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/internal.h"
28 #include "libavutil/log.h"
29 #include "libavutil/fifo.h"
30 #include "libavutil/opt.h"
31 #include "libavutil/time.h"
32 #include "libavcodec/avcodec.h"
33 #include "libavformat/avformat.h"
34 #include "libavformat/internal.h"
35 #include "timefilter.h"
36 #include "avdevice.h"
37
38 /**
39 * Size of the internal FIFO buffers as a number of audio packets
40 */
41 #define FIFO_PACKETS_NUM 16
42
43 typedef struct JackData {
44 AVClass *class;
45 jack_client_t * client;
46 int activated;
47 sem_t packet_count;
48 jack_nframes_t sample_rate;
49 jack_nframes_t buffer_size;
50 jack_port_t ** ports;
51 int nports;
52 TimeFilter * timefilter;
53 AVFifoBuffer * new_pkts;
54 AVFifoBuffer * filled_pkts;
55 int pkt_xrun;
56 int jack_xrun;
57 } JackData;
58
process_callback(jack_nframes_t nframes,void * arg)59 static int process_callback(jack_nframes_t nframes, void *arg)
60 {
61 /* Warning: this function runs in realtime. One mustn't allocate memory here
62 * or do any other thing that could block. */
63
64 int i, j;
65 JackData *self = arg;
66 float * buffer;
67 jack_nframes_t latency, cycle_delay;
68 AVPacket pkt;
69 float *pkt_data;
70 double cycle_time;
71
72 if (!self->client)
73 return 0;
74
75 /* The approximate delay since the hardware interrupt as a number of frames */
76 cycle_delay = jack_frames_since_cycle_start(self->client);
77
78 /* Retrieve filtered cycle time */
79 cycle_time = ff_timefilter_update(self->timefilter,
80 av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
81 self->buffer_size);
82
83 /* Check if an empty packet is available, and if there's enough space to send it back once filled */
84 if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
85 self->pkt_xrun = 1;
86 return 0;
87 }
88
89 /* Retrieve empty (but allocated) packet */
90 av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);
91
92 pkt_data = (float *) pkt.data;
93 latency = 0;
94
95 /* Copy and interleave audio data from the JACK buffer into the packet */
96 for (i = 0; i < self->nports; i++) {
97 jack_latency_range_t range;
98 jack_port_get_latency_range(self->ports[i], JackCaptureLatency, &range);
99 latency += range.max;
100 buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
101 for (j = 0; j < self->buffer_size; j++)
102 pkt_data[j * self->nports + i] = buffer[j];
103 }
104
105 /* Timestamp the packet with the cycle start time minus the average latency */
106 pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;
107
108 /* Send the now filled packet back, and increase packet counter */
109 av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
110 sem_post(&self->packet_count);
111
112 return 0;
113 }
114
shutdown_callback(void * arg)115 static void shutdown_callback(void *arg)
116 {
117 JackData *self = arg;
118 self->client = NULL;
119 }
120
xrun_callback(void * arg)121 static int xrun_callback(void *arg)
122 {
123 JackData *self = arg;
124 self->jack_xrun = 1;
125 ff_timefilter_reset(self->timefilter);
126 return 0;
127 }
128
supply_new_packets(JackData * self,AVFormatContext * context)129 static int supply_new_packets(JackData *self, AVFormatContext *context)
130 {
131 AVPacket pkt;
132 int test, pkt_size = self->buffer_size * self->nports * sizeof(float);
133
134 /* Supply the process callback with new empty packets, by filling the new
135 * packets FIFO buffer with as many packets as possible. process_callback()
136 * can't do this by itself, because it can't allocate memory in realtime. */
137 while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
138 if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
139 av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
140 return test;
141 }
142 av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
143 }
144 return 0;
145 }
146
start_jack(AVFormatContext * context)147 static int start_jack(AVFormatContext *context)
148 {
149 JackData *self = context->priv_data;
150 jack_status_t status;
151 int i, test;
152
153 /* Register as a JACK client, using the context url as client name. */
154 self->client = jack_client_open(context->url, JackNullOption, &status);
155 if (!self->client) {
156 av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");
157 return AVERROR(EIO);
158 }
159
160 sem_init(&self->packet_count, 0, 0);
161
162 self->sample_rate = jack_get_sample_rate(self->client);
163 self->ports = av_malloc_array(self->nports, sizeof(*self->ports));
164 if (!self->ports)
165 return AVERROR(ENOMEM);
166 self->buffer_size = jack_get_buffer_size(self->client);
167
168 /* Register JACK ports */
169 for (i = 0; i < self->nports; i++) {
170 char str[16];
171 snprintf(str, sizeof(str), "input_%d", i + 1);
172 self->ports[i] = jack_port_register(self->client, str,
173 JACK_DEFAULT_AUDIO_TYPE,
174 JackPortIsInput, 0);
175 if (!self->ports[i]) {
176 av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",
177 context->url, str);
178 jack_client_close(self->client);
179 return AVERROR(EIO);
180 }
181 }
182
183 /* Register JACK callbacks */
184 jack_set_process_callback(self->client, process_callback, self);
185 jack_on_shutdown(self->client, shutdown_callback, self);
186 jack_set_xrun_callback(self->client, xrun_callback, self);
187
