From: Nikola Pavlica Subject: [PATCH 1/2] dsound: Revised 5.1 to stereo downmix Message-Id: <20190423180423.18445-1-pavlica.nikola@gmail.com> Date: Tue, 23 Apr 2019 20:04:22 +0200 Signed-off-by: Nikola Pavlica --- dlls/dsound/dsound_convert.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/dlls/dsound/dsound_convert.c b/dlls/dsound/dsound_convert.c index 26dbb3220a..0da9823298 100644 --- a/dlls/dsound/dsound_convert.c +++ b/dlls/dsound/dsound_convert.c @@ -216,39 +216,37 @@ void put_stereo2surround51(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD c void put_surround512stereo(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel, float value) { - /* based on pulseaudio's downmix algorithm */ + /* based on analyzing a recording of a dsound downmix */ switch(channel){ - case 4: /* back left */ - value *= 0.056f; /* (1/9) / (sum of left volumes) */ + case 4: /* surround left */ + value *= 0.24f; dsb->put_aux(dsb, pos, 0, value); break; case 0: /* front left */ - value *= 0.503f; /* 1 / (sum of left volumes) */ + value *= 1.0f; dsb->put_aux(dsb, pos, 0, value); break; - case 5: /* back right */ - value *= 0.056f; /* (1/9) / (sum of right volumes) */ + case 5: /* surround right */ + value *= 0.24f; dsb->put_aux(dsb, pos, 1, value); break; case 1: /* front right */ - value *= 0.503f; /* 1 / (sum of right volumes) */ + value *= 1.0f; dsb->put_aux(dsb, pos, 1, value); break; - case 2: /* front centre */ - value *= 0.252f; /* 0.5 / (sum of left/right volumes) */ + case 2: /* centre */ + value *= 0.7; dsb->put_aux(dsb, pos, 0, value); dsb->put_aux(dsb, pos, 1, value); break; - case 3: /* LFE */ - value *= 0.189f; /* 0.375 / (sum of left/right volumes) */ - dsb->put_aux(dsb, pos, 0, value); - dsb->put_aux(dsb, pos, 1, value); + case 3: + /* LFE is totally ignored in dsound when downmixing to 2 channels */ break; } } -- 2.21.0