// Copyright 2011 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

// VP8Iterator: block iterator

//

// Author: Skal (pascal.massimino@gmail.com)

#include <string.h>

#include "src/enc/vp8i_enc.h"

//------------------------------------------------------------------------------

// VP8Iterator

//------------------------------------------------------------------------------

static void InitLeft(VP8EncIterator* const it) {

  it->y_left_[-1] = it->u_left_[-1] = it->v_left_[-1] =

      (it->y_ > 0) ? 129 : 127;

  memset(it->y_left_, 129, 16);

  memset(it->u_left_, 129, 8);

  memset(it->v_left_, 129, 8);

  it->left_nz_[8] = 0;

  if (it->top_derr_ != NULL) {

    memset(&it->left_derr_, 0, sizeof(it->left_derr_));

  }

}

static void InitTop(VP8EncIterator* const it) {

  const VP8Encoder* const enc = it->enc_;

  const size_t top_size = enc->mb_w_ * 16;

  memset(enc->y_top_, 127, 2 * top_size);

  memset(enc->nz_, 0, enc->mb_w_ * sizeof(*enc->nz_));

  if (enc->top_derr_ != NULL) {

    memset(enc->top_derr_, 0, enc->mb_w_ * sizeof(*enc->top_derr_));

  }

}

void VP8IteratorSetRow(VP8EncIterator* const it, int y) {

  VP8Encoder* const enc = it->enc_;

  it->x_ = 0;

  it->y_ = y;

  it->bw_ = &enc->parts_[y & (enc->num_parts_ - 1)];

  it->preds_ = enc->preds_ + y * 4 * enc->preds_w_;

  it->nz_ = enc->nz_;

  it->mb_ = enc->mb_info_ + y * enc->mb_w_;

  it->y_top_ = enc->y_top_;

  it->uv_top_ = enc->uv_top_;

  InitLeft(it);

}

void VP8IteratorReset(VP8EncIterator* const it) {

  VP8Encoder* const enc = it->enc_;

  VP8IteratorSetRow(it, 0);

  VP8IteratorSetCountDown(it, enc->mb_w_ * enc->mb_h_);  // default

  InitTop(it);

  memset(it->bit_count_, 0, sizeof(it->bit_count_));

  it->do_trellis_ = 0;

}

void VP8IteratorSetCountDown(VP8EncIterator* const it, int count_down) {

  it->count_down_ = it->count_down0_ = count_down;

}

int VP8IteratorIsDone(const VP8EncIterator* const it) {

  return (it->count_down_ <= 0);

}

void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it) {

  it->enc_ = enc;

  it->yuv_in_   = (uint8_t*)WEBP_ALIGN(it->yuv_mem_);

  it->yuv_out_  = it->yuv_in_ + YUV_SIZE_ENC;

  it->yuv_out2_ = it->yuv_out_ + YUV_SIZE_ENC;

  it->yuv_p_    = it->yuv_out2_ + YUV_SIZE_ENC;

  it->lf_stats_ = enc->lf_stats_;

  it->percent0_ = enc->percent_;

  it->y_left_ = (uint8_t*)WEBP_ALIGN(it->yuv_left_mem_ + 1);

  it->u_left_ = it->y_left_ + 16 + 16;

  it->v_left_ = it->u_left_ + 16;

  it->top_derr_ = enc->top_derr_;

  VP8IteratorReset(it);

}

int VP8IteratorProgress(const VP8EncIterator* const it, int delta) {

  VP8Encoder* const enc = it->enc_;

  if (delta && enc->pic_->progress_hook != NULL) {

    const int done = it->count_down0_ - it->count_down_;

    const int percent = (it->count_down0_ <= 0)

                      ? it->percent0_

                      : it->percent0_ + delta * done / it->count_down0_;

    return WebPReportProgress(enc->pic_, percent, &enc->percent_);

  }

  return 1;

}

//------------------------------------------------------------------------------

// Import the source samples into the cache. Takes care of replicating

// boundary pixels if necessary.

static WEBP_INLINE int MinSize(int a, int b) { return (a < b) ? a : b; }

static void ImportBlock(const uint8_t* src, int src_stride,

                        uint8_t* dst, int w, int h, int size) {

  int i;

  for (i = 0; i < h; ++i) {

    memcpy(dst, src, w);

    if (w < size) {

      memset(dst + w, dst[w - 1], size - w);

    }

    dst += BPS;

    src += src_stride;

