libwebp: update snapshot to v0.2.0-rc1

third_party/libwebp/webp/decode_vp8.h

-// 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_WEBP_DECODE_VP8_H_
-#define WEBP_WEBP_DECODE_VP8_H_
-
-#include "./decode.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-//------------------------------------------------------------------------------
-// Lower-level API
-//
-// These 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;
-typedef int (*VP8IoPutHook)(const VP8Io* io);
-typedef int (*VP8IoSetupHook)(VP8Io* io);
-typedef void (*VP8IoTeardownHook)(const VP8Io* io);
-
-struct VP8Io {
-  // set by VP8GetHeaders()
-  int width, height;         // picture dimensions, in pixels (invariable).
-                             // These are the original, uncropped dimensions.
-                             // The actual area passed to put() is stored
-                             // in mb_w / mb_h fields.
-
-  // set before calling put()
-  int mb_y;                  // position of the current rows (in pixels)
-  int mb_w;                  // number of columns in the sample
-  int mb_h;                  // number of rows in the sample
-  const uint8_t* y, *u, *v;  // rows to copy (in yuv420 format)
-  int y_stride;              // row stride for luma
-  int uv_stride;             // row stride for chroma
-
-  void* opaque;              // user data
-
-  // called when fresh samples are available. Currently, samples are in
-  // YUV420 format, and can be up to width x 24 in size (depending on the
-  // in-loop filtering level, e.g.). Should return false in case of error
-  // or abort request. The actual size of the area to update is mb_w x mb_h
-  // in size, taking cropping into account.
-  VP8IoPutHook put;
-
-  // called just before starting to decode the blocks.
-  // Must return false in case of setup error, true otherwise. If false is
-  // returned, teardown() will NOT be called. But if the setup succeeded
-  // and true is returned, then teardown() will always be called afterward.
-  VP8IoSetupHook setup;
-
-  // Called just after block decoding is finished (or when an error occurred
-  // during put()). Is NOT called if setup() failed.
-  VP8IoTeardownHook teardown;
-
-  // this is a recommendation for the user-side yuv->rgb converter. This flag
-  // is set when calling setup() hook and can be overwritten by it. It then
-  // can be taken into consideration during the put() method.
-  int fancy_upsampling;
-
-  // Input buffer.
-  uint32_t data_size;
-  const uint8_t* data;
-
-  // If true, in-loop filtering will not be performed even if present in the
-  // bitstream. Switching off filtering may speed up decoding at the expense
-  // of more visible blocking. Note that output will also be non-compliant
-  // with the VP8 specifications.
-  int bypass_filtering;
-
-  // Cropping parameters.
-  int use_cropping;
-  int crop_left, crop_right, crop_top, crop_bottom;
-
-  // Scaling parameters.
-  int use_scaling;
-  int scaled_width, scaled_height;
-
-  // pointer to the alpha data (if present) corresponding to the rows
-  const uint8_t* a;
-};
-
-// Internal, version-checked, entry point
-WEBP_EXTERN(int) VP8InitIoInternal(VP8Io* const, int);
-
-// Set the custom IO function pointers and user-data. The setter for IO hooks
-// should be called before initiating incremental decoding. Returns true if
-// WebPIDecoder object is successfully modified, false otherwise.
-WEBP_EXTERN(int) WebPISetIOHooks(WebPIDecoder* const idec,
-                                 VP8IoPutHook put,
-                                 VP8IoSetupHook setup,
-                                 VP8IoTeardownHook teardown,
-                                 void* user_data);
-
-// Main decoding object. This is an opaque structure.
-typedef struct VP8Decoder VP8Decoder;
-
-// Create a new decoder object.
-WEBP_EXTERN(VP8Decoder*) VP8New(void);
-
-// Must be called to make sure 'io' is initialized properly.
-// Returns false in case of version mismatch. Upon such failure, no other
-// decoding function should be called (VP8Decode, VP8GetHeaders, ...)
-static inline int VP8InitIo(VP8Io* const io) {
-  return VP8InitIoInternal(io, WEBP_DECODER_ABI_VERSION);
-}
-
-// Start decoding a new picture. Returns true if ok.
-WEBP_EXTERN(int) VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io);
-
-// Decode a picture. Will call VP8GetHeaders() if it wasn't done already.
-// Returns false in case of error.
-WEBP_EXTERN(int) VP8Decode(VP8Decoder* const dec, VP8Io* const io);
-
-// Return current status of the decoder:
-WEBP_EXTERN(VP8StatusCode) VP8Status(VP8Decoder* const dec);
-
-// return readable string corresponding to the last status.
-WEBP_EXTERN(const char*) VP8StatusMessage(VP8Decoder* const dec);
-
-// Resets the decoder in its initial state, reclaiming memory.
-// Not a mandatory call between calls to VP8Decode().
-WEBP_EXTERN(void) VP8Clear(VP8Decoder* const dec);
-
-// Destroy the decoder object.
-WEBP_EXTERN(void) VP8Delete(VP8Decoder* const dec);
-
-//------------------------------------------------------------------------------
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif
-
-#endif  /* WEBP_WEBP_DECODE_VP8_H_ */