jack_audio.c 10 KB

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  1. /*
  2. * JACK Audio Connection Kit input device
  3. * Copyright (c) 2009 Samalyse
  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. */
  22. #include "config.h"
  23. #include <semaphore.h>
  24. #include <jack/jack.h>
  25. #include "libavutil/log.h"
  26. #include "libavutil/fifo.h"
  27. #include "libavcodec/avcodec.h"
  28. #include "libavformat/timefilter.h"
  29. #include "avdevice.h"
  30. /**
  31. * Size of the internal FIFO buffers as a number of audio packets
  32. */
  33. #define FIFO_PACKETS_NUM 16
  34. typedef struct {
  35. jack_client_t * client;
  36. int activated;
  37. sem_t packet_count;
  38. jack_nframes_t sample_rate;
  39. jack_nframes_t buffer_size;
  40. jack_port_t ** ports;
  41. int nports;
  42. TimeFilter * timefilter;
  43. AVFifoBuffer * new_pkts;
  44. AVFifoBuffer * filled_pkts;
  45. int pkt_xrun;
  46. int jack_xrun;
  47. } JackData;
  48. static int process_callback(jack_nframes_t nframes, void *arg)
  49. {
  50. /* Warning: this function runs in realtime. One mustn't allocate memory here
  51. * or do any other thing that could block. */
  52. int i, j;
  53. JackData *self = arg;
  54. float * buffer;
  55. jack_nframes_t latency, cycle_delay;
  56. AVPacket pkt;
  57. float *pkt_data;
  58. double cycle_time;
  59. if (!self->client)
  60. return 0;
  61. /* The approximate delay since the hardware interrupt as a number of frames */
  62. cycle_delay = jack_frames_since_cycle_start(self->client);
  63. /* Retrieve filtered cycle time */
  64. cycle_time = ff_timefilter_update(self->timefilter,
  65. av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
  66. self->buffer_size);
  67. /* Check if an empty packet is available, and if there's enough space to send it back once filled */
  68. if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
  69. self->pkt_xrun = 1;
  70. return 0;
  71. }
  72. /* Retrieve empty (but allocated) packet */
  73. av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);
  74. pkt_data = (float *) pkt.data;
  75. latency = 0;
  76. /* Copy and interleave audio data from the JACK buffer into the packet */
  77. for (i = 0; i < self->nports; i++) {
  78. latency += jack_port_get_total_latency(self->client, self->ports[i]);
  79. buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
  80. for (j = 0; j < self->buffer_size; j++)
  81. pkt_data[j * self->nports + i] = buffer[j];
  82. }
  83. /* Timestamp the packet with the cycle start time minus the average latency */
  84. pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;
  85. /* Send the now filled packet back, and increase packet counter */
  86. av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
  87. sem_post(&self->packet_count);
  88. return 0;
  89. }
  90. static void shutdown_callback(void *arg)
  91. {
  92. JackData *self = arg;
  93. self->client = NULL;
  94. }
  95. static int xrun_callback(void *arg)
  96. {
  97. JackData *self = arg;
  98. self->jack_xrun = 1;
  99. ff_timefilter_reset(self->timefilter);
  100. return 0;
  101. }
  102. static int supply_new_packets(JackData *self, AVFormatContext *context)
  103. {
  104. AVPacket pkt;
  105. int test, pkt_size = self->buffer_size * self->nports * sizeof(float);
  106. /* Supply the process callback with new empty packets, by filling the new
  107. * packets FIFO buffer with as many packets as possible. process_callback()
  108. * can't do this by itself, because it can't allocate memory in realtime. */
  109. while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
  110. if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
  111. av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
  112. return test;
  113. }
  114. av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
  115. }
  116. return 0;
  117. }
  118. static int start_jack(AVFormatContext *context, AVFormatParameters *params)
  119. {
  120. JackData *self = context->priv_data;
  121. jack_status_t status;
  122. int i, test;
  123. double o, period;
  124. /* Register as a JACK client, using the context filename as client name. */
  125. self->client = jack_client_open(context->filename, JackNullOption, &status);
  126. if (!self->client) {
  127. av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");
  128. return AVERROR(EIO);
  129. }
  130. sem_init(&self->packet_count, 0, 0);
  131. self->sample_rate = jack_get_sample_rate(self->client);
  132. self->nports = params->channels;
  133. self->ports = av_malloc(self->nports * sizeof(*self->ports));
  134. self->buffer_size = jack_get_buffer_size(self->client);
  135. /* Register JACK ports */
  136. for (i = 0; i < self->nports; i++) {
  137. char str[16];
  138. snprintf(str, sizeof(str), "input_%d", i + 1);
  139. self->ports[i] = jack_port_register(self->client, str,
  140. JACK_DEFAULT_AUDIO_TYPE,
  141. JackPortIsInput, 0);
  142. if (!self->ports[i]) {
