FFmpeg: libavdevice/jack_audio.c Source File

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libavdevice

jack_audio.c

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1 /*

2 * JACK Audio Connection Kit input device

4 * Author: Olivier Guilyardi <olivier samalyse com>

5 *

6 * This file is part of FFmpeg.

7 *

8 * FFmpeg is free software; you can redistribute it and/or

9 * modify it under the terms of the GNU Lesser General Public

10 * License as published by the Free Software Foundation; either

11 * version 2.1 of the License, or (at your option) any later version.

12 *

13 * FFmpeg is distributed in the hope that it will be useful,

14 * but WITHOUT ANY WARRANTY; without even the implied warranty of

15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

16 * Lesser General Public License for more details.

17 *

18 * You should have received a copy of the GNU Lesser General Public

19 * License along with FFmpeg; if not, write to the Free Software

20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

21 */

23 #include "config.h"

24 #include <semaphore.h>

25 #include <jack/jack.h>

27 #include "libavutil/log.h"

28 #include "libavutil/fifo.h"

29 #include "libavutil/opt.h"

30 #include "libavutil/time.h"

31 #include "libavcodec/avcodec.h"

32 #include "libavformat/avformat.h"

33 #include "libavformat/internal.h"

34 #include "timefilter.h"

35 #include "avdevice.h"

37 /**

38 * Size of the internal FIFO buffers as a number of audio packets

39 */

40 #define FIFO_PACKETS_NUM 16

42 typedef struct {

43 AVClass *class;

44 jack_client_t * client;

45 int activated;

46 sem_t packet_count;

47 jack_nframes_t sample_rate;

48 jack_nframes_t buffer_size;

49 jack_port_t ** ports;

50 int nports;

51 TimeFilter * timefilter;

52 AVFifoBuffer * new_pkts;

53 AVFifoBuffer * filled_pkts;

54 int pkt_xrun;

55 int jack_xrun;

56 } JackData;

58 static int process_callback(jack_nframes_t nframes, void *arg)

59 {

60 /* Warning: this function runs in realtime. One mustn't allocate memory here

61 * or do any other thing that could block. */

63 int i, j;

64 JackData *self = arg;

65 float * buffer;

66 jack_nframes_t latency, cycle_delay;

67 AVPacket pkt;

68 float *pkt_data;

69 double cycle_time;

71 if (!self->client)

72 return 0;

74 /* The approximate delay since the hardware interrupt as a number of frames */

75 cycle_delay = jack_frames_since_cycle_start(self->client);

77 /* Retrieve filtered cycle time */

78 cycle_time = ff_timefilter_update(self->timefilter,

79 av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,

80 self->buffer_size);

82 /* Check if an empty packet is available, and if there's enough space to send it back once filled */

83 if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {

84 self->pkt_xrun = 1;

85 return 0;

86 }

88 /* Retrieve empty (but allocated) packet */

89 av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);

91 pkt_data = (float *) pkt.data;

92 latency = 0;

94 /* Copy and interleave audio data from the JACK buffer into the packet */

95 for (i = 0; i < self->nports; i++) {

96 #if HAVE_JACK_PORT_GET_LATENCY_RANGE

97 jack_latency_range_t range;

98 jack_port_get_latency_range(self->ports[i], JackCaptureLatency, &range);

99 latency += range.max;

100 #else

101 latency += jack_port_get_total_latency(self->client, self->ports[i]);

102 #endif

103 buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);

104 for (j = 0; j < self->buffer_size; j++)

105 pkt_data[j * self->nports + i] = buffer[j];

106 }

107

108 /* Timestamp the packet with the cycle start time minus the average latency */

109 pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;

110

111 /* Send the now filled packet back, and increase packet counter */

112 av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);

113 sem_post(&self->packet_count);

114

115 return 0;

116 }

117

118 static void shutdown_callback(void *arg)

119 {

120 JackData *self = arg;

121 self->client = NULL;

122 }

123

124 static int xrun_callback(void *arg)

125 {

126 JackData *self = arg;

127 self->jack_xrun = 1;

128 ff_timefilter_reset(self->timefilter);

129 return 0;

130 }

131

132 static int supply_new_packets(JackData *self, AVFormatContext *context)

133 {

134 AVPacket pkt;

135 int test, pkt_size = self->buffer_size * self->nports * sizeof(float);

136

137 /* Supply the process callback with new empty packets, by filling the new

138 * packets FIFO buffer with as many packets as possible. process_callback()

139 * can't do this by itself, because it can't allocate memory in realtime. */

140 while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {

141 if ((test = av_new_packet(&pkt, pkt_size)) < 0) {

142 av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);

143 return test;

144 }

145 av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);

146 }

147 return 0;

148 }

149

150 static int start_jack(AVFormatContext *context)

151 {

152 JackData *self = context->priv_data;

153 jack_status_t status;

154 int i, test;

155

156 /* Register as a JACK client, using the context filename as client name. */

157 self->client = jack_client_open(context->filename, JackNullOption, &status);

158 if (!self->client) {

159 av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");

160 return AVERROR(EIO);

161 }

162

163 sem_init(&self->packet_count, 0, 0);

164

165 self->sample_rate = jack_get_sample_rate(self->client);

166 self->ports = av_malloc_array(self->nports, sizeof(*self->ports));

167 self->buffer_size = jack_get_buffer_size(self->client);

168

169 /* Register JACK ports */

170 for (i = 0; i < self->nports; i++) {

171 char str[16];

172 snprintf(str, sizeof(str), "input_%d", i + 1);

173 self->ports[i] = jack_port_register(self->client, str,

174 JACK_DEFAULT_AUDIO_TYPE,

175 JackPortIsInput, 0);

176 if (!self->ports[i]) {

177 av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",

178 context->filename, str);

