[FFmpeg-cvslog] avcodec/hq_hqa: Use RL-VLC table

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Wed Apr  9 18:54:38 2025 +0200| [ce0074f97bdc11aeb4d948da4fd476bd0975241e] | committer: Andreas Rheinhardt

avcodec/hq_hqa: Use RL-VLC table

This moves indirections to init.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ce0074f97bdc11aeb4d948da4fd476bd0975241e
---

 libavcodec/hq_hqa.c     | 39 +++++++++++++++++++++++++++++++--------
 libavcodec/hq_hqadata.h |  2 ++
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/libavcodec/hq_hqa.c b/libavcodec/hq_hqa.c
index 5c90f2f749..f69bf6b290 100644
--- a/libavcodec/hq_hqa.c
+++ b/libavcodec/hq_hqa.c
@@ -60,7 +60,7 @@ typedef struct HQContext {
 
 static const int32_t *hq_quants[NUM_HQ_QUANTS][2][4];
 
-static VLCElem hq_ac_vlc[1184];
+static RL_VLC_ELEM hq_ac_rvlc[1184];
 
 static inline void put_blocks(HQContext *c, AVFrame *pic,
                               int plane, int x, int y, int ilace,
@@ -78,7 +78,6 @@ static int hq_decode_block(HQContext *c, GetBitContext *gb, int16_t block[64],
                            int qsel, int is_chroma, int is_hqa)
 {
     const int32_t *q;
-    int val, pos = 1;
 
     if (!is_hqa) {
         block[0] = get_sbits(gb, 9) * 64;
@@ -88,17 +87,23 @@ static int hq_decode_block(HQContext *c, GetBitContext *gb, int16_t block[64],
         block[0] = get_sbits(gb, 9) * 64;
     }
 
-    for (;;) {
-        val = get_vlc2(gb, hq_ac_vlc, 9, 2);
-        if (val < 0)
+    OPEN_READER(re, gb);
+    for (int pos = 1;;) {
+        int level, run;
+        UPDATE_CACHE(re, gb);
+        GET_RL_VLC(level, run, re, gb, hq_ac_rvlc, 9, 2, 0);
+        if (run == HQ_AC_INVALID_RUN) {
+            CLOSE_READER(re, gb);
             return AVERROR_INVALIDDATA;
+        }
 
-        pos += hq_ac_skips[val];
+        pos += run;
         if (pos >= 64)
             break;
-        block[ff_zigzag_direct[pos]] = (int)(hq_ac_syms[val] * (unsigned)q[pos]) >> 12;
+        block[ff_zigzag_direct[pos]] = (int)(level * (unsigned)q[pos]) >> 12;
         pos++;
     }
+    CLOSE_READER(re, gb);
 
     return 0;
 }
@@ -372,9 +377,27 @@ static int hq_hqa_decode_frame(AVCodecContext *avctx, AVFrame *pic,
 
 static av_cold void hq_init_static(void)
 {
-    VLC_INIT_STATIC_TABLE(hq_ac_vlc, 9, NUM_HQ_AC_ENTRIES,
+    VLC_INIT_STATIC_TABLE(hq_ac_rvlc, 9, NUM_HQ_AC_ENTRIES,
                           hq_ac_bits, 1, 1, hq_ac_codes, 2, 2, 0);
 
+    for (size_t i = 0; i < FF_ARRAY_ELEMS(hq_ac_rvlc); ++i) {
+        int len = hq_ac_rvlc[i].len;
+        int sym = hq_ac_rvlc[i].sym, level = sym;
+        int run;
+
+        if (len > 0) {
+            level = hq_ac_syms[sym];
+            run   = hq_ac_skips[sym];
+        } else if (len < 0) { // More bits needed
+            run   = 0;
+        } else { // Invalid code
+            run = HQ_AC_INVALID_RUN;
+        }
+        hq_ac_rvlc[i].len8  = len;
+        hq_ac_rvlc[i].run   = run;
+        hq_ac_rvlc[i].level = level;
+    }
+
     for (size_t i = 0; i < FF_ARRAY_ELEMS(hq_quants); ++i) {
         for (size_t j = 0; j < FF_ARRAY_ELEMS(hq_quants[0]); ++j) {
             for (size_t k = 0; k < FF_ARRAY_ELEMS(hq_quants[0][0]); ++k)
diff --git a/libavcodec/hq_hqadata.h b/libavcodec/hq_hqadata.h
index 31f6dc88a4..8948c3a64a 100644
--- a/libavcodec/hq_hqadata.h
+++ b/libavcodec/hq_hqadata.h
@@ -1155,6 +1155,8 @@ static const uint8_t hq_quant_map[NUM_HQ_QUANTS][2][4] =
     { { QMAT3A, QMAT48, QMAT4C, QMAT4C }, { QMAT3B, QMAT49, QMAT4D, QMAT4D } },
 };
 
+#define HQ_AC_INVALID_RUN 128
+
 static const uint8_t hq_ac_bits[NUM_HQ_AC_ENTRIES] = {
      3,  3,  4,  4,  4,  5,  5,  5,  5,  5,  5,  6,  6,  6,  6,  6,
      6,  6,  6,  7,  7,  7,  7,  7,  7,  7,  7,  8,  8,  8,  8,  8,