[FFmpeg-devel] [PATCH 11/13] avcodec/dcahuff: Replace DCAVLC by ordinary VLCs

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Tue Sep 13 14:33:08 EEST 2022


This is possible now that the offsets are already applied
when creating the VLC.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/dca_core.c | 10 +++++-----
 libavcodec/dcahuff.c  | 13 +++++--------
 libavcodec/dcahuff.h  |  9 ++-------
 3 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/libavcodec/dca_core.c b/libavcodec/dca_core.c
index 7b23a40df4..c204e41cb7 100644
--- a/libavcodec/dca_core.c
+++ b/libavcodec/dca_core.c
@@ -67,9 +67,9 @@ static const uint8_t block_code_nbits[7] = {
     7, 10, 12, 13, 15, 17, 19
 };
 
-static int dca_get_vlc(GetBitContext *s, DCAVLC *v, int i)
+static int dca_get_vlc(GetBitContext *s, const VLC *vlc)
 {
-    return get_vlc2(s, v->vlc[i].table, v->vlc[i].bits, 2);
+    return get_vlc2(s, vlc->table, vlc->bits, 2);
 }
 
 static void get_array(GetBitContext *s, int32_t *array, int size, int n)
@@ -435,7 +435,7 @@ static int parse_subframe_header(DCACoreDecoder *s, int sf,
             int abits;
 
             if (sel < 5)
-                abits = dca_get_vlc(&s->gb, &ff_dca_vlc_bit_allocation, sel);
+                abits = dca_get_vlc(&s->gb, &ff_dca_vlc_bit_allocation[sel]);
             else
                 abits = get_bits(&s->gb, sel - 1);
 
@@ -570,7 +570,7 @@ static inline int parse_huffman_codes(DCACoreDecoder *s, int32_t *audio, int abi
 
     // Extract Huffman codes from the bit stream
     for (i = 0; i < DCA_SUBBAND_SAMPLES; i++)
-        audio[i] = dca_get_vlc(&s->gb, &ff_dca_vlc_quant_index[abits - 1], sel);
+        audio[i] = dca_get_vlc(&s->gb, &ff_dca_vlc_quant_index[abits - 1][sel]);
 
     return 1;
 }
@@ -1340,7 +1340,7 @@ static int parse_x96_subframe_header(DCACoreDecoder *s, int xch_base)
         for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++) {
             // If Huffman code was used, the difference of abits was encoded
             if (sel < 7)
-                abits += dca_get_vlc(&s->gb, &ff_dca_vlc_quant_index[5 + 2 * s->x96_high_res], sel);
+                abits += dca_get_vlc(&s->gb, &ff_dca_vlc_quant_index[5 + 2 * s->x96_high_res][sel]);
             else
                 abits = get_bits(&s->gb, 3 + s->x96_high_res);
 
diff --git a/libavcodec/dcahuff.c b/libavcodec/dcahuff.c
index a7518aded8..937a87ee05 100644
--- a/libavcodec/dcahuff.c
+++ b/libavcodec/dcahuff.c
@@ -768,10 +768,10 @@ const uint8_t ff_dca_vlc_src_tables[][2] = {
     {   4,   3 }, {   0,   3 }, {   2,   2 }, {   3,   2 },
 };
 
-DCAVLC  ff_dca_vlc_bit_allocation;
+VLC     ff_dca_vlc_bit_allocation[5];
 VLC     ff_dca_vlc_transition_mode[4];
 VLC     ff_dca_vlc_scale_factor[5];
-DCAVLC  ff_dca_vlc_quant_index[DCA_CODE_BOOKS];
+VLC     ff_dca_vlc_quant_index[DCA_CODE_BOOKS][7];
 
 VLC     ff_dca_vlc_tnl_grp[5];
 VLC     ff_dca_vlc_tnl_scf;
@@ -791,7 +791,6 @@ av_cold void ff_dca_init_vlcs(void)
     static VLCElem dca_table[30218];
     const uint8_t (*src_table)[2] = ff_dca_vlc_src_tables;
     unsigned offset = 0;
-    int i;
 
 #define DCA_INIT_VLC(vlc, nb_bits, nb_codes, entry_offset)                  \
     do {                                                                    \
@@ -805,15 +804,13 @@ av_cold void ff_dca_init_vlcs(void)
     } while (0)
 
     for (unsigned i = 0; i < DCA_CODE_BOOKS; i++) {
-        ff_dca_vlc_quant_index[i].max_depth = 1 + (i > 4);
         for (unsigned j = 0; j < ff_dca_quant_index_group_size[i]; j++)
-            DCA_INIT_VLC(ff_dca_vlc_quant_index[i].vlc[j], bitalloc_maxbits[i][j],
+            DCA_INIT_VLC(ff_dca_vlc_quant_index[i][j], bitalloc_maxbits[i][j],
                          ff_dca_bitalloc_sizes[i], ff_dca_bitalloc_offsets[i]);
     }
 
-    ff_dca_vlc_bit_allocation.max_depth = 2;
-    for (i = 0; i < 5; i++)
-        DCA_INIT_VLC(ff_dca_vlc_bit_allocation.vlc[i], bitalloc_12_vlc_bits[i], 12, 1);
+    for (unsigned i = 0; i < FF_ARRAY_ELEMS(ff_dca_vlc_bit_allocation); i++)
+        DCA_INIT_VLC(ff_dca_vlc_bit_allocation[i], bitalloc_12_vlc_bits[i], 12, 1);
 
     for (unsigned i = 0; i < FF_ARRAY_ELEMS(ff_dca_vlc_scale_factor); i++)
         DCA_INIT_VLC(ff_dca_vlc_scale_factor[i], DCA_SCALES_VLC_BITS, 129, -64);
diff --git a/libavcodec/dcahuff.h b/libavcodec/dcahuff.h
index 8663f8ba12..eaae234479 100644
--- a/libavcodec/dcahuff.h
+++ b/libavcodec/dcahuff.h
@@ -35,17 +35,12 @@
                                 3 * (5 + 7 + 9 + 13) \
                                 + 7 * (17 + 25 + 33 + 65 + 129))
 
-typedef struct DCAVLC {
-    int max_depth;      ///< Parameter for get_vlc2()
-    VLC vlc[7];         ///< Actual codes
-} DCAVLC;
-
-extern DCAVLC   ff_dca_vlc_bit_allocation;
+extern VLC  ff_dca_vlc_bit_allocation[5];
 #define DCA_TMODE_VLC_BITS 3
 extern VLC  ff_dca_vlc_transition_mode[4];
 #define DCA_SCALES_VLC_BITS 9
 extern VLC  ff_dca_vlc_scale_factor[5];
-extern DCAVLC   ff_dca_vlc_quant_index[DCA_CODE_BOOKS];
+extern VLC  ff_dca_vlc_quant_index[DCA_CODE_BOOKS][7];
 
 extern VLC  ff_dca_vlc_tnl_grp[5];
 extern VLC  ff_dca_vlc_tnl_scf;
-- 
2.34.1



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