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[patch] The patch promised in the summary and explained in the description

surroundcvt.patch (text/plain), 13.76 KB, created by Solra Bizna on 2017-08-05 22:40:14 UTC

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Description:

Filename:

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Creator: Solra Bizna

Created: 2017-08-05 22:40:14 UTC

Size: 13.76 KB

patch

obsolete

>diff -r c630c47e8f96 src/audio/SDL_audiocvt.c
>--- a/src/audio/SDL_audiocvt.c	Fri Aug 04 23:01:01 2017 +0200
>+++ b/src/audio/SDL_audiocvt.c	Sat Aug 05 16:38:35 2017 -0600
>@@ -35,7 +35,7 @@
> #endif
> 
> #if HAVE_SSE3_INTRINSICS
>-/* Effectively mix right and left channels into a single channel */
>+/* Convert from stereo to mono. Average left and right. */
> static void SDLCALL
> SDL_ConvertStereoToMono_SSE3(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -70,7 +70,7 @@
> }
> #endif
> 
>-/* Effectively mix right and left channels into a single channel */
>+/* Convert from stereo to mono. Average left and right. */
> static void SDLCALL
> SDL_ConvertStereoToMono(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -92,7 +92,7 @@
> }
> 
> 
>-/* Convert from 5.1 to stereo. Average left and right, discard subwoofer. */
>+/* Convert from 5.1 to stereo. Average left and right, distribute center, discard LFE. */
> static void SDLCALL
> SDL_Convert51ToStereo(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -103,11 +103,11 @@
>     LOG_DEBUG_CONVERT("5.1", "stereo");
>     SDL_assert(format == AUDIO_F32SYS);
> 
>-    /* this assumes FL+FR+FC+subwoof+BL+BR layout. */
>+    /* SDL's 5.1 layout: FL+FR+FC+LFE+BL+BR */
>     for (i = cvt->len_cvt / (sizeof (float) * 6); i; --i, src += 6, dst += 2) {
>-        const double front_center = (double) src[2];
>-        dst[0] = (float) ((src[0] + front_center + src[4]) / 3.0);  /* left */
>-        dst[1] = (float) ((src[1] + front_center + src[5]) / 3.0);  /* right */
>+        const float front_center_distributed = src[2] * 0.707107f;
>+        dst[0] = (src[0] + front_center_distributed + src[4]) / 2.707107f;  /* left */
>+        dst[1] = (src[1] + front_center_distributed + src[5]) / 2.707107f;  /* right */
>     }
> 
>     cvt->len_cvt /= 3;
>@@ -117,7 +117,60 @@
> }
> 
> 
>-/* Convert from 5.1 to quad */
>+/* Convert from quad to stereo. Average left and right. */
>+static void SDLCALL
>+SDL_ConvertQuadToStereo(SDL_AudioCVT * cvt, SDL_AudioFormat format)
>+{
>+    float *dst = (float *) cvt->buf;
>+    const float *src = dst;
>+    int i;
>+
>+    LOG_DEBUG_CONVERT("quad", "stereo");
>+    SDL_assert(format == AUDIO_F32SYS);
>+
>+    for (i = cvt->len_cvt / (sizeof (float) * 4); i; --i, src += 4, dst += 2) {
>+        dst[0] = (src[0] + src[2]) * 0.5f; /* left */
>+        dst[1] = (src[1] + src[3]) * 0.5f; /* right */
>+    }
>+
>+    cvt->len_cvt /= 3;
>+    if (cvt->filters[++cvt->filter_index]) {
>+        cvt->filters[cvt->filter_index] (cvt, format);
>+    }
>+}
>+
>+
>+/* Convert from 7.1 to 5.1. Distribute sides across front and back. */
>+static void SDLCALL
>+SDL_Convert71To51(SDL_AudioCVT * cvt, SDL_AudioFormat format)
>+{
>+    float *dst = (float *) cvt->buf;
>+    const float *src = dst;
>+    int i;
>+
>+    LOG_DEBUG_CONVERT("7.1", "5.1");
>+    SDL_assert(format == AUDIO_F32SYS);
>+
>+    for (i = cvt->len_cvt / (sizeof (float) * 8); i; --i, src += 8, dst += 6) {
>+        const float surround_left_distributed = src[6] * 0.707107f;
>+        const float surround_right_distributed = src[7] * 0.707107f;
>+        dst[0] = (src[0] + surround_left_distributed) / 1.707107f;  /* FL */
