// 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.

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

//

// Header syntax writing

//

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

#include <assert.h>

#include <stddef.h>

#include "src/dec/common_dec.h"

#include "src/enc/vp8i_enc.h"

#include "src/utils/bit_writer_utils.h"

#include "src/utils/utils.h"

#include "src/webp/encode.h"

#include "src/webp/format_constants.h"  // RIFF constants

#include "src/webp/mux_types.h"         // ALPHA_FLAG

#include "src/webp/types.h"

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

// Helper functions

static int IsVP8XNeeded(const VP8Encoder* const enc) {

  return !!enc->has_alpha;  // Currently the only case when VP8X is needed.

                            // This could change in the future.

}

static int PutPaddingByte(const WebPPicture* const pic) {

  const uint8_t pad_byte[1] = {0};

  return !!pic->writer(pad_byte, 1, pic);

}

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

// Writers for header's various pieces (in order of appearance)

static WebPEncodingError PutRIFFHeader(const VP8Encoder* const enc,

                                       size_t riff_size) {

  const WebPPicture* const pic = enc->pic;

  uint8_t riff[RIFF_HEADER_SIZE] = {'R', 'I', 'F', 'F', 0,   0,

                                    0,   0,   'W', 'E', 'B', 'P'};

  assert(riff_size == (uint32_t)riff_size);

  PutLE32(riff + TAG_SIZE, (uint32_t)riff_size);

  if (!pic->writer(riff, sizeof(riff), pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  return VP8_ENC_OK;

}

static WebPEncodingError PutVP8XHeader(const VP8Encoder* const enc) {

  const WebPPicture* const pic = enc->pic;

  uint8_t vp8x[CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE] = {'V', 'P', '8', 'X'};

  uint32_t flags = 0;

  assert(IsVP8XNeeded(enc));

  assert(pic->width >= 1 && pic->height >= 1);

  assert(pic->width <= MAX_CANVAS_SIZE && pic->height <= MAX_CANVAS_SIZE);

  if (enc->has_alpha) {

    flags |= ALPHA_FLAG;

  }

  PutLE32(vp8x + TAG_SIZE, VP8X_CHUNK_SIZE);

  PutLE32(vp8x + CHUNK_HEADER_SIZE, flags);

  PutLE24(vp8x + CHUNK_HEADER_SIZE + 4, pic->width - 1);

  PutLE24(vp8x + CHUNK_HEADER_SIZE + 7, pic->height - 1);

  if (!pic->writer(vp8x, sizeof(vp8x), pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  return VP8_ENC_OK;

}

static WebPEncodingError PutAlphaChunk(const VP8Encoder* const enc) {

  const WebPPicture* const pic = enc->pic;

  uint8_t alpha_chunk_hdr[CHUNK_HEADER_SIZE] = {'A', 'L', 'P', 'H'};

  assert(enc->has_alpha);

  // Alpha chunk header.

  PutLE32(alpha_chunk_hdr + TAG_SIZE, enc->alpha_data_size);

  if (!pic->writer(alpha_chunk_hdr, sizeof(alpha_chunk_hdr), pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  // Alpha chunk data.

  if (!pic->writer(enc->alpha_data, enc->alpha_data_size, pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  // Padding.

  if ((enc->alpha_data_size & 1) && !PutPaddingByte(pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  return VP8_ENC_OK;

}

static WebPEncodingError PutVP8Header(const WebPPicture* const pic,

                                      size_t vp8_size) {

  uint8_t vp8_chunk_hdr[CHUNK_HEADER_SIZE] = {'V', 'P', '8', ' '};

  assert(vp8_size == (uint32_t)vp8_size);

  PutLE32(vp8_chunk_hdr + TAG_SIZE, (uint32_t)vp8_size);

  if (!pic->writer(vp8_chunk_hdr, sizeof(vp8_chunk_hdr), pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  return VP8_ENC_OK;

