swscale: Implement alphablendaway for planar 4:4:4 formats

Fixes Ticket4746

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 101 insertions, 0 deletions

diff --git a/libswscale/utils.c b/libswscale/utils.c
index 106101ab0b..d00164361b 100644
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@@ -979,6 +979,58 @@ static uint16_t * alloc_gamma_tbl(double e)
     return tbl;
 }
 
+static enum AVPixelFormat alphaless_fmt(enum AVPixelFormat fmt)
+{
+    switch(fmt) {
+//     case AV_PIX_FMT_ARGB:       return AV_PIX_FMT_RGB24;
+//     case AV_PIX_FMT_RGBA:       return AV_PIX_FMT_RGB24;
+//     case AV_PIX_FMT_ABGR:       return AV_PIX_FMT_BGR24;
+//     case AV_PIX_FMT_BGRA:       return AV_PIX_FMT_BGR24;
+//     case AV_PIX_FMT_YA8:        return AV_PIX_FMT_GRAY8;
+//
+//     case AV_PIX_FMT_YUVA420P:   return AV_PIX_FMT_YUV420P;
+//     case AV_PIX_FMT_YUVA422P:   return AV_PIX_FMT_YUV422P;
+    case AV_PIX_FMT_YUVA444P:           return AV_PIX_FMT_YUV444P;
+
+    case AV_PIX_FMT_GBRAP:              return AV_PIX_FMT_GBRP;
+
+    case AV_PIX_FMT_GBRAP16LE:          return AV_PIX_FMT_GBRP16;
+    case AV_PIX_FMT_GBRAP16BE:          return AV_PIX_FMT_GBRP16;
+
+//     case AV_PIX_FMT_RGBA64LE:   return AV_PIX_FMT_RGB48;
+//     case AV_PIX_FMT_RGBA64BE:   return AV_PIX_FMT_RGB48;
+//     case AV_PIX_FMT_BGRA64LE:   return AV_PIX_FMT_BGR48;
+//     case AV_PIX_FMT_BGRA64BE:   return AV_PIX_FMT_BGR48;
+
+//     case AV_PIX_FMT_YA16BE:             return AV_PIX_FMT_GRAY16;
+//     case AV_PIX_FMT_YA16LE:             return AV_PIX_FMT_GRAY16;
+
+//     case AV_PIX_FMT_YUVA420P9BE:        return AV_PIX_FMT_YUV420P9;
+//     case AV_PIX_FMT_YUVA422P9BE:        return AV_PIX_FMT_YUV422P9;
+    case AV_PIX_FMT_YUVA444P9BE:        return AV_PIX_FMT_YUV444P9;
+//     case AV_PIX_FMT_YUVA420P9LE:        return AV_PIX_FMT_YUV420P9;
+//     case AV_PIX_FMT_YUVA422P9LE:        return AV_PIX_FMT_YUV422P9;
+    case AV_PIX_FMT_YUVA444P9LE:        return AV_PIX_FMT_YUV444P9;
+//     case AV_PIX_FMT_YUVA420P10BE:       return AV_PIX_FMT_YUV420P10;
+//     case AV_PIX_FMT_YUVA422P10BE:       return AV_PIX_FMT_YUV422P10;
+    case AV_PIX_FMT_YUVA444P10BE:       return AV_PIX_FMT_YUV444P10;
+//     case AV_PIX_FMT_YUVA420P10LE:       return AV_PIX_FMT_YUV420P10;
+//     case AV_PIX_FMT_YUVA422P10LE:       return AV_PIX_FMT_YUV422P10;
+    case AV_PIX_FMT_YUVA444P10LE:       return AV_PIX_FMT_YUV444P10;
+//     case AV_PIX_FMT_YUVA420P16BE:       return AV_PIX_FMT_YUV420P16;
+//     case AV_PIX_FMT_YUVA422P16BE:       return AV_PIX_FMT_YUV422P16;
+    case AV_PIX_FMT_YUVA444P16BE:       return AV_PIX_FMT_YUV444P16;
+//     case AV_PIX_FMT_YUVA420P16LE:       return AV_PIX_FMT_YUV420P16;
+//     case AV_PIX_FMT_YUVA422P16LE:       return AV_PIX_FMT_YUV422P16;
+    case AV_PIX_FMT_YUVA444P16LE:       return AV_PIX_FMT_YUV444P16;
+
+//     case AV_PIX_FMT_AYUV64LE:
+//     case AV_PIX_FMT_AYUV64BE:
+//     case AV_PIX_FMT_PAL8:
+    default: return AV_PIX_FMT_NONE;
+    }
+}
+
 av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
                              SwsFilter *dstFilter)
 {
@@ -1340,6 +1392,39 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
         }
     }
 
+    if (CONFIG_SWSCALE_ALPHA && isALPHA(srcFormat) && !isALPHA(dstFormat)) {
+        enum AVPixelFormat tmpFormat = alphaless_fmt(srcFormat);
+
+        if (tmpFormat != AV_PIX_FMT_NONE && c->alphablend != SWS_ALPHA_BLEND_NONE)
+        if (!unscaled ||
+            dstFormat != tmpFormat ||
+            usesHFilter || usesVFilter ||
+            c->srcRange != c->dstRange
+        ) {
+            ret = av_image_alloc(c->cascaded_tmp, c->cascaded_tmpStride,
+                                srcW, srcH, tmpFormat, 64);
+            if (ret < 0)
+                return ret;
+
+            c->cascaded_context[0] = sws_alloc_set_opts(srcW, srcH, srcFormat,
+                                                        srcW, srcH, tmpFormat,
+                                                        flags, c->param);
+            if (!c->cascaded_context[0])
+                return -1;
+            c->cascaded_context[0]->alphablend = c->alphablend;
+            ret = sws_init_context(c->cascaded_context[0], NULL , NULL);
+            if (ret < 0)
+                return ret;
+
+            c->cascaded_context[1] = sws_getContext(srcW, srcH, tmpFormat,
+                                                    dstW, dstH, dstFormat,
+                                                    flags, srcFilter, dstFilter, c->param);
+            if (!c->cascaded_context[1])
+                return -1;
+            return 0;
+        }
+    }
+
 #define USE_MMAP (HAVE_MMAP && HAVE_MPROTECT && defined MAP_ANONYMOUS)
 
     /* precalculate horizontal scaler filter coefficients */
@@ -1586,6 +1671,22 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
                c->chrXInc, c->chrYInc);
     }
 
+    /* alpha blend special case, note this has been split via cascaded contexts if its scaled */
+    if (unscaled && !usesHFilter && !usesVFilter &&
+        c->alphablend != SWS_ALPHA_BLEND_NONE &&
+        isALPHA(srcFormat) &&
+        (c->srcRange == c->dstRange || isAnyRGB(dstFormat)) &&
+        alphaless_fmt(srcFormat) == dstFormat
+    ) {
+        c->swscale = ff_sws_alphablendaway;
+
+        if (flags & SWS_PRINT_INFO)
+            av_log(c, AV_LOG_INFO,
+                    "using alpha blendaway %s -> %s special converter\n",
+                    av_get_pix_fmt_name(srcFormat), av_get_pix_fmt_name(dstFormat));
+        return 0;
+    }
+
     /* unscaled special cases */
     if (unscaled && !usesHFilter && !usesVFilter &&
         (c->srcRange == c->dstRange || isAnyRGB(dstFormat))) {