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 38typedef 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 53static 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 107static void shutdown_callback(void *arg) 108{ 109 JackData *self = arg; 110 self->client = NULL; 111} 112 113static 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 121static 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 139static 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 198static 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 208static 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 222static 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 = AVMEDIA_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 253static 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 310static int audio_read_close(AVFormatContext *context) 311{ 312 JackData *self = context->priv_data; 313 stop_jack(self); 314 return 0; 315} 316 317AVInputFormat 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}; 327