}

static WebPEncodingError PutVP8FrameHeader(const WebPPicture* const pic,

                                           int profile, size_t size0) {

  uint8_t vp8_frm_hdr[VP8_FRAME_HEADER_SIZE];

  uint32_t bits;

  if (size0 >= VP8_MAX_PARTITION0_SIZE) {  // partition #0 is too big to fit

    return VP8_ENC_ERROR_PARTITION0_OVERFLOW;

  }

  // Paragraph 9.1.

  bits = 0                          // keyframe (1b)

         | (profile << 1)           // profile (3b)

         | (1 << 4)                 // visible (1b)

         | ((uint32_t)size0 << 5);  // partition length (19b)

  vp8_frm_hdr[0] = (bits >> 0) & 0xff;

  vp8_frm_hdr[1] = (bits >> 8) & 0xff;

  vp8_frm_hdr[2] = (bits >> 16) & 0xff;

  // signature

  vp8_frm_hdr[3] = (VP8_SIGNATURE >> 16) & 0xff;

  vp8_frm_hdr[4] = (VP8_SIGNATURE >> 8) & 0xff;

  vp8_frm_hdr[5] = (VP8_SIGNATURE >> 0) & 0xff;

  // dimensions

  vp8_frm_hdr[6] = pic->width & 0xff;

  vp8_frm_hdr[7] = pic->width >> 8;

  vp8_frm_hdr[8] = pic->height & 0xff;

  vp8_frm_hdr[9] = pic->height >> 8;

  if (!pic->writer(vp8_frm_hdr, sizeof(vp8_frm_hdr), pic)) {

    return VP8_ENC_ERROR_BAD_WRITE;

  }

  return VP8_ENC_OK;

}

// WebP Headers.

static int PutWebPHeaders(const VP8Encoder* const enc, size_t size0,

                          size_t vp8_size, size_t riff_size) {

  WebPPicture* const pic = enc->pic;

  WebPEncodingError err = VP8_ENC_OK;

  // RIFF header.

  err = PutRIFFHeader(enc, riff_size);

  if (err != VP8_ENC_OK) goto Error;

  // VP8X.

  if (IsVP8XNeeded(enc)) {

    err = PutVP8XHeader(enc);

    if (err != VP8_ENC_OK) goto Error;

  }

  // Alpha.

  if (enc->has_alpha) {

    err = PutAlphaChunk(enc);

    if (err != VP8_ENC_OK) goto Error;

  }

  // VP8 header.

  err = PutVP8Header(pic, vp8_size);

  if (err != VP8_ENC_OK) goto Error;

  // VP8 frame header.

  err = PutVP8FrameHeader(pic, enc->profile, size0);

  if (err != VP8_ENC_OK) goto Error;

  // All OK.

  return 1;

  // Error.

Error:

  return WebPEncodingSetError(pic, err);

}

// Segmentation header

static void PutSegmentHeader(VP8BitWriter* const bw,

                             const VP8Encoder* const enc) {

  const VP8EncSegmentHeader* const hdr = &enc->segment_hdr;

  const VP8EncProba* const proba = &enc->proba;

  if (VP8PutBitUniform(bw, (hdr->num_segments > 1))) {

    // We always 'update' the quant and filter strength values

    const int update_data = 1;

    int s;

    VP8PutBitUniform(bw, hdr->update_map);

    if (VP8PutBitUniform(bw, update_data)) {

      // we always use absolute values, not relative ones

      VP8PutBitUniform(bw, 1);  // (segment_feature_mode = 1. Paragraph 9.3.)