>+        dst[1] = (src[1] + surround_right_distributed) / 1.707107f;  /* FR */
>+        dst[2] = src[2] / 1.707107f; /* CC */
>+        dst[3] = src[3] / 1.707107f; /* LFE */
>+        dst[4] = (src[4] + surround_left_distributed) / 1.707107f;  /* BL */
>+        dst[5] = (src[5] + surround_right_distributed) / 1.707107f;  /* BR */
>+    }
>+
>+    cvt->len_cvt /= 8;
>+    cvt->len_cvt *= 6;
>+    if (cvt->filters[++cvt->filter_index]) {
>+        cvt->filters[cvt->filter_index] (cvt, format);
>+    }
>+}
>+
>+
>+/* Convert from 5.1 to quad. Distribute center across front, discard LFE. */
> static void SDLCALL
> SDL_Convert51ToQuad(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -128,14 +181,14 @@
>     LOG_DEBUG_CONVERT("5.1", "quad");
>     SDL_assert(format == AUDIO_F32SYS);
> 
>-    /* assumes quad is FL+FR+BL+BR layout and 5.1 is FL+FR+FC+subwoof+BL+BR */
>+    /* SDL's 4.0 layout: FL+FR+BL+BR */
>+    /* SDL's 5.1 layout: FL+FR+FC+LFE+BL+BR */
>     for (i = cvt->len_cvt / (sizeof (float) * 6); i; --i, src += 6, dst += 4) {
>-        /* FIXME: this is a good candidate for SIMD. */
>-        const double front_center = (double) src[2];
>-        dst[0] = (float) ((src[0] + front_center) * 0.5);  /* FL */
>-        dst[1] = (float) ((src[1] + front_center) * 0.5);  /* FR */
>-        dst[2] = (float) ((src[4] + front_center) * 0.5);  /* BL */
>-        dst[3] = (float) ((src[5] + front_center) * 0.5);  /* BR */
>+        const float front_center_distributed = src[2] * 0.707107f;
>+        dst[0] = (src[0] + front_center_distributed) / 1.707107f;  /* FL */
>+        dst[1] = (src[1] + front_center_distributed) / 1.707107f;  /* FR */
>+        dst[2] = src[4] / 1.707107f;  /* BL */
>+        dst[3] = src[5] / 1.707107f;  /* BR */
>     }
> 
>     cvt->len_cvt /= 6;
>@@ -146,7 +199,7 @@
> }
> 
> 
>-/* Duplicate a mono channel to both stereo channels */
>+/* Upmix mono to stereo (by duplication) */
> static void SDLCALL
> SDL_ConvertMonoToStereo(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -170,7 +223,7 @@
> }
> 
> 
>-/* Duplicate a stereo channel to a pseudo-5.1 stream */
>+/* Upmix stereo to a pseudo-5.1 stream */
> static void SDLCALL
> SDL_ConvertStereoTo51(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -182,16 +235,17 @@
>     LOG_DEBUG_CONVERT("stereo", "5.1");
>     SDL_assert(format == AUDIO_F32SYS);
> 
>-    for (i = cvt->len_cvt / 8; i; --i) {
>+    for (i = cvt->len_cvt / (sizeof(float) * 2); i; --i) {
>         dst -= 6;
>         src -= 2;
>         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[2] = ce;  /* FC */
>-        dst[3] = ce;  /* !!! FIXME: wrong! This is the subwoofer. */
>+        dst[3] = 0;   /* LFE (only meant for special LFE effects) */
>         dst[4] = lf;  /* BL */
>         dst[5] = rf;  /* BR */
>     }
>@@ -203,7 +257,44 @@
> }
> 
> 
>-/* Duplicate a stereo channel to a pseudo-4.0 stream */
>+/* Upmix quad to a pseudo-5.1 stream */
>+static void SDLCALL
>+SDL_ConvertQuadTo51(SDL_AudioCVT * cvt, SDL_AudioFormat format)
>+{
>+    int i;
>+    float lf, rf, lb, rb, ce;
>+    const float *src = (const float *) (cvt->buf + cvt->len_cvt);
>+    float *dst = (float *) (cvt->buf + cvt->len_cvt * 3 / 2);
>+
>+    LOG_DEBUG_CONVERT("quad", "5.1");
>+    SDL_assert(format == AUDIO_F32SYS);
>+    SDL_assert(cvt->len_cvt % (sizeof(float) * 4) == 0);
>+
>+    for (i = cvt->len_cvt / (sizeof(float) * 4); i; --i) {
>+        dst -= 6;
>+        src -= 4;
>+        lf = src[0];
>+        rf = src[1];
>+        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[2] = ce;  /* FC */
>+        dst[3] = 0;   /* LFE (only meant for special LFE effects) */
>+        dst[4] = lb;  /* BL */