  }

  for (i = h; i < size; ++i) {

    memcpy(dst, dst - BPS, size);

    dst += BPS;

  }

}

static void ImportLine(const uint8_t* src, int src_stride,

                       uint8_t* dst, int len, int total_len) {

  int i;

  for (i = 0; i < len; ++i, src += src_stride) dst[i] = *src;

  for (; i < total_len; ++i) dst[i] = dst[len - 1];

}

void VP8IteratorImport(VP8EncIterator* const it, uint8_t* tmp_32) {

  const VP8Encoder* const enc = it->enc_;

  const int x = it->x_, y = it->y_;

  const WebPPicture* const pic = enc->pic_;

  const uint8_t* const ysrc = pic->y + (y * pic->y_stride  + x) * 16;

  const uint8_t* const usrc = pic->u + (y * pic->uv_stride + x) * 8;

  const uint8_t* const vsrc = pic->v + (y * pic->uv_stride + x) * 8;

  const int w = MinSize(pic->width - x * 16, 16);

  const int h = MinSize(pic->height - y * 16, 16);

  const int uv_w = (w + 1) >> 1;

  const int uv_h = (h + 1) >> 1;

  ImportBlock(ysrc, pic->y_stride,  it->yuv_in_ + Y_OFF_ENC, w, h, 16);

  ImportBlock(usrc, pic->uv_stride, it->yuv_in_ + U_OFF_ENC, uv_w, uv_h, 8);

  ImportBlock(vsrc, pic->uv_stride, it->yuv_in_ + V_OFF_ENC, uv_w, uv_h, 8);

  if (tmp_32 == NULL) return;

  // Import source (uncompressed) samples into boundary.

  if (x == 0) {

    InitLeft(it);

  } else {

    if (y == 0) {

      it->y_left_[-1] = it->u_left_[-1] = it->v_left_[-1] = 127;

    } else {

      it->y_left_[-1] = ysrc[- 1 - pic->y_stride];

      it->u_left_[-1] = usrc[- 1 - pic->uv_stride];

      it->v_left_[-1] = vsrc[- 1 - pic->uv_stride];

    }

    ImportLine(ysrc - 1, pic->y_stride,  it->y_left_, h,   16);

    ImportLine(usrc - 1, pic->uv_stride, it->u_left_, uv_h, 8);

    ImportLine(vsrc - 1, pic->uv_stride, it->v_left_, uv_h, 8);

  }

  it->y_top_  = tmp_32 + 0;

  it->uv_top_ = tmp_32 + 16;

  if (y == 0) {

    memset(tmp_32, 127, 32 * sizeof(*tmp_32));

  } else {

    ImportLine(ysrc - pic->y_stride,  1, tmp_32,          w,   16);

    ImportLine(usrc - pic->uv_stride, 1, tmp_32 + 16,     uv_w, 8);

    ImportLine(vsrc - pic->uv_stride, 1, tmp_32 + 16 + 8, uv_w, 8);

  }

}

//------------------------------------------------------------------------------

// Copy back the compressed samples into user space if requested.

static void ExportBlock(const uint8_t* src, uint8_t* dst, int dst_stride,

                        int w, int h) {

  while (h-- > 0) {

    memcpy(dst, src, w);

    dst += dst_stride;

    src += BPS;

  }

}

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_ENC;

    const uint8_t* const usrc = it->yuv_out_ + U_OFF_ENC;

    const uint8_t* const vsrc = it->yuv_out_ + V_OFF_ENC;

    const WebPPicture* const pic = enc->pic_;

    uint8_t* const ydst = pic->y + (y * pic->y_stride + x) * 16;

    uint8_t* const udst = pic->u + (y * pic->uv_stride + x) * 8;

    uint8_t* const vdst = pic->v + (y * pic->uv_stride + x) * 8;

    int w = (pic->width - x * 16);

    int h = (pic->height - y * 16);

    if (w > 16) w = 16;

    if (h > 16) h = 16;

    // Luma plane

    ExportBlock(ysrc, ydst, pic->y_stride, w, h);

    {   // U/V planes

      const int uv_w = (w + 1) >> 1;

      const int uv_h = (h + 1) >> 1;

      ExportBlock(usrc, udst, pic->uv_stride, uv_w, uv_h);

      ExportBlock(vsrc, vdst, pic->uv_stride, uv_w, uv_h);