      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {

        VP8PutSignedBits(bw, enc->dqm[s].quant, 7);

      }

      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {

        VP8PutSignedBits(bw, enc->dqm[s].fstrength, 6);

      }

    }

    if (hdr->update_map) {

      for (s = 0; s < 3; ++s) {

        if (VP8PutBitUniform(bw, (proba->segments[s] != 255u))) {

          VP8PutBits(bw, proba->segments[s], 8);

        }

      }

    }

  }

}

// Filtering parameters header

static void PutFilterHeader(VP8BitWriter* const bw,

                            const VP8EncFilterHeader* const hdr) {

  const int use_lf_delta = (hdr->i4x4_lf_delta != 0);

  VP8PutBitUniform(bw, hdr->simple);

  VP8PutBits(bw, hdr->level, 6);

  VP8PutBits(bw, hdr->sharpness, 3);

  if (VP8PutBitUniform(bw, use_lf_delta)) {

    // '0' is the default value for i4x4_lf_delta at frame #0.

    const int need_update = (hdr->i4x4_lf_delta != 0);

    if (VP8PutBitUniform(bw, need_update)) {

      // we don't use ref_lf_delta => emit four 0 bits

      VP8PutBits(bw, 0, 4);

      // we use mode_lf_delta for i4x4

      VP8PutSignedBits(bw, hdr->i4x4_lf_delta, 6);

      VP8PutBits(bw, 0, 3);  // all others unused

    }

  }

}

// Nominal quantization parameters

static void PutQuant(VP8BitWriter* const bw, const VP8Encoder* const enc) {

  VP8PutBits(bw, enc->base_quant, 7);

  VP8PutSignedBits(bw, enc->dq_y1_dc, 4);

  VP8PutSignedBits(bw, enc->dq_y2_dc, 4);

  VP8PutSignedBits(bw, enc->dq_y2_ac, 4);

  VP8PutSignedBits(bw, enc->dq_uv_dc, 4);

  VP8PutSignedBits(bw, enc->dq_uv_ac, 4);

}

// Partition sizes

static int EmitPartitionsSize(const VP8Encoder* const enc,

                              WebPPicture* const pic) {

  uint8_t buf[3 * (MAX_NUM_PARTITIONS - 1)];

  int p;

  for (p = 0; p < enc->num_parts - 1; ++p) {

    const size_t part_size = VP8BitWriterSize(enc->parts + p);

    if (part_size >= VP8_MAX_PARTITION_SIZE) {

      return WebPEncodingSetError(pic, VP8_ENC_ERROR_PARTITION_OVERFLOW);

    }

    buf[3 * p + 0] = (part_size >> 0) & 0xff;

    buf[3 * p + 1] = (part_size >> 8) & 0xff;

    buf[3 * p + 2] = (part_size >> 16) & 0xff;

  }

  if (p && !pic->writer(buf, 3 * p, pic)) {

    return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);

  }

  return 1;

}

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

static int GeneratePartition0(VP8Encoder* const enc) {

  VP8BitWriter* const bw = &enc->bw;

  const int mb_size = enc->mb_w * enc->mb_h;

  uint64_t pos1, pos2, pos3;

  pos1 = VP8BitWriterPos(bw);

  if (!VP8BitWriterInit(bw, mb_size * 7 / 8)) {  // ~7 bits per macroblock

    return WebPEncodingSetError(enc->pic, VP8_ENC_ERROR_OUT_OF_MEMORY);

  }

  VP8PutBitUniform(bw, 0);  // colorspace

  VP8PutBitUniform(bw, 0);  // clamp type

  PutSegmentHeader(bw, enc);

  PutFilterHeader(bw, &enc->filter_hdr);

  VP8PutBits(bw,

             enc->num_parts == 8   ? 3

             : enc->num_parts == 4 ? 2

             : enc->num_parts == 2 ? 1

                                   : 0,

             2);

  PutQuant(bw, enc);

  VP8PutBitUniform(bw, 0);  // no proba update

  VP8WriteProbas(bw, &enc->proba);

  pos2 = VP8BitWriterPos(bw);

  VP8CodeIntraModes(enc);

  VP8BitWriterFinish(bw);

  pos3 = VP8BitWriterPos(bw);

