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| author | Justin Ruggles <justin.ruggles@gmail.com> | 2011-01-27 23:58:27 +0000 |
|---|---|---|
| committer | Mans Rullgard <mans@mansr.com> | 2011-01-28 00:04:02 +0000 |
| commit | 37cb3eb53449ccefbbe8ea7dc5e66f9036aafe6e (patch) | |
| tree | c86ba204bee600fe3139345d7a3e7787be991d1a | |
| parent | d1b6f33bf2ce56f013a1c5a013a19671c0f30ea0 (diff) | |
| download | ffmpeg-37cb3eb53449ccefbbe8ea7dc5e66f9036aafe6e.tar.gz | |
Add special case for 2nd-order IIR filter.
40% faster in ff_iir_filter_flt() when c->order == 2.
| -rw-r--r-- | libavcodec/iirfilter.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/libavcodec/iirfilter.c b/libavcodec/iirfilter.c index 46b4973f85..bc63c3991a 100644 --- a/libavcodec/iirfilter.c +++ b/libavcodec/iirfilter.c @@ -256,11 +256,29 @@ av_cold struct FFIIRFilterState* ff_iir_filter_init_state(int order) } \ } +#define FILTER_O2(type, fmt) { \ + int i; \ + const type *src0 = src; \ + type *dst0 = dst; \ + for (i = 0; i < size; i++) { \ + float in = *src0 * c->gain + \ + s->x[0] * c->cy[0] + \ + s->x[1] * c->cy[1]; \ + CONV_##fmt(*dst0, s->x[0] + in + s->x[1] * c->cx[1]) \ + s->x[0] = s->x[1]; \ + s->x[1] = in; \ + src0 += sstep; \ + dst0 += dstep; \ + } \ +} + void ff_iir_filter(const struct FFIIRFilterCoeffs *c, struct FFIIRFilterState *s, int size, const int16_t *src, int sstep, int16_t *dst, int dstep) { - if (c->order == 4) { + if (c->order == 2) { + FILTER_O2(int16_t, S16) + } else if (c->order == 4) { FILTER_BW_O4(int16_t, S16) } else { FILTER_DIRECT_FORM_II(int16_t, S16) @@ -271,7 +289,9 @@ void ff_iir_filter_flt(const struct FFIIRFilterCoeffs *c, struct FFIIRFilterState *s, int size, const float *src, int sstep, float *dst, int dstep) { - if (c->order == 4) { + if (c->order == 2) { + FILTER_O2(float, FLT) + } else if (c->order == 4) { FILTER_BW_O4(float, FLT) } else { FILTER_DIRECT_FORM_II(float, FLT) |