From d6f910ea47255b519e0b71c33d74c409a29ab3db Mon Sep 17 00:00:00 2001
From: Alexandre Colucci <alexandre@elgato.com>
Date: Wed, 27 Apr 2011 18:39:57 +0200
Subject: [PATCH] Fix decoding of DXSA subtitles.
These have a DXSA tag and contain alpha in addition to
color values for palette.
---
libavcodec/xsubdec.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/libavcodec/xsubdec.c b/libavcodec/xsubdec.c
index a577ac8f284..d7babe4cd26 100644
--- a/libavcodec/xsubdec.c
+++ b/libavcodec/xsubdec.c
@@ -54,6 +54,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
int w, h, x, y, rlelen, i;
int64_t packet_time = 0;
GetBitContext gb;
+ 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) {
@@ -100,8 +101,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
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 = 1; i < sub->rects[0]->nb_colors; i++)
- ((uint32_t*)sub->rects[0]->pict.data[1])[i] |= 0xff000000;
+ 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;
// process RLE-compressed data
rlelen = FFMIN(rlelen, buf_end - buf);
--
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