FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
jack.c
Go to the documentation of this file.
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;
48  jack_nframes_t sample_rate;
49  jack_nframes_t buffer_size;
50  jack_port_t ** ports;
51  int nports;
55  int pkt_xrun;
56  int jack_xrun;
57 } JackData;
58 
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 
115 static void shutdown_callback(void *arg)
116 {
117  JackData *self = arg;
118  self->client = NULL;
119 }
120 
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 
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 
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 
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 
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 
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 
252 #if HAVE_BIGENDIAN
254 #else
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 
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 
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,
343 };
344 
346  .name = "jack",
347  .long_name = NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
348  .priv_data_size = sizeof(JackData),
352  .flags = AVFMT_NOFILE,
353  .priv_class = &jack_indev_class,
354 };
jack_client_t * client
Definition: jack.c:45
#define NULL
Definition: coverity.c:32
int pkt_xrun
Definition: jack.c:55
AVOption.
Definition: opt.h:246
void ff_timefilter_destroy(TimeFilter *self)
Free all resources associated with the filter.
Definition: timefilter.c:62
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
void ff_timefilter_reset(TimeFilter *self)
Reset the filter.
Definition: timefilter.c:67
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4882
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3900
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
int jack_xrun
Definition: jack.c:56
static AVPacket pkt
#define sem_t
Definition: semaphore.h:25
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int(*func)(void *, void *, int))
Feed data from a user-supplied callback to an AVFifoBuffer.
Definition: fifo.c:122
Definition: jack.c:43
Format I/O context.
Definition: avformat.h:1351
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
Opaque type representing a time filter state.
Definition: timefilter.c:30
AVOptions.
static int supply_new_packets(JackData *self, AVFormatContext *context)
Definition: jack.c:129
int av_fifo_space(const AVFifoBuffer *f)
Return the amount of space in bytes in the AVFifoBuffer, that is the amount of data you can write int...
Definition: fifo.c:82
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4455
AVInputFormat ff_jack_demuxer
Definition: jack.c:345
AVFifoBuffer * filled_pkts
Definition: jack.c:54
static void free_pkt_fifo(AVFifoBuffer **fifo)
Definition: jack.c:212
jack_port_t ** ports
Definition: jack.c:50
#define sem_init
Definition: semaphore.h:40
uint8_t * data
Definition: avcodec.h:1445
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
#define FIFO_PACKETS_NUM
Size of the internal FIFO buffers as a number of audio packets.
Definition: jack.c:41
#define sem_post(psem)
Definition: semaphore.h:26
#define av_log(a,...)
Main libavdevice API header.
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
int nports
Definition: jack.c:51
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
char * url
input or output URL.
Definition: avformat.h:1447
int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void(*func)(void *, void *, int))
Feed data from an AVFifoBuffer to a user-supplied callback.
Definition: fifo.c:213
static const AVOption options[]
Definition: jack.c:332
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3896
const char * arg
Definition: jacosubdec.c:66
#define sem_destroy(psem)
Definition: semaphore.h:29
static int start_jack(AVFormatContext *context)
Definition: jack.c:147
int activated
Definition: jack.c:46
common internal API header
sem_t packet_count
Definition: jack.c:47
#define sem_timedwait(psem, val)
Definition: semaphore.h:28
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
int64_t av_gettime(void)
Get the current time in microseconds.
Definition: time.c:39
Stream structure.
Definition: avformat.h:874
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
TimeFilter * ff_timefilter_new(double time_base, double period, double bandwidth)
Create a new Delay Locked Loop time filter.
Definition: timefilter.c:46
Libavcodec external API header.
static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
Definition: jack.c:264
int av_fifo_size(const AVFifoBuffer *f)
Return the amount of data in bytes in the AVFifoBuffer, that is the amount of data you can read from ...
Definition: fifo.c:77
static void test(const char *pattern, const char *host)
Definition: noproxy.c:23
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:598
jack_nframes_t sample_rate
Definition: jack.c:48
a very simple circular buffer FIFO implementation
Describe the class of an AVClass context structure.
Definition: log.h:67
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:277
#define snprintf
Definition: snprintf.h:34
#define OFFSET(x)
Definition: jack.c:331
static int process_callback(jack_nframes_t nframes, void *arg)
Definition: jack.c:59
static void shutdown_callback(void *arg)
Definition: jack.c:115
#define flags(name, subs,...)
Definition: cbs_av1.c:596
AVFifoBuffer * av_fifo_alloc_array(size_t nmemb, size_t size)
Initialize an AVFifoBuffer.
Definition: fifo.c:49
static int audio_read_close(AVFormatContext *context)
Definition: jack.c:324
int av_strerror(int errnum, char *errbuf, size_t errbuf_size)
Put a description of the AVERROR code errnum in errbuf.
Definition: error.c:105
int sample_rate
Audio only.
Definition: avcodec.h:4010
TimeFilter * timefilter
Definition: jack.c:52
Main libavformat public API header.
double ff_timefilter_update(TimeFilter *self, double system_time, double period)
Update the filter.
Definition: timefilter.c:72
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:465
static int audio_read_header(AVFormatContext *context)
Definition: jack.c:236
static int xrun_callback(void *arg)
Definition: jack.c:121
static const AVClass jack_indev_class
Definition: jack.c:337
void * priv_data
Format private data.
Definition: avformat.h:1379
int channels
Audio only.
Definition: avcodec.h:4006
#define av_freep(p)
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:647
void av_fifo_freep(AVFifoBuffer **f)
Free an AVFifoBuffer and reset pointer to NULL.
Definition: fifo.c:63
jack_nframes_t buffer_size
Definition: jack.c:49
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1021
#define av_malloc_array(a, b)
This structure stores compressed data.
Definition: avcodec.h:1422
static void stop_jack(JackData *self)
Definition: jack.c:222
AVFifoBuffer * new_pkts
Definition: jack.c:53
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1438
for(j=16;j >0;--j)
GLuint buffer
Definition: opengl_enc.c:102