/* * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVCODEC_AVDCT_H#define AVCODEC_AVDCT_H #include "libavutil/opt.h" /** * AVDCT context. * @note function pointers can be NULL if the specific features have been *       disabled at build time. */typedef struct AVDCT {    const AVClass *av_class;     void (*idct)(int16_t *block /* align 16 */);     /**     * IDCT input permutation.     * Several optimized IDCTs need a permutated input (relative to the     * normal order of the reference IDCT).     * This permutation must be performed before the idct_put/add.     * Note, normally this can be merged with the zigzag/alternate scan<br>     * An example to avoid confusion:     * - (->decode coeffs -> zigzag reorder -> dequant -> reference IDCT -> ...)     * - (x -> reference DCT -> reference IDCT -> x)     * - (x -> reference DCT -> simple_mmx_perm = idct_permutation     *    -> simple_idct_mmx -> x)     * - (-> decode coeffs -> zigzag reorder -> simple_mmx_perm -> dequant     *    -> simple_idct_mmx -> ...)     */    uint8_t idct_permutation[64];     void (*fdct)(int16_t *block /* align 16 */);      /**     * DCT algorithm.     * must use AVOptions to set this field.     */    int dct_algo;     /**     * IDCT algorithm.     * must use AVOptions to set this field.     */    int idct_algo;     void (*get_pixels)(int16_t *block /* align 16 */,                       const uint8_t *pixels /* align 8 */,                       ptrdiff_t line_size);     int bits_per_sample;} AVDCT; /** * Allocates a AVDCT context. * This needs to be initialized with avcodec_dct_init() after optionally * configuring it with AVOptions. * * To free it use av_free() */AVDCT *avcodec_dct_alloc(void);int avcodec_dct_init(AVDCT *); const AVClass *avcodec_dct_get_class(void); #endif /* AVCODEC_AVDCT_H */