From f8695185331460106f34286ebe466cb605f85bb6 Mon Sep 17 00:00:00 2001 From: Sylvain Date: Tue, 27 Apr 2021 11:07:51 +0200 Subject: [PATCH] Audio: normalize conversion Stereo to 5.1, Quad to 7.1, 5.1 to 7.1 (bug #4104) --- src/audio/SDL_audiocvt.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/src/audio/SDL_audiocvt.c b/src/audio/SDL_audiocvt.c index ca307f84e..e4e858f14 100644 --- a/src/audio/SDL_audiocvt.c +++ b/src/audio/SDL_audiocvt.c @@ -246,9 +246,8 @@ SDL_ConvertStereoTo51(SDL_AudioCVT * cvt, SDL_AudioFormat format) lf = src[0]; rf = src[1]; ce = (lf + rf) * 0.5f; - /* !!! FIXME: FL and FR may clip */ - dst[0] = lf + (lf - ce); /* FL */ - dst[1] = rf + (rf - ce); /* FR */ + dst[0] = 0.5 * (lf + (lf - ce)); /* FL */ + dst[1] = 0.5 * (rf + (rf - ce)); /* FR */ dst[2] = ce; /* FC */ dst[3] = 0; /* LFE (only meant for special LFE effects) */ dst[4] = lf; /* BL */ @@ -283,9 +282,8 @@ SDL_ConvertQuadTo51(SDL_AudioCVT * cvt, SDL_AudioFormat format) lb = src[2]; rb = src[3]; ce = (lf + rf) * 0.5f; - /* !!! FIXME: FL and FR may clip */ - dst[0] = lf + (lf - ce); /* FL */ - dst[1] = rf + (rf - ce); /* FR */ + dst[0] = 0.5 * (lf + (lf - ce)); /* FL */ + dst[1] = 0.5 * (rf + (rf - ce)); /* FR */ dst[2] = ce; /* FC */ dst[3] = 0; /* LFE (only meant for special LFE effects) */ dst[4] = lb; /* BL */ @@ -351,7 +349,6 @@ SDL_Convert51To71(SDL_AudioCVT * cvt, SDL_AudioFormat format) rb = src[5]; ls = (lf + lb) * 0.5f; rs = (rf + rb) * 0.5f; - /* !!! FIXME: these four may clip */ lf += lf - ls; rf += rf - rs; lb += lb - ls; @@ -360,10 +357,10 @@ SDL_Convert51To71(SDL_AudioCVT * cvt, SDL_AudioFormat format) dst[2] = src[2]; /* FC */ dst[7] = rs; /* SR */ dst[6] = ls; /* SL */ - dst[5] = rb; /* BR */ - dst[4] = lb; /* BL */ - dst[1] = rf; /* FR */ - dst[0] = lf; /* FL */ + dst[5] = 0.5 * rb; /* BR */ + dst[4] = 0.5 * lb; /* BL */ + dst[1] = 0.5 * rf; /* FR */ + dst[0] = 0.5 * lf; /* FL */ } cvt->len_cvt = cvt->len_cvt * 4 / 3;