// 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 "src/utils/utils.h"

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

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

#include "src/enc/vp8i_enc.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;

}

return p ? pic->writer(buf, 3 * p, pic) : 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;

}

// Sanity check.

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_);

return ok;

}

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