[FFmpeg-devel] [PATCH 2/5] avcodec/utvideodec: hardcode vlc bits

[Michael Niedermayer]

2.5% faster vlc decoding

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/utvideodec.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/libavcodec/utvideodec.c b/libavcodec/utvideodec.c
index 815b71cfb6..411df47730 100644
--- a/libavcodec/utvideodec.c
+++ b/libavcodec/utvideodec.c
@@ -73,8 +73,8 @@ static int build_huff10(const uint8_t *src, VLC *vlc, int *fsym)
         syms[i]  = he[i].sym;
         code += 0x80000000u >> (he[i].len - 1);
     }
-
-    return ff_init_vlc_sparse(vlc, FFMIN(he[last].len, 11), last + 1,
+#define VLC_BITS 11
+    return ff_init_vlc_sparse(vlc, VLC_BITS, last + 1,
                               bits,  sizeof(*bits),  sizeof(*bits),
                               codes, sizeof(*codes), sizeof(*codes),
                               syms,  sizeof(*syms),  sizeof(*syms), 0);
@@ -117,7 +117,8 @@ static int build_huff(const uint8_t *src, VLC *vlc, int *fsym)
         code += 0x80000000u >> (he[i].len - 1);
     }
 
-    return ff_init_vlc_sparse(vlc, FFMIN(he[last].len, 11), last + 1,
+#define VLC_BITS 11
+    return ff_init_vlc_sparse(vlc, VLC_BITS, last + 1,
                               bits,  sizeof(*bits),  sizeof(*bits),
                               codes, sizeof(*codes), sizeof(*codes),
                               syms,  sizeof(*syms),  sizeof(*syms), 0);
@@ -196,7 +197,7 @@ static int decode_plane10(UtvideoContext *c, int plane_no,
         prev = 0x200;
         for (j = sstart; j < send; j++) {
             for (i = 0; i < width * step; i += step) {
-                pix = get_vlc2(&gb, vlc.table, vlc.bits, 3);
+                pix = get_vlc2(&gb, vlc.table, VLC_BITS, 3);
                 if (pix < 0) {
                     av_log(c->avctx, AV_LOG_ERROR, "Decoding error\n");
                     goto fail;
@@ -302,7 +303,7 @@ static int decode_plane(UtvideoContext *c, int plane_no,
         prev = 0x80;
         for (j = sstart; j < send; j++) {
             for (i = 0; i < width * step; i += step) {
-                pix = get_vlc2(&gb, vlc.table, vlc.bits, 3);
+                pix = get_vlc2(&gb, vlc.table, VLC_BITS, 3);
                 if (pix < 0) {
                     av_log(c->avctx, AV_LOG_ERROR, "Decoding error\n");
                     goto fail;
-- 
2.13.0