    }

  }

}

//------------------------------------------------------------------------------

// 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];

  int* const top_nz = it->top_nz_;

  int* const left_nz = it->left_nz_;

  // Top-Y

  top_nz[0] = BIT(tnz, 12);

  top_nz[1] = BIT(tnz, 13);

  top_nz[2] = BIT(tnz, 14);

  top_nz[3] = BIT(tnz, 15);

  // Top-U

  top_nz[4] = BIT(tnz, 18);

  top_nz[5] = BIT(tnz, 19);

  // Top-V

  top_nz[6] = BIT(tnz, 22);

  top_nz[7] = BIT(tnz, 23);

  // DC

  top_nz[8] = BIT(tnz, 24);

  // left-Y

  left_nz[0] = BIT(lnz,  3);

  left_nz[1] = BIT(lnz,  7);

  left_nz[2] = BIT(lnz, 11);

  left_nz[3] = BIT(lnz, 15);

  // left-U

  left_nz[4] = BIT(lnz, 17);

  left_nz[5] = BIT(lnz, 19);

  // left-V

  left_nz[6] = BIT(lnz, 21);

  left_nz[7] = BIT(lnz, 23);

  // left-DC is special, iterated separately

}

void VP8IteratorBytesToNz(VP8EncIterator* const it) {

  uint32_t nz = 0;

  const int* const top_nz = it->top_nz_;

  const int* const left_nz = it->left_nz_;

  // top

  nz |= (top_nz[0] << 12) | (top_nz[1] << 13);

  nz |= (top_nz[2] << 14) | (top_nz[3] << 15);

  nz |= (top_nz[4] << 18) | (top_nz[5] << 19);

  nz |= (top_nz[6] << 22) | (top_nz[7] << 23);

  nz |= (top_nz[8] << 24);  // we propagate the _top_ bit, esp. for intra4

  // left

  nz |= (left_nz[0] << 3) | (left_nz[1] << 7);

  nz |= (left_nz[2] << 11);

  nz |= (left_nz[4] << 17) | (left_nz[6] << 21);

  *it->nz_ = nz;

}

#undef BIT

//------------------------------------------------------------------------------

// Advance to the next position, doing the bookkeeping.

void VP8IteratorSaveBoundary(VP8EncIterator* const it) {

  VP8Encoder* const enc = it->enc_;

  const int x = it->x_, y = it->y_;

  const uint8_t* const ysrc = it->yuv_out_ + Y_OFF_ENC;

  const uint8_t* const uvsrc = it->yuv_out_ + U_OFF_ENC;

  if (x < enc->mb_w_ - 1) {   // left

    int i;

    for (i = 0; i < 16; ++i) {

      it->y_left_[i] = ysrc[15 + i * BPS];

    }

    for (i = 0; i < 8; ++i) {

      it->u_left_[i] = uvsrc[7 + i * BPS];

      it->v_left_[i] = uvsrc[15 + i * BPS];

    }

    // top-left (before 'top'!)

    it->y_left_[-1] = it->y_top_[15];

    it->u_left_[-1] = it->uv_top_[0 + 7];

    it->v_left_[-1] = it->uv_top_[8 + 7];

  }

  if (y < enc->mb_h_ - 1) {  // top

    memcpy(it->y_top_, ysrc + 15 * BPS, 16);

    memcpy(it->uv_top_, uvsrc + 7 * BPS, 8 + 8);

  }

}

int VP8IteratorNext(VP8EncIterator* const it) {

  if (++it->x_ == it->enc_->mb_w_) {

    VP8IteratorSetRow(it, ++it->y_);

  } else {

    it->preds_ += 4;

    it->mb_ += 1;

    it->nz_ += 1;

    it->y_top_ += 16;

    it->uv_top_ += 16;

  }

  return (0 < --it->count_down_);

}

//------------------------------------------------------------------------------

// Helper function to set mode properties

void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode) {

  uint8_t* preds = it->preds_;

  int y;

  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, const uint8_t* modes) {

  uint8_t* preds = it->preds_;

  int y;

  for (y = 4; y > 0; --y) {

    memcpy(preds, modes, 4 * sizeof(*modes));

    preds += it->enc_->preds_w_;

    modes += 4;

  }

  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) {

  const 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] = it->y_left_[15 - i];

  }

  for (i = 0; i < 16; ++i) {    // top

    it->i4_boundary_[17 + i] = it->y_top_[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] = it->y_top_[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;

}

//------------------------------------------------------------------------------