Libav
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 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/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 
40 #define FIFO_PACKETS_NUM 16
41 
42 typedef struct JackData {
43  AVClass *class;
44  jack_client_t * client;
45  int activated;
47  jack_nframes_t sample_rate;
48  jack_nframes_t buffer_size;
49  jack_port_t ** ports;
50  int nports;
54  int pkt_xrun;
55  int jack_xrun;
56 } JackData;
57 
58 static int process_callback(jack_nframes_t nframes, void *arg)
59 {
60  /* Warning: this function runs in realtime. One mustn't allocate memory here
61  * or do any other thing that could block. */
62 
63  int i, j;
64  JackData *self = arg;
65  float * buffer;
66  jack_nframes_t latency, cycle_delay;
67  AVPacket pkt;
68  float *pkt_data;
69  double cycle_time;
70 
71  if (!self->client)
72  return 0;
73 
74  /* The approximate delay since the hardware interrupt as a number of frames */
75  cycle_delay = jack_frames_since_cycle_start(self->client);
76 
77  /* Retrieve filtered cycle time */
78  cycle_time = ff_timefilter_update(self->timefilter,
79  av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
80  self->buffer_size);
81 
82  /* Check if an empty packet is available, and if there's enough space to send it back once filled */
83  if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
84  self->pkt_xrun = 1;
85  return 0;
86  }
87 
88  /* Retrieve empty (but allocated) packet */
89  av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);
90 
91  pkt_data = (float *) pkt.data;
92  latency = 0;
93 
94  /* Copy and interleave audio data from the JACK buffer into the packet */
95  for (i = 0; i < self->nports; i++) {
96  #if HAVE_JACK_PORT_GET_LATENCY_RANGE
97  jack_latency_range_t range;
98  jack_port_get_latency_range(self->ports[i], JackCaptureLatency, &range);
99  latency += range.max;
100  #else
101  latency += jack_port_get_total_latency(self->client, self->ports[i]);
102  #endif
103  buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
104  for (j = 0; j < self->buffer_size; j++)
105  pkt_data[j * self->nports + i] = buffer[j];
106  }
107 
108  /* Timestamp the packet with the cycle start time minus the average latency */
109  pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;
110 
111  /* Send the now filled packet back, and increase packet counter */
112  av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
113  sem_post(&self->packet_count);
114 
115  return 0;
116 }
117 
118 static void shutdown_callback(void *arg)
119 {
120  JackData *self = arg;
121  self->client = NULL;
122 }
123 
124 static int xrun_callback(void *arg)
125 {
126  JackData *self = arg;
127  self->jack_xrun = 1;
128  ff_timefilter_reset(self->timefilter);
129  return 0;
130 }
131 
132 static int supply_new_packets(JackData *self, AVFormatContext *context)
133 {
134  AVPacket pkt;
135  int test, pkt_size = self->buffer_size * self->nports * sizeof(float);
136 
137  /* Supply the process callback with new empty packets, by filling the new
138  * packets FIFO buffer with as many packets as possible. process_callback()
139  * can't do this by itself, because it can't allocate memory in realtime. */
140  while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
141  if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
142  av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
143  return test;
144  }
145  av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
146  }
147  return 0;
148 }
149 
150 static int start_jack(AVFormatContext *context)
151 {
152  JackData *self = context->priv_data;
153  jack_status_t status;
154  int i, test;
155  double o, period;
156 
157  /* Register as a JACK client, using the context filename as client name. */
158  self->client = jack_client_open(context->filename, JackNullOption, &status);
159  if (!self->client) {
160  av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");
161  return AVERROR(EIO);
162  }
163 
164  sem_init(&self->packet_count, 0, 0);
165 
166  self->sample_rate = jack_get_sample_rate(self->client);
167  self->ports = av_malloc(self->nports * sizeof(*self->ports));
168  if (!self->ports)
169  return AVERROR(ENOMEM);
170  self->buffer_size = jack_get_buffer_size(self->client);
171 
172  /* Register JACK ports */
173  for (i = 0; i < self->nports; i++) {
174  char str[16];
175  snprintf(str, sizeof(str), "input_%d", i + 1);
176  self->ports[i] = jack_port_register(self->client, str,
177  JACK_DEFAULT_AUDIO_TYPE,
178  JackPortIsInput, 0);
179  if (!self->ports[i]) {
180  av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",
181  context->filename, str);
182  jack_client_close(self->client);
183  return AVERROR(EIO);
184  }
185  }
186 
187  /* Register JACK callbacks */
188  jack_set_process_callback(self->client, process_callback, self);
189  jack_on_shutdown(self->client, shutdown_callback, self);
190  jack_set_xrun_callback(self->client, xrun_callback, self);
191 
