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 Libav.
   7  *
   8  * Libav 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  * Libav 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 Libav; 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 "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
  36 /**
  37  * Size of the internal FIFO buffers as a number of audio packets
  38  */
  39 #define FIFO_PACKETS_NUM 16
  40
  41 typedef struct {
  42     AVClass        *class;
  43     jack_client_t * client;
  44     int             activated;
  45     sem_t           packet_count;
  46     jack_nframes_t  sample_rate;
  47     jack_nframes_t  buffer_size;
  48     jack_port_t **  ports;
  49     int             nports;
  50     TimeFilter *    timefilter;
  51     AVFifoBuffer *  new_pkts;
  52     AVFifoBuffer *  filled_pkts;
  53     int             pkt_xrun;
  54     int             jack_xrun;
  55 } JackData;
  56
  57 static int process_callback(jack_nframes_t nframes, void *arg)
  58 {
  59     /* Warning: this function runs in realtime. One mustn't allocate memory here
  60      * or do any other thing that could block. */
  61
  62     int i, j;
  63     JackData *self = arg;
  64     float * buffer;
  65     jack_nframes_t latency, cycle_delay;
  66     AVPacket pkt;
  67     float *pkt_data;
  68     double cycle_time;
  69
  70     if (!self->client)
  71         return 0;
  72
  73     /* The approximate delay since the hardware interrupt as a number of frames */
  74     cycle_delay = jack_frames_since_cycle_start(self->client);
  75
  76     /* Retrieve filtered cycle time */
  77     cycle_time = ff_timefilter_update(self->timefilter,
  78                                       av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
  79                                       self->buffer_size);
  80
  81     /* Check if an empty packet is available, and if there's enough space to send it back once filled */
  82     if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
  83         self->pkt_xrun = 1;
  84         return 0;
  85     }
  86
  87     /* Retrieve empty (but allocated) packet */
  88     av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);
  89
  90     pkt_data  = (float *) pkt.data;
  91     latency   = 0;
  92
  93     /* Copy and interleave audio data from the JACK buffer into the packet */
  94     for (i = 0; i < self->nports; i++) {
  95     #if HAVE_JACK_PORT_GET_LATENCY_RANGE
  96         jack_latency_range_t range;
  97         jack_port_get_latency_range(self->ports[i], JackCaptureLatency, &range);
  98         latency += range.max;
  99     #else
 100         latency += jack_port_get_total_latency(self->client, self->ports[i]);
 101     #endif
 102         buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
 103         for (j = 0; j < self->buffer_size; j++)
 104             pkt_data[j * self->nports + i] = buffer[j];
 105     }
 106
 107     /* Timestamp the packet with the cycle start time minus the average latency */
 108     pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;
 109
 110     /* Send the now filled packet back, and increase packet counter */
 111     av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
 112     sem_post(&self->packet_count);
 113
 114     return 0;
 115 }
 116
 117 static void shutdown_callback(void *arg)
 118 {
 119     JackData *self = arg;
 120     self->client = NULL;
 121 }
 122
 123 static int xrun_callback(void *arg)
 124 {
 125     JackData *self = arg;
 126     self->jack_xrun = 1;
 127     ff_timefilter_reset(self->timefilter);
 128     return 0;
 129 }
 130
 131 static int supply_new_packets(JackData *self, AVFormatContext *context)
 132 {
 133     AVPacket pkt;
 134     int test, pkt_size = self->buffer_size * self->nports * sizeof(float);
 135
 136     /* Supply the process callback with new empty packets, by filling the new
 137      * packets FIFO buffer with as many packets as possible. process_callback()
 138      * can't do this by itself, because it can't allocate memory in realtime. */
 139     while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
 140         if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
 141             av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
 142             return test;
 143         }
 144         av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
 145     }
 146     return 0;
 147 }
 148
 149 static int start_jack(AVFormatContext *context)
 150 {
 151     JackData *self = context->priv_data;
 152     jack_status_t status;
 153     int i, test;
 154     double o, period;
 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(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     period            = (double) self->buffer_size / self->sample_rate;
 191     o                 = 2 * M_PI * 1.5 * period; /// bandwidth: 1.5Hz
 192     self->timefilter  = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o);
 193
 194     /* Create FIFO buffers */
 195     self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket));
 196     /* New packets FIFO with one extra packet for safety against underruns */
