// Copyright 2011 Google Inc.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// VP8Iterator: block iterator
//
// Author: Skal (pascal.massimino@gmail.com)
#include <stdlib.h>
#include <string.h>
#include "vp8enci.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//-----------------------------------------------------------------------------
// VP8Iterator
//-----------------------------------------------------------------------------
static void InitLeft(VP8EncIterator* const it) {
const VP8Encoder* const enc = it->enc_;
enc->y_left_[-1] = enc->u_left_[-1] = enc->v_left_[-1] =
(it->y_) > 0 ? 129 : 127;
memset(enc->y_left_, 129, 16);
memset(enc->u_left_, 129, 8);
memset(enc->v_left_, 129, 8);
it->left_nz_[8] = 0;
}
static void InitTop(VP8EncIterator* const it) {
const VP8Encoder* const enc = it->enc_;
const int top_size = enc->mb_w_ * 16;
memset(enc->y_top_, 127, 2 * top_size);
memset(enc->nz_, 0, enc->mb_w_ * sizeof(*enc->nz_));
}
void VP8IteratorReset(VP8EncIterator* const it) {
VP8Encoder* const enc = it->enc_;
it->x_ = 0;
it->y_ = 0;
it->y_offset_ = 0;
it->uv_offset_ = 0;
it->mb_ = enc->mb_info_;
it->preds_ = enc->preds_;
it->nz_ = enc->nz_;
it->bw_ = &enc->parts_[0];
it->done_ = enc->mb_w_* enc->mb_h_;
InitTop(it);
InitLeft(it);
memset(it->bit_count_, 0, sizeof(it->bit_count_));
it->do_trellis_ = 0;
}
void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it) {
it->enc_ = enc;
it->y_stride_ = enc->pic_->y_stride;
it->uv_stride_ = enc->pic_->uv_stride;
// TODO(later): for multithreading, these should be owned by 'it'.
it->yuv_in_ = enc->yuv_in_;
it->yuv_out_ = enc->yuv_out_;
it->yuv_out2_ = enc->yuv_out2_;
it->yuv_p_ = enc->yuv_p_;
it->lf_stats_ = enc->lf_stats_;
VP8IteratorReset(it);
}
//-----------------------------------------------------------------------------
// Import the source samples into the cache. Takes care of replicating
// boundary pixels if necessary.
void VP8IteratorImport(const VP8EncIterator* const it) {
const VP8Encoder* const enc = it->enc_;
const int x = it->x_, y = it->y_;
const WebPPicture* const pic = enc->pic_;
const uint8_t* ysrc = pic->y + (y * pic->y_stride + x) * 16;
const uint8_t* usrc = pic->u + (y * pic->uv_stride + x) * 8;
const uint8_t* vsrc = pic->v + (y * pic->uv_stride + x) * 8;
uint8_t* ydst = it->yuv_in_ + Y_OFF;
uint8_t* udst = it->yuv_in_ + U_OFF;
uint8_t* vdst = it->yuv_in_ + V_OFF;
int w = (pic->width - x * 16);
int h = (pic->height - y * 16);
int i;
if (w > 16) w = 16;
if (h > 16) h = 16;
// Luma plane
for (i = 0; i < h; ++i) {
memcpy(ydst, ysrc, w);
if (w < 16) memset(ydst + w, ydst[w - 1], 16 - w);
ydst += BPS;
ysrc += pic->y_stride;
}
for (i = h; i < 16; ++i) {
memcpy(ydst, ydst - BPS, 16);
ydst += BPS;
}
// U/V plane
w = (w + 1) / 2;
h = (h + 1) / 2;
for (i = 0; i < h; ++i) {
memcpy(udst, usrc, w);
memcpy(vdst, vsrc, w);
if (w < 8) {
memset(udst + w, udst[w - 1], 8 - w);
memset(vdst + w, vdst[w - 1], 8 - w);
}
udst += BPS;
vdst += BPS;
usrc += pic->uv_stride;
vsrc += pic->uv_stride;
}
for (i = h; i < 8; ++i) {
memcpy(udst, udst - BPS, 8);
memcpy(vdst, vdst - BPS, 8);
udst += BPS;
vdst += BPS;
}
}
//-----------------------------------------------------------------------------
// Copy back the compressed samples into user space if requested.