192  /* Create time filter */
193  period = (double) self->buffer_size / self->sample_rate;
194  o = 2 * M_PI * 1.5 * period;
195  self->timefilter = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o);
196  if (!self->timefilter) {
197  jack_client_close(self->client);
198  return AVERROR(ENOMEM);
199  }
200 
201  /* Create FIFO buffers */
202  self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket));
203  /* New packets FIFO with one extra packet for safety against underruns */
204  self->new_pkts = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket));
205  if (!self->new_pkts) {
206  jack_client_close(self->client);
207  return AVERROR(ENOMEM);
208  }
209  if ((test = supply_new_packets(self, context))) {
210  jack_client_close(self->client);
211  return test;
212  }
213 
214  return 0;
215 
216 }
217 
218 static void free_pkt_fifo(AVFifoBuffer *fifo)
219 {
220  AVPacket pkt;
221  while (av_fifo_size(fifo)) {
222  av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL);
223  av_packet_unref(&pkt);
224  }
225  av_fifo_free(fifo);
226 }
227 
228 static void stop_jack(JackData *self)
229 {
230  if (self->client) {
231  if (self->activated)
232  jack_deactivate(self->client);
233  jack_client_close(self->client);
234  }
235  sem_destroy(&self->packet_count);
236  free_pkt_fifo(self->new_pkts);
237  free_pkt_fifo(self->filled_pkts);
238  av_freep(&self->ports);
239  ff_timefilter_destroy(self->timefilter);
240 }
241 
242 static int audio_read_header(AVFormatContext *context)
243 {
244  JackData *self = context->priv_data;
245  AVStream *stream;
246  int test;
247 
248  if ((test = start_jack(context)))
249  return test;
250 
251  stream = avformat_new_stream(context, NULL);
252  if (!stream) {
253  stop_jack(self);
254  return AVERROR(ENOMEM);
255  }
256 
258 #if HAVE_BIGENDIAN
260 #else
262 #endif
263  stream->codecpar->sample_rate = self->sample_rate;
264  stream->codecpar->channels = self->nports;
265 
266  avpriv_set_pts_info(stream, 64, 1, 1000000); /* 64 bits pts in us */
267  return 0;
268 }
269 
270 static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
271 {
272  JackData *self = context->priv_data;
273  struct timespec timeout = {0, 0};
274  int test;
275 
276  /* Activate the JACK client on first packet read. Activating the JACK client
277  * means that process_callback() starts to get called at regular interval.
278  * If we activate it in audio_read_header(), we're actually reading audio data
279  * from the device before instructed to, and that may result in an overrun. */
280  if (!self->activated) {
281  if (!jack_activate(self->client)) {
282  self->activated = 1;
283  av_log(context, AV_LOG_INFO,
284  "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
285  self->sample_rate, self->buffer_size);
286  } else {
287  av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
288  return AVERROR(EIO);
289  }
290  }
291 
292  /* Wait for a packet coming back from process_callback(), if one isn't available yet */
293  timeout.tv_sec = av_gettime() / 1000000 + 2;
294  if (sem_timedwait(&self->packet_count, &timeout)) {
295  if (errno == ETIMEDOUT) {
296  av_log(context, AV_LOG_ERROR,
297  "Input error: timed out when waiting for JACK process callback output\n");
298  } else {
299  char errbuf[128];
300  int ret = AVERROR(errno);
301  av_strerror(ret, errbuf, sizeof(errbuf));
302  av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
303  errbuf);
304  }
305  if (!self->client)
306  av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");
307 
308  return AVERROR(EIO);
309  }
310 
311  if (self->pkt_xrun) {
312  av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
313  self->pkt_xrun = 0;
314  }
315 
316  if (self->jack_xrun) {
317  av_log(context, AV_LOG_WARNING, "JACK xrun\n");
318  self->jack_xrun = 0;
319  }
320 
321  /* Retrieve the packet filled with audio data by process_callback() */
322  av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);
323 
324  if ((test = supply_new_packets(self, context)))
325  return test;
326 
327  return 0;
328 }
329 
330 static int audio_read_close(AVFormatContext *context)
331 {
332  JackData *self = context->priv_data;
333  stop_jack(self);
334  return 0;
335 }
336 
337 #define OFFSET(x) offsetof(JackData, x)
338 static const AVOption options[] = {
339  { "channels", "Number of audio channels.", OFFSET(nports), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
340  { NULL },
341 };
342 
343 static const AVClass jack_indev_class = {
344  .class_name = "JACK indev",
345  .item_name = av_default_item_name,
346  .option = options,
347  .version = LIBAVUTIL_VERSION_INT,
348 };
349 
351  .name = "jack",
352  .long_name = NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
353  .priv_data_size = sizeof(JackData),
357  .flags = AVFMT_NOFILE,
358  .priv_class = &jack_indev_class,
359 };
jack_client_t * client
Definition: jack.c:44
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
int pkt_xrun
Definition: jack.c:54
AVOption.
