libavcodec/dct.h

   1 /*
   2  * (I)DCT Transforms
   3  * Copyright (c) 2009 Peter Ross <pross@xvid.org>
   4  * Copyright (c) 2010 Alex Converse <alex.converse@gmail.com>
   5  * Copyright (c) 2010 Vitor Sessak
   6  *
   7  * This file is part of Libav.
   8  *
   9  * Libav is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * Libav is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with Libav; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  22  */
  23
  24 #ifndef AVCODEC_DCT_H
  25 #define AVCODEC_DCT_H
  26
  27 #include "rdft.h"
  28
  29 struct DCTContext {
  30     int nbits;
  31     int inverse;
  32     RDFTContext rdft;
  33     const float *costab;
  34     FFTSample *csc2;
  35     void (*dct_calc)(struct DCTContext *s, FFTSample *data);
  36     void (*dct32)(FFTSample *out, const FFTSample *in);
  37 };
  38
  39 /**
  40  * Set up DCT.
  41  * @param nbits           size of the input array:
  42  *                        (1 << nbits)     for DCT-II, DCT-III and DST-I
  43  *                        (1 << nbits) + 1 for DCT-I
  44  *
  45  * @note the first element of the input of DST-I is ignored
  46  */
  47 int  ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType type);
  48 void ff_dct_end (DCTContext *s);
  49
  50 void ff_dct_init_x86(DCTContext *s);
  51
  52 #endif /* AVCODEC_DCT_H */