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Diffstat (limited to 'thirdparty/libwebp/dec/alpha_dec.c')
-rw-r--r--thirdparty/libwebp/dec/alpha_dec.c232
1 files changed, 0 insertions, 232 deletions
diff --git a/thirdparty/libwebp/dec/alpha_dec.c b/thirdparty/libwebp/dec/alpha_dec.c
deleted file mode 100644
index 83ffd4b609..0000000000
--- a/thirdparty/libwebp/dec/alpha_dec.c
+++ /dev/null
@@ -1,232 +0,0 @@
-// 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.
-// -----------------------------------------------------------------------------
-//
-// Alpha-plane decompression.
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include <stdlib.h>
-#include "./alphai_dec.h"
-#include "./vp8i_dec.h"
-#include "./vp8li_dec.h"
-#include "../dsp/dsp.h"
-#include "../utils/quant_levels_dec_utils.h"
-#include "../utils/utils.h"
-#include "../webp/format_constants.h"
-
-//------------------------------------------------------------------------------
-// ALPHDecoder object.
-
-// Allocates a new alpha decoder instance.
-static ALPHDecoder* ALPHNew(void) {
- ALPHDecoder* const dec = (ALPHDecoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
- return dec;
-}
-
-// Clears and deallocates an alpha decoder instance.
-static void ALPHDelete(ALPHDecoder* const dec) {
- if (dec != NULL) {
- VP8LDelete(dec->vp8l_dec_);
- dec->vp8l_dec_ = NULL;
- WebPSafeFree(dec);
- }
-}
-
-//------------------------------------------------------------------------------
-// Decoding.
-
-// Initialize alpha decoding by parsing the alpha header and decoding the image
-// header for alpha data stored using lossless compression.
-// Returns false in case of error in alpha header (data too short, invalid
-// compression method or filter, error in lossless header data etc).
-static int ALPHInit(ALPHDecoder* const dec, const uint8_t* data,
- size_t data_size, const VP8Io* const src_io,
- uint8_t* output) {
- int ok = 0;
- const uint8_t* const alpha_data = data + ALPHA_HEADER_LEN;
- const size_t alpha_data_size = data_size - ALPHA_HEADER_LEN;
- int rsrv;
- VP8Io* const io = &dec->io_;
-
- assert(data != NULL && output != NULL && src_io != NULL);
-
- VP8FiltersInit();
- dec->output_ = output;
- dec->width_ = src_io->width;
- dec->height_ = src_io->height;
- assert(dec->width_ > 0 && dec->height_ > 0);
-
- if (data_size <= ALPHA_HEADER_LEN) {
- return 0;
- }
-
- dec->method_ = (data[0] >> 0) & 0x03;
- dec->filter_ = (WEBP_FILTER_TYPE)((data[0] >> 2) & 0x03);
- dec->pre_processing_ = (data[0] >> 4) & 0x03;
- rsrv = (data[0] >> 6) & 0x03;
- if (dec->method_ < ALPHA_NO_COMPRESSION ||
- dec->method_ > ALPHA_LOSSLESS_COMPRESSION ||
- dec->filter_ >= WEBP_FILTER_LAST ||
- dec->pre_processing_ > ALPHA_PREPROCESSED_LEVELS ||
- rsrv != 0) {
- return 0;
- }
-
- // Copy the necessary parameters from src_io to io
- VP8InitIo(io);
- WebPInitCustomIo(NULL, io);
- io->opaque = dec;
- io->width = src_io->width;
- io->height = src_io->height;
-
- io->use_cropping = src_io->use_cropping;
- io->crop_left = src_io->crop_left;
- io->crop_right = src_io->crop_right;
- io->crop_top = src_io->crop_top;
- io->crop_bottom = src_io->crop_bottom;
- // No need to copy the scaling parameters.
-
- if (dec->method_ == ALPHA_NO_COMPRESSION) {
- const size_t alpha_decoded_size = dec->width_ * dec->height_;
- ok = (alpha_data_size >= alpha_decoded_size);
- } else {
- assert(dec->method_ == ALPHA_LOSSLESS_COMPRESSION);
- ok = VP8LDecodeAlphaHeader(dec, alpha_data, alpha_data_size);
- }
-
- return ok;
-}
-
-// Decodes, unfilters and dequantizes *at least* 'num_rows' rows of alpha
-// starting from row number 'row'. It assumes that rows up to (row - 1) have
-// already been decoded.
-// Returns false in case of bitstream error.
