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-rw-r--r--media/libwebp/src/enc/syntax_enc.c388
1 files changed, 388 insertions, 0 deletions
diff --git a/media/libwebp/src/enc/syntax_enc.c b/media/libwebp/src/enc/syntax_enc.c
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+++ b/media/libwebp/src/enc/syntax_enc.c
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+// 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;
+ }
+ // 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_);
+ return ok;
+}
+
+//------------------------------------------------------------------------------
+
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