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, 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->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 av_cold int audio_read_header(AVFormatContext *s1)
{
AlsaData *s = s1->priv_data;
AVStream *st;
int ret;
enum AVCodecID codec_id;
st = avformat_new_stream(s1, NULL);
if (!st) {
av_log(s1, AV_LOG_ERROR, "Cannot add stream\n");
return AVERROR(ENOMEM);
}
codec_id = s1->audio_codec_id;
ret = ff_alsa_open(s1, SND_PCM_STREAM_CAPTURE, &s->sample_rate, s->channels,
&codec_id);
if (ret < 0) {
return AVERROR(EIO);
}
/* take real parameters */
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = codec_id;
st->codecpar->sample_rate = s->sample_rate;
st->codecpar->channels = s->channels;
st->codecpar->frame_size = s->frame_size;
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
/* microseconds instead of seconds, MHz instead of Hz */
s->timefilter = ff_timefilter_new(1000000.0 / s->sample_rate,
s->period_size, 1.5E-6);
if (!s->timefilter)
goto fail;
return 0;
fail:
snd_pcm_close(s->h);
return AVERROR(EIO);
}
int main(void)
{
AVLFG prng;
double n0,n1;
#define SAMPLES 1000
double ideal[SAMPLES];
double samples[SAMPLES];
#if 1
for(n0= 0; n0<40; n0=2*n0+1){
for(n1= 0; n1<10; n1=2*n1+1){
#else
{{
n0=7;
n1=1;
#endif
double best_error= 1000000000;
double bestpar0=1;
double bestpar1=0.001;
int better, i;
av_lfg_init(&prng, 123);
for(i=0; i<SAMPLES; i++){
ideal[i] = 10 + i + n1*i/(1000);
samples[i] = ideal[i] + n0 * (av_lfg_get(&prng) - LFG_MAX / 2)
/ (LFG_MAX * 10LL);
}
do{
double par0, par1;
better=0;
for(par0= bestpar0*0.8; par0<=bestpar0*1.21; par0+=bestpar0*0.05){
for(par1= bestpar1*0.8; par1<=bestpar1*1.21; par1+=bestpar1*0.05){
double error=0;
TimeFilter *tf= ff_timefilter_new(1, par0, par1);
for(i=0; i<SAMPLES; i++){
double filtered;
filtered= ff_timefilter_update(tf, samples[i], 1);
error += (filtered - ideal[i]) * (filtered - ideal[i]);
}
ff_timefilter_destroy(tf);
if(error < best_error){
best_error= error;
bestpar0= par0;
bestpar1= par1;
better=1;
}
}
}
}while(better);
#if 0
double lastfil=9;
TimeFilter *tf= ff_timefilter_new(1, bestpar0, bestpar1);
for(i=0; i<SAMPLES; i++){
double filtered;
filtered= ff_timefilter_update(tf, samples[i], 1);
printf("%f %f %f %f\n", i - samples[i] + 10, filtered - samples[i], samples[FFMAX(i, 1)] - samples[FFMAX(i-1, 0)], filtered - lastfil);
lastfil= filtered;
}
ff_timefilter_destroy(tf);
#else
printf(" [%f %f %9f]", bestpar0, bestpar1, best_error);
#endif
}
printf("\n");
}
return 0;
}