 197     self->new_pkts    = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket));
 198     if ((test = supply_new_packets(self, context))) {
 199         jack_client_close(self->client);
 200         return test;
 201     }
 202
 203     return 0;
 204
 205 }
 206
 207 static void free_pkt_fifo(AVFifoBuffer *fifo)
 208 {
 209     AVPacket pkt;
 210     while (av_fifo_size(fifo)) {
 211         av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL);
 212         av_free_packet(&pkt);
 213     }
 214     av_fifo_free(fifo);
 215 }
 216
 217 static void stop_jack(JackData *self)
 218 {
 219     if (self->client) {
 220         if (self->activated)
 221             jack_deactivate(self->client);
 222         jack_client_close(self->client);
 223     }
 224     sem_destroy(&self->packet_count);
 225     free_pkt_fifo(self->new_pkts);
 226     free_pkt_fifo(self->filled_pkts);
 227     av_freep(&self->ports);
 228     ff_timefilter_destroy(self->timefilter);
 229 }
 230
 231 static int audio_read_header(AVFormatContext *context)
 232 {
 233     JackData *self = context->priv_data;
 234     AVStream *stream;
 235     int test;
 236
 237     if ((test = start_jack(context)))
 238         return test;
 239
 240     stream = avformat_new_stream(context, NULL);
 241     if (!stream) {
 242         stop_jack(self);
 243         return AVERROR(ENOMEM);
 244     }
 245
 246     stream->codec->codec_type   = AVMEDIA_TYPE_AUDIO;
 247 #if HAVE_BIGENDIAN
 248     stream->codec->codec_id     = AV_CODEC_ID_PCM_F32BE;
 249 #else
 250     stream->codec->codec_id     = AV_CODEC_ID_PCM_F32LE;
 251 #endif
 252     stream->codec->sample_rate  = self->sample_rate;
 253     stream->codec->channels     = self->nports;
 254
 255     avpriv_set_pts_info(stream, 64, 1, 1000000);  /* 64 bits pts in us */
 256     return 0;
 257 }
 258
 259 static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
 260 {
 261     JackData *self = context->priv_data;
 262     struct timespec timeout = {0, 0};
 263     int test;
 264
 265     /* Activate the JACK client on first packet read. Activating the JACK client
 266      * means that process_callback() starts to get called at regular interval.
 267      * If we activate it in audio_read_header(), we're actually reading audio data
 268      * from the device before instructed to, and that may result in an overrun. */
 269     if (!self->activated) {
 270         if (!jack_activate(self->client)) {
 271             self->activated = 1;
 272             av_log(context, AV_LOG_INFO,
 273                    "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
 274                    self->sample_rate, self->buffer_size);
 275         } else {
 276             av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
 277             return AVERROR(EIO);
 278         }
 279     }
 280
 281     /* Wait for a packet coming back from process_callback(), if one isn't available yet */
 282     timeout.tv_sec = av_gettime() / 1000000 + 2;
 283     if (sem_timedwait(&self->packet_count, &timeout)) {
 284         if (errno == ETIMEDOUT) {
 285             av_log(context, AV_LOG_ERROR,
 286                    "Input error: timed out when waiting for JACK process callback output\n");
 287         } else {
 288             av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
 289                    strerror(errno));
 290         }
 291         if (!self->client)
 292             av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");
 293
 294         return AVERROR(EIO);
 295     }
 296
 297     if (self->pkt_xrun) {
 298         av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
 299         self->pkt_xrun = 0;
 300     }
 301
 302     if (self->jack_xrun) {
 303         av_log(context, AV_LOG_WARNING, "JACK xrun\n");
 304         self->jack_xrun = 0;
 305     }
 306
 307     /* Retrieve the packet filled with audio data by process_callback() */
 308     av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);
 309
 310     if ((test = supply_new_packets(self, context)))
 311         return test;
 312
 313     return 0;
 314 }
 315
 316 static int audio_read_close(AVFormatContext *context)
 317 {
 318     JackData *self = context->priv_data;
 319     stop_jack(self);
 320     return 0;
 321 }
 322
 323 #define OFFSET(x) offsetof(JackData, x)
 324 static const AVOption options[] = {
 325     { "channels", "Number of audio channels.", OFFSET(nports), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
 326     { NULL },
 327 };
 328
 329 static const AVClass jack_indev_class = {
 330     .class_name     = "JACK indev",
 331     .item_name      = av_default_item_name,
 332     .option         = options,
 333     .version        = LIBAVUTIL_VERSION_INT,
 334 };
 335
 336 AVInputFormat ff_jack_demuxer = {
 337     .name           = "jack",
 338     .long_name      = NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
 339     .priv_data_size = sizeof(JackData),
 340     .read_header    = audio_read_header,
 341     .read_packet    = audio_read_packet,
 342     .read_close     = audio_read_close,
 343     .flags          = AVFMT_NOFILE,
 344     .priv_class     = &jack_indev_class,
 345 };