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FFmpeg/libavcodec/ac3enc_fixed.h
Justin Ruggles ac05f9030e Convert floating-point MDCT coefficients to 24-bit fixed-point all at once
instead of doing it separately in 2 different functions.
This makes float AC-3 encoding approx. 3-7% faster overall.
Also, the coefficient conversion can now be easily SIMD-optimized.

Originally committed as revision 26232 to svn://svn.ffmpeg.org/ffmpeg/trunk
2011-01-05 20:35:36 +00:00

59 lines
1.9 KiB
C

/*
* The simplest AC-3 encoder
* Copyright (c) 2000 Fabrice Bellard
* Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
* Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
*
* 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
*/
/**
* @file
* fixed-point AC-3 encoder header.
*/
#ifndef AVCODEC_AC3ENC_FIXED_H
#define AVCODEC_AC3ENC_FIXED_H
#include <stdint.h>
typedef int16_t SampleType;
typedef int32_t CoefType;
/**
* Compex number.
* Used in fixed-point MDCT calculation.
*/
typedef struct IComplex {
int16_t re,im;
} IComplex;
typedef struct AC3MDCTContext {
const int16_t *window; ///< MDCT window function
int nbits; ///< log2(transform size)
int16_t *costab; ///< FFT cos table
int16_t *sintab; ///< FFT sin table
int16_t *xcos1; ///< MDCT cos table
int16_t *xsin1; ///< MDCT sin table
int16_t *rot_tmp; ///< temp buffer for pre-rotated samples
IComplex *cplx_tmp; ///< temp buffer for complex pre-rotated samples
} AC3MDCTContext;
#endif /* AVCODEC_AC3ENC_FIXED_H */