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avcodec/smacker: Use symbols table 

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>
This commit is contained in:
Andreas Rheinhardt 2020-07-24 19:57:56 +02:00
parent 45ffbb756b
commit 43d02b4634
1 changed files with 30 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
libavcodec/smacker.c
View File

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