FFmpeg
avdct.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
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12  * Lesser General Public License for more details.
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17  */
18 
19 #ifndef AVCODEC_AVDCT_H
20 #define AVCODEC_AVDCT_H
21 
22 #include "libavutil/opt.h"
23 
24 /**
25  * AVDCT context.
26  * @note function pointers can be NULL if the specific features have been
27  * disabled at build time.
28  */
29 typedef struct AVDCT {
30  const AVClass *av_class;
31 
32  void (*idct)(int16_t *block /* align 16 */);
33 
34  /**
35  * IDCT input permutation.
36  * Several optimized IDCTs need a permutated input (relative to the
37  * normal order of the reference IDCT).
38  * This permutation must be performed before the idct_put/add.
39  * Note, normally this can be merged with the zigzag/alternate scan<br>
40  * An example to avoid confusion:
41  * - (->decode coeffs -> zigzag reorder -> dequant -> reference IDCT -> ...)
42  * - (x -> reference DCT -> reference IDCT -> x)
43  * - (x -> reference DCT -> simple_mmx_perm = idct_permutation
44  * -> simple_idct_mmx -> x)
45  * - (-> decode coeffs -> zigzag reorder -> simple_mmx_perm -> dequant
46  * -> simple_idct_mmx -> ...)
47  */
49 
50  void (*fdct)(int16_t *block /* align 16 */);
51 
52 
53  /**
54  * DCT algorithm.
55  * must use AVOptions to set this field.
56  */
57  int dct_algo;
58 
59  /**
60  * IDCT algorithm.
61  * must use AVOptions to set this field.
62  */
63  int idct_algo;
64 
65  void (*get_pixels)(int16_t *block /* align 16 */,
66  const uint8_t *pixels /* align 8 */,
67  ptrdiff_t line_size);
68 
70 } AVDCT;
71 
72 /**
73  * Allocates a AVDCT context.
74  * This needs to be initialized with avcodec_dct_init() after optionally
75  * configuring it with AVOptions.
76  *
77  * To free it use av_free()
78  */
80 int avcodec_dct_init(AVDCT *);
81 
82 const AVClass *avcodec_dct_get_class(void);
83 
84 #endif /* AVCODEC_AVDCT_H */
The exact code depends on how similar the blocks are and how related they are to the block
uint8_t
AVOptions.
AVDCT * avcodec_dct_alloc(void)
Allocates a AVDCT context.
Definition: avdct.c:75
const AVClass * avcodec_dct_get_class(void)
Definition: avdct.c:70
uint8_t idct_permutation[64]
IDCT input permutation.
Definition: avdct.h:48
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int dct_algo
DCT algorithm.
Definition: avdct.h:57
void(* get_pixels)(int16_t *block, const uint8_t *pixels, ptrdiff_t line_size)
Definition: avdct.h:65
void(* idct)(int16_t *block)
Definition: avdct.h:32
Describe the class of an AVClass context structure.
Definition: log.h:67
void(* fdct)(int16_t *block)
Definition: avdct.h:50
AVDCT context.
Definition: avdct.h:29
const AVClass * av_class
Definition: avdct.h:30
int pixels
Definition: avisynth_c.h:429
int avcodec_dct_init(AVDCT *)
Definition: avdct.c:88
int idct_algo
IDCT algorithm.
Definition: avdct.h:63
int bits_per_sample
Definition: avdct.h:69