Implement JACK input device.

Patch by Olivier Guilyardi list samalyse com.
See the thread: "[FFmpeg-devel] [PATCH] libavdevice: JACK demuxer".

Originally committed as revision 18322 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1112,6 +1112,8 @@ avisynth_demuxer_deps="avisynth"
 bktr_demuxer_deps_any="dev_bktr_ioctl_bt848_h machine_ioctl_bt848_h dev_video_bktr_ioctl_bt848_h dev_ic_bt8xx_h"
 dirac_demuxer_deps="dirac_parser"
 dv1394_demuxer_deps="dv1394 dv_demuxer"
+jack_demuxer_deps="jack_jack_h"
+jack_demuxer_extralibs="-ljack"
 libdc1394_demuxer_deps="libdc1394"
 libnut_demuxer_deps="libnut"
 libnut_muxer_deps="libnut"
@@ -2149,6 +2151,8 @@ check_header soundcard.h
 
 check_lib2 alsa/asoundlib.h snd_pcm_htimestamp -lasound
 
+check_lib2 jack/jack.h jack_client_open -ljack
+
 # deal with the X11 frame grabber
 enabled x11grab                         &&
 check_header X11/Xlib.h                 &&

doc/general.texi

@@ -653,6 +653,7 @@ performance on systems without hardware floating point support).
 @item BEOS audio        @tab X      @tab X
 @item BKTR              @tab X      @tab
 @item DV1394            @tab X      @tab
+@item JACK              @tab X      @tab
 @item LIBDC1394         @tab X      @tab
 @item OSS               @tab X      @tab X
 @item Video4Linux       @tab X      @tab

libavdevice/Makefile

@@ -12,6 +12,7 @@ OBJS-$(CONFIG_ALSA_DEMUXER)              += alsa-audio-common.o alsa-audio-dec.o
 OBJS-$(CONFIG_ALSA_MUXER)                += alsa-audio-common.o alsa-audio-enc.o
 OBJS-$(CONFIG_BKTR_DEMUXER)              += bktr.o
 OBJS-$(CONFIG_DV1394_DEMUXER)            += dv1394.o
+OBJS-$(CONFIG_JACK_DEMUXER)              += jack_audio.o
 OBJS-$(CONFIG_OSS_DEMUXER)               += oss_audio.o
 OBJS-$(CONFIG_OSS_MUXER)                 += oss_audio.o
 OBJS-$(CONFIG_V4L2_DEMUXER)              += v4l2.o

libavdevice/alldevices.c

@@ -48,6 +48,7 @@ void avdevice_register_all(void)
     REGISTER_MUXDEMUX (AUDIO_BEOS, audio_beos);
     REGISTER_DEMUXER  (BKTR, bktr);
     REGISTER_DEMUXER  (DV1394, dv1394);
+    REGISTER_DEMUXER  (JACK, jack);
     REGISTER_MUXDEMUX (OSS, oss);
     REGISTER_DEMUXER  (V4L2, v4l2);
     REGISTER_DEMUXER  (V4L, v4l);

libavdevice/avdevice.h

@@ -20,7 +20,7 @@
 #define AVDEVICE_AVDEVICE_H
 
 #define LIBAVDEVICE_VERSION_MAJOR 52
-#define LIBAVDEVICE_VERSION_MINOR  1
+#define LIBAVDEVICE_VERSION_MINOR  2
 #define LIBAVDEVICE_VERSION_MICRO  0
 
 #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \

libavdevice/jack_audio.c

@@ -0,0 +1,326 @@
+/*
+ * 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 "libavcodec/avcodec.h"
+#include "libavformat/avformat.h"
+#include "libavformat/timefilter.h"
+
+/**
+ * Size of the internal FIFO buffers as a number of audio packets
+ */
+#define FIFO_PACKETS_NUM 16
+
+typedef struct {
+    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, AVFormatParameters *params)
+{
+    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, 0, &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->nports      = params->channels;
+    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 (params->sample_rate <= 0 || params->channels <= 0)
+        return -1;
+
+    if ((test = start_jack(context, params)))
+        return test;
+
+    stream = av_new_stream(context, 0);
+    if (!stream) {
+        stop_jack(self);
+        return AVERROR(ENOMEM);
+    }
+
+    stream->codec->codec_type   = CODEC_TYPE_AUDIO;
+#ifdef WORDS_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;
+
+    av_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 comming 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;
+}
+
+AVInputFormat jack_demuxer = {
+    "jack",
+    NULL_IF_CONFIG_SMALL("JACK Audio Connection Kit"),
+    sizeof(JackData),
+    NULL,
+    audio_read_header,
+    audio_read_packet,
+    audio_read_close,
+    .flags = AVFMT_NOFILE,
+};

libavformat/Makefile

@@ -243,6 +243,9 @@ OBJS-$(CONFIG_RTP_PROTOCOL)              += rtpproto.o
 OBJS-$(CONFIG_TCP_PROTOCOL)              += tcp.o
 OBJS-$(CONFIG_UDP_PROTOCOL)              += udp.o
 
+# libavdevice dependencies
+OBJS-$(CONFIG_JACK_DEMUXER)              += timefilter.o
+
 EXAMPLES  = output
 TESTPROGS = timefilter