-// Parts of the code is adapted from Adriaensen's project Zita-ajbridge,
-// although it has been heavily reworked for this use case. Original copyright follows:
+// Parts of the code is adapted from Adriaensen's project Zita-ajbridge
+// (as of November 2015), although it has been heavily reworked for this use
+// case. Original copyright follows:
//
// Copyright (C) 2012-2015 Fons Adriaensen <fons@linuxaudio.org>
//
#include "resampling_queue.h"
+#include <assert.h>
#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <zita-resampler/vresampler.h>
-ResamplingQueue::ResamplingQueue(unsigned freq_in, unsigned freq_out, unsigned num_channels)
- : freq_in(freq_in), freq_out(freq_out), num_channels(num_channels),
+ResamplingQueue::ResamplingQueue(unsigned card_num, unsigned freq_in, unsigned freq_out, unsigned num_channels)
+ : card_num(card_num), freq_in(freq_in), freq_out(freq_out), num_channels(num_channels),
ratio(double(freq_out) / double(freq_in))
{
vresampler.setup(ratio, num_channels, /*hlen=*/32);
void ResamplingQueue::add_input_samples(double pts, const float *samples, ssize_t num_samples)
{
+ if (num_samples == 0) {
+ return;
+ }
if (first_input) {
// Synthesize a fake length.
last_input_len = double(num_samples) / freq_in;
bool ResamplingQueue::get_output_samples(double pts, float *samples, ssize_t num_samples)
{
+ if (first_input) {
+ // No data yet, just return zeros.
+ memset(samples, 0, num_samples * 2 * sizeof(float));
+ return true;
+ }
+
double last_output_len;
if (first_output) {
// Synthesize a fake length.
// Using the time point since just before the last call to add_input_samples() as a base,
// estimate actual delay based on activity since then, measured in number of input samples:
double actual_delay = 0.0;
+ assert(last_input_len != 0);
actual_delay += (k_a1 - k_a0) * last_output_len / last_input_len; // Inserted samples since k_a0, rescaled for the different time periods.
actual_delay += k_a0 - total_consumed_samples; // Samples inserted before k_a0 but not consumed yet.
actual_delay += vresampler.inpdist(); // Delay in the resampler itself.
}
total_consumed_samples -= delay_samples_to_add; // Equivalent to increasing k_a0 and k_a1.
err += delay_samples_to_add;
- first_output = false;
}
+ first_output = false;
// Compute loop filter coefficients for the two filters. We need to compute them
// every time, since they depend on the number of samples the user asked for.
double rcorr = 1.0 - z2 - z3;
if (rcorr > 1.05) rcorr = 1.05;
if (rcorr < 0.95) rcorr = 0.95;
+ assert(!isnan(rcorr));
vresampler.set_rratio(rcorr);
// Finally actually resample, consuming exactly <num_samples> output samples.
if (buffer.empty()) {
// This should never happen unless delay is set way too low,
// or we're dropping a lot of data.
- fprintf(stderr, "PANIC: Out of input samples to resample, still need %d output samples!\n",
- int(vresampler.out_count));
+ fprintf(stderr, "Card %u: PANIC: Out of input samples to resample, still need %d output samples! (correction factor is %f)\n",
+ card_num, int(vresampler.out_count), rcorr);
memset(vresampler.out_data, 0, vresampler.out_count * 2 * sizeof(float));
return false;
}
vresampler.inp_count = num_input_samples;
vresampler.inp_data = inbuf;
- vresampler.process();
+ int err = vresampler.process();
+ assert(err == 0);
size_t consumed_samples = num_input_samples - vresampler.inp_count;
total_consumed_samples += consumed_samples;