[FFmpeg-cvslog] avcodec/photocd: Simplify parsing Huffman tables a bit

Andreas Rheinhardt git at videolan.org
Sat Sep 26 22:12:13 EEST 2020


ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Wed Sep 23 04:57:53 2020 +0200| [a902c24994dea7cbdf84bff70ad8709958b1008d] | committer: Andreas Rheinhardt

avcodec/photocd: Simplify parsing Huffman tables a bit

Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a902c24994dea7cbdf84bff70ad8709958b1008d
---

 libavcodec/photocd.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/libavcodec/photocd.c b/libavcodec/photocd.c
index 057c9d33d4..8fd4536a65 100644
--- a/libavcodec/photocd.c
+++ b/libavcodec/photocd.c
@@ -245,21 +245,20 @@ static av_noinline int decode_huff(AVCodecContext *avctx, AVFrame *frame,
         int x2, idx;
 
         for (; get_bits_left(&g) > 0;) {
-            if ((show_bits(&g, 24) & 0xfff000) == 0xfff000)
+            if (show_bits(&g, 12) == 0xfff)
                 break;
             skip_bits(&g, 8);
         }
 
-        shiftreg = show_bits_long(&g, 32) & 0xffffff00;
-        while (shiftreg != 0xfffffe00) {
+        shiftreg = show_bits(&g, 24);
+        while (shiftreg != 0xfffffe) {
             if (get_bits_left(&g) <= 0)
                 return AVERROR_INVALIDDATA;
             skip_bits(&g, 1);
-            shiftreg = show_bits_long(&g, 32) & 0xffffff00;
+            shiftreg = show_bits(&g, 24);
         }
-        skip_bits(&g, 16);
-        y = show_bits_long(&g, 23) & 0x1fff;
-        skip_bits(&g, 8);
+        skip_bits(&g, 24);
+        y = show_bits(&g, 15) & 0x1fff;
         if (y >= height)
             break;
         type = get_bits(&g, 2);



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