[FFmpeg-devel] [PATCH 18/61] avcodec/atrac9dec: Avoid superfluous VLC structures

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

Of all these VLCs here, only VLC.table was really used
after init, so use the ff_vlc_init_tables API
to get rid of them.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/atrac9dec.c | 52 ++++++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 27 deletions(-)

diff --git a/libavcodec/atrac9dec.c b/libavcodec/atrac9dec.c
index d24a8e3f79..5b84f0c6d6 100644
--- a/libavcodec/atrac9dec.c
+++ b/libavcodec/atrac9dec.c
@@ -105,8 +105,8 @@ typedef struct ATRAC9Context {
     DECLARE_ALIGNED(32, float, temp)[2048];
 } ATRAC9Context;
 
-static VLC sf_vlc[2][8];            /* Signed/unsigned, length */
-static VLC coeff_vlc[2][8][4];      /* Cookbook, precision, cookbook index */
+static const VLCElem *sf_vlc[2][8];       /* Signed/unsigned, length */
+static const VLCElem *coeff_vlc[2][8][4]; /* Cookbook, precision, cookbook index */
 
 static inline int parse_gradient(ATRAC9Context *s, ATRAC9BlockData *b,
                                  GetBitContext *gb)
@@ -277,12 +277,12 @@ static inline int read_scalefactors(ATRAC9Context *s, ATRAC9BlockData *b,
         const uint8_t *sf_weights = at9_tab_sf_weights[get_bits(gb, 3)];
         const int base = get_bits(gb, 5);
         const int len = get_bits(gb, 2) + 3;
-        const VLC *tab = &sf_vlc[0][len];
+        const VLCElem *tab = sf_vlc[0][len];
 
         c->scalefactors[0] = get_bits(gb, len);
 
         for (int i = 1; i < b->band_ext_q_unit; i++) {
-            int val = c->scalefactors[i - 1] + get_vlc2(gb, tab->table,
+            int val = c->scalefactors[i - 1] + get_vlc2(gb, tab,
                                                         ATRAC9_SF_VLC_BITS, 1);
             c->scalefactors[i] = val & ((1 << len) - 1);
         }
@@ -310,10 +310,10 @@ static inline int read_scalefactors(ATRAC9Context *s, ATRAC9BlockData *b,
 
         const int len = get_bits(gb, 2) + 2;
         const int unit_cnt = FFMIN(b->band_ext_q_unit, baseline_len);
-        const VLC *tab = &sf_vlc[1][len];
+        const VLCElem *tab = sf_vlc[1][len];
 
         for (int i = 0; i < unit_cnt; i++) {
-            int dist = get_vlc2(gb, tab->table, ATRAC9_SF_VLC_BITS, 1);
+            int dist = get_vlc2(gb, tab, ATRAC9_SF_VLC_BITS, 1);
             c->scalefactors[i] = baseline[i] + dist;
         }
 
@@ -331,12 +331,12 @@ static inline int read_scalefactors(ATRAC9Context *s, ATRAC9BlockData *b,
         const int base = get_bits(gb, 5) - (1 << (5 - 1));
         const int len = get_bits(gb, 2) + 1;
         const int unit_cnt = FFMIN(b->band_ext_q_unit, baseline_len);
-        const VLC *tab = &sf_vlc[0][len];
+        const VLCElem *tab = sf_vlc[0][len];
 
         c->scalefactors[0] = get_bits(gb, len);
 
         for (int i = 1; i < unit_cnt; i++) {
-            int val = c->scalefactors[i - 1] + get_vlc2(gb, tab->table,
+            int val = c->scalefactors[i - 1] + get_vlc2(gb, tab,
                                                         ATRAC9_SF_VLC_BITS, 1);
             c->scalefactors[i] = val & ((1 << len) - 1);
         }
@@ -418,12 +418,12 @@ static inline void read_coeffs_coarse(ATRAC9Context *s, ATRAC9BlockData *b,
         if (prec <= max_prec) {
             const int cb = c->codebookset[i];
             const int cbi = at9_q_unit_to_codebookidx[i];
-            const VLC *tab = &coeff_vlc[cb][prec][cbi];
+            const VLCElem *tab = coeff_vlc[cb][prec][cbi];
             const HuffmanCodebook *huff = &at9_huffman_coeffs[cb][prec][cbi];
             const int groups = bands >> huff->value_cnt_pow;
 