>+        dst[5] = rb;  /* BR */
>+    }
>+
>+    cvt->len_cvt = cvt->len_cvt * 3 / 2;
>+    if (cvt->filters[++cvt->filter_index]) {
>+        cvt->filters[cvt->filter_index] (cvt, format);
>+    }
>+}
>+
>+
>+/* Upmix stereo to a pseudo-4.0 stream (by duplication) */
> static void SDLCALL
> SDL_ConvertStereoToQuad(SDL_AudioCVT * cvt, SDL_AudioFormat format)
> {
>@@ -215,7 +306,7 @@
>     LOG_DEBUG_CONVERT("stereo", "quad");
>     SDL_assert(format == AUDIO_F32SYS);
> 
>-    for (i = cvt->len_cvt / 8; i; --i) {
>+    for (i = cvt->len_cvt / (sizeof(float) * 2); i; --i) {
>         dst -= 4;
>         src -= 2;
>         lf = src[0];
>@@ -232,6 +323,52 @@
>     }
> }
> 
>+
>+/* Upmix 5.1 to 7.1 */
>+static void SDLCALL
>+SDL_Convert51To71(SDL_AudioCVT * cvt, SDL_AudioFormat format)
>+{
>+    float lf, rf, lb, rb, ls, rs;
>+    int i;
>+    const float *src = (const float *) (cvt->buf + cvt->len_cvt);
>+    float *dst = (float *) (cvt->buf + cvt->len_cvt * 4 / 3);
>+
>+    LOG_DEBUG_CONVERT("5.1", "7.1");
>+    SDL_assert(format == AUDIO_F32SYS);
>+    SDL_assert(cvt->len_cvt % (sizeof(float) * 6) == 0);
>+
>+    for (i = cvt->len_cvt / (sizeof(float) * 6); i; --i) {
>+        dst -= 8;
>+        src -= 6;
>+        lf = src[0];
>+        rf = src[1];
>+        lb = src[4];
>+        rb = src[5];
>+        ls = (lf + lb) * 0.5f;
>+        rs = (rf + rb) * 0.5f;
>+        /* !!! FIXME: these four may clip */
>+        lf += lf - ls;
>+        rf += rf - ls;
>+        lb += lb - ls;
>+        rb += rb - ls;
>+        dst[3] = src[3];  /* LFE */
>+        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 */
>+    }
>+
>+    cvt->len_cvt = cvt->len_cvt * 4 / 3;
>+
>+    if (cvt->filters[++cvt->filter_index]) {
>+        cvt->filters[cvt->filter_index] (cvt, format);
>+    }
>+}
>+
>+
> static int
> SDL_ResampleAudioSimple(const int chans, const double rate_incr,
>                         float *last_sample, const float *inbuf,
>@@ -731,9 +868,9 @@
>         case 2:  /* stereo */
>         case 4:  /* quad */
>         case 6:  /* 5.1 */
>-            return SDL_TRUE;  /* supported. */
>+        case 8:  /* 7.1 */
>+          return SDL_TRUE;  /* supported. */
> 
>-        case 8:  /* !!! FIXME: 7.1 */
>         default:
>             break;
>     }
>@@ -851,7 +988,9 @@
>     }
> 
>     /* Channel conversion */
>-    if (src_channels != dst_channels) {
>+    if (src_channels < dst_channels) {
>+        /* Upmixing */
>+        /* Mono -> Stereo [-> ...] */
>         if ((src_channels == 1) && (dst_channels > 1)) {
>             if (SDL_AddAudioCVTFilter(cvt, SDL_ConvertMonoToStereo) < 0) {
>                 return -1;
>@@ -860,7 +999,8 @@
>             src_channels = 2;
>             cvt->len_ratio *= 2;
>         }
>-        if ((src_channels == 2) && (dst_channels == 6)) {
>+        /* [Mono ->] Stereo -> 5.1 [-> 7.1] */
>+        if ((src_channels == 2) && (dst_channels >= 6)) {
>             if (SDL_AddAudioCVTFilter(cvt, SDL_ConvertStereoTo51) < 0) {
>                 return -1;
>             }
>@@ -868,6 +1008,27 @@
>             cvt->len_mult *= 3;
>             cvt->len_ratio *= 3;
>         }
>+        /* Quad -> 5.1 [-> 7.1] */
>+        if ((src_channels == 4) && (dst_channels >= 6)) {
>+            if (SDL_AddAudioCVTFilter(cvt, SDL_ConvertQuadTo51) < 0) {
>+                return -1;
>+            }
>+            src_channels = 6;
>+            cvt->len_mult = (cvt->len_mult * 3 + 1) / 2;
>+            cvt->len_ratio *= 1.5;
>+        }
>+        /* [[Mono ->] Stereo ->] 5.1 -> 7.1 */
>+        if ((src_channels == 6) && (dst_channels == 8)) {
