1 // Copyright 2013 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/alsa/audio_manager_alsa.h"
6
7 #include <stddef.h>
8
9 #include "base/command_line.h"
10 #include "base/logging.h"
11 #include "base/memory/free_deleter.h"
12 #include "base/metrics/histogram.h"
13 #include "base/stl_util.h"
14 #include "media/audio/audio_device_description.h"
15 #include "media/audio/audio_output_dispatcher.h"
16 #include "media/audio/alsa/alsa_input.h"
17 #include "media/audio/alsa/alsa_output.h"
18 #include "media/audio/alsa/alsa_wrapper.h"
19 #if defined(USE_PULSEAUDIO)
20 #include "media/audio/pulse/audio_manager_pulse.h"
21 #endif
22 #include "media/base/audio_parameters.h"
23 #include "media/base/channel_layout.h"
24 #include "media/base/limits.h"
25 #include "media/base/media_switches.h"
26
27 namespace media {
28
29 // Maximum number of output streams that can be open simultaneously.
30 static const int kMaxOutputStreams = 50;
31
32 // Default sample rate for input and output streams.
33 static const int kDefaultSampleRate = 48000;
34
35 // Since "default", "pulse" and "dmix" devices are virtual devices mapped to
36 // real devices, we remove them from the list to avoiding duplicate counting.
37 // In addition, note that we support no more than 2 channels for recording,
38 // hence surround devices are not stored in the list.
39 static const char* const kInvalidAudioInputDevices[] = {
40 "default", "dmix", "null", "pulse", "surround",
41 };
42
AudioManagerAlsa(std::unique_ptr<AudioThread> audio_thread,AudioLogFactory * audio_log_factory)43 AudioManagerAlsa::AudioManagerAlsa(std::unique_ptr<AudioThread> audio_thread,
44 AudioLogFactory* audio_log_factory)
45 : AudioManagerBase(std::move(audio_thread), audio_log_factory),
46 wrapper_(new AlsaWrapper()) {
47 SetMaxOutputStreamsAllowed(kMaxOutputStreams);
48 }
49
50 AudioManagerAlsa::~AudioManagerAlsa() = default;
51
HasAudioOutputDevices()52 bool AudioManagerAlsa::HasAudioOutputDevices() {
53 return HasAnyAlsaAudioDevice(kStreamPlayback);
54 }
55
HasAudioInputDevices()56 bool AudioManagerAlsa::HasAudioInputDevices() {
57 return HasAnyAlsaAudioDevice(kStreamCapture);
58 }
59
GetAudioInputDeviceNames(AudioDeviceNames * device_names)60 void AudioManagerAlsa::GetAudioInputDeviceNames(
61 AudioDeviceNames* device_names) {
62 DCHECK(device_names->empty());
63 GetAlsaAudioDevices(kStreamCapture, device_names);
64 }
65
GetAudioOutputDeviceNames(AudioDeviceNames * device_names)66 void AudioManagerAlsa::GetAudioOutputDeviceNames(
67 AudioDeviceNames* device_names) {
68 DCHECK(device_names->empty());
69 GetAlsaAudioDevices(kStreamPlayback, device_names);
70 }
71
GetInputStreamParameters(const std::string & device_id)72 AudioParameters AudioManagerAlsa::GetInputStreamParameters(
73 const std::string& device_id) {
74 static const int kDefaultInputBufferSize = 1024;
75
76 return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
77 CHANNEL_LAYOUT_STEREO, kDefaultSampleRate,
78 kDefaultInputBufferSize);
79 }
80
GetName()81 const char* AudioManagerAlsa::GetName() {
82 return "ALSA";
83 }
84
GetAlsaAudioDevices(StreamType type,AudioDeviceNames * device_names)85 void AudioManagerAlsa::GetAlsaAudioDevices(StreamType type,
86 AudioDeviceNames* device_names) {
87 // Constants specified by the ALSA API for device hints.
88 static const char kPcmInterfaceName[] = "pcm";
89 int card = -1;
90
91 // Loop through the sound cards to get ALSA device hints.
92 #if defined(OS_LINUX)
93 while (!wrapper_->CardNext(&card) && card >= 0) {
94 #endif
95 void** hints = NULL;
96 int error = wrapper_->DeviceNameHint(card, kPcmInterfaceName, &hints);
97 if (!error) {
98 GetAlsaDevicesInfo(type, hints, device_names);
99
100 // Destroy the hints now that we're done with it.
101 wrapper_->DeviceNameFreeHint(hints);
102 } else {
103 DLOG(WARNING) << "GetAlsaAudioDevices: unable to get device hints: "
104 << wrapper_->StrError(error);
105 }
106 #if defined(OS_LINUX)
107 }
108 #endif
109 }
110
GetAlsaDevicesInfo(AudioManagerAlsa::StreamType type,void ** hints,AudioDeviceNames * device_names)111 void AudioManagerAlsa::GetAlsaDevicesInfo(AudioManagerAlsa::StreamType type,
112 void** hints,
113 AudioDeviceNames* device_names) {
114 static const char kIoHintName[] = "IOID";
115 static const char kNameHintName[] = "NAME";
116 static const char kDescriptionHintName[] = "DESC";
117
118 const char* unwanted_device_type = UnwantedDeviceTypeWhenEnumerating(type);
119
120 for (void** hint_iter = hints; *hint_iter != NULL; hint_iter++) {
121 // Only examine devices of the right type. Valid values are
122 // "Input", "Output", and NULL which means both input and output.
