libavdevice/jack_audio.c

   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
  23 #include "config.h"
  24 #include <semaphore.h>
  25 #include <jack/jack.h>
  26
  27 #include "libavutil/log.h"
  28 #include "libavutil/fifo.h"
  29 #include "libavcodec/avcodec.h"
  30 #include "libavformat/avformat.h"
  31 #include "libavformat/timefilter.h"
  32
  33 /**
  34  * Size of the internal FIFO buffers as a number of audio packets
  35  */
  36 #define FIFO_PACKETS_NUM 16
  37
  38 typedef struct {
  39     jack_client_t * client;
  40     int             activated;
  41     sem_t           packet_count;
  42     jack_nframes_t  sample_rate;
  43     jack_nframes_t  buffer_size;
  44     jack_port_t **  ports;
  45     int             nports;
  46     TimeFilter *    timefilter;
  47     AVFifoBuffer *  new_pkts;
  48     AVFifoBuffer *  filled_pkts;
  49     int             pkt_xrun;
  50     int             jack_xrun;
  51 } JackData;
  52
  53 static int process_callback(jack_nframes_t nframes, void *arg)
  54 {
  55     /* Warning: this function runs in realtime. One mustn't allocate memory here
  56      * or do any other thing that could block. */
  57
  58     int i, j;
  59     JackData *self = arg;
  60     float * buffer;
  61     jack_nframes_t latency, cycle_delay;
  62     AVPacket pkt;
  63     float *pkt_data;
  64     double cycle_time;
  65
  66     if (!self->client)
  67         return 0;
  68
  69     /* The approximate delay since the hardware interrupt as a number of frames */
  70     cycle_delay = jack_frames_since_cycle_start(self->client);
  71
  72     /* Retrieve filtered cycle time */
  73     cycle_time = ff_timefilter_update(self->timefilter,
  74                                       av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
  75                                       self->buffer_size);
  76
  77     /* Check if an empty packet is available, and if there's enough space to send it back once filled */
  78     if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
  79         self->pkt_xrun = 1;
  80         return 0;
  81     }
  82
  83     /* Retrieve empty (but allocated) packet */
  84     av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);
  85
  86     pkt_data  = (float *) pkt.data;
  87     latency   = 0;
  88
  89     /* Copy and interleave audio data from the JACK buffer into the packet */
  90     for (i = 0; i < self->nports; i++) {
  91         latency += jack_port_get_total_latency(self->client, self->ports[i]);
  92         buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
  93         for (j = 0; j < self->buffer_size; j++)
  94             pkt_data[j * self->nports + i] = buffer[j];
  95     }
  96
  97     /* Timestamp the packet with the cycle start time minus the average latency */
  98     pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;
  99
 100     /* Send the now filled packet back, and increase packet counter */
 101     av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
 102     sem_post(&self->packet_count);
 103
 104     return 0;
 105 }
 106
 107 static void shutdown_callback(void *arg)
 108 {
 109     JackData *self = arg;
 110     self->client = NULL;
 111 }
 112
 113 static int xrun_callback(void *arg)
 114 {
 115     JackData *self = arg;
 116     self->jack_xrun = 1;
 117     ff_timefilter_reset(self->timefilter);
 118     return 0;
 119 }
 120
 121 static int supply_new_packets(JackData *self, AVFormatContext *context)
 122 {
 123     AVPacket pkt;
 124     int test, pkt_size = self->buffer_size * self->nports * sizeof(float);
 125
 126     /* Supply the process callback with new empty packets, by filling the new
 127      * packets FIFO buffer with as many packets as possible. process_callback()
 128      * can't do this by itself, because it can't allocate memory in realtime. */
 129     while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
 130         if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
 131             av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
 132             return test;
 133         }
 134         av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
 135     }
 136     return 0;
 137 }
 138
 139 static int start_jack(AVFormatContext *context, AVFormatParameters *params)
 140 {
 141     JackData *self = context->priv_data;
 142     jack_status_t status;
 143     int i, test;
 144     double o, period;
 145
 146     /* Register as a JACK client, using the context filename as client name. */
 147     self->client = jack_client_open(context->filename, JackNullOption, &status);
 148     if (!self->client) {
 149         av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");
 150         return AVERROR(EIO);
 151     }
 152
 153     sem_init(&self->packet_count, 0, 0);
 154
 155     self->sample_rate = jack_get_sample_rate(self->client);
 156     self->nports      = params->channels;
 157     self->ports       = av_malloc(self->nports * sizeof(*self->ports));
 158     self->buffer_size = jack_get_buffer_size(self->client);
 159
 160     /* Register JACK ports */
 161     for (i = 0; i < self->nports; i++) {
 162         char str[16];
 163         snprintf(str, sizeof(str), "input_%d", i + 1);
 164         self->ports[i] = jack_port_register(self->client, str,
 165                                             JACK_DEFAULT_AUDIO_TYPE,
 166                                             JackPortIsInput, 0);
 167         if (!self->ports[i]) {
 168             av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",
