aboutsummaryrefslogtreecommitdiffstats
path: root/libavdevice/jack_audio.c
blob: d0a09ee2185cc1fa1f2e89aafca81bb59e889b25 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
/*
 * JACK Audio Connection Kit input device
 * Copyright (c) 2009 Samalyse
 * Author: Olivier Guilyardi <olivier samalyse com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config.h"
#include <semaphore.h>
#include <jack/jack.h>

#include "libavutil/log.h"
#include "libavutil/fifo.h"
#include "libavutil/opt.h"
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
#include "timefilter.h"
#include "avdevice.h"

/**
 * Size of the internal FIFO buffers as a number of audio packets
 */
#define FIFO_PACKETS_NUM 16

typedef struct {
    AVClass        *class;
    jack_client_t * client;
    int             activated;
    sem_t           packet_count;
    jack_nframes_t  sample_rate;
    jack_nframes_t  buffer_size;
    jack_port_t **  ports;
    int             nports;
    TimeFilter *    timefilter;
    AVFifoBuffer *  new_pkts;
    AVFifoBuffer *  filled_pkts;
    int             pkt_xrun;
    int             jack_xrun;
} JackData;

static int process_callback(jack_nframes_t nframes, void *arg)
{
    /* Warning: this function runs in realtime. One mustn't allocate memory here
     * or do any other thing that could block. */

    int i, j;
    JackData *self = arg;
    float * buffer;
    jack_nframes_t latency, cycle_delay;
    AVPacket pkt;
    float *pkt_data;
    double cycle_time;

    if (!self->client)
        return 0;

    /* The approximate delay since the hardware interrupt as a number of frames */
    cycle_delay = jack_frames_since_cycle_start(self->client);

    /* Retrieve filtered cycle time */
    cycle_time = ff_timefilter_update(self->timefilter,
                                      av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
                                      self->buffer_size);

    /* Check if an empty packet is available, and if there's enough space to send it back once filled */
    if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
        self->pkt_xrun = 1;
        return 0;
    }

    /* Retrieve empty (but allocated) packet */
    av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);

    pkt_data  = (float *) pkt.data;
    latency   = 0;

    /* Copy and interleave audio data from the JACK buffer into the packet */
    for (i = 0; i < self->nports; i++) {
        latency += jack_port_get_total_latency(self->client, self->ports[i]);
        buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
        for (j = 0; j < self->buffer_size; j++)
            pkt_data[j * self->nports + i] = buffer[j];
    }

    /* Timestamp the packet with the cycle start time minus the average latency */
    pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;

    /* Send the now filled packet back, and increase packet counter */
    av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
    sem_post(&self->packet_count);

    return 0;
}

static void shutdown_callback(void *arg)
{
    JackData *self = arg;
    self->client = NULL;
}

static int xrun_callback(void *arg)
{
    JackData *self = arg;
    self->jack_xrun = 1;
    ff_timefilter_reset(self->timefilter);
    return 0;
}

static int supply_new_packets(JackData *self, AVFormatContext *context)
{
    AVPacket pkt;
    int test, pkt_size = self->buffer_size * self->nports * sizeof(float);

    /* Supply the process callback with new empty packets, by filling the new
     * packets FIFO buffer with as many packets as possible. process_callback()
     * can't do this by itself, because it can't allocate memory in realtime. */
    while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
        if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
            av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
            return test;
        }
        av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
    }
    return 0;
}

static int start_jack(AVFormatContext *context)
{
    JackData *self = context->priv_data;
    jack_status_t status;
    int i, test;
    double o, period;

    /* Register as a JACK client, using the context filename as client name. */
    self->client = jack_client_open(context->filename, JackNullOption, &status);
    if (!self->client) {
        av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");
        return AVERROR(EIO);
    }

    sem_init(&self->packet_count, 0, 0);

    self->sample_rate = jack_get_sample_rate(self->client);
    self->ports       = av_malloc(self->nports * sizeof(*self->ports));
    self->buffer_size = jack_get_buffer_size(self->client);

    /* Register JACK ports */
    for (i = 0; i < self->nports; i++) {
        char str[16];
        snprintf(str, sizeof(str), "input_%d", i + 1);
        self->ports[i] = jack_port_register(self->client, str,
                                            JACK_DEFAULT_AUDIO_TYPE,
                                            JackPortIsInput, 0);
        if (!self->ports[i]) {
            av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",
                   context->filename, str);
            jack_client_close(self->client);
            return AVERROR(EIO);
        }
    }

