Merge commit '5a1addd7'

* commit '5a1addd7':
  xsub: Support DXSA subtitles

Conflicts:
	libavcodec/xsubdec.c

See: d6f910eaMerged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/xsubdec.c

@@ -59,7 +59,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     int has_alpha = avctx->codec_tag == MKTAG('D','X','S','A');
 
     // check that at least header fits
-    if (buf_size < 27 + 7 * 2 + 4 * 3) {
+    if (buf_size < 27 + 7 * 2 + 4 * (3 + has_alpha)) {
         av_log(avctx, AV_LOG_ERROR, "coded frame size %d too small\n", buf_size);
         return -1;
     }
@@ -106,9 +106,15 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     // read palette
     for (i = 0; i < sub->rects[0]->nb_colors; i++)
         ((uint32_t*)sub->rects[0]->pict.data[1])[i] = bytestream_get_be24(&buf);
-    // make all except background (first entry) non-transparent
-    for (i = 0; i < sub->rects[0]->nb_colors; i++)
-        ((uint32_t*)sub->rects[0]->pict.data[1])[i] |= (has_alpha ? *buf++ : (i ? 0xff : 0)) << 24;
+
+    if (!has_alpha) {
+        // make all except background (first entry) non-transparent
+        for (i = 1; i < sub->rects[0]->nb_colors; i++)
+            ((uint32_t *)sub->rects[0]->pict.data[1])[i] |= 0xff000000;
+    } else {
+        for (i = 0; i < sub->rects[0]->nb_colors; i++)
+            ((uint32_t *)sub->rects[0]->pict.data[1])[i] |= *buf++ << 24;
+    }
 
     // process RLE-compressed data
     init_get_bits(&gb, buf, (buf_end - buf) * 8);