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FFmpeg/libavcodec/mpeg12dec.h
Andreas Rheinhardt 7e2120c4d9 avcodec/mpeg12: Avoid unnecessary VLC structures
Everything besides VLC.table is basically write-only
and even VLC.table can be removed by accessing the
underlying tables directly.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2023-10-31 21:44:48 +01:00

51 lines
1.6 KiB
C

/*
* MPEG-1/2 decoder header
* 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_MPEG12DEC_H
#define AVCODEC_MPEG12DEC_H
#include "get_bits.h"
#include "mpeg12vlc.h"
static inline int decode_dc(GetBitContext *gb, int component)
{
int code, diff;
if (component == 0) {
code = get_vlc2(gb, ff_dc_lum_vlc, DC_VLC_BITS, 2);
} else {
code = get_vlc2(gb, ff_dc_chroma_vlc, DC_VLC_BITS, 2);
}
if (code == 0) {
diff = 0;
} else {
diff = get_xbits(gb, code);
}
return diff;
}
int ff_mpeg1_decode_block_intra(GetBitContext *gb,
const uint16_t *quant_matrix,
const uint8_t *scantable, int last_dc[3],
int16_t *block, int index, int qscale);
#endif /* AVCODEC_MPEG12DEC_H */