FFmpeg/libavcodec/elbg.h

/*
 * Copyright (C) 2007 Vitor Sessak <vitor1001@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef FFMPEG_ELBG_H
#define FFMPEG_ELBG_H

#include "libavutil/random.h"

/**
 * Implementation of the Enhanced LBG Algorithm
 * Based on the paper "Neural Networks 14:1219-1237" that can be found in
 * http://citeseer.ist.psu.edu/patan01enhanced.html .
 *
 * @param points Input points.
 * @param dim Dimension of the points.
 * @param numpoints Num of points in **points.
 * @param codebook Pointer to the output codebook. Must be allocated.
 * @param numCB Number of points in the codebook.
 * @param num_steps The maximum number of steps. One step is already a good compromise between time and quality.
 * @param closest_cb Return the closest codebook to each point. Must be allocated.
 * @param rand_state A random number generator state. Should be already initialised by av_init_random.
 */
void ff_do_elbg(int *points, int dim, int numpoints, int *codebook,
                int numCB, int num_steps, int *closest_cb,
                AVRandomState *rand_state);

/**
 * Initialize the **codebook vector for the elbg algorithm. If you have already
 * a codebook and you want to refine it, you shouldn't call this function.
 * If numpoints < 8*numCB this function fills **codebook with random numbers.
 * If not, it calls ff_do_elbg for a (smaller) random sample of the points in
 * **points. Get the same parameters as ff_do_elbg.
 */
void ff_init_elbg(int *points, int dim, int numpoints, int *codebook,
                  int numCB, int num_steps, int *closest_cb,
                  AVRandomState *rand_state);

#endif /* FFMPEG_ELBG_H */