[FFmpeg-devel] [PATCH 58/61] avcodec/mpeg12: Avoid unnecessary VLC structures

[Andreas Rheinhardt <andreas.rheinhardt@outlook.com>]

Everything besides VLC.table is basically write-only
and even VLC.table can be removed by accessing the
underlying tables directly.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/mpeg12.c    | 58 +++++++++++++++++++++---------------------
 libavcodec/mpeg12dec.c | 12 ++++-----
 libavcodec/mpeg12dec.h |  4 +--
 libavcodec/mpeg12vlc.h | 14 +++++-----
 4 files changed, 44 insertions(+), 44 deletions(-)

diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 70033ec725..8d88820c46 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -115,43 +115,43 @@ void ff_mpeg1_clean_buffers(MpegEncContext *s)
 /******************************************/
 /* decoding */
 
-VLC ff_mv_vlc;
+VLCElem ff_mv_vlc[266];
 
-VLC ff_dc_lum_vlc;
-VLC ff_dc_chroma_vlc;
+VLCElem ff_dc_lum_vlc[512];
+VLCElem ff_dc_chroma_vlc[514];
 
-VLC ff_mbincr_vlc;
-VLC ff_mb_ptype_vlc;
-VLC ff_mb_btype_vlc;
-VLC ff_mb_pat_vlc;
+VLCElem ff_mbincr_vlc[538];
+VLCElem ff_mb_ptype_vlc[64];
+VLCElem ff_mb_btype_vlc[64];
+VLCElem ff_mb_pat_vlc[512];
 
 RL_VLC_ELEM ff_mpeg1_rl_vlc[680];
 RL_VLC_ELEM ff_mpeg2_rl_vlc[674];
 
 static av_cold void mpeg12_init_vlcs(void)
 {
-    VLC_INIT_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
-                    ff_mpeg12_vlc_dc_lum_bits, 1, 1,
-                    ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
-    VLC_INIT_STATIC(&ff_dc_chroma_vlc,  DC_VLC_BITS, 12,
-                    ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
-                    ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
-    VLC_INIT_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
-                    &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
-                    &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 266);
-    VLC_INIT_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
-                    &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
-                    &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
-    VLC_INIT_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
-                    &ff_mpeg12_mbPatTable[0][1], 2, 1,
-                    &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
-
-    VLC_INIT_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
-                    &table_mb_ptype[0][1], 2, 1,
-                    &table_mb_ptype[0][0], 2, 1, 64);
-    VLC_INIT_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
-                    &table_mb_btype[0][1], 2, 1,
-                    &table_mb_btype[0][0], 2, 1, 64);
+    VLC_INIT_STATIC_TABLE(ff_dc_lum_vlc, DC_VLC_BITS, 12,
+                          ff_mpeg12_vlc_dc_lum_bits, 1, 1,
+                          ff_mpeg12_vlc_dc_lum_code, 2, 2, 0);
+    VLC_INIT_STATIC_TABLE(ff_dc_chroma_vlc,  DC_VLC_BITS, 12,
+                          ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
+                          ff_mpeg12_vlc_dc_chroma_code, 2, 2, 0);
+    VLC_INIT_STATIC_TABLE(ff_mv_vlc, MV_VLC_BITS, 17,
+                          &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
+                          &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 0);
+    VLC_INIT_STATIC_TABLE(ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
+                          &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
+                          &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 0);
+    VLC_INIT_STATIC_TABLE(ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
+                          &ff_mpeg12_mbPatTable[0][1], 2, 1,
+                          &ff_mpeg12_mbPatTable[0][0], 2, 1, 0);
+
+    VLC_INIT_STATIC_TABLE(ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
+                          &table_mb_ptype[0][1], 2, 1,
+                          &table_mb_ptype[0][0], 2, 1, 0);
+    VLC_INIT_STATIC_TABLE(ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
+                          &table_mb_btype[0][1], 2, 1,
+                          &table_mb_btype[0][0], 2, 1, 0);
 
     ff_init_2d_vlc_rl(ff_mpeg1_vlc_table, ff_mpeg1_rl_vlc, ff_mpeg12_run,
                       ff_mpeg12_level, MPEG12_RL_NB_ELEMS,
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c
index 92ef6944fa..5f7ff4bb7a 100644
--- a/libavcodec/mpeg12dec.c
+++ b/libavcodec/mpeg12dec.c
@@ -117,7 +117,7 @@ static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 {
     int code, sign, val, shift;
 
