Clicking while resampling from 16kHz to 48kHz

[Michael FIG]

Hi,

Thanks for soxr, it (nearly) does what I want.

I get random clicking/popping artifacts in the output buffer with the following initialization and soxr_process call. Is this a bug?

soxr_io_spec_t io_spec = soxr_io_spec(SOXR_INT16_S, SOXR_INT16_S);
soxr_quality_spec_t quality_spec = soxr_quality_spec(SOXR_HQ, 0);
soxr_error_t err;
soxr_ = soxr_create(16000, 48000, 2,

&err, &io_spec, &quality_spec, NULL);

int16_t obuf[2][olen];
soxr_cbuf_t obufs[] = {obuf[0], obuf[1]};
soxr_cbuf_t ibufs[] = {pcm_l, pcm_r}; // pcm_l and pcm_r are int16_t arrays.

size_t nframes = 0;
soxr_process(soxr, ibufs, nsamples, NULL,
obufs, olen, &nframes);

Thanks for any help you can offer,
Michael.

[Michael FIG]

My fault: it turns out my input stream is mono, so the pcm_r array contained garbage. Copying the pcm_l stream to the right stereo channel made it all turn out fine!

Thanks,
Michael.

[robs]

Hi Michael, I'm afraid I can't spot any problem in the code above. Perhaps the problem is in some of the other code around the code you have posted?

I'm not aware of any bug in soxr in this area. For example, using soxr example number 4 (which exercises split-channel I/O) with a test signal and your parameters above, the resultant spectrogram looks clean and as expected:

sox -c2 -r16k -n 16.s16 synth 8 sin 0:8k sin 8k:0 gain -1
./4-split-channels 16000 48000 2 3 3 < 16.s16 > 48.s16
sox -c2 -r48k 48.s16 -n spectrogram -wk -o 48.png