>+            if (SDL_AddAudioCVTFilter(cvt, SDL_Convert51To71) < 0) {
>+                return -1;
>+            }
>+            src_channels = 8;
>+            cvt->len_mult = (cvt->len_mult * 4 + 2) / 3;
>+            /* Should be numerically exact with every valid input to this
>+               function */
>+            cvt->len_ratio = cvt->len_ratio * 4 / 3;
>+        }
>+        /* [Mono ->] Stereo -> Quad */
>         if ((src_channels == 2) && (dst_channels == 4)) {
>             if (SDL_AddAudioCVTFilter(cvt, SDL_ConvertStereoToQuad) < 0) {
>                 return -1;
>@@ -876,14 +1037,18 @@
>             cvt->len_mult *= 2;
>             cvt->len_ratio *= 2;
>         }
>-        while ((src_channels * 2) <= dst_channels) {
>-            if (SDL_AddAudioCVTFilter(cvt, SDL_ConvertMonoToStereo) < 0) {
>+    } else if (src_channels > dst_channels) {
>+        /* Downmixing */
>+        /* 7.1 -> 5.1 [-> Stereo [-> Mono]] */
>+        /* 7.1 -> 5.1 [-> Quad] */
>+        if ((src_channels == 8) && (dst_channels <= 6)) {
>+            if (SDL_AddAudioCVTFilter(cvt, SDL_Convert71To51) < 0) {
>                 return -1;
>             }
>-            cvt->len_mult *= 2;
>-            src_channels *= 2;
>-            cvt->len_ratio *= 2;
>+            src_channels = 6;
>+            cvt->len_ratio *= 0.75;
>         }
>+        /* [7.1 ->] 5.1 -> Stereo [-> Mono] */
>         if ((src_channels == 6) && (dst_channels <= 2)) {
>             if (SDL_AddAudioCVTFilter(cvt, SDL_Convert51ToStereo) < 0) {
>                 return -1;
>@@ -891,19 +1056,24 @@
>             src_channels = 2;
>             cvt->len_ratio /= 3;
>         }
>+        /* 5.1 -> Quad */
>         if ((src_channels == 6) && (dst_channels == 4)) {
>             if (SDL_AddAudioCVTFilter(cvt, SDL_Convert51ToQuad) < 0) {
>                 return -1;
>             }
>             src_channels = 4;
>+            cvt->len_ratio = cvt->len_ratio * 2 / 3;
>+        }
>+        /* Quad -> Stereo [-> Mono] */
>+        if ((src_channels == 4) && (dst_channels <= 2)) {
>+            if (SDL_AddAudioCVTFilter(cvt, SDL_ConvertQuadToStereo) < 0) {
>+                return -1;
>+            }
>+            src_channels = 2;
>             cvt->len_ratio /= 2;
>         }
>-        /* This assumes that 4 channel audio is in the format:
>-           Left {front/back} + Right {front/back}
>-           so converting to L/R stereo works properly.
>-         */
>-        while (((src_channels % 2) == 0) &&
>-               ((src_channels / 2) >= dst_channels)) {
>+        /* [... ->] Stereo -> Mono */
>+        if ((src_channels == 2) && (dst_channels == 1)) {
>             SDL_AudioFilter filter = NULL;
> 
>             #if HAVE_SSE3_INTRINSICS
>@@ -920,14 +1090,17 @@
>                 return -1;
>             }
> 
>-            src_channels /= 2;
>+            src_channels = 1;
>             cvt->len_ratio /= 2;
>         }
>-        if (src_channels != dst_channels) {
>-            /* Uh oh.. */ ;
>-        }
>     }
> 
>+    if (src_channels != dst_channels) {
>+        /* All combinations of supported channel counts should have been
>+           handled by now, but let's be defensive */
>+      return SDL_SetError("Invalid channel combination");
>+    }
>+    
>     /* Do rate conversion, if necessary. Updates (cvt). */
>     if (SDL_BuildAudioResampleCVT(cvt, dst_channels, src_rate, dst_rate) < 0) {
>         return -1;              /* shouldn't happen, but just in case... */

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Attachments on bug 3727: 2820 | 2821

We are currently migrating Bugzilla to GitHub issues.Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.