diff options
Diffstat (limited to 'libswresample/resample.c')
| -rw-r--r-- | libswresample/resample.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/libswresample/resample.c b/libswresample/resample.c index 4aa53ee776..cef2a81734 100644 --- a/libswresample/resample.c +++ b/libswresample/resample.c @@ -29,9 +29,6 @@ #include "libavutil/avassert.h" #include "swresample_internal.h" -#define WINDOW_TYPE 9 - - typedef struct ResampleContext { const AVClass *av_class; @@ -47,6 +44,8 @@ typedef struct ResampleContext { int phase_shift; int phase_mask; int linear; + enum SwrFilterType filter_type; + int kaiser_beta; double factor; enum AVSampleFormat format; int felem_size; @@ -87,10 +86,12 @@ static double bessel(double x){ * builds a polyphase filterbank. * @param factor resampling factor * @param scale wanted sum of coefficients for each filter - * @param type 0->cubic, 1->blackman nuttall windowed sinc, 2..16->kaiser windowed sinc beta=2..16 + * @param filter_type filter type + * @param kaiser_beta kaiser window beta * @return 0 on success, negative on error */ -static int build_filter(ResampleContext *c, void *filter, double factor, int tap_count, int alloc, int phase_count, int scale, int type){ +static int build_filter(ResampleContext *c, void *filter, double factor, int tap_count, int alloc, int phase_count, int scale, + int filter_type, int kaiser_beta){ int ph, i; double x, y, w; double *tab = av_malloc(tap_count * sizeof(*tab)); @@ -109,21 +110,23 @@ static int build_filter(ResampleContext *c, void *filter, double factor, int tap x = M_PI * ((double)(i - center) - (double)ph / phase_count) * factor; if (x == 0) y = 1.0; else y = sin(x) / x; - switch(type){ - case 0:{ + switch(filter_type){ + case SWR_FILTER_TYPE_CUBIC:{ const float d= -0.5; //first order derivative = -0.5 x = fabs(((double)(i - center) - (double)ph / phase_count) * factor); if(x<1.0) y= 1 - 3*x*x + 2*x*x*x + d*( -x*x + x*x*x); else y= d*(-4 + 8*x - 5*x*x + x*x*x); break;} - case 1: + case SWR_FILTER_TYPE_BLACKMAN_NUTTALL: w = 2.0*x / (factor*tap_count) + M_PI; y *= 0.3635819 - 0.4891775 * cos(w) + 0.1365995 * cos(2*w) - 0.0106411 * cos(3*w); break; - default: + case SWR_FILTER_TYPE_KAISER: w = 2.0*x / (factor*tap_count*M_PI); - y *= bessel(type*sqrt(FFMAX(1-w*w, 0))); + y *= bessel(kaiser_beta*sqrt(FFMAX(1-w*w, 0))); break; + default: + av_assert0(0); } tab[i] = y; @@ -191,12 +194,14 @@ static int build_filter(ResampleContext *c, void *filter, double factor, int tap return 0; } -ResampleContext *swri_resample_init(ResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff, enum AVSampleFormat format){ +ResampleContext *swri_resample_init(ResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear, + double cutoff, enum AVSampleFormat format, enum SwrFilterType filter_type, int kaiser_beta){ double factor= FFMIN(out_rate * cutoff / in_rate, 1.0); int phase_count= 1<<phase_shift; if (!c || c->phase_shift != phase_shift || c->linear!=linear || c->factor != factor - || c->filter_length != FFMAX((int)ceil(filter_size/factor), 1) || c->format != format) { + || c->filter_length != FFMAX((int)ceil(filter_size/factor), 1) || c->format != format + || c->filter_type != filter_type || c->kaiser_beta != kaiser_beta) { c = av_mallocz(sizeof(*c)); if (!c) return NULL; @@ -228,9 +233,11 @@ ResampleContext *swri_resample_init(ResampleContext *c, int out_rate, int in_rat c->filter_length = FFMAX((int)ceil(filter_size/factor), 1); c->filter_alloc = FFALIGN(c->filter_length, 8); c->filter_bank = av_mallocz(c->filter_alloc*(phase_count+1)*c->felem_size); + c->filter_type = filter_type; + c->kaiser_beta = kaiser_beta; if (!c->filter_bank) goto error; - if (build_filter(c, (void*)c->filter_bank, factor, c->filter_length, c->filter_alloc, phase_count, 1<<c->filter_shift, WINDOW_TYPE)) + if (build_filter(c, (void*)c->filter_bank, factor, c->filter_length, c->filter_alloc, phase_count, 1<<c->filter_shift, filter_type, kaiser_beta)) goto error; memcpy(c->filter_bank + (c->filter_alloc*phase_count+1)*c->felem_size, c->filter_bank, (c->filter_alloc-1)*c->felem_size); memcpy(c->filter_bank + (c->filter_alloc*phase_count )*c->felem_size, c->filter_bank + (c->filter_alloc - 1)*c->felem_size, c->felem_size); |