CCITT Fax Group 3 and 4 decompression by kostya.

Will be activated after a little more reviewing and fixing by me.
Commited now, so as to not lose history of that.

Originally committed as revision 16323 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/faxcompr.h

+/*
+ * CCITT Fax Group 3 and 4 decompression
+ * Copyright (c) 2008 Konstantin Shishkov
+ *
+ * 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
+ */
+
+/**
+ * CCITT Fax Group 3 and 4 decompression
+ * @file faxcompr.h
+ * @author Konstantin Shishkov
+ */
+#ifndef AVCODEC_FAXCOMPR_H
+#define AVCODEC_FAXCOMPR_H
+
+#include "avcodec.h"
+
+/**
+ * initialize upacker code
+ */
+void ff_ccitt_unpack_init();
+
+/**
+ * unpack data compressed with CCITT Group 3 1-D method
+ */
+int ff_ccitt_unpack_1d(AVCodecContext *avctx,
+                       const uint8_t *src, int srcsize,
+                       uint8_t *dst, int height, int stride);
+
+/**
+ * unpack data compressed with CCITT Group 3 2-D or Group 4 method
+ */
+int ff_ccitt_unpack_2d(AVCodecContext *avctx,
+                       const uint8_t *src, int srcsize,
+                       uint8_t *dst, int height, int stride, int g4);
+
+#endif /* AVCODEC_FAXCOMPR_H */