#if !defined(WEBP_DISABLE_STATS)

  if (enc->pic->stats) {

    enc->pic->stats->header_bytes[0] = (int)((pos2 - pos1 + 7) >> 3);

    enc->pic->stats->header_bytes[1] = (int)((pos3 - pos2 + 7) >> 3);

    enc->pic->stats->alpha_data_size = (int)enc->alpha_data_size;

  }

#else

  (void)pos1;

  (void)pos2;

  (void)pos3;

#endif

  if (bw->error) {

    return WebPEncodingSetError(enc->pic, VP8_ENC_ERROR_OUT_OF_MEMORY);

  }

  return 1;

}

void VP8EncFreeBitWriters(VP8Encoder* const enc) {

  int p;

  VP8BitWriterWipeOut(&enc->bw);

  for (p = 0; p < enc->num_parts; ++p) {

    VP8BitWriterWipeOut(enc->parts + p);

  }

}

int VP8EncWrite(VP8Encoder* const enc) {

  WebPPicture* const pic = enc->pic;

  VP8BitWriter* const bw = &enc->bw;

  const int task_percent = 19;

  const int percent_per_part = task_percent / enc->num_parts;

  const int final_percent = enc->percent + task_percent;

  int ok = 0;

  size_t vp8_size, pad, riff_size;

  int p;

  // Partition #0 with header and partition sizes

  ok = GeneratePartition0(enc);

  if (!ok) return 0;

  // Compute VP8 size

  vp8_size =

      VP8_FRAME_HEADER_SIZE + VP8BitWriterSize(bw) + 3 * (enc->num_parts - 1);

  for (p = 0; p < enc->num_parts; ++p) {

    vp8_size += VP8BitWriterSize(enc->parts + p);

  }

  pad = vp8_size & 1;

  vp8_size += pad;

  // Compute RIFF size

  // At the minimum it is: "WEBPVP8 nnnn" + VP8 data size.

  riff_size = TAG_SIZE + CHUNK_HEADER_SIZE + vp8_size;

  if (IsVP8XNeeded(enc)) {  // Add size for: VP8X header + data.

    riff_size += CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE;

  }

  if (enc->has_alpha) {  // Add size for: ALPH header + data.

    const uint32_t padded_alpha_size =

        enc->alpha_data_size + (enc->alpha_data_size & 1);

    riff_size += CHUNK_HEADER_SIZE + padded_alpha_size;

  }

  // RIFF size should fit in 32-bits.

  if (riff_size > 0xfffffffeU) {

    return WebPEncodingSetError(pic, VP8_ENC_ERROR_FILE_TOO_BIG);

  }

  // Emit headers and partition #0

  {

    const uint8_t* const part0 = VP8BitWriterBuf(bw);

    const size_t size0 = VP8BitWriterSize(bw);

    ok = ok && PutWebPHeaders(enc, size0, vp8_size, riff_size) &&

         pic->writer(part0, size0, pic) && EmitPartitionsSize(enc, pic);

    VP8BitWriterWipeOut(bw);  // will free the internal buffer.

  }

  // Token partitions

  for (p = 0; p < enc->num_parts; ++p) {

    const uint8_t* const buf = VP8BitWriterBuf(enc->parts + p);

    const size_t size = VP8BitWriterSize(enc->parts + p);

    if (size) ok = ok && pic->writer(buf, size, pic);

    VP8BitWriterWipeOut(enc->parts + p);  // will free the internal buffer.

    ok = ok && WebPReportProgress(pic, enc->percent + percent_per_part,

                                  &enc->percent);

  }

  // Padding byte

  if (ok && pad) {

    ok = PutPaddingByte(pic);

  }

  enc->coded_size = (int)(CHUNK_HEADER_SIZE + riff_size);

  ok = ok && WebPReportProgress(pic, final_percent, &enc->percent);

  if (!ok) WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);

  return ok;

}

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