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add dsp/lossless.[hc] from experimental

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Pulled from the current HEAD (218c32e).
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.

Change-Id: I40538799dbf999abb9408ac83f55b897d8e22498
This commit is contained in:
James Zern
2012-04-10 17:23:38 -07:00
parent 9c67291d67
commit 514d008921
2 changed files with 512 additions and 0 deletions
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59
src/dsp/lossless.h Normal file
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// Copyright 2012 Google Inc. All Rights Reserved.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// Image transforms and color space conversion methods for lossless decoder.
//
// Author: Vikas Arora (vikaas.arora@gmail.com)
// jyrki@google.com (Jyrki Alakuijala)
#ifndef WEBP_DSP_LOSSLESS_H_
#define WEBP_DSP_LOSSLESS_H_
#include "../webp/types.h"
#include "../webp/decode.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//------------------------------------------------------------------------------
// Inverse image transforms.
struct VP8LTransform; // Defined in dec/vp8li.h.
// Performs inverse transform of data given transform information, start and end
// rows. Transform will be applied to rows [row_start, row_end[.
// The data_in & data_out are source and destination data pointers respectively
// corresponding to the intermediate row (row_start).
void VP8LInverseTransform(const struct VP8LTransform* const transform,
size_t row_start, size_t row_end,
uint32_t* const data_in, uint32_t* const data_out);
//------------------------------------------------------------------------------
// Color space conversion.
// Converts from BGRA to other color spaces.
void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
WEBP_CSP_MODE out_colorspace,
uint8_t* const rgba);
//------------------------------------------------------------------------------
// Misc methods.
// Computes sampled size of 'size' when sampling using 'sampling bits'.
static WEBP_INLINE uint32_t VP8LSubSampleSize(uint32_t size,
uint32_t sampling_bits) {
return (size + (1 << sampling_bits) - 1) >> sampling_bits;
}
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif
#endif // WEBP_DSP_LOSSLESS_H_