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/log.h"
28#include "libavutil/fifo.h"
29#include "libavcodec/avcodec.h"
30#include "libavformat/avformat.h"
31#include "libavformat/timefilter.h"
32
33/**
34 * Size of the internal FIFO buffers as a number of audio packets
35 */
36#define FIFO_PACKETS_NUM 16
37
38typedef struct {
39    jack_client_t * client;
40    int             activated;
41    sem_t           packet_count;
42    jack_nframes_t  sample_rate;
43    jack_nframes_t  buffer_size;
44    jack_port_t **  ports;
45    int             nports;
46    TimeFilter *    timefilter;
47    AVFifoBuffer *  new_pkts;
48    AVFifoBuffer *  filled_pkts;
49    int             pkt_xrun;
50    int             jack_xrun;
51} JackData;
52
53static int process_callback(jack_nframes_t nframes, void *arg)
54{
55    /* Warning: this function runs in realtime. One mustn't allocate memory here
56     * or do any other thing that could block. */
57
58    int i, j;
59    JackData *self = arg;
60    float * buffer;
61    jack_nframes_t latency, cycle_delay;
62    AVPacket pkt;
63    float *pkt_data;
64    double cycle_time;
65
66    if (!self->client)
67        return 0;
68
69    /* The approximate delay since the hardware interrupt as a number of frames */
70    cycle_delay = jack_frames_since_cycle_start(self->client);
71
72    /* Retrieve filtered cycle time */
73    cycle_time = ff_timefilter_update(self->timefilter,
74                                      av_gettime() / 1000000.0 - (double) cycle_delay / self->sample_rate,
75                                      self->buffer_size);
76
77    /* Check if an empty packet is available, and if there's enough space to send it back once filled */
78    if ((av_fifo_size(self->new_pkts) < sizeof(pkt)) || (av_fifo_space(self->filled_pkts) < sizeof(pkt))) {
79        self->pkt_xrun = 1;
80        return 0;
81    }
82
83    /* Retrieve empty (but allocated) packet */
84    av_fifo_generic_read(self->new_pkts, &pkt, sizeof(pkt), NULL);
85
86    pkt_data  = (float *) pkt.data;
87    latency   = 0;
88
89    /* Copy and interleave audio data from the JACK buffer into the packet */
90    for (i = 0; i < self->nports; i++) {
91        latency += jack_port_get_total_latency(self->client, self->ports[i]);
92        buffer = jack_port_get_buffer(self->ports[i], self->buffer_size);
93        for (j = 0; j < self->buffer_size; j++)
94            pkt_data[j * self->nports + i] = buffer[j];
95    }
96
97    /* Timestamp the packet with the cycle start time minus the average latency */
98    pkt.pts = (cycle_time - (double) latency / (self->nports * self->sample_rate)) * 1000000.0;
99
100    /* Send the now filled packet back, and increase packet counter */
101    av_fifo_generic_write(self->filled_pkts, &pkt, sizeof(pkt), NULL);
102    sem_post(&self->packet_count);
103
104    return 0;
105}
106
107static void shutdown_callback(void *arg)
108{
109    JackData *self = arg;
110    self->client = NULL;
111}
112
113static int xrun_callback(void *arg)
114{
115    JackData *self = arg;
116    self->jack_xrun = 1;
117    ff_timefilter_reset(self->timefilter);
118    return 0;
119}
120
121static int supply_new_packets(JackData *self, AVFormatContext *context)
122{
123    AVPacket pkt;
124    int test, pkt_size = self->buffer_size * self->nports * sizeof(float);
125
126    /* Supply the process callback with new empty packets, by filling the new
127     * packets FIFO buffer with as many packets as possible. process_callback()
128     * can't do this by itself, because it can't allocate memory in realtime. */
129    while (av_fifo_space(self->new_pkts) >= sizeof(pkt)) {
130        if ((test = av_new_packet(&pkt, pkt_size)) < 0) {
131            av_log(context, AV_LOG_ERROR, "Could not create packet of size %d\n", pkt_size);
132            return test;
133        }
134        av_fifo_generic_write(self->new_pkts, &pkt, sizeof(pkt), NULL);
135    }
136    return 0;
137}
138
139static int start_jack(AVFormatContext *context, AVFormatParameters *params)
140{
141    JackData *self = context->priv_data;
142    jack_status_t status;
143    int i, test;
144    double o, period;
145
146    /* Register as a JACK client, using the context filename as client name. */
147    self->client = jack_client_open(context->filename, JackNullOption, &status);
148    if (!self->client) {
149        av_log(context, AV_LOG_ERROR, "Unable to register as a JACK client\n");
150        return AVERROR(EIO);
151    }
152
153    sem_init(&self->packet_count, 0, 0);
154
155    self->sample_rate = jack_get_sample_rate(self->client);
156    self->nports      = params->channels;
157    self->ports       = av_malloc(self->nports * sizeof(*self->ports));
158    self->buffer_size = jack_get_buffer_size(self->client);
159
160    /* Register JACK ports */
161    for (i = 0; i < self->nports; i++) {
162        char str[16];
163        snprintf(str, sizeof(str), "input_%d", i + 1);
164        self->ports[i] = jack_port_register(self->client, str,
165                                            JACK_DEFAULT_AUDIO_TYPE,
166                                            JackPortIsInput, 0);
167        if (!self->ports[i]) {
168            av_log(context, AV_LOG_ERROR, "Unable to register port %s:%s\n",
169                   context->filename, str);
