static int arequest_frame(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
LoopContext *s = ctx->priv;
int ret = 0;
if ((!s->size) ||
(s->nb_samples < s->size) ||
(s->nb_samples >= s->size && s->loop == 0)) {
int nb_samples = av_audio_fifo_size(s->left);
if (s->loop == 0 && nb_samples > 0) {
AVFrame *out;
out = ff_get_audio_buffer(outlink, nb_samples);
if (!out)
return AVERROR(ENOMEM);
av_audio_fifo_read(s->left, (void **)out->extended_data, nb_samples);
out->pts = s->pts;
s->pts += nb_samples;
ret = ff_filter_frame(outlink, out);
if (ret < 0)
return ret;
}
ret = ff_request_frame(ctx->inputs[0]);
} else {
ret = push_samples(ctx, 1024);
}
if (ret == AVERROR_EOF && s->nb_samples > 0 && s->loop != 0) {
ret = push_samples(ctx, outlink->sample_rate);
}
return ret;
}
static int read_subframe(const struct sr_dev_inst *sdi, uint8_t *buf)
{
struct dev_context *devc = sdi->priv;
uint8_t sig[3], ctrl;
unsigned int num;
gboolean interleave;
interleave = readout_steps[devc->step].interleave;
ctrl = C1284_NSTROBE;
if ((interleave && devc->adc2) || (!interleave && devc->channel == 2))
ctrl |= C1284_NAUTOFD;
ieee1284_write_control(sdi->conn, ctrl);
num = readout_steps[devc->step].num;
if (num < 1000)
skip_samples(sdi->conn, ctrl, 1000 - num);
read_samples(sdi->conn, ctrl, buf + (devc->adc2 ? 1 : 0), num,
interleave ? 2 : 1);
read_samples(sdi->conn, ctrl, sig, 3, 1);
if (sig[0] != 0x01 || sig[1] != 0xfe || sig[2] != 0x80) {
if (--devc->retries) {
sr_dbg("Missing signature at end of buffer, %i tries remaining",
devc->retries);
return TRUE;
} else {
sr_err("Failed to read frame without transfer errors");
devc->step = 0;
}
} else {
if (interleave && !devc->adc2) {
devc->adc2 = TRUE;
devc->retries = MAX_RETRIES;
return TRUE;
} else {
if (interleave)
num *= 2;
if (!devc->step) {
struct sr_datafeed_packet packet = {
.type = SR_DF_TRIGGER
};
push_samples(sdi, buf, 6);
sr_session_send(sdi, &packet);
buf += 6;
num -= 6;
}
push_samples(sdi, buf, num);
if (++devc->step > devc->last_step)
devc->step = 0;
}
}
devc->adc2 = FALSE;
devc->retries = MAX_RETRIES;
return devc->step > 0;
}
static int afilter_frame(AVFilterLink *inlink, AVFrame *frame)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
LoopContext *s = ctx->priv;
int ret = 0;
if (s->ignored_samples + frame->nb_samples > s->start && s->size > 0 && s->loop != 0) {
if (s->nb_samples < s->size) {
int written = FFMIN(frame->nb_samples, s->size - s->nb_samples);
int drain = 0;
ret = av_audio_fifo_write(s->fifo, (void **)frame->extended_data, written);
if (ret < 0)
return ret;
if (!s->nb_samples) {
drain = FFMAX(0, s->start - s->ignored_samples);
s->pts = frame->pts;
av_audio_fifo_drain(s->fifo, drain);
s->pts += s->start - s->ignored_samples;
}
s->nb_samples += ret - drain;
drain = frame->nb_samples - written;
if (s->nb_samples == s->size && drain > 0) {
int ret2;
ret2 = av_audio_fifo_write(s->left, (void **)frame->extended_data, frame->nb_samples);
if (ret2 < 0)
return ret2;
av_audio_fifo_drain(s->left, drain);
}
frame->nb_samples = ret;
s->pts += ret;
ret = ff_filter_frame(outlink, frame);
} else {
int nb_samples = frame->nb_samples;
av_frame_free(&frame);
ret = push_samples(ctx, nb_samples);
}
} else {
s->ignored_samples += frame->nb_samples;
frame->pts = s->pts;
s->pts += frame->nb_samples;
ret = ff_filter_frame(outlink, frame);
}
return ret;
}