  143. av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",
  144. context->filename, str);
  145. jack_client_close(self->client);
  146. return AVERROR(EIO);
  147. }
  148. }
  149. /* Register JACK callbacks */
  150. jack_set_process_callback(self->client, process_callback, self);
  151. jack_on_shutdown(self->client, shutdown_callback, self);
  152. jack_set_xrun_callback(self->client, xrun_callback, self);
  153. /* Create time filter */
  154. period = (double) self->buffer_size / self->sample_rate;
  155. o = 2 * M_PI * 1.5 * period; /// bandwidth: 1.5Hz
  156. self->timefilter = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o);
  157. /* Create FIFO buffers */
  158. self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket));
  159. /* New packets FIFO with one extra packet for safety against underruns */
  160. self->new_pkts = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket));
  161. if ((test = supply_new_packets(self, context))) {
  162. jack_client_close(self->client);
  163. return test;
  164. }
  165. return 0;
  166. }
  167. static void free_pkt_fifo(AVFifoBuffer *fifo)
  168. {
  169. AVPacket pkt;
  170. while (av_fifo_size(fifo)) {
  171. av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL);
  172. av_free_packet(&pkt);
  173. }
  174. av_fifo_free(fifo);
  175. }
  176. static void stop_jack(JackData *self)
  177. {
  178. if (self->client) {
  179. if (self->activated)
  180. jack_deactivate(self->client);
  181. jack_client_close(self->client);
  182. }
  183. sem_destroy(&self->packet_count);
  184. free_pkt_fifo(self->new_pkts);
  185. free_pkt_fifo(self->filled_pkts);
  186. av_freep(&self->ports);
  187. ff_timefilter_destroy(self->timefilter);
  188. }
  189. static int audio_read_header(AVFormatContext *context, AVFormatParameters *params)
  190. {
  191. JackData *self = context->priv_data;
  192. AVStream *stream;
  193. int test;
  194. if (params->sample_rate <= 0 || params->channels <= 0)
  195. return -1;
  196. if ((test = start_jack(context, params)))
  197. return test;
  198. stream = av_new_stream(context, 0);
  199. if (!stream) {
  200. stop_jack(self);
  201. return AVERROR(ENOMEM);
  202. }
  203. stream->codec->codec_type = AVMEDIA_TYPE_AUDIO;
  204. #if HAVE_BIGENDIAN
  205. stream->codec->codec_id = CODEC_ID_PCM_F32BE;
  206. #else
  207. stream->codec->codec_id = CODEC_ID_PCM_F32LE;
  208. #endif
  209. stream->codec->sample_rate = self->sample_rate;
  210. stream->codec->channels = self->nports;
  211. av_set_pts_info(stream, 64, 1, 1000000); /* 64 bits pts in us */
  212. return 0;
  213. }
  214. static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
  215. {
  216. JackData *self = context->priv_data;
  217. struct timespec timeout = {0, 0};
  218. int test;
  219. /* Activate the JACK client on first packet read. Activating the JACK client
  220. * means that process_callback() starts to get called at regular interval.
  221. * If we activate it in audio_read_header(), we're actually reading audio data
  222. * from the device before instructed to, and that may result in an overrun. */
  223. if (!self->activated) {
  224. if (!jack_activate(self->client)) {
  225. self->activated = 1;
  226. av_log(context, AV_LOG_INFO,
  227. "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
  228. self->sample_rate, self->buffer_size);
  229. } else {
  230. av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
  231. return AVERROR(EIO);
  232. }
  233. }
  234. /* Wait for a packet comming back from process_callback(), if one isn't available yet */
  235. timeout.tv_sec = av_gettime() / 1000000 + 2;
  236. if (sem_timedwait(&self->packet_count, &timeout)) {
  237. if (errno == ETIMEDOUT) {
  238. av_log(context, AV_LOG_ERROR,
  239. "Input error: timed out when waiting for JACK process callback output\n");
  240. } else {
  241. av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
  242. strerror(errno));
  243. }
  244. if (!self->client)
  245. av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");
  246. return AVERROR(EIO);
  247. }
  248. if (self->pkt_xrun) {
  249. av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
  250. self->pkt_xrun = 0;
  251. }
  252. if (self->jack_xrun) {
  253. av_log(context, AV_LOG_WARNING, "JACK xrun\n");
  254. self->jack_xrun = 0;
  255. }
  256. /* Retrieve the packet filled with audio data by process_callback() */
  257. av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);
  258. if ((test = supply_new_packets(self, context)))
  259. return test;
  260. return 0;
  261. }
  262. static int audio_read_close(AVFormatContext *context)
  263. {
  264. JackData *self = context->priv_data;
  265. stop_jack(self);
  266. return 0;
  267. }
  268. AVInputFormat ff_jack_demuxer = {
  269. "jack",
  270. NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
  271. sizeof(JackData),
  272. NULL,
  273. audio_read_header,
  274. audio_read_packet,
  275. audio_read_close,
  276. .flags = AVFMT_NOFILE,
  277. };