188 /* Create time filter */
189 self->timefilter = ff_timefilter_new (1.0 / self->sample_rate, self->buffer_size, 1.5);
190 if (!self->timefilter) {
191 jack_client_close(self->client);
192 return AVERROR(ENOMEM);
193 }
194
195 /* Create FIFO buffers */
196 self->filled_pkts = av_fifo_alloc_array(FIFO_PACKETS_NUM, sizeof(AVPacket));
197 /* New packets FIFO with one extra packet for safety against underruns */
198 self->new_pkts = av_fifo_alloc_array((FIFO_PACKETS_NUM + 1), sizeof(AVPacket));
199 if (!self->new_pkts) {
200 jack_client_close(self->client);
201 return AVERROR(ENOMEM);
202 }
203 if ((test = supply_new_packets(self, context))) {
204 jack_client_close(self->client);
205 return test;
206 }
207
208 return 0;
209
210 }
211
free_pkt_fifo(AVFifoBuffer ** fifo)212 static void free_pkt_fifo(AVFifoBuffer **fifo)
213 {
214 AVPacket pkt;
215 while (av_fifo_size(*fifo)) {
216 av_fifo_generic_read(*fifo, &pkt, sizeof(pkt), NULL);
217 av_packet_unref(&pkt);
218 }
219 av_fifo_freep(fifo);
220 }
221
stop_jack(JackData * self)222 static void stop_jack(JackData *self)
223 {
224 if (self->client) {
225 if (self->activated)
226 jack_deactivate(self->client);
227 jack_client_close(self->client);
228 }
229 sem_destroy(&self->packet_count);
230 free_pkt_fifo(&self->new_pkts);
231 free_pkt_fifo(&self->filled_pkts);
232 av_freep(&self->ports);
233 ff_timefilter_destroy(self->timefilter);
234 }
235
audio_read_header(AVFormatContext * context)236 static int audio_read_header(AVFormatContext *context)
237 {
238 JackData *self = context->priv_data;
239 AVStream *stream;
240 int test;
241
242 if ((test = start_jack(context)))
243 return test;
244
245 stream = avformat_new_stream(context, NULL);
246 if (!stream) {
247 stop_jack(self);
248 return AVERROR(ENOMEM);
249 }
250
251 stream->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
252 #if HAVE_BIGENDIAN
253 stream->codecpar->codec_id = AV_CODEC_ID_PCM_F32BE;
254 #else
255 stream->codecpar->codec_id = AV_CODEC_ID_PCM_F32LE;
256 #endif
257 stream->codecpar->sample_rate = self->sample_rate;
258 stream->codecpar->channels = self->nports;
259
260 avpriv_set_pts_info(stream, 64, 1, 1000000); /* 64 bits pts in us */
261 return 0;
262 }
263
audio_read_packet(AVFormatContext * context,AVPacket * pkt)264 static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
265 {
266 JackData *self = context->priv_data;
267 struct timespec timeout = {0, 0};
268 int test;
269
270 /* Activate the JACK client on first packet read. Activating the JACK client
271 * means that process_callback() starts to get called at regular interval.
272 * If we activate it in audio_read_header(), we're actually reading audio data
273 * from the device before instructed to, and that may result in an overrun. */
274 if (!self->activated) {
275 if (!jack_activate(self->client)) {
276 self->activated = 1;
277 av_log(context, AV_LOG_INFO,
278 "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
279 self->sample_rate, self->buffer_size);
280 } else {
281 av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
282 return AVERROR(EIO);
283 }
284 }
285
286 /* Wait for a packet coming back from process_callback(), if one isn't available yet */
287 timeout.tv_sec = av_gettime() / 1000000 + 2;
288 if (sem_timedwait(&self->packet_count, &timeout)) {
289 if (errno == ETIMEDOUT) {
290 av_log(context, AV_LOG_ERROR,
291 "Input error: timed out when waiting for JACK process callback output\n");
292 } else {
293 char errbuf[128];
294 int ret = AVERROR(errno);
295 av_strerror(ret, errbuf, sizeof(errbuf));
296 av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
297 errbuf);
298 }
299 if (!self->client)
300 av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");
301
302 return AVERROR(EIO);
303 }
304
305 if (self->pkt_xrun) {
306 av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
307 self->pkt_xrun = 0;
308 }
309
310 if (self->jack_xrun) {
311 av_log(context, AV_LOG_WARNING, "JACK xrun\n");
312 self->jack_xrun = 0;
313 }
314
315 /* Retrieve the packet filled with audio data by process_callback() */
316 av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);
317
318 if ((test = supply_new_packets(self, context)))
319 return test;
320
321 return 0;
322 }
323
audio_read_close(AVFormatContext * context)324 static int audio_read_close(AVFormatContext *context)
325 {
326 JackData *self = context->priv_data;
327 stop_jack(self);
328 return 0;
329 }
330
331 #define OFFSET(x) offsetof(JackData, x)
332 static const AVOption options[] = {
333 { "channels", "Number of audio channels.", OFFSET(nports), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
334 { NULL },
335 };
336
337 static const AVClass jack_indev_class = {
338 .class_name = "JACK indev",
339 .item_name = av_default_item_name,
340 .option = options,
341 .version = LIBAVUTIL_VERSION_INT,
342 .category = AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
343 };
344
345 AVInputFormat ff_jack_demuxer = {
346 .name = "jack",
347 .long_name = NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
348 .priv_data_size = sizeof(JackData),
349 .read_header = audio_read_header,
350 .read_packet = audio_read_packet,
351 .read_close = audio_read_close,
352 .flags = AVFMT_NOFILE,
353 .priv_class = &jack_indev_class,
354 };
355