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