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// Copyright 2010 Google Inc.
//
// 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/
// -----------------------------------------------------------------------------
//
// Low-level API for VP8 decoder
//
// Author: Skal (pascal.massimino@gmail.com)
#ifndef WEBP_DECODE_WEBP_DECODE_VP8_H_
#define WEBP_DECODE_WEBP_DECODE_VP8_H_
#include "decode.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//-----------------------------------------------------------------------------
// Lower-level API
//
// Thes functions provide fine-grained control of the decoding process.
// The call flow should resemble:
//
// VP8Io io;
// VP8InitIo(&io);
// io.data = data;
// io.data_size = size;
// /* customize io's functions (setup()/put()/teardown()) if needed. */
//
// VP8Decoder* dec = VP8New();
// bool ok = VP8Decode(dec);
// if (!ok) printf("Error: %s\n", VP8StatusMessage(dec));
// VP8Delete(dec);
// return ok;
// Input / Output
typedef struct VP8Io VP8Io;
struct VP8Io {
// set by VP8GetHeaders()
int width, height; // picture dimensions, in pixels
// set before calling put()
int mb_x, mb_y; // position of the current sample (in pixels)
int mb_w, mb_h; // size of the current sample (usually 16x16)
const uint8_t *y, *u, *v; // samples to copy
int y_stride; // stride for luma
int uv_stride; // stride for chroma
void* opaque; // user data
// called when fresh samples are available (1 block of 16x16 pixels)
void (*put)(const VP8Io* io);
// called just before starting to decode the blocks
void (*setup)(const VP8Io* io);
// called just after block decoding is finished
void (*teardown)(const VP8Io* io);
// Input buffer.
uint32_t data_size;
const uint8_t* data;
};
// Main decoding object. This is an opaque structure.
typedef struct VP8Decoder VP8Decoder;
// Create a new decoder object.
VP8Decoder* VP8New();
// Can be called to make sure 'io' is initialized properly.
void VP8InitIo(VP8Io* const io);
// Start decoding a new picture. Returns true if ok.
int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io);
// Decode a picture. Will call VP8GetHeaders() if it wasn't done already.
int VP8Decode(VP8Decoder* const dec, VP8Io* const io);
// Return current status of the decoder:
// 0 = OK
// 1 = OUT_OF_MEMORY
// 2 = INVALID_PARAM
// 3 = BITSTREAM_ERROR
// 4 = UNSUPPORTED_FEATURE
int VP8Status(VP8Decoder* const dec);
// return readable string corresponding to the last status.
const char* VP8StatusMessage(VP8Decoder* const dec);
// Resets the decoder in its initial state, reclaiming memory.
// Not a mandatory call between calls to VP8Decode().
void VP8Clear(VP8Decoder* const dec);
// Destroy the decoder object.
void VP8Delete(VP8Decoder* const dec);
//-----------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif
#endif // WEBP_DECODE_WEBP_DECODE_VP8_H_
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