media/ffvpx/libavcodec/avdct.h

   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
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  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      */
  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
  69     int bits_per_sample;
  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  */
  83 AVDCT *avcodec_dct_alloc(void);
  84 int avcodec_dct_init(AVDCT *);
  85
  86 const AVClass *avcodec_dct_get_class(void);
  87
  88 #endif /* AVCODEC_AVDCT_H */