looks like in the remap_channels method, calling oil_vectoradd_s16, the constant to multiply by is set to 1. if (r->map_table[oc][ic] >= 1.0) { static const int16_t one = 1; oil_vectoradd_s16( (int16_t*) dst + oc, o_skip, (int16_t*) dst + oc, o_skip, (int16_t*) src + ic, i_skip, (int) n_frames, &one, &one); } shouldn't there be a divide by 2 somewhere if we are adding two channels together? <div class="gmail_quote">On Wed, Sep 15, 2010 at 2:54 PM, Baek Chang <<a href="mailto:baeksan@ccrma.stanford.edu">baeksan@ccrma.stanford.edu</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> I am seeing warp around happening due to overflow when doing the following. parec -r --device=alsa_output.pci_8086_269a_sound_card_0_alsa_playback_0.monitor output.raw --format=s16le --rate=44100 --channels=1 paplay --format=s16le --rate=44100 --channels=2 if i use parec with the same configuration as the sink that I am playing the wave file on, then there is no overflow/wraparound. It seems to be a problem with the remapping of the channels from stereo to mono. Is there an additional gain stage applied in this remapping that might be causing this? I am using pulseaudio 0.9.14 Thanks </blockquote></div>