[FFmpeg-devel] [PATCH 59/61] avcodec/wmaprodec: Avoid superfluous VLC structures
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Wed Sep 27 01:17:30 EEST 2023
For all VLCs here, the number of bits of the VLC is write-only,
because it is hardcoded at the call site. Therefore one can replace
these VLC structures with the only thing that is actually used:
The pointer to the VLCElem table. And in most cases one can even
avoid this.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
libavcodec/wma.c | 4 +--
libavcodec/wma.h | 2 +-
libavcodec/wmadec.c | 2 +-
libavcodec/wmaprodec.c | 73 ++++++++++++++++++++++--------------------
4 files changed, 43 insertions(+), 38 deletions(-)
diff --git a/libavcodec/wma.c b/libavcodec/wma.c
index 3b4d049a83..5eacf230fa 100644
--- a/libavcodec/wma.c
+++ b/libavcodec/wma.c
@@ -424,7 +424,7 @@ unsigned int ff_wma_get_large_val(GetBitContext *gb)
* @return 0 on success, -1 otherwise
*/
int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
- VLC *vlc, const float *level_table,
+ const VLCElem *vlc, const float *level_table,
const uint16_t *run_table, int version,
WMACoef *ptr, int offset, int num_coefs,
int block_len, int frame_len_bits,
@@ -435,7 +435,7 @@ int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
uint32_t *iptr = (uint32_t *) ptr;
const unsigned int coef_mask = block_len - 1;
for (; offset < num_coefs; offset++) {
- code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
+ code = get_vlc2(gb, vlc, VLCBITS, VLCMAX);
if (code > 1) {
/** normal code */
offset += run_table[code];
diff --git a/libavcodec/wma.h b/libavcodec/wma.h
index 5dc604154d..3d0d872ea3 100644
--- a/libavcodec/wma.h
+++ b/libavcodec/wma.h
@@ -155,7 +155,7 @@ int ff_wma_total_gain_to_bits(int total_gain);
int ff_wma_end(AVCodecContext *avctx);
unsigned int ff_wma_get_large_val(GetBitContext *gb);
int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
- VLC *vlc, const float *level_table,
+ const VLCElem *vlc, const float *level_table,
const uint16_t *run_table, int version,
WMACoef *ptr, int offset, int num_coefs,
int block_len, int frame_len_bits,
diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
index ab48e28ebc..3427e482dc 100644
--- a/libavcodec/wmadec.c
+++ b/libavcodec/wmadec.c
@@ -616,7 +616,7 @@ static int wma_decode_block(WMACodecContext *s)
* there is potentially less energy there */
tindex = (ch == 1 && s->ms_stereo);
memset(ptr, 0, s->block_len * sizeof(WMACoef));
- ret = ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
+ ret = ff_wma_run_level_decode(s->avctx, &s->gb, s->coef_vlc[tindex].table,
s->level_table[tindex], s->run_table[tindex],
0, ptr, 0, nb_coefs[ch],
s->block_len, s->frame_len_bits, coef_nb_bits);
diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
index 61b86ad6d1..65b269adda 100644
--- a/libavcodec/wmaprodec.c
+++ b/libavcodec/wmaprodec.c
@@ -132,12 +132,12 @@
#define SCALEMAXDEPTH ((HUFF_SCALE_MAXBITS+SCALEVLCBITS-1)/SCALEVLCBITS)
#define SCALERLMAXDEPTH ((HUFF_SCALE_RL_MAXBITS+VLCBITS-1)/VLCBITS)
-static VLC sf_vlc; ///< scale factor DPCM vlc
-static VLC sf_rl_vlc; ///< scale factor run length vlc
-static VLC vec4_vlc; ///< 4 coefficients per symbol
-static VLC vec2_vlc; ///< 2 coefficients per symbol
-static VLC vec1_vlc; ///< 1 coefficient per symbol
-static VLC coef_vlc[2]; ///< coefficient run length vlc codes
+static VLCElem sf_vlc[616]; ///< scale factor DPCM vlc
+static VLCElem sf_rl_vlc[1406]; ///< scale factor run length vlc
+static VLCElem vec4_vlc[604]; ///< 4 coefficients per symbol
+static VLCElem vec2_vlc[562]; ///< 2 coefficients per symbol
+static VLCElem vec1_vlc[562]; ///< 1 coefficient per symbol
+static const VLCElem *coef_vlc[2]; ///< coefficient run length vlc codes
static float sin64[33]; ///< sine table for decorrelation
/**
@@ -320,27 +320,32 @@ static av_cold int get_rate(AVCodecContext *avctx)
static av_cold void decode_init_static(void)
{
- VLC_INIT_STATIC_FROM_LENGTHS(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE,
- &scale_table[0][1], 2,
- &scale_table[0][0], 2, 1, -60, 0, 616);