 169                    context->filename, str);
 170             jack_client_close(self->client);
 171             return AVERROR(EIO);
 172         }
 173     }
 174
 175     /* Register JACK callbacks */
 176     jack_set_process_callback(self->client, process_callback, self);
 177     jack_on_shutdown(self->client, shutdown_callback, self);
 178     jack_set_xrun_callback(self->client, xrun_callback, self);
 179
 180     /* Create time filter */
 181     period            = (double) self->buffer_size / self->sample_rate;
 182     o                 = 2 * M_PI * 1.5 * period; /// bandwidth: 1.5Hz
 183     self->timefilter  = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o);
 184
 185     /* Create FIFO buffers */
 186     self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket));
 187     /* New packets FIFO with one extra packet for safety against underruns */
 188     self->new_pkts    = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket));
 189     if ((test = supply_new_packets(self, context))) {
 190         jack_client_close(self->client);
 191         return test;
 192     }
 193
 194     return 0;
 195
 196 }
 197
 198 static void free_pkt_fifo(AVFifoBuffer *fifo)
 199 {
 200     AVPacket pkt;
 201     while (av_fifo_size(fifo)) {
 202         av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL);
 203         av_free_packet(&pkt);
 204     }
 205     av_fifo_free(fifo);
 206 }
 207
 208 static void stop_jack(JackData *self)
 209 {
 210     if (self->client) {
 211         if (self->activated)
 212             jack_deactivate(self->client);
 213         jack_client_close(self->client);
 214     }
 215     sem_destroy(&self->packet_count);
 216     free_pkt_fifo(self->new_pkts);
 217     free_pkt_fifo(self->filled_pkts);
 218     av_freep(&self->ports);
 219     ff_timefilter_destroy(self->timefilter);
 220 }
 221
 222 static int audio_read_header(AVFormatContext *context, AVFormatParameters *params)
 223 {
 224     JackData *self = context->priv_data;
 225     AVStream *stream;
 226     int test;
 227
 228     if (params->sample_rate <= 0 || params->channels <= 0)
 229         return -1;
 230
 231     if ((test = start_jack(context, params)))
 232         return test;
 233
 234     stream = av_new_stream(context, 0);
 235     if (!stream) {
 236         stop_jack(self);
 237         return AVERROR(ENOMEM);
 238     }
 239
 240     stream->codec->codec_type   = CODEC_TYPE_AUDIO;
 241 #if HAVE_BIGENDIAN
 242     stream->codec->codec_id     = CODEC_ID_PCM_F32BE;
 243 #else
 244     stream->codec->codec_id     = CODEC_ID_PCM_F32LE;
 245 #endif
 246     stream->codec->sample_rate  = self->sample_rate;
 247     stream->codec->channels     = self->nports;
 248
 249     av_set_pts_info(stream, 64, 1, 1000000);  /* 64 bits pts in us */
 250     return 0;
 251 }
 252
 253 static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
 254 {
 255     JackData *self = context->priv_data;
 256     struct timespec timeout = {0, 0};
 257     int test;
 258
 259     /* Activate the JACK client on first packet read. Activating the JACK client
 260      * means that process_callback() starts to get called at regular interval.
 261      * If we activate it in audio_read_header(), we're actually reading audio data
 262      * from the device before instructed to, and that may result in an overrun. */
 263     if (!self->activated) {
 264         if (!jack_activate(self->client)) {
 265             self->activated = 1;
 266             av_log(context, AV_LOG_INFO,
 267                    "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
 268                    self->sample_rate, self->buffer_size);
 269         } else {
 270             av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
 271             return AVERROR(EIO);
 272         }
 273     }
 274
 275     /* Wait for a packet comming back from process_callback(), if one isn't available yet */
 276     timeout.tv_sec = av_gettime() / 1000000 + 2;
 277     if (sem_timedwait(&self->packet_count, &timeout)) {
 278         if (errno == ETIMEDOUT) {
 279             av_log(context, AV_LOG_ERROR,
 280                    "Input error: timed out when waiting for JACK process callback output\n");
 281         } else {
 282             av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
 283                    strerror(errno));
 284         }
 285         if (!self->client)
 286             av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");
 287
 288         return AVERROR(EIO);
 289     }
 290
 291     if (self->pkt_xrun) {
 292         av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
 293         self->pkt_xrun = 0;
 294     }
 295
 296     if (self->jack_xrun) {
 297         av_log(context, AV_LOG_WARNING, "JACK xrun\n");
 298         self->jack_xrun = 0;
 299     }
 300
 301     /* Retrieve the packet filled with audio data by process_callback() */
 302     av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);
 303
 304     if ((test = supply_new_packets(self, context)))
 305         return test;
 306
 307     return 0;
 308 }
 309
 310 static int audio_read_close(AVFormatContext *context)
 311 {
 312     JackData *self = context->priv_data;
 313     stop_jack(self);
 314     return 0;
 315 }
 316
 317 AVInputFormat jack_demuxer = {
 318     "jack",
 319     NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
 320     sizeof(JackData),
 321     NULL,
 322     audio_read_header,
 323     audio_read_packet,
 324     audio_read_close,
 325     .flags = AVFMT_NOFILE,
 326 };