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Merge "remove the PACK() bit-packing tricks"

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This commit is contained in:
skal 2013-09-04 23:55:41 -07:00 committed by Gerrit Code Review
commit 7e2d65950f
3 changed files with 43 additions and 58 deletions
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16
src/dec/frame.c
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@ -595,6 +595,7 @@ void VP8ReconstructBlock(const VP8Decoder* const dec) {
// predict and add residuals
if (block->is_i4x4_) { // 4x4
uint32_t* const top_right = (uint32_t*)(y_dst - BPS + 16);
uint32_t bits = (block->non_zero_ & 0xffff) | (block->non_zero_ac_ << 16);
if (dec->mb_y_ > 0) {
if (dec->mb_x_ >= dec->mb_w_ - 1) { // on rightmost border
@ -607,25 +608,26 @@ void VP8ReconstructBlock(const VP8Decoder* const dec) {
top_right[BPS] = top_right[2 * BPS] = top_right[3 * BPS] = top_right[0];
// predict and add residuals for all 4x4 blocks in turn.
for (n = 0; n < 16; n++) {
for (n = 0; n < 16; ++n, bits <<= 1) {
uint8_t* const dst = y_dst + kScan[n];
VP8PredLuma4[block->imodes_[n]](dst);
if (block->non_zero_ac_ & (1 << n)) {
if (bits & (1UL << 31)) {
VP8Transform(coeffs + n * 16, dst, 0);
} else if (block->non_zero_ & (1 << n)) { // only DC is present
} else if (bits & (1UL << 15)) { // only DC is present
VP8TransformDC(coeffs + n * 16, dst);
}
}
} else { // 16x16
const int pred_func = CheckMode(dec->mb_x_, dec->mb_y_,
block->imodes_[0]);
uint32_t bits = (block->non_zero_ & 0xffff) | (block->non_zero_ac_ << 16);
VP8PredLuma16[pred_func](y_dst);
if (block->non_zero_ & 0xffff) {
for (n = 0; n < 16; n++) {
if (bits & 0xffff) {
for (n = 0; n < 16; ++n, bits <<= 1) {
uint8_t* const dst = y_dst + kScan[n];
if (block->non_zero_ac_ & (1 << n)) {
if (bits & (1UL << 31)) {
VP8Transform(coeffs + n * 16, dst, 0);
} else if (block->non_zero_ & (1 << n)) { // only DC is present
} else if (bits & (1UL << 15)) { // only DC is present
VP8TransformDC(coeffs + n * 16, dst);
}
}

