avdct.h (2726B)
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 */