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| author | Nedeljko Babic <nbabic@mips.com> | 2013-06-03 16:11:12 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2013-08-04 14:01:41 +0200 |
| commit | 18d7074b4e5a1112cfa6a53dde0faa25d2bd0b15 (patch) | |
| tree | 0d23cbed3eb59d91ba5c734a7222a6ae02c72cba /libavcodec/fft-internal.h | |
| parent | 27cc3e72f8502d6239dcd0f1dd3fe73f1c85355d (diff) | |
| download | ffmpeg-18d7074b4e5a1112cfa6a53dde0faa25d2bd0b15.tar.gz | |
libavcodec: Implementation of 32 bit fixed point FFT
Iterative implementation of 32 bit fixed point split-radix FFT.
Max FFT that can be calculated currently is 2^12.
Signed-off-by: Nedeljko Babic <nbabic@mips.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/fft-internal.h')
| -rw-r--r-- | libavcodec/fft-internal.h | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/libavcodec/fft-internal.h b/libavcodec/fft-internal.h index d66731fb48..065eeccef1 100644 --- a/libavcodec/fft-internal.h +++ b/libavcodec/fft-internal.h @@ -36,12 +36,29 @@ #else +#define SCALE_FLOAT(a, bits) lrint((a) * (double)(1 << (bits))) + +#if CONFIG_FFT_FIXED_32 + +#define CMUL(dre, dim, are, aim, bre, bim) do { \ + int64_t accu; \ + (accu) = (int64_t)(bre) * (are); \ + (accu) -= (int64_t)(bim) * (aim); \ + (dre) = (int)(((accu) + 0x40000000) >> 31); \ + (accu) = (int64_t)(bre) * (aim); \ + (accu) += (int64_t)(bim) * (are); \ + (dim) = (int)(((accu) + 0x40000000) >> 31); \ + } while (0) + +#define FIX15(a) av_clip(SCALE_FLOAT(a, 31), -2147483647, 2147483647) + +#else /* CONFIG_FFT_FIXED_32 */ + #include "fft.h" #include "mathops.h" void ff_mdct_calcw_c(FFTContext *s, FFTDouble *output, const FFTSample *input); -#define SCALE_FLOAT(a, bits) lrint((a) * (double)(1 << (bits))) #define FIX15(a) av_clip(SCALE_FLOAT(a, 15), -32767, 32767) #define sqrthalf ((int16_t)((1<<15)*M_SQRT1_2)) @@ -62,6 +79,8 @@ void ff_mdct_calcw_c(FFTContext *s, FFTDouble *output, const FFTSample *input); #define CMULL(dre, dim, are, aim, bre, bim) \ CMULS(dre, dim, are, aim, bre, bim, 0) +#endif /* CONFIG_FFT_FIXED_32 */ + #endif /* CONFIG_FFT_FLOAT */ #define ff_imdct_calc_c FFT_NAME(ff_imdct_calc_c) |