void VP8IteratorExport(const VP8EncIterator* const it) {
const VP8Encoder* const enc = it->enc_;
if (enc->config_->show_compressed) {
const int x = it->x_, y = it->y_;
const uint8_t* const ysrc = it->yuv_out_ + Y_OFF;
const uint8_t* const usrc = it->yuv_out_ + U_OFF;
const uint8_t* const vsrc = it->yuv_out_ + V_OFF;
const WebPPicture* const pic = enc->pic_;
uint8_t* ydst = pic->y + (y * pic->y_stride + x) * 16;
uint8_t* udst = pic->u + (y * pic->uv_stride + x) * 8;
uint8_t* vdst = pic->v + (y * pic->uv_stride + x) * 8;
int w = (pic->width - x * 16);
int h = (pic->height - y * 16);
int i;
if (w > 16) w = 16;
if (h > 16) h = 16;
// Luma plane
for (i = 0; i < h; ++i) {
memcpy(ydst + i * pic->y_stride, ysrc + i * BPS, w);
}
// U/V plane
{
const int uv_w = (w + 1) / 2;
const int uv_h = (h + 1) / 2;
for (i = 0; i < uv_h; ++i) {
memcpy(udst + i * pic->uv_stride, usrc + i * BPS, uv_w);
memcpy(vdst + i * pic->uv_stride, vsrc + i * BPS, uv_w);
}
}
}
}
//-----------------------------------------------------------------------------
// Non-zero contexts setup/teardown
// Nz bits:
// 0 1 2 3 Y
// 4 5 6 7
// 8 9 10 11
// 12 13 14 15
// 16 17 U
// 18 19
// 20 21 V
// 22 23
// 24 DC-intra16
// Convert packed context to byte array
#define BIT(nz, n) (!!((nz) & (1 << (n))))
void VP8IteratorNzToBytes(VP8EncIterator* const it) {
const int tnz = it->nz_[0], lnz = it->nz_[-1];
// Top-Y
it->top_nz_[0] = BIT(tnz, 12);
it->top_nz_[1] = BIT(tnz, 13);
it->top_nz_[2] = BIT(tnz, 14);
it->top_nz_[3] = BIT(tnz, 15);
// Top-U
it->top_nz_[4] = BIT(tnz, 18);
it->top_nz_[5] = BIT(tnz, 19);
// Top-V
it->top_nz_[6] = BIT(tnz, 22);
it->top_nz_[7] = BIT(tnz, 23);
// DC
it->top_nz_[8] = BIT(tnz, 24);
// left-Y
it->left_nz_[0] = BIT(lnz, 3);
it->left_nz_[1] = BIT(lnz, 7);
it->left_nz_[2] = BIT(lnz, 11);
it->left_nz_[3] = BIT(lnz, 15);
// left-U
it->left_nz_[4] = BIT(lnz, 17);
it->left_nz_[5] = BIT(lnz, 19);
// left-V
it->left_nz_[6] = BIT(lnz, 21);
it->left_nz_[7] = BIT(lnz, 23);
// left-DC is special, iterated separately
}
void VP8IteratorBytesToNz(VP8EncIterator* const it) {
uint32_t nz = 0;
// top
nz |= (it->top_nz_[0] << 12) | (it->top_nz_[1] << 13);
nz |= (it->top_nz_[2] << 14) | (it->top_nz_[3] << 15);
nz |= (it->top_nz_[4] << 18) | (it->top_nz_[5] << 19);
nz |= (it->top_nz_[6] << 22) | (it->top_nz_[7] << 23);
nz |= (it->top_nz_[8] << 24); // we propagate the _top_ bit, esp. for intra4
// left
nz |= (it->left_nz_[0] << 3) | (it->left_nz_[1] << 7);
nz |= (it->left_nz_[2] << 11);
nz |= (it->left_nz_[4] << 17) | (it->left_nz_[6] << 21);
*it->nz_ = nz;
}
#undef BIT
//-----------------------------------------------------------------------------
// Advance to the next position, doing the bookeeping.
int VP8IteratorNext(VP8EncIterator* const it,
const uint8_t* const block_to_save) {
VP8Encoder* const enc = it->enc_;
if (block_to_save) {
const int x = it->x_, y = it->y_;
const uint8_t* const ysrc = block_to_save + Y_OFF;
const uint8_t* const usrc = block_to_save + U_OFF;
if (x < enc->mb_w_ - 1) { // left
int i;
for (i = 0; i < 16; ++i) {
enc->y_left_[i] = ysrc[15 + i * BPS];
}
for (i = 0; i < 8; ++i) {
enc->u_left_[i] = usrc[7 + i * BPS];
enc->v_left_[i] = usrc[15 + i * BPS];
}
// top-left (before 'top'!)
