libwebp/extras/extras.h
skal e8ab6a825a VP8EstimateQuality(): roughty estimate webp bitstream quality factor
This function returns a rough estimation of the quality factor used
for compressing the WebP bitstream.

Simple command line: 'webp_quality [-quiet] in.webp'
should print the estimated quality factor.

Change-Id: Ifba3e489461f5a587003ac9f08cc7556e9b24ac2
2016-07-20 21:50:25 -07:00

60 lines
2.2 KiB
C

// Copyright 2015 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.
// -----------------------------------------------------------------------------
//
#ifndef WEBP_EXTRAS_EXTRAS_H_
#define WEBP_EXTRAS_EXTRAS_H_
#include "webp/types.h"
#ifdef __cplusplus
extern "C" {
#endif
#include "webp/encode.h"
#define WEBP_EXTRAS_ABI_VERSION 0x0000 // MAJOR(8b) + MINOR(8b)
//------------------------------------------------------------------------------
// Returns the version number of the extras library, packed in hexadecimal using
// 8bits for each of major/minor/revision. E.g: v2.5.7 is 0x020507.
WEBP_EXTERN(int) WebPGetExtrasVersion(void);
//------------------------------------------------------------------------------
// Ad-hoc colorspace importers.
// Import luma sample (gray scale image) into 'picture'. The 'picture'
// width and height must be set prior to calling this function.
WEBP_EXTERN(int) WebPImportGray(const uint8_t* gray, WebPPicture* picture);
// Import rgb sample in RGB565 packed format into 'picture'. The 'picture'
// width and height must be set prior to calling this function.
WEBP_EXTERN(int) WebPImportRGB565(const uint8_t* rgb565, WebPPicture* pic);
// Import rgb sample in RGB4444 packed format into 'picture'. The 'picture'
// width and height must be set prior to calling this function.
WEBP_EXTERN(int) WebPImportRGB4444(const uint8_t* rgb4444, WebPPicture* pic);
//------------------------------------------------------------------------------
// Parse a bitstream, search for VP8 (lossy) header and report a
// rough estimation of the quality factor used for compressing the bitstream.
// Any error (invalid bitstream, lossless compression, incomplete header, etc.)
// will return a value of -1.
WEBP_EXTERN(int) VP8EstimateQuality(const uint8_t* const data, size_t size);
//------------------------------------------------------------------------------
#ifdef __cplusplus
} // extern "C"
#endif
#endif /* WEBP_EXTRAS_EXTRAS_H_ */