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author | Justin Ruggles <justin.ruggles@gmail.com> | 2008-08-23 06:04:36 +0400 |
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committer | Justin Ruggles <justin.ruggles@gmail.com> | 2008-08-23 06:04:36 +0400 |
commit | 602031305c4eba88710ddac15be5399de17e4bcf (patch) | |
tree | 127bd0f4043b9f303d7373e843080cdf0bae9b02 | |
parent | 0569993ea4f2ebe0ba20544fb5534c8b67e7d47e (diff) |
add more OKed parts of the E-AC-3 decoder
Originally committed as revision 14912 to svn://svn.ffmpeg.org/ffmpeg/trunk
-rw-r--r-- | libavcodec/eac3dec.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/libavcodec/eac3dec.c b/libavcodec/eac3dec.c new file mode 100644 index 0000000000..d5c619897c --- /dev/null +++ b/libavcodec/eac3dec.c @@ -0,0 +1,80 @@ +/* + * E-AC-3 decoder + * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com> + * Copyright (c) 2008 Justin Ruggles + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 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 + * General Public License for more details. + * + * You should have received a copy of the GNU 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 + */ + +#include "avcodec.h" +#include "ac3.h" +#include "ac3_parser.h" +#include "ac3dec.h" +#include "ac3dec_data.h" + +/** gain adaptive quantization mode */ +typedef enum { + EAC3_GAQ_NO =0, + EAC3_GAQ_12, + EAC3_GAQ_14, + EAC3_GAQ_124 +} EAC3GaqMode; + +#define EAC3_SR_CODE_REDUCED 3 + +/** lrint(M_SQRT2*cos(2*M_PI/12)*(1<<23)) */ +#define COEFF_0 10273905LL + +/** lrint(M_SQRT2*cos(0*M_PI/12)*(1<<23)) = lrint(M_SQRT2*(1<<23)) */ +#define COEFF_1 11863283LL + +/** lrint(M_SQRT2*cos(5*M_PI/12)*(1<<23)) */ +#define COEFF_2 3070444LL + +/** + * Calculate 6-point IDCT of the pre-mantissas. + * All calculations are 24-bit fixed-point. + */ +static void idct6(int pre_mant[6]) +{ + int tmp; + int even0, even1, even2, odd0, odd1, odd2; + + odd1 = pre_mant[1] - pre_mant[3] - pre_mant[5]; + + even2 = ( pre_mant[2] * COEFF_0) >> 23; + tmp = ( pre_mant[4] * COEFF_1) >> 23; + odd0 = ((pre_mant[1] + pre_mant[5]) * COEFF_2) >> 23; + + even0 = pre_mant[0] + (tmp >> 1); + even1 = pre_mant[0] - tmp; + + tmp = even0; + even0 = tmp + even2; + even2 = tmp - even2; + + tmp = odd0; + odd0 = tmp + pre_mant[1] + pre_mant[3]; + odd2 = tmp + pre_mant[5] - pre_mant[3]; + + pre_mant[0] = even0 + odd0; + pre_mant[1] = even1 + odd1; + pre_mant[2] = even2 + odd2; + pre_mant[3] = even2 - odd2; + pre_mant[4] = even1 - odd1; + pre_mant[5] = even0 - odd0; +} |