Codebook generator using the ELBG algorithm

patch by Vitor: printf(vitor%d gmail com, 1001)
original thread: Re: [FFmpeg-devel] [PATCH] Add a codebook generator
                 (was: [PATCH] RoQ video encoder, take 2)
date: 05/28/2007 01:21 PM

Originally committed as revision 9196 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 50 insertions, 0 deletions

diff --git a/libavcodec/elbg.h b/libavcodec/elbg.h
new file mode 100644
index 0000000000..ab711b5b7c
--- /dev/null
+++ b/libavcodec/elbg.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2007 Vitor <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
+ */
+
+#include "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);