cras_input.cc revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd 
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/bind.h"
11#include "base/logging.h"
12#include "base/time.h"
13#include "media/audio/audio_manager.h"
14#include "media/audio/cras/audio_manager_cras.h"
15#include "media/audio/linux/alsa_util.h"
16
17namespace media {
18
19CrasInputStream::CrasInputStream(const AudioParameters& params,
20                                 AudioManagerCras* manager)
21    : audio_manager_(manager),
22      bytes_per_frame_(0),
23      callback_(NULL),
24      client_(NULL),
25      params_(params),
26      started_(false),
27      stream_id_(0) {
28  DCHECK(audio_manager_);
29}
30
31CrasInputStream::~CrasInputStream() {
32  DCHECK(!client_);
33}
34
35bool CrasInputStream::Open() {
36  if (client_) {
37    NOTREACHED() << "CrasInputStream already open";
38    return false;  // Already open.
39  }
40
41  // Sanity check input values.
42  if (params_.sample_rate() <= 0) {
43    DLOG(WARNING) << "Unsupported audio frequency.";
44    return false;
45  }
46
47  if (AudioParameters::AUDIO_PCM_LINEAR != params_.format() &&
48      AudioParameters::AUDIO_PCM_LOW_LATENCY != params_.format()) {
49    DLOG(WARNING) << "Unsupported audio format.";
50    return false;
51  }
52
53  snd_pcm_format_t pcm_format =
54      alsa_util::BitsToFormat(params_.bits_per_sample());
55  if (pcm_format == SND_PCM_FORMAT_UNKNOWN) {
56    DLOG(WARNING) << "Unsupported bits/sample: " << params_.bits_per_sample();
57    return false;
58  }
59
60  // Create the client and connect to the CRAS server.
61  if (cras_client_create(&client_) < 0) {
62    DLOG(WARNING) << "Couldn't create CRAS client.\n";
63    client_ = NULL;
64    return false;
65  }
66
67  if (cras_client_connect(client_)) {
68    DLOG(WARNING) << "Couldn't connect CRAS client.\n";
69    cras_client_destroy(client_);
70    client_ = NULL;
71    return false;
72  }
73
74  // Then start running the client.
75  if (cras_client_run_thread(client_)) {
76    DLOG(WARNING) << "Couldn't run CRAS client.\n";
77    cras_client_destroy(client_);
78    client_ = NULL;
79    return false;
80  }
81
82  return true;
83}
84
85void CrasInputStream::Close() {
86  if (client_) {
87    cras_client_stop(client_);
88    cras_client_destroy(client_);
89    client_ = NULL;
90  }
91
92  if (callback_) {
93    callback_->OnClose(this);
94    callback_ = NULL;
95  }
96
97  // Signal to the manager that we're closed and can be removed.
98  // Should be last call in the method as it deletes "this".
99  audio_manager_->ReleaseInputStream(this);
100}
101
102void CrasInputStream::Start(AudioInputCallback* callback) {
103  DCHECK(client_);
104  DCHECK(callback);
105
106  // If already playing, stop before re-starting.
107  if (started_)
108    return;
109
110  callback_ = callback;
111
112  // Prepare |audio_format| and |stream_params| for the stream we
113  // will create.
114  cras_audio_format* audio_format = cras_audio_format_create(
115      alsa_util::BitsToFormat(params_.bits_per_sample()),
116      params_.sample_rate(),
117      params_.channels());
118  if (!audio_format) {
119    DLOG(WARNING) << "Error setting up audio parameters.";
120    callback_->OnError(this);
121    callback_ = NULL;
122    return;
123  }
124
125  unsigned int frames_per_packet = params_.frames_per_buffer();
126  cras_stream_params* stream_params = cras_client_stream_params_create(
127      CRAS_STREAM_INPUT,
128      frames_per_packet,  // Total latency.
129      frames_per_packet,  // Call back when this many ready.
130      frames_per_packet,  // Minimum Callback level ignored for capture streams.
131      CRAS_STREAM_TYPE_DEFAULT,
132      0,  // Unused flags.
133      this,
134      CrasInputStream::SamplesReady,
135      CrasInputStream::StreamError,
136      audio_format);
137  if (!stream_params) {
138    DLOG(WARNING) << "Error setting up stream parameters.";
139    callback_->OnError(this);
140    callback_ = NULL;
141    cras_audio_format_destroy(audio_format);
142    return;
143  }
144
145  // Before starting the stream, save the number of bytes in a frame for use in
146  // the callback.
147  bytes_per_frame_ = cras_client_format_bytes_per_frame(audio_format);
148
149  // Adding the stream will start the audio callbacks.
150  if (cras_client_add_stream(client_, &stream_id_, stream_params) == 0) {
151    audio_manager_->IncreaseActiveInputStreamCount();
152  } else {
153    DLOG(WARNING) << "Failed to add the stream.";
154    callback_->OnError(this);
155    callback_ = NULL;
156  }
157
158  // Done with config params.
159  cras_audio_format_destroy(audio_format);
160  cras_client_stream_params_destroy(stream_params);
161
162  started_ = true;
163}
164
165void CrasInputStream::Stop() {
166  DCHECK(client_);
167
168  if (!callback_ || !started_)
169    return;
170
171  // Removing the stream from the client stops audio.
172  cras_client_rm_stream(client_, stream_id_);
173
174  audio_manager_->DecreaseActiveInputStreamCount();
175
176  started_ = false;
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  QueryAgcVolume(&normalized_volume);
225
226  callback_->OnData(this,
227                    buffer,
228                    frames * bytes_per_frame_,
229                    bytes_latency,
230                    normalized_volume);
231}
232
233void CrasInputStream::NotifyStreamError(int err) {
234  if (callback_)
235    callback_->OnError(this);
236}
237
238double CrasInputStream::GetMaxVolume() {
239  DCHECK(client_);
240
241  // Capture gain is returned as dB * 100 (150 => 1.5dBFS).  Convert the dB
242  // value to a ratio before returning.
243  double dB = cras_client_get_system_max_capture_gain(client_) / 100.0;
244  return GetVolumeRatioFromDecibels(dB);
245}
246
247void CrasInputStream::SetVolume(double volume) {
248  DCHECK(client_);
249
250  // Convert from the passed volume ratio, to dB * 100.
251  double dB = GetDecibelsFromVolumeRatio(volume);
252  cras_client_set_system_capture_gain(client_, static_cast<long>(dB * 100.0));
253
254  // Update the AGC volume level based on the last setting above. Note that,
255  // the volume-level resolution is not infinite and it is therefore not
256  // possible to assume that the volume provided as input parameter can be
257  // used directly. Instead, a new query to the audio hardware is required.
258  // This method does nothing if AGC is disabled.
259  UpdateAgcVolume();
260}
261
262double CrasInputStream::GetVolume() {
263  if (!client_)
264    return 0.0;
265
266  long dB = cras_client_get_system_capture_gain(client_) / 100.0;
267  return GetVolumeRatioFromDecibels(dB);
268}
269
270double CrasInputStream::GetVolumeRatioFromDecibels(double dB) const {
271  return pow(10, dB / 20.0);
272}
273
274double CrasInputStream::GetDecibelsFromVolumeRatio(double volume_ratio) const {
275  return 20 * log10(volume_ratio);
276}
277
278}  // namespace media
279