FFmpeg/libavcodec/mpeg12.h

/*
 * MPEG1/2 common code
 * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
 *
 * 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 AVCODEC_MPEG12_H
#define AVCODEC_MPEG12_H

#include "mpegvideo.h"

#define DC_VLC_BITS 9
#define TEX_VLC_BITS 9

static VLC dc_lum_vlc;
static VLC dc_chroma_vlc;

extern uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];

void ff_mpeg12_common_init(MpegEncContext *s);
void ff_mpeg12_init_vlcs(void);

static inline int decode_dc(GetBitContext *gb, int component)
{
    int code, diff;

    if (component == 0) {
        code = get_vlc2(gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
    } else {
        code = get_vlc2(gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
    }
    if (code < 0){
        av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
        return 0xffff;
    }
    if (code == 0) {
        diff = 0;
    } else {
        diff = get_xbits(gb, code);
    }
    return diff;
}

#endif /* AVCODEC_MPEG12_H */