Commit f8695185331460106f34286ebe466cb605f85bb6
2021-04-27T11:07:51
Audio: normalize conversion Stereo to 5.1, Quad to 7.1, 5.1 to 7.1 (bug #4104)
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diff --git a/src/audio/SDL_audiocvt.c b/src/audio/SDL_audiocvt.c
index ca307f8..e4e858f 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;