enc->y_left_[-1] = enc->y_top_[x * 16 + 15];
enc->u_left_[-1] = enc->uv_top_[x * 16 + 0 + 7];
enc->v_left_[-1] = enc->uv_top_[x * 16 + 8 + 7];
}
if (y < enc->mb_h_ - 1) { // top
memcpy(enc->y_top_ + x * 16, ysrc + 15 * BPS, 16);
memcpy(enc->uv_top_ + x * 16, usrc + 7 * BPS, 8 + 8);
}
}
it->mb_++;
it->preds_ += 4;
it->nz_++;
it->x_++;
if (it->x_ == enc->mb_w_) {
it->x_ = 0;
it->y_++;
it->bw_ = &enc->parts_[it->y_ & (enc->num_parts_ - 1)];
it->preds_ = enc->preds_ + it->y_ * 4 * enc->preds_w_;
it->nz_ = enc->nz_;
InitLeft(it);
}
return (0 < --it->done_);
}
//-----------------------------------------------------------------------------
// Helper function to set mode properties
void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode) {
int y;
uint8_t* preds = it->preds_;
for (y = 0; y < 4; ++y) {
memset(preds, mode, 4);
preds += it->enc_->preds_w_;
}
it->mb_->type_ = 1;
}
void VP8SetIntra4Mode(const VP8EncIterator* const it, int modes[16]) {
int x, y;
uint8_t* preds = it->preds_;
for (y = 0; y < 4; ++y) {
for (x = 0; x < 4; ++x) {
preds[x] = modes[x + y * 4];
}
preds += it->enc_->preds_w_;
}
it->mb_->type_ = 0;
}
void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode) {
it->mb_->uv_mode_ = mode;
}
void VP8SetSkip(const VP8EncIterator* const it, int skip) {
it->mb_->skip_ = skip;
}
void VP8SetSegment(const VP8EncIterator* const it, int segment) {
it->mb_->segment_ = segment;
}
//-----------------------------------------------------------------------------
// Intra4x4 sub-blocks iteration
//
// We store and update the boundary samples into an array of 37 pixels. They
// are updated as we iterate and reconstructs each intra4x4 blocks in turn.
// The position of the samples has the following snake pattern:
//
// 16|17 18 19 20|21 22 23 24|25 26 27 28|29 30 31 32|33 34 35 36 <- Top-right
// --+-----------+-----------+-----------+-----------+
// 15| 19| 23| 27| 31|
// 14| 18| 22| 26| 30|
// 13| 17| 21| 25| 29|
// 12|13 14 15 16|17 18 19 20|21 22 23 24|25 26 27 28|
// --+-----------+-----------+-----------+-----------+
// 11| 15| 19| 23| 27|
// 10| 14| 18| 22| 26|
// 9| 13| 17| 21| 25|
// 8| 9 10 11 12|13 14 15 16|17 18 19 20|21 22 23 24|
// --+-----------+-----------+-----------+-----------+
// 7| 11| 15| 19| 23|
// 6| 10| 14| 18| 22|
// 5| 9| 13| 17| 21|
// 4| 5 6 7 8| 9 10 11 12|13 14 15 16|17 18 19 20|
// --+-----------+-----------+-----------+-----------+
// 3| 7| 11| 15| 19|
// 2| 6| 10| 14| 18|
// 1| 5| 9| 13| 17|
// 0| 1 2 3 4| 5 6 7 8| 9 10 11 12|13 14 15 16|
// --+-----------+-----------+-----------+-----------+
// Array to record the position of the top sample to pass to the prediction
// functions in dsp.c.
static const uint8_t VP8TopLeftI4[16] = {
17, 21, 25, 29,
13, 17, 21, 25,
9, 13, 17, 21,
5, 9, 13, 17
};
void VP8IteratorStartI4(VP8EncIterator* const it) {
VP8Encoder* const enc = it->enc_;
int i;
it->i4_ = 0; // first 4x4 sub-block
it->i4_top_ = it->i4_boundary_ + VP8TopLeftI4[0];
// Import the boundary samples
for (i = 0; i < 17; ++i) { // left
it->i4_boundary_[i] = enc->y_left_[15 - i];
}
for (i = 0; i < 16; ++i) { // top
it->i4_boundary_[17 + i] = enc->y_top_[it->x_ * 16 + i];
}
// top-right samples have a special case on the far right of the picture
if (it->x_ < enc->mb_w_ - 1) {
for (i = 16; i < 16 + 4; ++i) {
it->i4_boundary_[17 + i] = enc->y_top_[it->x_ * 16 + i];
}
} else { // else, replicate the last valid pixel four times
for (i = 16; i < 16 + 4; ++i) {
it->i4_boundary_[17 + i] = it->i4_boundary_[17 + 15];
}
}
VP8IteratorNzToBytes(it); // import the non-zero context
}
int VP8IteratorRotateI4(VP8EncIterator* const it,
const uint8_t* const yuv_out) {
const uint8_t* const blk = yuv_out + VP8Scan[it->i4_];
uint8_t* const top = it->i4_top_;
int i;
// Update the cache with 7 fresh samples
for (i = 0; i <= 3; ++i) {
top[-4 + i] = blk[i + 3 * BPS]; // store future top samples
}
if ((it->i4_ & 3) != 3) { // if not on the right sub-blocks #3, #7, #11, #15
for (i = 0; i <= 2; ++i) { // store future left samples
top[i] = blk[3 + (2 - i) * BPS];
}
} else { // else replicate top-right samples, as says the specs.
for (i = 0; i <= 3; ++i) {
top[i] = top[i + 4];
}
}
// move pointers to next sub-block
it->i4_++;
if (it->i4_ == 16) { // we're done
return 0;
}
it->i4_top_ = it->i4_boundary_ + VP8TopLeftI4[it->i4_];
return 1;
}
//-----------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif