Skip to content

F
ffmpeg.wasm-core
Commit 53cb0bab authored by zhaoxiu.zeng's avatar zhaoxiu.zeng Committed by Michael Niedermayer
Browse files
Options

avcodec/vc1: simplify offset table and access 

Signed-off-by: 's avatarMichael Niedermayer <michaelni@gmx.at>
parent 5ee3a40f
Hide whitespace changes
Inline Side-by-side
Showing with 21 additions and 29 deletions
libavcodec/vc1_block.c
View file @ 53cb0bab
......@@ -40,8 +40,10 @@
#define DC_VLC_BITS 9
// offset tables for interlaced picture MVDATA decoding
static const int offset_table1[9] = { 0, 1, 2, 4, 8, 16, 32, 64, 128 };
static const int offset_table2[9] = { 0, 1, 3, 7, 15, 31, 63, 127, 255 };
static const uint8_t offset_table[2][9] = {
{ 0, 1, 2, 4, 8, 16, 32, 64, 128 },
{ 0, 1, 3, 7, 15, 31, 63, 127, 255 },
};
/***********************************************************************/
/**
......@@ -216,22 +218,22 @@ static void vc1_put_signed_blocks_clamped(VC1Context *v)
s->mb_intra = 1; \
} else { \
index1 = index % 6; \
if (!s->quarter_sample && index1 == 5) val = 1; \
else val = 0; \
if (size_table[index1] - val > 0) \
val = get_bits(gb, size_table[index1] - val); \
else val = 0; \
sign = 0 - (val&1); \
_dmv_x = (sign ^ ((val>>1) + offset_table[index1])) - sign; \
_dmv_x = offset_table[1][index1]; \
val = size_table[index1] - (!s->quarter_sample && index1 == 5); \
if (val > 0) { \
val = get_bits(gb, val); \
sign = 0 - (val & 1); \
_dmv_x = (sign ^ ((val >> 1) + _dmv_x)) - sign; \
} \
\
index1 = index / 6; \
if (!s->quarter_sample && index1 == 5) val = 1; \
else val = 0; \
if (size_table[index1] - val > 0) \
val = get_bits(gb, size_table[index1] - val); \
else val = 0; \
sign = 0 - (val & 1); \
_dmv_y = (sign ^ ((val >> 1) + offset_table[index1])) - sign; \
_dmv_y = offset_table[1][index1]; \
val = size_table[index1] - (!s->quarter_sample && index1 == 5); \
if (val > 0) { \
val = get_bits(gb, val); \
sign = 0 - (val & 1); \
_dmv_y = (sign ^ ((val >> 1) + _dmv_y)) - sign; \
} \
}
static av_always_inline void get_mvdata_interlaced(VC1Context *v, int *dmv_x,
......@@ -242,7 +244,6 @@ static av_always_inline void get_mvdata_interlaced(VC1Context *v, int *dmv_x,
GetBitContext *gb = &v->s.gb;
int bits, esc;
int val, sign;
const int* offs_tab;
if (v->numref) {
bits = VC1_2REF_MVDATA_VLC_BITS;
......@@ -277,26 +278,18 @@ static av_always_inline void get_mvdata_interlaced(VC1Context *v, int *dmv_x,
}
else {
av_assert0(index < esc);
if (extend_x)
offs_tab = offset_table2;
else
offs_tab = offset_table1;
index1 = (index + 1) % 9;
if (index1 != 0) {
val = get_bits(gb, index1 + extend_x);
sign = 0 -(val & 1);
*dmv_x = (sign ^ ((val >> 1) + offs_tab[index1])) - sign;
sign = 0 - (val & 1);
*dmv_x = (sign ^ ((val >> 1) + offset_table[extend_x][index1])) - sign;
} else
*dmv_x = 0;
if (extend_y)
offs_tab = offset_table2;
else
offs_tab = offset_table1;
index1 = (index + 1) / 9;
if (index1 > v->numref) {
val = get_bits(gb, (index1 + (extend_y << v->numref)) >> v->numref);
sign = 0 - (val & 1);
*dmv_y = (sign ^ ((val >> 1) + offs_tab[index1 >> v->numref])) - sign;
*dmv_y = (sign ^ ((val >> 1) + offset_table[extend_y][index1 >> v->numref])) - sign;
} else
*dmv_y = 0;
if (v->numref && pred_flag)
......@@ -1321,7 +1314,6 @@ static int vc1_decode_p_block(VC1Context *v, int16_t block[64], int n,
/** @} */ // Macroblock group
static const int size_table [6] = { 0, 2, 3, 4, 5, 8 };
static const int offset_table[6] = { 0, 1, 3, 7, 15, 31 };
/** Decode one P-frame MB
*/
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment