Libav
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00001 /* 00002 * JACK Audio Connection Kit input device 00003 * Copyright (c) 2009 Samalyse 00004 * Author: Olivier Guilyardi <olivier samalyse com> 00005 * 00006 * This file is part of FFmpeg. 00007 * 00008 * FFmpeg is free software; you can redistribute it and/or 00009 * modify it under the terms of the GNU Lesser General Public 00010 * License as published by the Free Software Foundation; either 00011 * version 2.1 of the License, or (at your option) any later version. 00012 * 00013 * FFmpeg is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00016 * Lesser General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU Lesser General Public 00019 * License along with FFmpeg; if not, write to the Free Software 00020 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00021 */ 00022 00023 #include "config.h" 00024 #include <semaphore.h> 00025 #include <jack/jack.h> 00026 00027 #include "libavutil/log.h" 00028 #include "libavutil/fifo.h" 00029 #include "libavcodec/avcodec.h" 00030 #include "libavformat/avformat.h" 00031 #include "libavformat/timefilter.h" 00032 00036 #define FIFO_PACKETS_NUM 16 00037 00038 typedef struct { 00039 jack_client_t * client; 00040 int activated; 00041 sem_t packet_count; 00042 jack_nframes_t sample_rate; 00043 jack_nframes_t buffer_size; 00044 jack_port_t ** ports; 00045 int nports; 00046 TimeFilter * timefilter; 00047 AVFifoBuffer * new_pkts; 00048 AVFifoBuffer * filled_pkts; 00049 int pkt_xrun; 00050 int jack_xrun; 00051 } JackData; 00052 00053 static int process_callback(jack_nframes_t nframes, void *arg) 00054 { 00055 /* Warning: this function runs in realtime. One mustn't allocate memory here 00056 * or do any other thing that could block. */ 00057 00058 int i, j; 00059 JackData *self = arg; 00060 float * buffer; 00061 jack_nframes_t latency, cycle_delay; 00062 AVPacket pkt; 00063 float *pkt_data; 00064 double cycle_time; 00065 00066 if (!self->client) 00067 return 0; 00068 00069 /* The approximate delay since the hardware interrupt as a number of frames */ 00070 cycle_delay = jack_frames_since_cycle_start(self->client); 00071 00072 /* Retrieve filtered cycle time */ 00073 cycle_time = ff_timefilter_update(self->timefilter, 00074 av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate, 00075 self->buffer_size); 00076 00077 /* Check if an empty packet is available, and if there's enough space to send it back once filled */ 00078 if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) { 00079 self->pkt_xrun = 1; 00080 return 0; 00081 } 00082 00083 /* Retrieve empty (but allocated) packet */ 00084 av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL); 00085 00086 pkt_data = (float *) pkt.data; 00087 latency = 0; 00088 00089 /* Copy and interleave audio data from the JACK buffer into the packet */ 00090 for (i = 0; i < self->nports; i++) { 00091 latency += jack_port_get_total_latency(self->client, self->ports[i]); 00092 buffer = jack_port_get_buffer(self->ports[i], self->buffer_size); 00093 for (j = 0; j < self->buffer_size; j++) 00094 pkt_data[j * self->nports + i] = buffer[j]; 00095 } 00096 00097 /* Timestamp the packet with the cycle start time minus the average latency */ 00098 pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0; 00099 00100 /* Send the now filled packet back, and increase packet counter */ 00101 av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL); 00102 sem_post(&self->packet_count); 00103 00104 return 0; 00105 } 00106 00107 static void shutdown_callback(void *arg) 00108 { 00109 JackData *self = arg; 00110 self->client = NULL; 00111 } 00112 00113 static int xrun_callback(void *arg) 00114 { 00115 JackData *self = arg; 00116 self->jack_xrun = 1; 00117 ff_timefilter_reset(self->timefilter); 00118 return 0; 00119 } 00120 00121 static int supply_new_packets(JackData *self, AVFormatContext *context) 00122 { 00123 AVPacket pkt; 00124 int test, pkt_size = self->buffer_size * self->nports * sizeof(float); 00125 00126 /* Supply the process callback with new empty packets, by filling the new 00127 * packets FIFO buffer with as many packets as possible. process_callback() 00128 * can't do this by itself, because it can't allocate memory in realtime. */ 00129 while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) { 00130 if ((test = av_new_packet(&pkt, pkt_size)) < 0) { 00131 av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size); 00132 return test; 00133 } 00134 av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL); 00135 } 00136 return 0; 00137 } 00138 00139 static int start_jack(AVFormatContext *context, AVFormatParameters *params) 00140 { 00141 JackData *self = context->priv_data; 00142 jack_status_t status; 00143 int i, test; 00144 double o, period; 00145 00146 /* Register as a JACK client, using the context filename as client name. */ 00147 self->client = jack_client_open(context->filename, JackNullOption, &status); 00148 if (!self->client) { 00149 av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n"); 00150 return AVERROR(EIO); 00151 } 00152 00153 sem_init(&self->packet_count, 0, 0); 00154 00155 self->sample_rate = jack_get_sample_rate(self->client); 00156 self->nports = params->channels; 00157 self->ports = av_malloc(self->nports * sizeof(*self->ports)); 00158 self->buffer_size = jack_get_buffer_size(self->client); 