[FFmpeg-devel] [PATCH] avcodec/dnxhddec: Use VLC symbol table to avoid lookup

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Sat Sep 16 05:25:24 EEST 2023


Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/dnxhddec.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/libavcodec/dnxhddec.c b/libavcodec/dnxhddec.c
index b5f4e053c0..703d0e341c 100644
--- a/libavcodec/dnxhddec.c
+++ b/libavcodec/dnxhddec.c
@@ -142,9 +142,10 @@ static int dnxhd_init_vlc(DNXHDContext *ctx, uint32_t cid, int bitdepth)
                  ctx->cid_table->dc_bits, 1, 1,
                  ctx->cid_table->dc_codes, 1, 1, 0)) < 0)
             goto out;
-        if ((ret = vlc_init(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
+        if ((ret = ff_vlc_init_sparse(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
                  ctx->cid_table->run_bits, 1, 1,
-                 ctx->cid_table->run_codes, 2, 2, 0)) < 0)
+                 ctx->cid_table->run_codes, 2, 2,
+                 ctx->cid_table->run, 1, 1, 0)) < 0)
             goto out;
 
         ctx->cid = cid;
@@ -358,7 +359,7 @@ static av_always_inline int dnxhd_decode_dct_block(const DNXHDContext *ctx,
                                                    int level_shift,
                                                    int dc_shift)
 {
-    int i, j, index1, index2, len, flags;
+    int i, j, index1, len, flags;
     int level, component, sign;
     const int *scale;
     const uint8_t *weight_matrix;
@@ -425,10 +426,11 @@ static av_always_inline int dnxhd_decode_dct_block(const DNXHDContext *ctx,
         }
 
         if (flags & 2) {
+            int run;
             UPDATE_CACHE(bs, &row->gb);
-            GET_VLC(index2, bs, &row->gb, ctx->run_vlc.table,
+            GET_VLC(run, bs, &row->gb, ctx->run_vlc.table,
                     DNXHD_VLC_BITS, 2);
-            i += ctx->cid_table->run[index2];
+            i += run;
         }
 
         if (++i > 63) {
-- 
2.34.1



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