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73f52133a1
When '-mixed' option is given, each frame would be heuristically chosen to be encoded using lossy or lossless compression. The heuristic is based on the number of colors in the image: - If num_colors <= 31, pick lossless compression - If num_colors >= 194, pick lossy compression - Otherwise, try both and pick the one that compresses better. Change-Id: I908c73493ddc38e8db35b7b1959300569e6d3a97
81 lines
3.0 KiB
C
81 lines
3.0 KiB
C
// Copyright 2013 Google Inc. All Rights Reserved.
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//
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// Use of this source code is governed by a BSD-style license
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// that can be found in the COPYING file in the root of the source
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// tree. An additional intellectual property rights grant can be found
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// in the file PATENTS. All contributing project authors may
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// be found in the AUTHORS file in the root of the source tree.
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// -----------------------------------------------------------------------------
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//
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// Helper structs and methods for gif2webp tool.
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//
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// Author: Urvang (urvang@google.com)
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#ifndef WEBP_EXAMPLES_GIF2WEBP_UTIL_H_
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#define WEBP_EXAMPLES_GIF2WEBP_UTIL_H_
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#include <stdlib.h>
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#include "webp/mux.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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//------------------------------------------------------------------------------
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// Helper utilities.
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#define WEBP_UTIL_TRANSPARENT_COLOR 0x00ffffff
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struct WebPPicture;
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typedef struct {
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int x_offset, y_offset, width, height;
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} WebPFrameRect;
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// Clear pixels in 'picture' within given 'rect' to transparent color.
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void WebPUtilClearPic(struct WebPPicture* const picture,
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const WebPFrameRect* const rect);
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//------------------------------------------------------------------------------
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// Frame cache.
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typedef struct WebPFrameCache WebPFrameCache;
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// Given the minimum distance between key frames 'kmin' and maximum distance
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// between key frames 'kmax', returns an appropriately allocated cache object.
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// If 'allow_mixed' is true, the subsequent calls to WebPFrameCacheAddFrame()
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// will heuristically pick lossy or lossless compression for each frame.
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// Use WebPFrameCacheDelete() to deallocate the 'cache'.
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WebPFrameCache* WebPFrameCacheNew(int width, int height,
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size_t kmin, size_t kmax, int allow_mixed);
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// Release all the frame data from 'cache' and free 'cache'.
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void WebPFrameCacheDelete(WebPFrameCache* const cache);
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// Given an image described by 'frame', 'info' and 'orig_rect', optimize it for
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// WebP, encode it and add it to 'cache'.
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// This takes care of frame disposal too, according to 'info->dispose_method'.
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int WebPFrameCacheAddFrame(WebPFrameCache* const cache,
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const WebPConfig* const config,
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const WebPFrameRect* const orig_rect,
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WebPPicture* const frame,
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WebPMuxFrameInfo* const info);
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// Flush the *ready* frames from cache and add them to 'mux'. If 'verbose' is
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// true, prints the information about these frames.
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WebPMuxError WebPFrameCacheFlush(WebPFrameCache* const cache, int verbose,
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WebPMux* const mux);
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// Similar to 'WebPFrameCacheFlushFrames()', but flushes *all* the frames.
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WebPMuxError WebPFrameCacheFlushAll(WebPFrameCache* const cache, int verbose,
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WebPMux* const mux);
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//------------------------------------------------------------------------------
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#if defined(__cplusplus) || defined(c_plusplus)
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} // extern "C"
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#endif
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#endif // WEBP_EXAMPLES_GIF2WEBP_UTIL_H_
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