-static int ALPHDecode(VP8Decoder* const dec, int row, int num_rows) {
- ALPHDecoder* const alph_dec = dec->alph_dec_;
- const int width = alph_dec->width_;
- const int height = alph_dec->io_.crop_bottom;
- if (alph_dec->method_ == ALPHA_NO_COMPRESSION) {
- int y;
- const uint8_t* prev_line = dec->alpha_prev_line_;
- const uint8_t* deltas = dec->alpha_data_ + ALPHA_HEADER_LEN + row * width;
- uint8_t* dst = dec->alpha_plane_ + row * width;
- assert(deltas <= &dec->alpha_data_[dec->alpha_data_size_]);
- if (alph_dec->filter_ != WEBP_FILTER_NONE) {
- assert(WebPUnfilters[alph_dec->filter_] != NULL);
- for (y = 0; y < num_rows; ++y) {
- WebPUnfilters[alph_dec->filter_](prev_line, deltas, dst, width);
- prev_line = dst;
- dst += width;
- deltas += width;
- }
- } else {
- for (y = 0; y < num_rows; ++y) {
- memcpy(dst, deltas, width * sizeof(*dst));
- prev_line = dst;
- dst += width;
- deltas += width;
- }
- }
- dec->alpha_prev_line_ = prev_line;
- } else { // alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION
- assert(alph_dec->vp8l_dec_ != NULL);
- if (!VP8LDecodeAlphaImageStream(alph_dec, row + num_rows)) {
- return 0;
- }
- }
-
- if (row + num_rows >= height) {
- dec->is_alpha_decoded_ = 1;
- }
- return 1;
-}
-
-static int AllocateAlphaPlane(VP8Decoder* const dec, const VP8Io* const io) {
- const int stride = io->width;
- const int height = io->crop_bottom;
- const uint64_t alpha_size = (uint64_t)stride * height;
- assert(dec->alpha_plane_mem_ == NULL);
- dec->alpha_plane_mem_ =
- (uint8_t*)WebPSafeMalloc(alpha_size, sizeof(*dec->alpha_plane_));
- if (dec->alpha_plane_mem_ == NULL) {
- return 0;
- }
- dec->alpha_plane_ = dec->alpha_plane_mem_;
- dec->alpha_prev_line_ = NULL;
- return 1;
-}
-
-void WebPDeallocateAlphaMemory(VP8Decoder* const dec) {
- assert(dec != NULL);
- WebPSafeFree(dec->alpha_plane_mem_);
- dec->alpha_plane_mem_ = NULL;
- dec->alpha_plane_ = NULL;
- ALPHDelete(dec->alph_dec_);
- dec->alph_dec_ = NULL;
-}
-
-//------------------------------------------------------------------------------
-// Main entry point.
-
-const uint8_t* VP8DecompressAlphaRows(VP8Decoder* const dec,
- const VP8Io* const io,
- int row, int num_rows) {
- const int width = io->width;
- const int height = io->crop_bottom;
-
- assert(dec != NULL && io != NULL);
-
- if (row < 0 || num_rows <= 0 || row + num_rows > height) {
- return NULL; // sanity check.
- }
-
- if (!dec->is_alpha_decoded_) {
- if (dec->alph_dec_ == NULL) { // Initialize decoder.
- dec->alph_dec_ = ALPHNew();
- if (dec->alph_dec_ == NULL) return NULL;
- if (!AllocateAlphaPlane(dec, io)) goto Error;
- if (!ALPHInit(dec->alph_dec_, dec->alpha_data_, dec->alpha_data_size_,
- io, dec->alpha_plane_)) {
- goto Error;
- }
- // if we allowed use of alpha dithering, check whether it's needed at all
- if (dec->alph_dec_->pre_processing_ != ALPHA_PREPROCESSED_LEVELS) {
- dec->alpha_dithering_ = 0; // disable dithering
- } else {
- num_rows = height - row; // decode everything in one pass
- }
- }
-
- assert(dec->alph_dec_ != NULL);
- assert(row + num_rows <= height);
- if (!ALPHDecode(dec, row, num_rows)) goto Error;
-
- if (dec->is_alpha_decoded_) { // finished?
- ALPHDelete(dec->alph_dec_);
- dec->alph_dec_ = NULL;
- if (dec->alpha_dithering_ > 0) {
- uint8_t* const alpha = dec->alpha_plane_ + io->crop_top * width
- + io->crop_left;
- if (!WebPDequantizeLevels(alpha,
- io->crop_right - io->crop_left,
- io->crop_bottom - io->crop_top,
- width, dec->alpha_dithering_)) {
- goto Error;
- }
- }
- }
- }
-
- // Return a pointer to the current decoded row.
- return dec->alpha_plane_ + row * width;
-
- Error:
- WebPDeallocateAlphaMemory(dec);
- return NULL;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-18 04:47:33 +0000