diff options
Diffstat (limited to 'libavutil/tx_template.c')
| -rw-r--r-- | libavutil/tx_template.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/libavutil/tx_template.c b/libavutil/tx_template.c index cee8458970..1e4354580b 100644 --- a/libavutil/tx_template.c +++ b/libavutil/tx_template.c @@ -1277,6 +1277,134 @@ DECL_COMP_MDCT(7) DECL_COMP_MDCT(9) DECL_COMP_MDCT(15) +static av_cold int TX_NAME(ff_tx_rdft_init)(AVTXContext *s, + const FFTXCodelet *cd, + uint64_t flags, + FFTXCodeletOptions *opts, + int len, int inv, + const void *scale) +{ + int ret; + double f, m; + TXSample *tab; + + s->scale_d = *((SCALE_TYPE *)scale); + s->scale_f = s->scale_d; + + if ((ret = ff_tx_init_subtx(s, TX_TYPE(FFT), flags, NULL, len >> 1, inv, scale))) + return ret; + + if (!(s->exp = av_mallocz((8 + (len >> 2) - 1)*sizeof(*s->exp)))) + return AVERROR(ENOMEM); + + tab = (TXSample *)s->exp; + + f = 2*M_PI/len; + + m = (inv ? 2*s->scale_d : s->scale_d); + + *tab++ = RESCALE((inv ? 0.5 : 1.0) * m); + *tab++ = RESCALE(inv ? 0.5*m : 1.0); + *tab++ = RESCALE( m); + *tab++ = RESCALE(-m); + + *tab++ = RESCALE( (0.5 - 0.0) * m); + *tab++ = RESCALE( (0.0 - 0.5) * m); + *tab++ = RESCALE( (0.5 - inv) * m); + *tab++ = RESCALE(-(0.5 - inv) * m); + + for (int i = 0; i < len >> 2; i++) + *tab++ = RESCALE(cos(i*f)); + for (int i = len >> 2; i >= 0; i--) + *tab++ = RESCALE(cos(i*f) * (inv ? +1.0 : -1.0)); + + return 0; +} + +#define DECL_RDFT(name, inv) \ +static void TX_NAME(ff_tx_rdft_ ##name)(AVTXContext *s, void *_dst, \ + void *_src, ptrdiff_t stride) \ +{ \ + const int len2 = s->len >> 1; \ + const int len4 = s->len >> 2; \ + const TXSample *fact = (void *)s->exp; \ + const TXSample *tcos = fact + 8; \ + const TXSample *tsin = tcos + len4; \ + TXComplex *data = inv ? _src : _dst; \ + TXComplex t[3]; \ + \ + if (!inv) \ + s->fn[0](&s->sub[0], data, _src, sizeof(TXComplex)); \ + else \ + data[0].im = data[len2].re; \ + \ + /* The DC value's both components are real, but we need to change them \ + * into complex values. Also, the middle of the array is special-cased. \ + * These operations can be done before or after the loop. */ \ + t[0].re = data[0].re; \ + data[0].re = t[0].re + data[0].im; \ + data[0].im = t[0].re - data[0].im; \ + data[ 0].re = MULT(fact[0], data[ 0].re); \ + data[ 0].im = MULT(fact[1], data[ 0].im); \ + data[len4].re = MULT(fact[2], data[len4].re); \ + data[len4].im = MULT(fact[3], data[len4].im); \ + \ + for (int i = 1; i < len4; i++) { \ + /* Separate even and odd FFTs */ \ + t[0].re = MULT(fact[4], (data[i].re + data[len2 - i].re)); \ + t[0].im = MULT(fact[5], (data[i].im - data[len2 - i].im)); \ + t[1].re = MULT(fact[6], (data[i].im + data[len2 - i].im)); \ + t[1].im = MULT(fact[7], (data[i].re - data[len2 - i].re)); \ + \ + /* Apply twiddle factors to the odd FFT and add to the even FFT */ \ + CMUL(t[2].re, t[2].im, t[1].re, t[1].im, tcos[i], tsin[i]); \ + \ + data[ i].re = t[0].re + t[2].re; \ + data[ i].im = t[2].im - t[0].im; \ + data[len2 - i].re = t[0].re - t[2].re; \ + data[len2 - i].im = t[2].im + t[0].im; \ + } \ + \ + if (inv) { \ + s->fn[0](&s->sub[0], _dst, data, sizeof(TXComplex)); \ + } else { \ + /* Move [0].im to the last position, as convention requires */ \ + data[len2].re = data[0].im; \ + data[ 0].im = 0; \ + } \ +} + +DECL_RDFT(r2c, 0) +DECL_RDFT(c2r, 1) + +static const FFTXCodelet TX_NAME(ff_tx_rdft_r2c_def) = { + .name = TX_NAME_STR("rdft_r2c"), + .function = TX_NAME(ff_tx_rdft_r2c), + .type = TX_TYPE(RDFT), + .flags = AV_TX_UNALIGNED | AV_TX_INPLACE | + FF_TX_OUT_OF_PLACE | FF_TX_FORWARD_ONLY, + .factors = { 2, TX_FACTOR_ANY }, + .min_len = 2, + .max_len = TX_LEN_UNLIMITED, + .init = TX_NAME(ff_tx_rdft_init), + .cpu_flags = FF_TX_CPU_FLAGS_ALL, + .prio = FF_TX_PRIO_BASE, +}; + +static const FFTXCodelet TX_NAME(ff_tx_rdft_c2r_def) = { + .name = TX_NAME_STR("rdft_c2r"), + .function = TX_NAME(ff_tx_rdft_c2r), + .type = TX_TYPE(RDFT), + .flags = AV_TX_UNALIGNED | AV_TX_INPLACE | + FF_TX_OUT_OF_PLACE | FF_TX_INVERSE_ONLY, + .factors = { 2, TX_FACTOR_ANY }, + .min_len = 2, + .max_len = TX_LEN_UNLIMITED, + .init = TX_NAME(ff_tx_rdft_init), + .cpu_flags = FF_TX_CPU_FLAGS_ALL, + .prio = FF_TX_PRIO_BASE, +}; + int TX_TAB(ff_tx_mdct_gen_exp)(AVTXContext *s) { int len4 = s->len >> 1; @@ -1340,6 +1468,8 @@ const FFTXCodelet * const TX_NAME(ff_tx_codelet_list)[] = { &TX_NAME(ff_tx_mdct_naive_fwd_def), &TX_NAME(ff_tx_mdct_naive_inv_def), &TX_NAME(ff_tx_mdct_inv_full_def), + &TX_NAME(ff_tx_rdft_r2c_def), + &TX_NAME(ff_tx_rdft_c2r_def), NULL, }; |