diff options
Diffstat (limited to 'src/libac3/imdct.c')
| -rw-r--r-- | src/libac3/imdct.c | 118 |
1 files changed, 34 insertions, 84 deletions
diff --git a/src/libac3/imdct.c b/src/libac3/imdct.c index a2e83d423..030026a54 100644 --- a/src/libac3/imdct.c +++ b/src/libac3/imdct.c @@ -24,32 +24,23 @@ #include "config.h" +#include <inttypes.h> #include <stdlib.h> #include <stdio.h> #include <math.h> #include "ac3.h" #include "ac3_internal.h" - -#include "decode.h" -#include "imdct.h" - -void imdct_do_256(float data[],float delay[]); -void imdct_do_512(float data[],float delay[]); - -void imdct_do_256_mlib(float data[],float delay[]); -void imdct_do_512_mlib(float data[],float delay[]); +void (* imdct_256) (float data[], float delay[]); +void (* imdct_512) (float data[], float delay[]); typedef struct complex_s { - float real; - float imag; + float real; + float imag; } complex_t; -#define N 512 - - /* 128 point bit-reverse LUT */ static uint8_t bit_reverse_512[] = { 0x00, 0x40, 0x20, 0x60, 0x10, 0x50, 0x30, 0x70, @@ -82,7 +73,6 @@ static uint8_t bit_reverse_256[] = { static complex_t buf[128]; /* Twiddle factor LUT */ -static complex_t *w[7]; static complex_t w_1[1]; static complex_t w_2[2]; static complex_t w_4[4]; @@ -90,6 +80,7 @@ static complex_t w_8[8]; static complex_t w_16[16]; static complex_t w_32[32]; static complex_t w_64[64]; +static complex_t * w[7] = {w_1, w_2, w_4, w_8, w_16, w_32, w_64}; /* Twiddle factors for IMDCT */ static float xcos1[128]; @@ -97,9 +88,6 @@ static float xsin1[128]; static float xcos2[64]; static float xsin2[64]; -/* Delay buffer for time domain interleaving */ -static float delay[6][256]; - /* Windowing function for Modified DCT - Thank you acroread */ float imdct_window[] = { 0.00014, 0.00024, 0.00037, 0.00051, 0.00067, 0.00086, 0.00107, 0.00130, @@ -157,51 +145,6 @@ static inline complex_t cmplx_mult(complex_t a, complex_t b) return ret; } -void imdct_init(void) -{ - int i,k; - complex_t angle_step; - complex_t current_angle; - -#ifdef LIBAC3_MLIB - return; -#endif - - /* Twiddle factors to turn IFFT into IMDCT */ - for( i=0; i < 128; i++) { - xcos1[i] = -cos(2.0f * M_PI * (8*i+1)/(8*N)) ; - xsin1[i] = -sin(2.0f * M_PI * (8*i+1)/(8*N)) ; - } - - /* More twiddle factors to turn IFFT into IMDCT */ - for( i=0; i < 64; i++) { - xcos2[i] = -cos(2.0f * M_PI * (8*i+1)/(4*N)) ; - xsin2[i] = -sin(2.0f * M_PI * (8*i+1)/(4*N)) ; - } - - /* Canonical twiddle factors for FFT */ - w[0] = w_1; - w[1] = w_2; - w[2] = w_4; - w[3] = w_8; - w[4] = w_16; - w[5] = w_32; - w[6] = w_64; - - for( i = 0; i < 7; i++) { - angle_step.real = cos(-2.0 * M_PI / (1 << (i+1))); - angle_step.imag = sin(-2.0 * M_PI / (1 << (i+1))); - - current_angle.real = 1.0; - current_angle.imag = 0.0; - - for (k = 0; k < 1 << i; k++) { - w[i][k] = current_angle; - current_angle = cmplx_mult(current_angle,angle_step); - } - } -} - void imdct_do_512(float data[],float delay[]) { @@ -429,30 +372,37 @@ imdct_do_256(float data[],float delay[]) } } -void -imdct(ac3_state_t *state,audblk_t *audblk, stream_samples_t samples) { - int i; - +void imdct_init (void) +{ #ifdef LIBAC3_MLIB - for(i=0; i<state->nfchans;i++) { - if(audblk->blksw[i]) - imdct_do_256_mlib(samples[i],delay[i]); - else - imdct_do_512_mlib(samples[i],delay[i]); + void imdct_do_256_mlib(float data[],float delay[]); + void imdct_do_512_mlib(float data[],float delay[]); + + imdct_512 = imdct_do_512_mlib; + imdct_256 = imdct_do_256_mlib; +#else + int i, j, k; + + /* Twiddle factors to turn IFFT into IMDCT */ + for (i = 0; i < 128; i++) { + xcos1[i] = -cos ((M_PI / 2048) * (8 * i + 1)); + xsin1[i] = -sin ((M_PI / 2048) * (8 * i + 1)); } - return; -#endif - for(i=0; i<state->nfchans;i++) { - if(audblk->blksw[i]) - imdct_do_256(samples[i],delay[i]); - else - imdct_do_512(samples[i],delay[i]); + /* More twiddle factors to turn IFFT into IMDCT */ + for (i = 0; i < 64; i++) { + xcos2[i] = -cos ((M_PI / 1024) * (8 * i + 1)); + xsin2[i] = -sin ((M_PI / 1024) * (8 * i + 1)); } - //XXX We don't bother with the IMDCT for the LFE as it's currently - //unused. - //if (state->lfeon) - // imdct_do_512(coeffs->lfe,samples->channel[5],delay[5]); - // + for (i = 0; i < 7; i++) { + j = 1 << i; + for (k = 0; k < j; k++) { + w[i][k].real = cos (-M_PI * k / j); + w[i][k].imag = sin (-M_PI * k / j); + } + } + imdct_512 = imdct_do_512; + imdct_256 = imdct_do_256; +#endif } |