- VLC_INIT_STATIC_FROM_LENGTHS(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE,
- &scale_rl_table[0][1], 2,
- &scale_rl_table[0][0], 2, 1, 0, 0, 1406);
- VLC_INIT_STATIC_FROM_LENGTHS(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE,
- coef0_lens, 1,
- coef0_syms, 2, 2, 0, 0, 2108);
- VLC_INIT_STATIC_FROM_LENGTHS(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE,
+ static VLCElem vlc_buf[2108 + 3912];
+ VLCInitState state = VLC_INIT_STATE(vlc_buf);
+
+ VLC_INIT_STATIC_TABLE_FROM_LENGTHS(sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE,
+ &scale_table[0][1], 2,
+ &scale_table[0][0], 2, 1, -60, 0);
+ VLC_INIT_STATIC_TABLE_FROM_LENGTHS(sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE,
+ &scale_rl_table[0][1], 2,
+ &scale_rl_table[0][0], 2, 1, 0, 0);
+ coef_vlc[0] =
+ ff_vlc_init_tables_from_lengths(&state, VLCBITS, HUFF_COEF0_SIZE,
+ coef0_lens, 1,
+ coef0_syms, 2, 2, 0, 0);
+ coef_vlc[1] =
+ ff_vlc_init_tables_from_lengths(&state, VLCBITS, HUFF_COEF1_SIZE,
&coef1_table[0][1], 2,
- &coef1_table[0][0], 2, 1, 0, 0, 3912);
- VLC_INIT_STATIC_FROM_LENGTHS(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
- vec4_lens, 1,
- vec4_syms, 2, 2, -1, 0, 604);
- VLC_INIT_STATIC_FROM_LENGTHS(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
- &vec2_table[0][1], 2,
- &vec2_table[0][0], 2, 1, -1, 0, 562);
- VLC_INIT_STATIC_FROM_LENGTHS(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
- &vec1_table[0][1], 2,
- &vec1_table[0][0], 2, 1, 0, 0, 562);
+ &coef1_table[0][0], 2, 1, 0, 0);
+ VLC_INIT_STATIC_TABLE_FROM_LENGTHS(vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
+ vec4_lens, 1,
+ vec4_syms, 2, 2, -1, 0);
+ VLC_INIT_STATIC_TABLE_FROM_LENGTHS(vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
+ &vec2_table[0][1], 2,
+ &vec2_table[0][0], 2, 1, -1, 0);
+ VLC_INIT_STATIC_TABLE_FROM_LENGTHS(vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
+ &vec1_table[0][1], 2,
+ &vec1_table[0][0], 2, 1, 0, 0);
/** calculate sine values for the decorrelation matrix */
for (int i = 0; i < 33; i++)
@@ -929,7 +934,7 @@ static int decode_coeffs(WMAProDecodeCtx *s, int c)
0x41400000, 0x41500000, 0x41600000, 0x41700000,
};
int vlctable;
- VLC* vlc;
+ const VLCElem *vlc;
WMAProChannelCtx* ci = &s->channel[c];
int rl_mode = 0;
int cur_coeff = 0;
@@ -940,7 +945,7 @@ static int decode_coeffs(WMAProDecodeCtx *s, int c)
ff_dlog(s->avctx, "decode coefficients for channel %i\n", c);
vlctable = get_bits1(&s->gb);
- vlc = &coef_vlc[vlctable];
+ vlc = coef_vlc[vlctable];
if (vlctable) {
run = coef1_run;
@@ -958,17 +963,17 @@ static int decode_coeffs(WMAProDecodeCtx *s, int c)
int i;
unsigned int idx;
- idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH);
+ idx = get_vlc2(&s->gb, vec4_vlc, VLCBITS, VEC4MAXDEPTH);
if ((int)idx < 0) {
for (i = 0; i < 4; i += 2) {
- idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH);
+ idx = get_vlc2(&s->gb, vec2_vlc, VLCBITS, VEC2MAXDEPTH);
if ((int)idx < 0) {
uint32_t v0, v1;
- v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
+ v0 = get_vlc2(&s->gb, vec1_vlc, VLCBITS, VEC1MAXDEPTH);
if (v0 == HUFF_VEC1_SIZE - 1)
v0 += ff_wma_get_large_val(&s->gb);
- v1 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
+ v1 = get_vlc2(&s->gb, vec1_vlc, VLCBITS, VEC1MAXDEPTH);
if (v1 == HUFF_VEC1_SIZE - 1)
v1 += ff_wma_get_large_val(&s->gb);
vals[i ] = av_float2int(v0);
@@ -1059,7 +1064,7 @@ static int decode_scale_factors(WMAProDecodeCtx* s)
s->channel[c].scale_factor_step = get_bits(&s->gb, 2) + 1;
val = 45 / s->channel[c].scale_factor_step;
for (sf = s->channel[c].scale_factors; sf < sf_end; sf++) {
- val += get_vlc2(&s->gb, sf_vlc.table, SCALEVLCBITS, SCALEMAXDEPTH);
+ val += get_vlc2(&s->gb, sf_vlc, SCALEVLCBITS, SCALEMAXDEPTH);
*sf = val;
}
} else {
@@ -1071,7 +1076,7 @@ static int decode_scale_factors(WMAProDecodeCtx* s)
int val;
int sign;
- idx = get_vlc2(&s->gb, sf_rl_vlc.table, VLCBITS, SCALERLMAXDEPTH);
+ idx = get_vlc2(&s->gb, sf_rl_vlc, VLCBITS, SCALERLMAXDEPTH);
if (!idx) {
uint32_t code = get_bits(&s->gb, 14);
--
2.34.1
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