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+// Copyright 2012 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.
+// -----------------------------------------------------------------------------
+//
+// Lossless decoder: internal header.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+// Vikas Arora(vikaas.arora@gmail.com)
+
+#ifndef WEBP_DEC_VP8LI_H_
+#define WEBP_DEC_VP8LI_H_
+
+#include <string.h> // for memcpy()
+#include "./webpi_dec.h"
+#include "../utils/bit_reader_utils.h"
+#include "../utils/color_cache_utils.h"
+#include "../utils/huffman_utils.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+ READ_DATA = 0,
+ READ_HDR = 1,
+ READ_DIM = 2
+} VP8LDecodeState;
+
+typedef struct VP8LTransform VP8LTransform;
+struct VP8LTransform {
+ VP8LImageTransformType type_; // transform type.
+ int bits_; // subsampling bits defining transform window.
+ int xsize_; // transform window X index.
+ int ysize_; // transform window Y index.
+ uint32_t *data_; // transform data.
+};
+
+typedef struct {
+ int color_cache_size_;
+ VP8LColorCache color_cache_;
+ VP8LColorCache saved_color_cache_; // for incremental
+
+ int huffman_mask_;
+ int huffman_subsample_bits_;
+ int huffman_xsize_;
+ uint32_t *huffman_image_;
+ int num_htree_groups_;
+ HTreeGroup *htree_groups_;
+ HuffmanCode *huffman_tables_;
+} VP8LMetadata;
+
+typedef struct VP8LDecoder VP8LDecoder;
+struct VP8LDecoder {
+ VP8StatusCode status_;
+ VP8LDecodeState state_;
+ VP8Io *io_;
+
+ const WebPDecBuffer *output_; // shortcut to io->opaque->output
+
+ uint32_t *pixels_; // Internal data: either uint8_t* for alpha
+ // or uint32_t* for BGRA.
+ uint32_t *argb_cache_; // Scratch buffer for temporary BGRA storage.
+
+ VP8LBitReader br_;
+ int incremental_; // if true, incremental decoding is expected
+ VP8LBitReader saved_br_; // note: could be local variables too
+ int saved_last_pixel_;
+
+ int width_;
+ int height_;
+ int last_row_; // last input row decoded so far.
+ int last_pixel_; // last pixel decoded so far. However, it may
+ // not be transformed, scaled and
+ // color-converted yet.
+ int last_out_row_; // last row output so far.
+
+ VP8LMetadata hdr_;
+
+ int next_transform_;
+ VP8LTransform transforms_[NUM_TRANSFORMS];
+ // or'd bitset storing the transforms types.
+ uint32_t transforms_seen_;
+
+ uint8_t *rescaler_memory; // Working memory for rescaling work.
+ WebPRescaler *rescaler; // Common rescaler for all channels.
+};
+
+//------------------------------------------------------------------------------
+// internal functions. Not public.
+
+struct ALPHDecoder; // Defined in dec/alphai.h.
+
+// in vp8l.c
+
+// Decodes image header for alpha data stored using lossless compression.
+// Returns false in case of error.
+int VP8LDecodeAlphaHeader(struct ALPHDecoder* const alph_dec,
+ const uint8_t* const data, size_t data_size);
+
+// Decodes *at least* 'last_row' rows of alpha. If some of the initial rows are
+// already decoded in previous call(s), it will resume decoding from where it
+// was paused.
+// Returns false in case of bitstream error.
+int VP8LDecodeAlphaImageStream(struct ALPHDecoder* const alph_dec,
+ int last_row);
+
+// Allocates and initialize a new lossless decoder instance.
+VP8LDecoder* VP8LNew(void);
+
+// Decodes the image header. Returns false in case of error.
+int VP8LDecodeHeader(VP8LDecoder* const dec, VP8Io* const io);
+
+// Decodes an image. It's required to decode the lossless header before calling
+// this function. Returns false in case of error, with updated dec->status_.
+int VP8LDecodeImage(VP8LDecoder* const dec);
+
+// Resets the decoder in its initial state, reclaiming memory.
+// Preserves the dec->status_ value.
+void VP8LClear(VP8LDecoder* const dec);
+
+// Clears and deallocate a lossless decoder instance.
+void VP8LDelete(VP8LDecoder* const dec);
+
+//------------------------------------------------------------------------------
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif /* WEBP_DEC_VP8LI_H_ */