FFmpeg
avdct.h
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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  */
48  uint8_t idct_permutation[64];
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 
71  void (*get_pixels_unaligned)(int16_t *block /* align 16 */,
72  const uint8_t *pixels,
73  ptrdiff_t line_size);
74 } AVDCT;
75 
76 /**
77  * Allocates a AVDCT context.
78  * This needs to be initialized with avcodec_dct_init() after optionally
79  * configuring it with AVOptions.
80  *
81  * To free it use av_free()
82  */
84 int avcodec_dct_init(AVDCT *);
85 
86 const AVClass *avcodec_dct_get_class(void);
87 
88 #endif /* AVCODEC_AVDCT_H */
opt.h
AVDCT::dct_algo
int dct_algo
DCT algorithm.
Definition: avdct.h:57
avcodec_dct_init
int avcodec_dct_init(AVDCT *)
Definition: avdct.c:88
AVDCT::fdct
void(* fdct)(int16_t *block)
Definition: avdct.h:50
AVDCT::idct_permutation
uint8_t idct_permutation[64]
IDCT input permutation.
Definition: avdct.h:48
AVDCT::bits_per_sample
int bits_per_sample
Definition: avdct.h:69
avcodec_dct_alloc
AVDCT * avcodec_dct_alloc(void)
Allocates a AVDCT context.
Definition: avdct.c:75
AVDCT::av_class
const AVClass * av_class
Definition: avdct.h:30
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
AVDCT::get_pixels
void(* get_pixels)(int16_t *block, const uint8_t *pixels, ptrdiff_t line_size)
Definition: avdct.h:65
AVDCT::idct
void(* idct)(int16_t *block)
Definition: avdct.h:32
avcodec_dct_get_class
const AVClass * avcodec_dct_get_class(void)
Definition: avdct.c:70
AVDCT
AVDCT context.
Definition: avdct.h:29
AVDCT::get_pixels_unaligned
void(* get_pixels_unaligned)(int16_t *block, const uint8_t *pixels, ptrdiff_t line_size)
Definition: avdct.h:71
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
AVDCT::idct_algo
int idct_algo
IDCT algorithm.
Definition: avdct.h:63