swscale/utils: If the source has no alpha then disable alpha blendaway

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
10 years ago · 816cf5181e
parent dfd3fd67bb
commit 816cf5181e
1 changed files with 4 additions and 0 deletions
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@ -1144,6 +1144,10 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
    desc_src = av_pix_fmt_desc_get(srcFormat);
    desc_dst = av_pix_fmt_desc_get(dstFormat);

+    // If the source has no alpha then disable alpha blendaway
+    if (c->src0Alpha)
+        c->alphablend = SWS_ALPHA_BLEND_NONE;
+
    if (!(unscaled && sws_isSupportedEndiannessConversion(srcFormat) &&
          av_pix_fmt_swap_endianness(srcFormat) == dstFormat)) {
    if (!sws_isSupportedInput(srcFormat)) {