-    code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
+    code = get_vlc2(&s->gb, ff_mv_vlc, MV_VLC_BITS, 2);
     if (code == 0)
         return pred;
     if (code < 0)
@@ -710,7 +710,7 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
         }
         break;
     case AV_PICTURE_TYPE_P:
-        mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
+        mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 1);
         if (mb_type < 0) {
             av_log(s->avctx, AV_LOG_ERROR,
                    "Invalid mb type in P-frame at %d %d\n", s->mb_x, s->mb_y);
@@ -719,7 +719,7 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
         mb_type = ptype2mb_type[mb_type];
         break;
     case AV_PICTURE_TYPE_B:
-        mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
+        mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 1);
         if (mb_type < 0) {
             av_log(s->avctx, AV_LOG_ERROR,
                    "Invalid mb type in B-frame at %d %d\n", s->mb_x, s->mb_y);
@@ -981,7 +981,7 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
         if (HAS_CBP(mb_type)) {
             s->bdsp.clear_blocks(s->block[0]);
 
-            cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
+            cbp = get_vlc2(&s->gb, ff_mb_pat_vlc, MB_PAT_VLC_BITS, 1);
             if (mb_block_count > 6) {
                 cbp *= 1 << mb_block_count - 6;
                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
@@ -1723,7 +1723,7 @@ static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
         skip_bits1(&s->gb);
     } else {
         while (get_bits_left(&s->gb) > 0) {
-            int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
+            int code = get_vlc2(&s->gb, ff_mbincr_vlc,
                                 MBINCR_VLC_BITS, 2);
             if (code < 0) {
                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
@@ -1892,7 +1892,7 @@ static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
             /* read increment again */
             s->mb_skip_run = 0;
             for (;;) {
-                int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
+                int code = get_vlc2(&s->gb, ff_mbincr_vlc,
                                     MBINCR_VLC_BITS, 2);
                 if (code < 0) {
                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
diff --git a/libavcodec/mpeg12dec.h b/libavcodec/mpeg12dec.h
index 4c015d3096..4641179149 100644
--- a/libavcodec/mpeg12dec.h
+++ b/libavcodec/mpeg12dec.h
@@ -30,9 +30,9 @@ static inline int decode_dc(GetBitContext *gb, int component)
     int code, diff;
 
     if (component == 0) {
-        code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);
+        code = get_vlc2(gb, ff_dc_lum_vlc, DC_VLC_BITS, 2);
     } else {
-        code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);
+        code = get_vlc2(gb, ff_dc_chroma_vlc, DC_VLC_BITS, 2);
     }
     if (code == 0) {
         diff = 0;
diff --git a/libavcodec/mpeg12vlc.h b/libavcodec/mpeg12vlc.h
index 3ed35968f6..53f53947c3 100644
--- a/libavcodec/mpeg12vlc.h
+++ b/libavcodec/mpeg12vlc.h
@@ -39,13 +39,13 @@
 #define MB_PTYPE_VLC_BITS 6
 #define MB_BTYPE_VLC_BITS 6
 
-extern VLC ff_dc_lum_vlc;
-extern VLC ff_dc_chroma_vlc;
-extern VLC ff_mbincr_vlc;
-extern VLC ff_mb_ptype_vlc;
-extern VLC ff_mb_btype_vlc;
-extern VLC ff_mb_pat_vlc;
-extern VLC ff_mv_vlc;
+extern VLCElem ff_dc_lum_vlc[];
+extern VLCElem ff_dc_chroma_vlc[];
+extern VLCElem ff_mbincr_vlc[];
+extern VLCElem ff_mb_ptype_vlc[];
+extern VLCElem ff_mb_btype_vlc[];
+extern VLCElem ff_mb_pat_vlc[];
+extern VLCElem ff_mv_vlc[];
 
 void ff_mpeg12_init_vlcs(void);
 
-- 
2.34.1

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