Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

avcodec/vc1_block: Optimize vc1_decode_i_block_adv()

Browse Source 
9127 -> 8936 decicycles (fate-suite/vc1/SA10143.vc1)
13855 -> 10976 decicycles  (fate-suite/vc1/SA20021.vc1)
tests done by the author over this function but with the whole
patchset applied not just this commit

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
pull/117/head
zhaoxiu.zeng 10 years ago committed by Michael Niedermayer
parent 21581182ca
commit 94f5ac93d7
1 changed files with 53 additions and 71 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 106
      libavcodec/vc1_block.c

106
libavcodec/vc1_block.c
Unescape View File

@ -729,39 +729,42 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
*dc_val = dcdiff;
/* Store the quantized DC coeff, used for prediction */
if (n < 4) {
block[0] = dcdiff * s->y_dc_scale;
} else {
block[0] = dcdiff * s->c_dc_scale;
}
//AC Decoding
i = 1;
if (n < 4)
scale = s->y_dc_scale;
else
scale = s->c_dc_scale;
block[0] = dcdiff * scale;
/* check if AC is needed at all */
if (!a_avail && !c_avail)
use_pred = 0;
ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
ac_val2 = ac_val;
scale = mquant * 2 + ((mquant == v->pq) ? v->halfpq : 0);
ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
ac_val2 = ac_val;
if (dc_pred_dir) // left
ac_val -= 16;
else // top
ac_val -= 16 * s->block_wrap[n];
q1 = s->current_picture.qscale_table[mb_pos];
if ( dc_pred_dir && c_avail && mb_pos)
q2 = s->current_picture.qscale_table[mb_pos - 1];
if (!dc_pred_dir && a_avail && mb_pos >= s->mb_stride)
q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
if ( dc_pred_dir && n == 1)
if (n == 3)
q2 = q1;
if (!dc_pred_dir && n == 2)
else if (dc_pred_dir) {
if (n == 1)
q2 = q1;
if (n == 3)
else if (c_avail && mb_pos)
q2 = s->current_picture.qscale_table[mb_pos - 1];
} else {
if (n == 2)
q2 = q1;
else if (a_avail && mb_pos >= s->mb_stride)
q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
}
//AC Decoding
i = 1;
if (coded) {
int last = 0, skip, value;
@ -794,28 +797,24 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
/* apply AC prediction if needed */
if (use_pred) {
int sh;
if (dc_pred_dir) { // left
sh = v->left_blk_sh;
} else { // top
sh = v->top_blk_sh;
ac_val += 8;
}
/* scale predictors if needed*/
if (q2 && q1 != q2) {
q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
if (q1 < 1)
return AVERROR_INVALIDDATA;
if (dc_pred_dir) { // left
for (k = 1; k < 8; k++)
block[k << v->left_blk_sh] += (ac_val[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
} else { // top
q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
for (k = 1; k < 8; k++)
block[k << v->top_blk_sh] += (ac_val[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
}
block[k << sh] += (ac_val[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
} else {
if (dc_pred_dir) { //left
for (k = 1; k < 8; k++)
block[k << v->left_blk_sh] += ac_val[k];
} else { //top
for (k = 1; k < 8; k++)
block[k << v->top_blk_sh] += ac_val[k + 8];
}
block[k << sh] += ac_val[k];
}
}
/* save AC coeffs for further prediction */
@ -832,13 +831,21 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
block[k] += (block[k] < 0) ? -mquant : mquant;
}
if (use_pred) i = 63;
} else { // no AC coeffs
int k;
memset(ac_val2, 0, 16 * 2);
if (dc_pred_dir) { // left
/* apply AC prediction if needed */
if (use_pred) {
int sh;
if (dc_pred_dir) { // left
sh = v->left_blk_sh;
} else { // top
sh = v->top_blk_sh;
ac_val += 8;
ac_val2 += 8;
}
memcpy(ac_val2, ac_val, 8 * 2);
if (q2 && q1 != q2) {
q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
@ -848,39 +855,14 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
for (k = 1; k < 8; k++)
ac_val2[k] = (ac_val2[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
}
}
} else { // top
if (use_pred) {
memcpy(ac_val2 + 8, ac_val + 8, 8 * 2);
if (q2 && q1 != q2) {
q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
if (q1 < 1)
return AVERROR_INVALIDDATA;
for (k = 1; k < 8; k++)
ac_val2[k + 8] = (ac_val2[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
}
}
}
/* apply AC prediction if needed */
if (use_pred) {
if (dc_pred_dir) { // left
for (k = 1; k < 8; k++) {
block[k << v->left_blk_sh] = ac_val2[k] * scale;
if (!v->pquantizer && block[k << v->left_blk_sh])
block[k << v->left_blk_sh] += (block[k << v->left_blk_sh] < 0) ? -mquant : mquant;
}
} else { // top
for (k = 1; k < 8; k++) {
block[k << v->top_blk_sh] = ac_val2[k + 8] * scale;
if (!v->pquantizer && block[k << v->top_blk_sh])
block[k << v->top_blk_sh] += (block[k << v->top_blk_sh] < 0) ? -mquant : mquant;
}
block[k << sh] = ac_val2[k] * scale;
if (!v->pquantizer && block[k << sh])
block[k << sh] += (block[k << sh] < 0) ? -mquant : mquant;
}
i = 63;
}
}
if (use_pred) i = 63;
s->block_last_index[n] = i;
return 0;

Write Preview
Loading…
Cancel
Save