    /* Register JACK callbacks */
    jack_set_process_callback(self->client, process_callback, self);
    jack_on_shutdown(self->client, shutdown_callback, self);
    jack_set_xrun_callback(self->client, xrun_callback, self);

    /* Create time filter */
    period            = (double) self->buffer_size / self->sample_rate;
    o                 = 2 * M_PI * 1.5 * period; /// bandwidth: 1.5Hz
    self->timefilter  = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o);

    /* Create FIFO buffers */
    self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket));
    /* New packets FIFO with one extra packet for safety against underruns */
    self->new_pkts    = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket));
    if ((test = supply_new_packets(self, context))) {
        jack_client_close(self->client);
        return test;
    }

    return 0;

}

static void free_pkt_fifo(AVFifoBuffer *fifo)
{
    AVPacket pkt;
    while (av_fifo_size(fifo)) {
        av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL);
        av_free_packet(&pkt);
    }
    av_fifo_free(fifo);
}

static void stop_jack(JackData *self)
{
    if (self->client) {
        if (self->activated)
            jack_deactivate(self->client);
        jack_client_close(self->client);
    }
    sem_destroy(&self->packet_count);
    free_pkt_fifo(self->new_pkts);
    free_pkt_fifo(self->filled_pkts);
    av_freep(&self->ports);
    ff_timefilter_destroy(self->timefilter);
}

static int audio_read_header(AVFormatContext *context, AVFormatParameters *params)
{
    JackData *self = context->priv_data;
    AVStream *stream;
    int test;

    if ((test = start_jack(context)))
        return test;

    stream = avformat_new_stream(context, NULL);
    if (!stream) {
        stop_jack(self);
        return AVERROR(ENOMEM);
    }

    stream->codec->codec_type   = AVMEDIA_TYPE_AUDIO;
#if HAVE_BIGENDIAN
    stream->codec->codec_id     = CODEC_ID_PCM_F32BE;
#else
    stream->codec->codec_id     = CODEC_ID_PCM_F32LE;
#endif
    stream->codec->sample_rate  = self->sample_rate;
    stream->codec->channels     = self->nports;

    avpriv_set_pts_info(stream, 64, 1, 1000000);  /* 64 bits pts in us */
    return 0;
}

static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
{
    JackData *self = context->priv_data;
    struct timespec timeout = {0, 0};
    int test;

    /* Activate the JACK client on first packet read. Activating the JACK client
     * means that process_callback() starts to get called at regular interval.
     * If we activate it in audio_read_header(), we're actually reading audio data
     * from the device before instructed to, and that may result in an overrun. */
    if (!self->activated) {
        if (!jack_activate(self->client)) {
            self->activated = 1;
            av_log(context, AV_LOG_INFO,
                   "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
                   self->sample_rate, self->buffer_size);
        } else {
            av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
            return AVERROR(EIO);
        }
    }

    /* Wait for a packet coming back from process_callback(), if one isn't available yet */
    timeout.tv_sec = av_gettime() / 1000000 + 2;
    if (sem_timedwait(&self->packet_count, &timeout)) {
        if (errno == ETIMEDOUT) {
            av_log(context, AV_LOG_ERROR,
                   "Input error: timed out when waiting for JACK process callback output\n");
        } else {
            av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
                   strerror(errno));
        }
        if (!self->client)
            av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");

        return AVERROR(EIO);
    }

    if (self->pkt_xrun) {
        av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
        self->pkt_xrun = 0;
    }

    if (self->jack_xrun) {
        av_log(context, AV_LOG_WARNING, "JACK xrun\n");
        self->jack_xrun = 0;
    }

    /* Retrieve the packet filled with audio data by process_callback() */
    av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);

    if ((test = supply_new_packets(self, context)))
        return test;

    return 0;
}

static int audio_read_close(AVFormatContext *context)
{
    JackData *self = context->priv_data;
    stop_jack(self);
    return 0;
}

#define OFFSET(x) offsetof(JackData, x)
static const AVOption options[] = {
    { "channels", "Number of audio channels.", OFFSET(nports), AV_OPT_TYPE_INT, { 2 }, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
    { NULL },
};

static const AVClass jack_indev_class = {
    .class_name     = "JACK indev",
    .item_name      = av_default_item_name,
    .option         = options,
    .version        = LIBAVUTIL_VERSION_INT,
};

AVInputFormat ff_jack_demuxer = {
    .name           = "jack",
    .long_name      = NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
    .priv_data_size = sizeof(JackData),
    .read_header    = audio_read_header,
    .read_packet    = audio_read_packet,
    .read_close     = audio_read_close,
    .flags          = AVFMT_NOFILE,
    .priv_class     = &jack_indev_class,
};