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Diffstat (limited to 'media/libwebp/enc/syntax_enc.c')
| -rw-r--r-- | media/libwebp/enc/syntax_enc.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/media/libwebp/enc/syntax_enc.c b/media/libwebp/enc/syntax_enc.c new file mode 100644 index 0000000000..28fd1f1ee0 --- /dev/null +++ b/media/libwebp/enc/syntax_enc.c @@ -0,0 +1,388 @@ +// 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 "../utils/utils.h" +#include "../webp/format_constants.h" // RIFF constants +#include "../webp/mux_types.h" // ALPHA_FLAG +#include "../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; +} + +//------------------------------------------------------------------------------ + |