             for (int j = 0; j < groups; j++) {
-                uint16_t val = get_vlc2(gb, tab->table, ATRAC9_COEFF_VLC_BITS, 2);
+                uint16_t val = get_vlc2(gb, tab, ATRAC9_COEFF_VLC_BITS, 2);
 
                 for (int k = 0; k < huff->value_cnt; k++) {
                     coeffs[k] = sign_extend(val, huff->value_bits);
@@ -841,33 +841,31 @@ static av_cold int atrac9_decode_close(AVCodecContext *avctx)
     return 0;
 }
 
-static av_cold void atrac9_init_vlc(VLC *vlc, int nb_bits, int nb_codes,
-                                    const uint8_t (**tab)[2],
-                                    unsigned *buf_offset, int offset)
+static av_cold const VLCElem *atrac9_init_vlc(VLCInitState *state,
+                                              int nb_bits, int nb_codes,
+                                              const uint8_t (**tab)[2], int offset)
 {
-    static VLCElem vlc_buf[24812];
+    const uint8_t (*table)[2] = *tab;
 
-    vlc->table           = &vlc_buf[*buf_offset];
-    vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *buf_offset;
-    ff_vlc_init_from_lengths(vlc, nb_bits, nb_codes,
-                             &(*tab)[0][1], 2, &(*tab)[0][0], 2, 1,
-                             offset, VLC_INIT_STATIC_OVERLONG, NULL);
-    *buf_offset += vlc->table_size;
     *tab        += nb_codes;
+    return ff_vlc_init_tables_from_lengths(state, nb_bits, nb_codes,
+                                           &table[0][1], 2, &table[0][0], 2, 1,
+                                           offset, 0);
 }
 
 static av_cold void atrac9_init_static(void)
 {
+    static VLCElem vlc_buf[24812];
+    VLCInitState state = VLC_INIT_STATE(vlc_buf);
     const uint8_t (*tab)[2];
-    unsigned offset = 0;
 
     /* Unsigned scalefactor VLCs */
     tab = at9_sfb_a_tab;
     for (int i = 1; i < 7; i++) {
         const HuffmanCodebook *hf = &at9_huffman_sf_unsigned[i];
 
-        atrac9_init_vlc(&sf_vlc[0][i], ATRAC9_SF_VLC_BITS,
-                        hf->size, &tab, &offset, 0);
+        sf_vlc[0][i] = atrac9_init_vlc(&state, ATRAC9_SF_VLC_BITS,
+                                       hf->size, &tab, 0);
     }
 
     /* Signed scalefactor VLCs */
@@ -878,8 +876,8 @@ static av_cold void atrac9_init_static(void)
         /* The symbols are signed integers in the range -16..15;
          * the values in the source table are offset by 16 to make
          * them fit into an uint8_t; the -16 reverses this shift. */
-        atrac9_init_vlc(&sf_vlc[1][i], ATRAC9_SF_VLC_BITS,
-                        hf->size, &tab, &offset, -16);
+        sf_vlc[1][i] = atrac9_init_vlc(&state, ATRAC9_SF_VLC_BITS,
+                                       hf->size, &tab, -16);
     }
 
     /* Coefficient VLCs */
@@ -888,8 +886,8 @@ static av_cold void atrac9_init_static(void)
         for (int j = 2; j < 8; j++) {
             for (int k = i; k < 4; k++) {
                 const HuffmanCodebook *hf = &at9_huffman_coeffs[i][j][k];
-                atrac9_init_vlc(&coeff_vlc[i][j][k], ATRAC9_COEFF_VLC_BITS,
-                                hf->size, &tab, &offset, 0);
+                coeff_vlc[i][j][k] = atrac9_init_vlc(&state, ATRAC9_COEFF_VLC_BITS,
+                                                     hf->size, &tab, 0);
             }
         }
     }
-- 
2.34.1

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