Patch credit: kwanghui When downmixing to mono, we should average the signal instead of summing it to avoid clipping. BugLink: http://pulseaudio.org/ticket/934 BugLink: https://bugs.launchpad.net/bugs/416190 Signed-off-by: David Henningsson <david.henningsson at canonical.com> --- src/pulsecore/resampler.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) Thanks to Peter Meerwald for discovering an irrelevant change. diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c index 9f19559..af749ae 100644 --- a/src/pulsecore/resampler.c +++ b/src/pulsecore/resampler.c @@ -716,7 +716,7 @@ static void calc_map_table(pa_resampler *r) { * * 2) Mono Handling: * S:Mono: Copy into all D:channels - * D:Mono: Copy in all S:channels + * D:Mono: Avg all S:channels * * 3) Mix D:Left, D:Right: * D:Left: If not connected, avg all S:Left @@ -759,12 +759,19 @@ static void calc_map_table(pa_resampler *r) { * best to pass it to L+R. */ - if (a == b || a == PA_CHANNEL_POSITION_MONO || b == PA_CHANNEL_POSITION_MONO) { + if (a == b || a == PA_CHANNEL_POSITION_MONO) { m->map_table_f[oc][ic] = 1.0; oc_connected = TRUE; ic_connected[ic] = TRUE; } + else if (b == PA_CHANNEL_POSITION_MONO) { + if(n_ic) + m->map_table_f[oc][ic] = 1.0f / (float) n_ic; + + oc_connected = TRUE; + ic_connected[ic] = TRUE; + } } if (!oc_connected && remix) { -- 1.7.9.5