123 std::unique_ptr<char, base::FreeDeleter> io(
124 wrapper_->DeviceNameGetHint(*hint_iter, kIoHintName));
125 if (io != NULL && strcmp(unwanted_device_type, io.get()) == 0)
126 continue;
127
128 // Found a device, prepend the default device since we always want
129 // it to be on the top of the list for all platforms. And there is
130 // no duplicate counting here since it is only done if the list is
131 // still empty. Note, pulse has exclusively opened the default
132 // device, so we must open the device via the "default" moniker.
133 if (device_names->empty())
134 device_names->push_front(AudioDeviceName::CreateDefault());
135
136 // Get the unique device name for the device.
137 std::unique_ptr<char, base::FreeDeleter> unique_device_name(
138 wrapper_->DeviceNameGetHint(*hint_iter, kNameHintName));
139
140 // Find out if the device is available.
141 if (IsAlsaDeviceAvailable(type, unique_device_name.get())) {
142 // Get the description for the device.
143 std::unique_ptr<char, base::FreeDeleter> desc(
144 wrapper_->DeviceNameGetHint(*hint_iter, kDescriptionHintName));
145
146 AudioDeviceName name;
147 name.unique_id = unique_device_name.get();
148 if (desc) {
149 // Use the more user friendly description as name.
150 // Replace '\n' with '-'.
151 char* pret = strchr(desc.get(), '\n');
152 if (pret)
153 *pret = '-';
154 name.device_name = desc.get();
155 } else {
156 // Virtual devices don't necessarily have descriptions.
157 // Use their names instead.
158 name.device_name = unique_device_name.get();
159 }
160
161 // Store the device information.
162 device_names->push_back(name);
163 }
164 }
165 }
166
167 // static
IsAlsaDeviceAvailable(AudioManagerAlsa::StreamType type,const char * device_name)168 bool AudioManagerAlsa::IsAlsaDeviceAvailable(
169 AudioManagerAlsa::StreamType type,
170 const char* device_name) {
171 if (!device_name)
172 return false;
173
174 // We do prefix matches on the device name to see whether to include
175 // it or not.
176 if (type == kStreamCapture) {
177 // Check if the device is in the list of invalid devices.
178 for (size_t i = 0; i < base::size(kInvalidAudioInputDevices); ++i) {
179 if (strncmp(kInvalidAudioInputDevices[i], device_name,
180 strlen(kInvalidAudioInputDevices[i])) == 0)
181 return false;
182 }
183 return true;
184 }
185
186 DCHECK_EQ(kStreamPlayback, type);
187 // We prefer the device type that maps straight to hardware but
188 // goes through software conversion if needed (e.g. incompatible
189 // sample rate).
190 // TODO(joi): Should we prefer "hw" instead?
191 #ifdef OS_LINUX
192 static const char kDeviceTypeDesired[] = "plughw";
193 #else
194 static const char kDeviceTypeDesired[] = "plug";
195 #endif
196 return strncmp(kDeviceTypeDesired, device_name,
197 base::size(kDeviceTypeDesired) - 1) == 0;
198 }
199
200 // static
UnwantedDeviceTypeWhenEnumerating(AudioManagerAlsa::StreamType wanted_type)201 const char* AudioManagerAlsa::UnwantedDeviceTypeWhenEnumerating(
202 AudioManagerAlsa::StreamType wanted_type) {
203 return wanted_type == kStreamPlayback ? "Input" : "Output";
204 }
205
HasAnyAlsaAudioDevice(AudioManagerAlsa::StreamType stream)206 bool AudioManagerAlsa::HasAnyAlsaAudioDevice(
207 AudioManagerAlsa::StreamType stream) {
208 static const char kPcmInterfaceName[] = "pcm";
209 static const char kIoHintName[] = "IOID";
210 void** hints = NULL;
211 bool has_device = false;
212 int card = -1;
213
214 // Loop through the sound cards.
215 // Don't use snd_device_name_hint(-1,..) since there is a access violation
216 // inside this ALSA API with libasound.so.2.0.0.
217 #if defined(OS_LINUX)
218 while (!wrapper_->CardNext(&card) && (card >= 0) && !has_device) {
219 #endif
220 int error = wrapper_->DeviceNameHint(card, kPcmInterfaceName, &hints);
221 if (!error) {
222 for (void** hint_iter = hints; *hint_iter != NULL; hint_iter++) {
223 // Only examine devices that are |stream| capable. Valid values are
224 // "Input", "Output", and NULL which means both input and output.
