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[FFmpeg-devel,4/4] avcodec/intrax8: Avoid indirection when accessing VLC table

Message ID DB6PR0101MB2214EEEFCD44E39ABC212EDE8F9B9@DB6PR0101MB2214.eurprd01.prod.exchangelabs.com
State Accepted
Headers show
Series [FFmpeg-devel,1/4] avcodec/intrax8: Remove unused IDCTDSPContext | expand

Checks

Context Check Description
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished

Commit Message

Andreas Rheinhardt July 31, 2022, 9:41 a.m. UTC 
To do so, store the pointer to the VLC table and not to the VLC.
This is possible, because all the VLCs of the same type use
the same number of bits.
Also use a const VLCElem*, because the target is static and must
therefore not be modified after its initialization.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/intrax8.c | 24 ++++++++++++------------
 libavcodec/intrax8.h |  6 +++---
 2 files changed, 15 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/libavcodec/intrax8.c b/libavcodec/intrax8.c
index b99e8590b1..e82cb8680e 100644
--- a/libavcodec/intrax8.c
+++ b/libavcodec/intrax8.c
@@ -91,9 +91,9 @@  static av_cold void x8_vlc_init(void)
 
 static void x8_reset_vlc_tables(IntraX8Context *w)
 {
-    memset(w->j_dc_vlc, 0, sizeof(w->j_dc_vlc));
-    memset(w->j_ac_vlc, 0, sizeof(w->j_ac_vlc));
-    w->j_orient_vlc = NULL;
+    memset(w->j_dc_vlc_table, 0, sizeof(w->j_dc_vlc_table));
+    memset(w->j_ac_vlc_table, 0, sizeof(w->j_ac_vlc_table));
+    w->j_orient_vlc_table = NULL;
 }
 
 static inline void x8_select_ac_table(IntraX8Context *const w, int mode)
@@ -102,23 +102,23 @@  static inline void x8_select_ac_table(IntraX8Context *const w, int mode)
 
     av_assert2(mode < 4);
 
-    if (w->j_ac_vlc[mode])
+    if (w->j_ac_vlc_table[mode])
         return;
 
     table_index       = get_bits(w->gb, 3);
     // 2 modes use same tables
-    w->j_ac_vlc[mode] = &j_ac_vlc[w->quant < 13][mode >> 1][table_index];
+    w->j_ac_vlc_table[mode] = j_ac_vlc[w->quant < 13][mode >> 1][table_index].table;
     av_assert2(w->j_ac_vlc[mode]);
 }
 
 static inline int x8_get_orient_vlc(IntraX8Context *w)
 {
-    if (!w->j_orient_vlc) {
+    if (!w->j_orient_vlc_table) {
         int table_index = get_bits(w->gb, 1 + (w->quant < 13));
-        w->j_orient_vlc = &j_orient_vlc[w->quant < 13][table_index];
+        w->j_orient_vlc_table = j_orient_vlc[w->quant < 13][table_index].table;
     }
 
-    return get_vlc2(w->gb, w->j_orient_vlc->table, OR_VLC_BITS, OR_VLC_MTD);
+    return get_vlc2(w->gb, w->j_orient_vlc_table, OR_VLC_BITS, OR_VLC_MTD);
 }
 
 #define extra_bits(eb)  (eb)        // 3 bits
@@ -174,7 +174,7 @@  static void x8_get_ac_rlf(IntraX8Context *const w, const int mode,
     int i, e;
 
 //    x8_select_ac_table(w, mode);
-    i = get_vlc2(w->gb, w->j_ac_vlc[mode]->table, AC_VLC_BITS, AC_VLC_MTD);
+    i = get_vlc2(w->gb, w->j_ac_vlc_table[mode], AC_VLC_BITS, AC_VLC_MTD);
 
     if (i < 46) { // [0-45]
         int t, l;
@@ -254,13 +254,13 @@  static int x8_get_dc_rlf(IntraX8Context *const w, const int mode,
     int i, e, c;
 
     av_assert2(mode < 3);
-    if (!w->j_dc_vlc[mode]) {
+    if (!w->j_dc_vlc_table[mode]) {
         int table_index = get_bits(w->gb, 3);
         // 4 modes, same table
-        w->j_dc_vlc[mode] = &j_dc_vlc[w->quant < 13][table_index];
+        w->j_dc_vlc_table[mode] = j_dc_vlc[w->quant < 13][table_index].table;
     }
 
-    i = get_vlc2(w->gb, w->j_dc_vlc[mode]->table, DC_VLC_BITS, DC_VLC_MTD);
+    i = get_vlc2(w->gb, w->j_dc_vlc_table[mode], DC_VLC_BITS, DC_VLC_MTD);
 
     /* (i >= 17) { i -= 17; final =1; } */
     c      = i > 16;
diff --git a/libavcodec/intrax8.h b/libavcodec/intrax8.h
index 3ebbf73434..c994b14abe 100644
--- a/libavcodec/intrax8.h
+++ b/libavcodec/intrax8.h
@@ -27,9 +27,9 @@ 
 #include "mpegpicture.h"
 
 typedef struct IntraX8Context {
-    VLC *j_ac_vlc[4]; // they point to the static j_mb_vlc
-    VLC *j_orient_vlc;
-    VLC *j_dc_vlc[3];
+    const VLCElem *j_ac_vlc_table[4]; // they point to the static j_mb_vlc
+    const VLCElem *j_orient_vlc_table;
+    const VLCElem *j_dc_vlc_table[3];
 
     int use_quant_matrix;