Definition: opt.h:234
void ff_timefilter_destroy(TimeFilter *self)
Free all resources associated with the filter.
Definition: timefilter.c:55
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:130
void ff_timefilter_reset(TimeFilter *self)
Reset the filter.
Definition: timefilter.c:60
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:2986
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3483
av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (%s)\, len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt), use_generic ? ac->func_descr_generic :ac->func_descr)
int jack_xrun
Definition: jack.c:55
#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:84
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:202
Definition: jack.c:42
Format I/O context.
Definition: avformat.h:940
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:39
static char buffer[20]
Definition: seek.c:32
Opaque type representing a time filter state.
Definition: timefilter.c:30
AVOptions.
static int supply_new_packets(JackData *self, AVFormatContext *context)
Definition: jack.c:132
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2648
AVInputFormat ff_jack_demuxer
Definition: jack.c:350
AVFifoBuffer * filled_pkts
Definition: jack.c:53
jack_port_t ** ports
Definition: jack.c:49
#define sem_init
Definition: semaphore.h:40
uint8_t * data
Definition: avcodec.h:1346
static int flags
Definition: log.c:50
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
void av_fifo_free(AVFifoBuffer *f)
Free an AVFifoBuffer.
Definition: fifo.c:38
#define FIFO_PACKETS_NUM
Size of the internal FIFO buffers as a number of audio packets.
Definition: jack.c:40
#define sem_post(psem)
Definition: semaphore.h:26
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:84
int nports
Definition: jack.c:50
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:124
#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:148
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:107
static const AVOption options[]
Definition: jack.c:338
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3479
#define sem_destroy(psem)
Definition: semaphore.h:29
static int start_jack(AVFormatContext *context)
Definition: jack.c:150
int activated
Definition: jack.c:45
common internal API header
char filename[1024]
input or output filename
Definition: avformat.h:1016
sem_t packet_count
Definition: jack.c:46
LIBAVUTIL_VERSION_INT
Definition: eval.c:55
#define sem_timedwait(psem, val)
Definition: semaphore.h:28
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:546
int64_t av_gettime(void)
Get the current time in microseconds.
Definition: time.c:40
Stream structure.
Definition: avformat.h:705
NULL
Definition: eval.c:55
int av_fifo_space(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:57
#define AV_LOG_INFO
Standard information.
Definition: log.h:135
Libavcodec external API header.
static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
Definition: jack.c:270
av_default_item_name
Definition: dnxhdenc.c:55
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:347
jack_nframes_t sample_rate
Definition: jack.c:47
a very simple circular buffer FIFO implementation
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
Describe the class of an AVClass context structure.
Definition: log.h:34
TimeFilter * ff_timefilter_new(double clock_period, double feedback2_factor, double feedback3_factor)
Create a new Delay Locked Loop time filter.
Definition: timefilter.c:40
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:265
#define OFFSET(x)
Definition: jack.c:337
static int process_callback(jack_nframes_t nframes, void *arg)
Definition: jack.c:58
static void shutdown_callback(void *arg)
Definition: jack.c:118
static int audio_read_close(AVFormatContext *context)
Definition: jack.c:330
int av_strerror(int errnum, char *errbuf, size_t errbuf_size)
Put a description of the AVERROR code errnum in errbuf.
Definition: error.c:23
int sample_rate
Audio only.
Definition: avcodec.h:3564
TimeFilter * timefilter
Definition: jack.c:51
Main libavformat public API header.
int av_fifo_size(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:52
double ff_timefilter_update(TimeFilter *self, double system_time, double period)
Update the filter.
Definition: timefilter.c:65
static void free_pkt_fifo(AVFifoBuffer *fifo)
Definition: jack.c:218
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:412
static int audio_read_header(AVFormatContext *context)
Definition: jack.c:242
static int xrun_callback(void *arg)
Definition: jack.c:124
static const AVClass jack_indev_class
Definition: jack.c:343
AVFifoBuffer * av_fifo_alloc(unsigned int size)
Initialize an AVFifoBuffer.
Definition: fifo.c:25
void * priv_data
Format private data.
Definition: avformat.h:968
int channels
Audio only.
Definition: avcodec.h:3560
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:529
jack_nframes_t buffer_size
Definition: jack.c:48
AVCodecParameters * codecpar
Definition: avformat.h:831
This structure stores compressed data.
Definition: avcodec.h:1323
static void stop_jack(JackData *self)
Definition: jack.c:228
AVFifoBuffer * new_pkts
Definition: jack.c:52
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1339
for(j=16;j >0;--j)