00159 00160 /* Register JACK ports */ 00161 for (i = 0; i < self->nports; i++) { 00162 char str[16]; 00163 snprintf(str, sizeof(str), "input_%d", i + 1); 00164 self->ports[i] = jack_port_register(self->client, str, 00165 JACK_DEFAULT_AUDIO_TYPE, 00166 JackPortIsInput, 0); 00167 if (!self->ports[i]) { 00168 av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n", 00169 context->filename, str); 00170 jack_client_close(self->client); 00171 return AVERROR(EIO); 00172 } 00173 } 00174 00175 /* Register JACK callbacks */ 00176 jack_set_process_callback(self->client, process_callback, self); 00177 jack_on_shutdown(self->client, shutdown_callback, self); 00178 jack_set_xrun_callback(self->client, xrun_callback, self); 00179 00180 /* Create time filter */ 00181 period = (double) self->buffer_size / self->sample_rate; 00182 o = 2 * M_PI * 1.5 * period; 00183 self->timefilter = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o); 00184 00185 /* Create FIFO buffers */ 00186 self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket)); 00187 /* New packets FIFO with one extra packet for safety against underruns */ 00188 self->new_pkts = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket)); 00189 if ((test = supply_new_packets(self, context))) { 00190 jack_client_close(self->client); 00191 return test; 00192 } 00193 00194 return 0; 00195 00196 } 00197 00198 static void free_pkt_fifo(AVFifoBuffer *fifo) 00199 { 00200 AVPacket pkt; 00201 while (av_fifo_size(fifo)) { 00202 av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL); 00203 av_free_packet(&pkt); 00204 } 00205 av_fifo_free(fifo); 00206 } 00207 00208 static void stop_jack(JackData *self) 00209 { 00210 if (self->client) { 00211 if (self->activated) 00212 jack_deactivate(self->client); 00213 jack_client_close(self->client); 00214 } 00215 sem_destroy(&self->packet_count); 00216 free_pkt_fifo(self->new_pkts); 00217 free_pkt_fifo(self->filled_pkts); 00218 av_freep(&self->ports); 00219 ff_timefilter_destroy(self->timefilter); 00220 } 00221 00222 static int audio_read_header(AVFormatContext *context, AVFormatParameters *params) 00223 { 00224 JackData *self = context->priv_data; 00225 AVStream *stream; 00226 int test; 00227 00228 if (params->sample_rate <= 0 || params->channels <= 0) 00229 return -1; 00230 00231 if ((test = start_jack(context, params))) 00232 return test; 00233 00234 stream = av_new_stream(context, 0); 00235 if (!stream) { 00236 stop_jack(self); 00237 return AVERROR(ENOMEM); 00238 } 00239 00240 stream->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00241 #if HAVE_BIGENDIAN 00242 stream->codec->codec_id = CODEC_ID_PCM_F32BE; 00243 #else 00244 stream->codec->codec_id = CODEC_ID_PCM_F32LE; 00245 #endif 00246 stream->codec->sample_rate = self->sample_rate; 00247 stream->codec->channels = self->nports; 00248 00249 av_set_pts_info(stream, 64, 1, 1000000); /* 64 bits pts in us */ 00250 return 0; 00251 } 00252 00253 static int audio_read_packet(AVFormatContext *context, AVPacket *pkt) 00254 { 00255 JackData *self = context->priv_data; 00256 struct timespec timeout = {0, 0}; 00257 int test; 00258 00259 /* Activate the JACK client on first packet read. Activating the JACK client 00260 * means that process_callback() starts to get called at regular interval. 00261 * If we activate it in audio_read_header(), we're actually reading audio data 00262 * from the device before instructed to, and that may result in an overrun. */ 00263 if (!self->activated) { 00264 if (!jack_activate(self->client)) { 00265 self->activated = 1; 00266 av_log(context, AV_LOG_INFO, 00267 "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n", 00268 self->sample_rate, self->buffer_size); 00269 } else { 00270 av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n"); 00271 return AVERROR(EIO); 00272 } 00273 } 00274 00275 /* Wait for a packet comming back from process_callback(), if one isn't available yet */ 00276 timeout.tv_sec = av_gettime() / 1000000 + 2; 00277 if (sem_timedwait(&self->packet_count, &timeout)) { 00278 if (errno == ETIMEDOUT) { 00279 av_log(context, AV_LOG_ERROR, 00280 "Input error: timed out when waiting for JACK process callback output\n"); 00281 } else { 00282 av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n", 00283 strerror(errno)); 00284 } 00285 if (!self->client) 00286 av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n"); 00287 00288 return AVERROR(EIO); 00289 } 00290 00291 if (self->pkt_xrun) { 00292 av_log(context, AV_LOG_WARNING, "Audio packet xrun\n"); 00293 self->pkt_xrun = 0; 00294 } 00295 00296 if (self->jack_xrun) { 00297 av_log(context, AV_LOG_WARNING, "JACK xrun\n"); 00298 self->jack_xrun = 0; 00299 } 00300 00301 /* Retrieve the packet filled with audio data by process_callback() */ 00302 av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL); 00303 00304 if ((test = supply_new_packets(self, context))) 00305 return test; 00306 00307 return 0; 00308 } 00309 00310 static int audio_read_close(AVFormatContext *context) 00311 { 00312 JackData *self = context->priv_data; 00313 stop_jack(self); 00314 return 0; 00315 } 00316 00317 AVInputFormat jack_demuxer = { 00318 "jack", 00319 NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"), 00320 sizeof(JackData), 00321 NULL, 00322 audio_read_header, 00323 audio_read_packet, 00324 audio_read_close, 00325 .flags = AVFMT_NOFILE, 00326 };