225 std::unique_ptr<char, base::FreeDeleter> io(
226 wrapper_->DeviceNameGetHint(*hint_iter, kIoHintName));
227 const char* unwanted_type = UnwantedDeviceTypeWhenEnumerating(stream);
228 if (io != NULL && strcmp(unwanted_type, io.get()) == 0)
229 continue; // Wrong type, skip the device.
230
231 // Found an input device.
232 has_device = true;
233 break;
234 }
235
236 // Destroy the hints now that we're done with it.
237 wrapper_->DeviceNameFreeHint(hints);
238 hints = NULL;
239 } else {
240 DLOG(WARNING) << "HasAnyAudioDevice: unable to get device hints: "
241 << wrapper_->StrError(error);
242 }
243 #if defined(OS_LINUX)
244 }
245 #endif
246
247 return has_device;
248 }
249
MakeLinearOutputStream(const AudioParameters & params,const LogCallback & log_callback)250 AudioOutputStream* AudioManagerAlsa::MakeLinearOutputStream(
251 const AudioParameters& params,
252 const LogCallback& log_callback) {
253 DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
254 return MakeOutputStream(params);
255 }
256
MakeLowLatencyOutputStream(const AudioParameters & params,const std::string & device_id,const LogCallback & log_callback)257 AudioOutputStream* AudioManagerAlsa::MakeLowLatencyOutputStream(
258 const AudioParameters& params,
259 const std::string& device_id,
260 const LogCallback& log_callback) {
261 DLOG_IF(ERROR, !device_id.empty()) << "Not implemented!";
262 DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
263 return MakeOutputStream(params);
264 }
265
MakeLinearInputStream(const AudioParameters & params,const std::string & device_id,const LogCallback & log_callback)266 AudioInputStream* AudioManagerAlsa::MakeLinearInputStream(
267 const AudioParameters& params,
268 const std::string& device_id,
269 const LogCallback& log_callback) {
270 DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
271 return MakeInputStream(params, device_id);
272 }
273
MakeLowLatencyInputStream(const AudioParameters & params,const std::string & device_id,const LogCallback & log_callback)274 AudioInputStream* AudioManagerAlsa::MakeLowLatencyInputStream(
275 const AudioParameters& params,
276 const std::string& device_id,
277 const LogCallback& log_callback) {
278 DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
279 return MakeInputStream(params, device_id);
280 }
281
GetPreferredOutputStreamParameters(const std::string & output_device_id,const AudioParameters & input_params)282 AudioParameters AudioManagerAlsa::GetPreferredOutputStreamParameters(
283 const std::string& output_device_id,
284 const AudioParameters& input_params) {
285 // TODO(tommi): Support |output_device_id|.
286 DLOG_IF(ERROR, !output_device_id.empty()) << "Not implemented!";
287 static const int kDefaultOutputBufferSize = 2048;
288 ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
289 int sample_rate = kDefaultSampleRate;
290 int buffer_size = kDefaultOutputBufferSize;
291 if (input_params.IsValid()) {
292 // Some clients, such as WebRTC, have a more limited use case and work
293 // acceptably with a smaller buffer size. The check below allows clients
294 // which want to try a smaller buffer size on Linux to do so.
295 // TODO(dalecurtis): This should include bits per channel and channel layout
296 // eventually.
297 sample_rate = input_params.sample_rate();
298 channel_layout = input_params.channel_layout();
299 buffer_size = std::min(input_params.frames_per_buffer(), buffer_size);
300 }
301
302 int user_buffer_size = GetUserBufferSize();
303 if (user_buffer_size)
304 buffer_size = user_buffer_size;
305
306 return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
307 sample_rate, buffer_size);
308 }
309
MakeOutputStream(const AudioParameters & params)310 AudioOutputStream* AudioManagerAlsa::MakeOutputStream(
311 const AudioParameters& params) {
312 std::string device_name = AlsaPcmOutputStream::kAutoSelectDevice;
313 if (base::CommandLine::ForCurrentProcess()->HasSwitch(
314 switches::kAlsaOutputDevice)) {
315 device_name = base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
316 switches::kAlsaOutputDevice);
317 }
318 return new AlsaPcmOutputStream(device_name, params, wrapper_.get(), this);
319 }
320
MakeInputStream(const AudioParameters & params,const std::string & device_id)321 AudioInputStream* AudioManagerAlsa::MakeInputStream(
322 const AudioParameters& params, const std::string& device_id) {
323 std::string device_name =
324 (device_id == AudioDeviceDescription::kDefaultDeviceId)
325 ? AlsaPcmInputStream::kAutoSelectDevice
326 : device_id;
327 if (base::CommandLine::ForCurrentProcess()->HasSwitch(
328 switches::kAlsaInputDevice)) {
329 device_name = base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
330 switches::kAlsaInputDevice);
331 }
332
333 return new AlsaPcmInputStream(this, device_name, params, wrapper_.get());
334 }
335
336 } // namespace media
337