commit e3f34e56c726d11d9ade2efe80484579a60acfab sin <sin@2f30.org> 2014-12-31 21:36:07 +0000 Add stereo to mono conversion
output.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/output.c b/output.c index bca53a8..ab8b696 100644 --- a/output.c +++ b/output.c @@ -162,6 +162,15 @@ s16monotostereo(short *in, short *out, size_t nsamples) } } +static void +s16stereotomono(short *in, short *out, size_t nsamples) +{ + size_t i; + + for (i = 0; i < nsamples; ++i) + out[i] = (in[i * 2] + in[i * 2 + 1]) / 2; +} + static int playoutput(Format *fmt, Outputdesc *desc, void *buf, size_t nbytes) { @@ -177,13 +186,20 @@ playoutput(Format *fmt, Outputdesc *desc, void *buf, size_t nbytes) if (!desc->active) return 0; - /* perform mono to stereo conversion */ if (fmt->channels == 1 && desc->fmt.channels == 2) { + /* perform mono to stereo conversion */ inbuf = malloc(nbytes * 2); if (!inbuf) err(1, "malloc"); s16monotostereo(buf, inbuf, nbytes / 2); nbytes *= 2; + } else if (fmt->channels == 2 && desc->fmt.channels == 1) { + /* perform stereo to mono conversion */ + inbuf = malloc(nbytes / 2); + if (!inbuf) + err(1, "malloc"); + s16stereotomono(buf, inbuf, nbytes / 4); + nbytes /= 2; } else { inbuf = malloc(nbytes); if (!inbuf)