214      latency_ts.tv_nsec / base::Time::kNanosecondsPerMicrosecond;
215  double frames_latency =
216      latency_usec * params_.sample_rate() / base::Time::kMicrosecondsPerSecond;
217  unsigned int bytes_latency =
218      static_cast<unsigned int>(frames_latency * bytes_per_frame_);
219
220  // Update the AGC volume level once every second. Note that, |volume| is
221  // also updated each time SetVolume() is called through IPC by the
222  // render-side AGC.
223  double normalized_volume = 0.0;
224  GetAgcVolume(&normalized_volume);
225
226  audio_bus_->FromInterleaved(
227      buffer, audio_bus_->frames(), params_.bits_per_sample() / 8);
228  callback_->OnData(this, audio_bus_.get(), bytes_latency, normalized_volume);
229}
230
231void CrasInputStream::NotifyStreamError(int err) {
232  if (callback_)
233    callback_->OnError(this);
234}
235
236double CrasInputStream::GetMaxVolume() {
237  DCHECK(client_);
238
239  // Capture gain is returned as dB * 100 (150 => 1.5dBFS).  Convert the dB
240  // value to a ratio before returning.
241  double dB = cras_client_get_system_max_capture_gain(client_) / 100.0;
242  return GetVolumeRatioFromDecibels(dB);
243}
244
245void CrasInputStream::SetVolume(double volume) {
246  DCHECK(client_);
247
248  // Convert from the passed volume ratio, to dB * 100.
249  double dB = GetDecibelsFromVolumeRatio(volume);
250  cras_client_set_system_capture_gain(client_, static_cast<long>(dB * 100.0));
251
252  // Update the AGC volume level based on the last setting above. Note that,
253  // the volume-level resolution is not infinite and it is therefore not
254  // possible to assume that the volume provided as input parameter can be
255  // used directly. Instead, a new query to the audio hardware is required.
256  // This method does nothing if AGC is disabled.
257  UpdateAgcVolume();
258}
259
260double CrasInputStream::GetVolume() {
261  if (!client_)
262    return 0.0;
263
264  long dB = cras_client_get_system_capture_gain(client_) / 100.0;
265  return GetVolumeRatioFromDecibels(dB);
266}
267
268double CrasInputStream::GetVolumeRatioFromDecibels(double dB) const {
269  return pow(10, dB / 20.0);
270}
271
272double CrasInputStream::GetDecibelsFromVolumeRatio(double volume_ratio) const {
273  return 20 * log10(volume_ratio);
274}
275
276}  // namespace media
277