179 jack_client_close(self->client);

180 return AVERROR(EIO);

181 }

182 }

183

184 /* Register JACK callbacks */

185 jack_set_process_callback(self->client, process_callback, self);

186 jack_on_shutdown(self->client, shutdown_callback, self);

187 jack_set_xrun_callback(self->client, xrun_callback, self);

188

189 /* Create time filter */

190 self->timefilter = ff_timefilter_new (1.0 / self->sample_rate, self->buffer_size, 1.5);

191 if (!self->timefilter) {

192 jack_client_close(self->client);

193 return AVERROR(ENOMEM);

194 }

195

196 /* Create FIFO buffers */

197 self->filled_pkts = av_fifo_alloc_array(FIFO_PACKETS_NUM, sizeof(AVPacket));

198 /* New packets FIFO with one extra packet for safety against underruns */

199 self->new_pkts = av_fifo_alloc_array((FIFO_PACKETS_NUM + 1), sizeof(AVPacket));

200 if ((test = supply_new_packets(self, context))) {

201 jack_client_close(self->client);

202 return test;

203 }

204

205 return 0;

206

207 }

208

209 static void free_pkt_fifo(AVFifoBuffer **fifo)

210 {

211 AVPacket pkt;

212 while (av_fifo_size(*fifo)) {

213 av_fifo_generic_read(*fifo, &pkt, sizeof(pkt), NULL);

214 av_free_packet(&pkt);

215 }

216 av_fifo_freep(fifo);

217 }

218

219 static void stop_jack(JackData *self)

220 {

221 if (self->client) {

222 if (self->activated)

223 jack_deactivate(self->client);

224 jack_client_close(self->client);

225 }

226 sem_destroy(&self->packet_count);

227 free_pkt_fifo(&self->new_pkts);

228 free_pkt_fifo(&self->filled_pkts);

229 av_freep(&self->ports);

230 ff_timefilter_destroy(self->timefilter);

231 }

232

233 static int audio_read_header(AVFormatContext *context)

234 {

235 JackData *self = context->priv_data;

236 AVStream *stream;

237 int test;

238

239 if ((test = start_jack(context)))

240 return test;

241

242 stream = avformat_new_stream(context, NULL);

243 if (!stream) {

244 stop_jack(self);

245 return AVERROR(ENOMEM);

246 }

247

248 stream->codec->codec_type = AVMEDIA_TYPE_AUDIO;

249 #if HAVE_BIGENDIAN

250 stream->codec->codec_id = AV_CODEC_ID_PCM_F32BE;

251 #else

252 stream->codec->codec_id = AV_CODEC_ID_PCM_F32LE;

253 #endif

254 stream->codec->sample_rate = self->sample_rate;

255 stream->codec->channels = self->nports;

256

257 avpriv_set_pts_info(stream, 64, 1, 1000000); /* 64 bits pts in us */

258 return 0;

259 }

260

261 static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)

262 {

263 JackData *self = context->priv_data;

264 struct timespec timeout = {0, 0};

265 int test;

266

267 /* Activate the JACK client on first packet read. Activating the JACK client

268 * means that process_callback() starts to get called at regular interval.

269 * If we activate it in audio_read_header(), we're actually reading audio data

270 * from the device before instructed to, and that may result in an overrun. */

271 if (!self->activated) {

272 if (!jack_activate(self->client)) {

273 self->activated = 1;

274 av_log(context, AV_LOG_INFO,

275 "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",

276 self->sample_rate, self->buffer_size);

277 } else {

278 av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");

279 return AVERROR(EIO);

280 }

281 }

282

283 /* Wait for a packet coming back from process_callback(), if one isn't available yet */

284 timeout.tv_sec = av_gettime() / 1000000 + 2;

285 if (sem_timedwait(&self->packet_count, &timeout)) {

286 if (errno == ETIMEDOUT) {

287 av_log(context, AV_LOG_ERROR,

288 "Input error: timed out when waiting for JACK process callback output\n");

289 } else {

290 av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",

291 strerror(errno));

292 }

293 if (!self->client)

294 av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");

295

296 return AVERROR(EIO);

297 }

298

299 if (self->pkt_xrun) {

300 av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");

301 self->pkt_xrun = 0;

302 }

303

304 if (self->jack_xrun) {

305 av_log(context, AV_LOG_WARNING, "JACK xrun\n");

306 self->jack_xrun = 0;

307 }

308

309 /* Retrieve the packet filled with audio data by process_callback() */

310 av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);

311

312 if ((test = supply_new_packets(self, context)))

313 return test;

314

315 return 0;

316 }

317

318 static int audio_read_close(AVFormatContext *context)

319 {

320 JackData *self = context->priv_data;

321 stop_jack(self);

322 return 0;

323 }

324

325 #define OFFSET(x) offsetof(JackData, x)

326 static const AVOption options[] = {

327 { "channels", "Number of audio channels.", OFFSET(nports), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },

328 { NULL },

329 };

330

331 static const AVClass jack_indev_class = {

332 .class_name = "JACK indev",

333 .item_name = av_default_item_name,

334 .option = options,

335 .version = LIBAVUTIL_VERSION_INT,

336 .category = AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,

337 };

338

339 AVInputFormat ff_jack_demuxer = {

340 .name = "jack",

341 .long_name = NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),

342 .priv_data_size = sizeof(JackData),

343 .read_header = audio_read_header,

344 .read_packet = audio_read_packet,

345 .read_close = audio_read_close,

346 .flags = AVFMT_NOFILE,

347 .priv_class = &jack_indev_class,

348 };

Generated on Sun Jul 20 2014 23:05:59 for FFmpeg by doxygen 1.8.2