170            jack_client_close(self->client);
171            return AVERROR(EIO);
172        }
173    }
174
175    /* Register JACK callbacks */
176    jack_set_process_callback(self->client, process_callback, self);
177    jack_on_shutdown(self->client, shutdown_callback, self);
178    jack_set_xrun_callback(self->client, xrun_callback, self);
179
180    /* Create time filter */
181    period            = (double) self->buffer_size / self->sample_rate;
182    o                 = 2 * M_PI * 1.5 * period; /// bandwidth: 1.5Hz
183    self->timefilter  = ff_timefilter_new (1.0 / self->sample_rate, sqrt(2 * o), o * o);
184
185    /* Create FIFO buffers */
186    self->filled_pkts = av_fifo_alloc(FIFO_PACKETS_NUM * sizeof(AVPacket));
187    /* New packets FIFO with one extra packet for safety against underruns */
188    self->new_pkts    = av_fifo_alloc((FIFO_PACKETS_NUM + 1) * sizeof(AVPacket));
189    if ((test = supply_new_packets(self, context))) {
190        jack_client_close(self->client);
191        return test;
192    }
193
194    return 0;
195
196}
197
198static void free_pkt_fifo(AVFifoBuffer *fifo)
199{
200    AVPacket pkt;
201    while (av_fifo_size(fifo)) {
202        av_fifo_generic_read(fifo, &pkt, sizeof(pkt), NULL);
203        av_free_packet(&pkt);
204    }
205    av_fifo_free(fifo);
206}
207
208static void stop_jack(JackData *self)
209{
210    if (self->client) {
211        if (self->activated)
212            jack_deactivate(self->client);
213        jack_client_close(self->client);
214    }
215    sem_destroy(&self->packet_count);
216    free_pkt_fifo(self->new_pkts);
217    free_pkt_fifo(self->filled_pkts);
218    av_freep(&self->ports);
219    ff_timefilter_destroy(self->timefilter);
220}
221
222static int audio_read_header(AVFormatContext *context, AVFormatParameters *params)
223{
224    JackData *self = context->priv_data;
225    AVStream *stream;
226    int test;
227
228    if (params->sample_rate <= 0 || params->channels <= 0)
229        return -1;
230
231    if ((test = start_jack(context, params)))
232        return test;
233
234    stream = av_new_stream(context, 0);
235    if (!stream) {
236        stop_jack(self);
237        return AVERROR(ENOMEM);
238    }
239
240    stream->codec->codec_type   = AVMEDIA_TYPE_AUDIO;
241#if HAVE_BIGENDIAN
242    stream->codec->codec_id     = CODEC_ID_PCM_F32BE;
243#else
244    stream->codec->codec_id     = CODEC_ID_PCM_F32LE;
245#endif
246    stream->codec->sample_rate  = self->sample_rate;
247    stream->codec->channels     = self->nports;
248
249    av_set_pts_info(stream, 64, 1, 1000000);  /* 64 bits pts in us */
250    return 0;
251}
252
253static int audio_read_packet(AVFormatContext *context, AVPacket *pkt)
254{
255    JackData *self = context->priv_data;
256    struct timespec timeout = {0, 0};
257    int test;
258
259    /* Activate the JACK client on first packet read. Activating the JACK client
260     * means that process_callback() starts to get called at regular interval.
261     * If we activate it in audio_read_header(), we're actually reading audio data
262     * from the device before instructed to, and that may result in an overrun. */
263    if (!self->activated) {
264        if (!jack_activate(self->client)) {
265            self->activated = 1;
266            av_log(context, AV_LOG_INFO,
267                   "JACK client registered and activated (rate=%dHz, buffer_size=%d frames)\n",
268                   self->sample_rate, self->buffer_size);
269        } else {
270            av_log(context, AV_LOG_ERROR, "Unable to activate JACK client\n");
271            return AVERROR(EIO);
272        }
273    }
274
275    /* Wait for a packet comming back from process_callback(), if one isn't available yet */
276    timeout.tv_sec = av_gettime() / 1000000 + 2;
277    if (sem_timedwait(&self->packet_count, &timeout)) {
278        if (errno == ETIMEDOUT) {
279            av_log(context, AV_LOG_ERROR,
280                   "Input error: timed out when waiting for JACK process callback output\n");
281        } else {
282            av_log(context, AV_LOG_ERROR, "Error while waiting for audio packet: %s\n",
283                   strerror(errno));
284        }
285        if (!self->client)
286            av_log(context, AV_LOG_ERROR, "Input error: JACK server is gone\n");
287
288        return AVERROR(EIO);
289    }
290
291    if (self->pkt_xrun) {
292        av_log(context, AV_LOG_WARNING, "Audio packet xrun\n");
293        self->pkt_xrun = 0;
294    }
295
296    if (self->jack_xrun) {
297        av_log(context, AV_LOG_WARNING, "JACK xrun\n");
298        self->jack_xrun = 0;
299    }
300
301    /* Retrieve the packet filled with audio data by process_callback() */
302    av_fifo_generic_read(self->filled_pkts, pkt, sizeof(*pkt), NULL);
303
304    if ((test = supply_new_packets(self, context)))
305        return test;
306
307    return 0;
308}
309
310static int audio_read_close(AVFormatContext *context)
311{
312    JackData *self = context->priv_data;
313    stop_jack(self);
314    return 0;
315}
316
317AVInputFormat jack_demuxer = {
318    "jack",
319    NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
320    sizeof(JackData),
321    NULL,
322    audio_read_header,
323    audio_read_packet,
324    audio_read_close,
325    .flags = AVFMT_NOFILE,
326};
327