FFmpeg: libavcodec/mpeg12dec.h Source File

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mpeg12dec.h

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1 /*

2 * MPEG-1/2 decoder header

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 #ifndef AVCODEC_MPEG12DEC_H

23 #define AVCODEC_MPEG12DEC_H

25 #include "get_bits.h"

26 #include "mpeg12vlc.h"

27 #include "rl.h"

29 #define INIT_2D_VLC_RL(rl, static_size, flags)\

30 {\

31 static RL_VLC_ELEM rl_vlc_table[static_size];\

32 rl.rl_vlc[0] = rl_vlc_table;\

33 ff_init_2d_vlc_rl(&rl, static_size, flags);\

34 }

36 void ff_init_2d_vlc_rl(RLTable *rl, unsigned static_size, int flags);

38 static inline int decode_dc(GetBitContext *gb, int component)

39 {

40 int code, diff;

42 if (component == 0) {

43 code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);

44 } else {

45 code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);

46 }

47 if (code == 0) {

48 diff = 0;

49 } else {

50 diff = get_xbits(gb, code);

51 }

52 return diff;

53 }

55 int ff_mpeg1_decode_block_intra(GetBitContext *gb,

56 const uint16_t *quant_matrix,

57 const uint8_t *scantable, int last_dc[3],

58 int16_t *block, int index, int qscale);

60 #endif /* AVCODEC_MPEG12DEC_H */

ff_init_2d_vlc_rl

void ff_init_2d_vlc_rl(RLTable *rl, unsigned static_size, int flags)

Definition: mpeg12.c:66

ff_dc_chroma_vlc

VLC ff_dc_chroma_vlc

Definition: mpeg12.c:126

RLTable

RLTable.

Definition: rl.h:39

GetBitContext

Definition: get_bits.h:61

mpeg12vlc.h

get_bits.h

get_vlc2

static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table, int bits, int max_depth)

Parse a vlc code.

Definition: get_bits.h:787

index

int index

Definition: gxfenc.c:89

get_xbits

static int get_xbits(GetBitContext *s, int n)

Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).

Definition: get_bits.h:321

code

and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code

Definition: filter_design.txt:178

ff_dc_lum_vlc

VLC ff_dc_lum_vlc

Definition: mpeg12.c:125

VLC::table

VLCElem * table

Definition: vlc.h:33

diff

static av_always_inline int diff(const uint32_t a, const uint32_t b)

Definition: vf_palettegen.c:139

ff_mpeg1_decode_block_intra

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)

Definition: mpeg12.c:236

rl.h

flags

#define flags(name, subs,...)

Definition: cbs_av1.c:561

block

The exact code depends on how similar the blocks are and how related they are to the block

Definition: filter_design.txt:207

DC_VLC_BITS

#define DC_VLC_BITS

Definition: intrax8.c:40

decode_dc

static int decode_dc(GetBitContext *gb, int component)

Definition: mpeg12dec.h:38

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