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avcodec/smacker: Use symbols table

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Up until now, the return value of get_vlc2() has been used as an index
in an array that contained the value one is really interested in. Yet
since b613bacca9 this is no longer
necessary, as one can store the value that is right now stored in the
array in the VLC internal table.

This also means that all the information from the eight bit Huffman trees
are now stored in the corresponding VLC table; this will enable us to
remove several allocations lateron.

This improved performance: For GCC 9 the time for one call of
smka_decode_frame() for the sample from ticket #2425 decreased from
1811706 to 1794494 decicycles; for Clang 9 the number went from 1471663
to 1449420 decicycles.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
pull/352/head
Andreas Rheinhardt 5 years ago
parent 45ffbb756b
commit 43d02b4634
1 changed files with 30 additions and 24 deletions
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  1. 54
      libavcodec/smacker.c

54
libavcodec/smacker.c
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@ -78,7 +78,7 @@ typedef struct DBCtx {
int current, length; int current, length;
int *values; int *values;
VLC *v1, *v2; VLC *v1, *v2;
const uint8_t *recode1, *recode2; uint8_t vals[2];
int escapes[3]; int escapes[3];
int *last; int *last;
} DBCtx; } DBCtx;
@ -156,9 +156,11 @@ static int smacker_decode_bigtree(GetBitContext *gb, DBCtx *ctx, int length)
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
if(!get_bits1(gb)){ //Leaf if(!get_bits1(gb)){ //Leaf
int val, i1, i2; int val, i1, i2;
i1 = ctx->v1->table ? get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3) : 0; i1 = ctx->v1->table ? get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3)
i2 = ctx->v2->table ? get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3) : 0; : ctx->vals[0];
val = ctx->recode1[i1] | (ctx->recode2[i2] << 8); i2 = ctx->v2->table ? get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3)
: ctx->vals[1];
val = i1 | (i2 << 8);
if(val == ctx->escapes[0]) { if(val == ctx->escapes[0]) {
ctx->last[0] = ctx->current; ctx->last[0] = ctx->current;
val = 0; val = 0;
@ -218,7 +220,7 @@ static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int
goto error; goto error;
} }
if (!get_bits1(gb)) { if (!get_bits1(gb)) {
h[i].values[0] = 0; ctx.vals[i] = 0;
av_log(smk->avctx, AV_LOG_ERROR, "Skipping %s bytes tree\n", av_log(smk->avctx, AV_LOG_ERROR, "Skipping %s bytes tree\n",
i ? "high" : "low"); i ? "high" : "low");
continue; continue;
@ -228,15 +230,17 @@ static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int
goto error; goto error;
skip_bits1(gb); skip_bits1(gb);
if (h[i].current > 1) { if (h[i].current > 1) {
err = init_vlc(&vlc[i], SMKTREE_BITS, h[i].current, err = ff_init_vlc_sparse(&vlc[i], SMKTREE_BITS, h[i].current,
INIT_VLC_DEFAULT_SIZES(h[i].lengths), INIT_VLC_DEFAULT_SIZES(h[i].lengths),
INIT_VLC_DEFAULT_SIZES(h[i].bits), INIT_VLC_DEFAULT_SIZES(h[i].bits),
INIT_VLC_DEFAULT_SIZES(h[i].values),
INIT_VLC_LE); INIT_VLC_LE);
if (err < 0) { if (err < 0) {
av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n"); av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
goto error; goto error;
} }
} } else
ctx.vals[i] = h[i].values[0];
} }
escapes[0] = get_bits(gb, 16); escapes[0] = get_bits(gb, 16);
@ -250,8 +254,6 @@ static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int
ctx.escapes[2] = escapes[2]; ctx.escapes[2] = escapes[2];
ctx.v1 = &vlc[0]; ctx.v1 = &vlc[0];
ctx.v2 = &vlc[1]; ctx.v2 = &vlc[1];
ctx.recode1 = h[0].values;
ctx.recode2 = h[1].values;
ctx.last = last; ctx.last = last;
ctx.length = (size + 3) >> 2; ctx.length = (size + 3) >> 2;
ctx.current = 0; ctx.current = 0;
@ -605,6 +607,7 @@ static int smka_decode_frame(AVCodecContext *avctx, void *data,
VLC vlc[4] = { { 0 } }; VLC vlc[4] = { { 0 } };
int16_t *samples; int16_t *samples;
uint8_t *samples8; uint8_t *samples8;
uint8_t values[4];
int val; int val;
int i, res, ret; int i, res, ret;
int unp_size; int unp_size;
@ -670,14 +673,17 @@ static int smka_decode_frame(AVCodecContext *avctx, void *data,
goto error; goto error;
skip_bits1(&gb); skip_bits1(&gb);
if(h[i].current > 1) { if(h[i].current > 1) {
ret = init_vlc(&vlc[i], SMKTREE_BITS, h[i].current, ret = ff_init_vlc_sparse(&vlc[i], SMKTREE_BITS, h[i].current,
INIT_VLC_DEFAULT_SIZES(h[i].lengths), INIT_VLC_DEFAULT_SIZES(h[i].lengths),
h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE); INIT_VLC_DEFAULT_SIZES(h[i].bits),
INIT_VLC_DEFAULT_SIZES(h[i].values),
INIT_VLC_LE);
if (ret < 0) { if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n"); av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
goto error; goto error;
} }
} } else
values[i] = h[i].values[0];
} }
/* this codec relies on wraparound instead of clipping audio */ /* this codec relies on wraparound instead of clipping audio */
if(bits) { //decode 16-bit data if(bits) { //decode 16-bit data
@ -694,26 +700,26 @@ static int smka_decode_frame(AVCodecContext *avctx, void *data,
if(vlc[2].table) if(vlc[2].table)
res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3); res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
else else
res = 0; res = values[2];
val = h[2].values[res]; val = res;
if(vlc[3].table) if(vlc[3].table)
res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3); res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
else else
res = 0; res = values[3];
val |= h[3].values[res] << 8; val |= res << 8;
pred[1] += (unsigned)sign_extend(val, 16); pred[1] += (unsigned)sign_extend(val, 16);
*samples++ = pred[1]; *samples++ = pred[1];
} else { } else {
if(vlc[0].table) if(vlc[0].table)
res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3); res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
else else
res = 0; res = values[0];
val = h[0].values[res]; val = res;
if(vlc[1].table) if(vlc[1].table)
res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3); res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
else else
res = 0; res = values[1];
val |= h[1].values[res] << 8; val |= res << 8;
pred[0] += (unsigned)sign_extend(val, 16); pred[0] += (unsigned)sign_extend(val, 16);
*samples++ = pred[0]; *samples++ = pred[0];
} }
@ -732,15 +738,15 @@ static int smka_decode_frame(AVCodecContext *avctx, void *data,
if(vlc[1].table) if(vlc[1].table)
res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3); res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
else else
res = 0; res = values[1];
pred[1] += sign_extend(h[1].values[res], 8); pred[1] += sign_extend(res, 8);
*samples8++ = pred[1]; *samples8++ = pred[1];
} else { } else {
if(vlc[0].table) if(vlc[0].table)
res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3); res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
else else
res = 0; res = values[0];
pred[0] += sign_extend(h[0].values[res], 8); pred[0] += sign_extend(res, 8);
*samples8++ = pred[0]; *samples8++ = pred[0];
} }
} }

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