81
src/dec/vp8.c
View File

@ -505,28 +505,6 @@ static int GetCoeffs(VP8BitReader* const br, ProbaArray prob,
return 16;
}
// Alias-safe way of converting 4bytes to 32bits.
typedef union {
uint8_t i8[4];
uint32_t i32;
} PackedNz;
// Table to unpack four bits into four bytes
static const PackedNz kUnpackTab[16] = {
{{0, 0, 0, 0}}, {{1, 0, 0, 0}}, {{0, 1, 0, 0}}, {{1, 1, 0, 0}},
{{0, 0, 1, 0}}, {{1, 0, 1, 0}}, {{0, 1, 1, 0}}, {{1, 1, 1, 0}},
{{0, 0, 0, 1}}, {{1, 0, 0, 1}}, {{0, 1, 0, 1}}, {{1, 1, 0, 1}},
{{0, 0, 1, 1}}, {{1, 0, 1, 1}}, {{0, 1, 1, 1}}, {{1, 1, 1, 1}} };
// Macro to pack four LSB of four bytes into four bits.
#if defined(__PPC__) || defined(_M_PPC) || defined(_ARCH_PPC) || \
defined(__BIG_ENDIAN__)
#define PACK_CST 0x08040201U
#else
#define PACK_CST 0x01020408U
#endif
#define PACK(X, S) ((((X).i32 * PACK_CST) & 0xff000000) >> (S))
static int ParseResiduals(VP8Decoder* const dec,
VP8MB* const mb, VP8BitReader* const token_br) {
uint32_t out_t_nz, out_l_nz;
@ -536,8 +514,7 @@ static int ParseResiduals(VP8Decoder* const dec,
VP8MBData* const block = dec->mb_data_;
int16_t* dst = block->coeffs_;
VP8MB* const left_mb = dec->mb_info_ - 1;
PackedNz nz_ac, nz_dc;
PackedNz tnz, lnz;
uint8_t tnz, lnz;
uint32_t non_zero_ac = 0;
uint32_t non_zero_dc = 0;
int x, y, ch;
@ -557,48 +534,55 @@ static int ParseResiduals(VP8Decoder* const dec,
ac_prob = (ProbaArray)dec->proba_.coeffs_[3];
}
tnz = kUnpackTab[mb->nz_ & 0xf];
lnz = kUnpackTab[left_mb->nz_ & 0xf];
tnz = mb->nz_ & 0x0f;
lnz = left_mb->nz_ & 0x0f;
for (y = 0; y < 4; ++y) {
int l = lnz.i8[y];
int l = lnz & 1;
uint32_t nz_dc = 0, nz_ac = 0;
for (x = 0; x < 4; ++x) {
const int ctx = l + tnz.i8[x];
const int ctx = l + (tnz & 1);
const int nz = GetCoeffs(token_br, ac_prob, ctx,
q->y1_mat_, first, dst);
tnz.i8[x] = l = (nz > 0);
nz_dc.i8[x] = (dst[0] != 0);
nz_ac.i8[x] = (nz > 1);
l = (nz > 0);
tnz = (tnz >> 1) | (l << 7);
nz_dc = (nz_dc << 1) | (dst[0] != 0);
nz_ac = (nz_ac << 1) | (nz > 1);
dst += 16;
}
lnz.i8[y] = l;
non_zero_dc |= PACK(nz_dc, 24 - y * 4);
non_zero_ac |= PACK(nz_ac, 24 - y * 4);
tnz >>= 4;
lnz = (lnz >> 1) | (l << 7);
non_zero_dc = (non_zero_dc << 4) | nz_dc;
non_zero_ac = (non_zero_ac << 4) | nz_ac;
}
out_t_nz = PACK(tnz, 24);
out_l_nz = PACK(lnz, 24);
out_t_nz = tnz;
out_l_nz = lnz >> 4;
tnz = kUnpackTab[mb->nz_ >> 4];
lnz = kUnpackTab[left_mb->nz_ >> 4];
for (ch = 0; ch < 4; ch += 2) {
uint32_t nz_dc = 0, nz_ac = 0;
tnz = mb->nz_ >> (4 + ch);
lnz = left_mb->nz_ >> (4 + ch);
for (y = 0; y < 2; ++y) {
int l = lnz.i8[ch + y];
int l = lnz & 1;
for (x = 0; x < 2; ++x) {
const int ctx = l + tnz.i8[ch + x];
const int ctx = l + (tnz & 1);
const int nz =
GetCoeffs(token_br, (ProbaArray)dec->proba_.coeffs_[2],
ctx, q->uv_mat_, 0, dst);
tnz.i8[ch + x] = l = (nz > 0);
nz_dc.i8[y * 2 + x] = (dst[0] != 0);
nz_ac.i8[y * 2 + x] = (nz > 1);
l = (nz > 0);
tnz = (tnz >> 1) | (l << 3);
nz_dc = (nz_dc << 1) | (dst[0] != 0);
nz_ac = (nz_ac << 1) | (nz > 1);
dst += 16;
}
lnz.i8[ch + y] = l;
tnz >>= 2;
lnz = (lnz >> 1) | (l << 5);
}
non_zero_dc |= PACK(nz_dc, 8 - ch * 2);
non_zero_ac |= PACK(nz_ac, 8 - ch * 2);
// Note: we don't really need the per-4x4 details for U/V blocks.
non_zero_dc |= (nz_dc & 0x0f) << (16 + 2 * ch);
non_zero_ac |= (nz_ac & 0x0f) << (16 + 2 * ch);
out_t_nz |= (tnz << 4) << ch;
out_l_nz |= (lnz & 0xf0) << ch;
}
out_t_nz |= PACK(tnz, 20);
out_l_nz |= PACK(lnz, 20);
mb->nz_ = out_t_nz;
left_mb->nz_ = out_l_nz;
@ -606,7 +590,6 @@ static int ParseResiduals(VP8Decoder* const dec,
block->non_zero_ = non_zero_ac | non_zero_dc;
return !block->non_zero_; // will be used for further optimization
}
#undef PACK
//------------------------------------------------------------------------------
// Main loop

4
src/dec/vp8i.h
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@ -177,8 +177,8 @@ typedef struct {
uint8_t imodes_[16]; // one 16x16 mode (#0) or sixteen 4x4 modes
uint8_t uvmode_; // chroma prediction mode
// bit-wise info about the content of each sub-4x4 blocks: there are 16 bits
// for luma (bits #0->#15), then 4 bits for chroma-u (#16->#19) and 4 bits for
// chroma-v (#20->#23), each corresponding to one 4x4 block in decoding order.
// for luma (bits #15->#0), then 4 bits for chroma-u (#19->#16) and 4 bits for
// chroma-v (#23->#20), each corresponding to one 4x4 block in decoding order.
// If the bit is set, the 4x4 block contains some non-zero coefficients.
uint32_t non_zero_;
uint32_t non_zero_ac_;