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src/Source/LibWebP/src/dec/vp8li.h  view on Meta::CPAN

  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,
                          uint8_t* const output);

// 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_ */