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lavr: resampling: add filter type and Kaiser window beta to AVOptions

This commit is contained in:
Justin Ruggles 2012-05-26 14:50:02 -04:00
parent 8ca08066fc
commit 372647aed0
4 changed files with 28 additions and 13 deletions
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7
libavresample/avresample.h
View File

@ -45,6 +45,13 @@ enum AVMixCoeffType {
AV_MIX_COEFF_TYPE_NB, /** Number of coeff types. Not part of ABI */
};
/** Resampling Filter Types */
enum AVResampleFilterType {
AV_RESAMPLE_FILTER_TYPE_CUBIC, /**< Cubic */
AV_RESAMPLE_FILTER_TYPE_BLACKMAN_NUTTALL, /**< Blackman Nuttall Windowed Sinc */
AV_RESAMPLE_FILTER_TYPE_KAISER, /**< Kaiser Windowed Sinc */
};
/**
* Return the LIBAVRESAMPLE_VERSION_INT constant.
*/

2
libavresample/internal.h
View File

@ -50,6 +50,8 @@ struct AVAudioResampleContext {
int phase_shift; /**< log2 of the number of entries in the resampling polyphase filterbank */
int linear_interp; /**< if 1 then the resampling FIR filter will be linearly interpolated */
double cutoff; /**< resampling cutoff frequency. 1.0 corresponds to half the output sample rate */
enum AVResampleFilterType filter_type; /**< resampling filter type */
int kaiser_beta; /**< beta value for Kaiser window (only applicable if filter_type == AV_FILTER_TYPE_KAISER) */
int in_channels; /**< number of input channels */
int out_channels; /**< number of output channels */

5
libavresample/options.c
View File

@ -56,6 +56,11 @@ static const AVOption options[] = {
{ "none", "None", 0, AV_OPT_TYPE_CONST, { AV_MATRIX_ENCODING_NONE }, INT_MIN, INT_MAX, PARAM, "matrix_encoding" },
{ "dolby", "Dolby", 0, AV_OPT_TYPE_CONST, { AV_MATRIX_ENCODING_DOLBY }, INT_MIN, INT_MAX, PARAM, "matrix_encoding" },
{ "dplii", "Dolby Pro Logic II", 0, AV_OPT_TYPE_CONST, { AV_MATRIX_ENCODING_DPLII }, INT_MIN, INT_MAX, PARAM, "matrix_encoding" },
{ "filter_type", "Filter Type", OFFSET(filter_type), AV_OPT_TYPE_INT, { AV_RESAMPLE_FILTER_TYPE_KAISER }, AV_RESAMPLE_FILTER_TYPE_CUBIC, AV_RESAMPLE_FILTER_TYPE_KAISER, PARAM, "filter_type" },
{ "cubic", "Cubic", 0, AV_OPT_TYPE_CONST, { AV_RESAMPLE_FILTER_TYPE_CUBIC }, INT_MIN, INT_MAX, PARAM, "filter_type" },
{ "blackman_nuttall", "Blackman Nuttall Windowed Sinc", 0, AV_OPT_TYPE_CONST, { AV_RESAMPLE_FILTER_TYPE_BLACKMAN_NUTTALL }, INT_MIN, INT_MAX, PARAM, "filter_type" },
{ "kaiser", "Kaiser Windowed Sinc", 0, AV_OPT_TYPE_CONST, { AV_RESAMPLE_FILTER_TYPE_KAISER }, INT_MIN, INT_MAX, PARAM, "filter_type" },
{ "kaiser_beta", "Kaiser Window Beta", OFFSET(kaiser_beta), AV_OPT_TYPE_INT, { 9 }, 2, 16, PARAM },
{ NULL },
};

27
libavresample/resample.c
View File

@ -30,7 +30,6 @@
#define FELEM float
#define FELEM2 float
#define FELEML float
#define WINDOW_TYPE 24
#elifdef CONFIG_RESAMPLE_S32
/* s32 template */
#define FILTER_SHIFT 30
@ -39,7 +38,6 @@
#define FELEML int64_t
#define FELEM_MAX INT32_MAX
#define FELEM_MIN INT32_MIN
#define WINDOW_TYPE 12
#else
/* s16 template */
#define FILTER_SHIFT 15
@ -48,7 +46,6 @@
#define FELEML int64_t
#define FELEM_MAX INT16_MAX
#define FELEM_MIN INT16_MIN
#define WINDOW_TYPE 9
#endif
struct ResampleContext {
@ -65,6 +62,8 @@ struct ResampleContext {
int phase_shift;
int phase_mask;
int linear;
enum AVResampleFilterType filter_type;
int kaiser_beta;
double factor;
};
@ -95,13 +94,13 @@ static double bessel(double x)
* @param tap_count tap count
* @param phase_count phase count
* @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 AVERROR code on failure
*/
static int build_filter(FELEM *filter, double factor, int tap_count,
int phase_count, int scale, int type)
int phase_count, int scale, int filter_type,
int kaiser_beta)
{
int ph, i;
double x, y, w;
@ -122,23 +121,23 @@ static int build_filter(FELEM *filter, double factor, int tap_count,
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 AV_RESAMPLE_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 AV_RESAMPLE_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 AV_RESAMPLE_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;
}
@ -186,13 +185,15 @@ ResampleContext *ff_audio_resample_init(AVAudioResampleContext *avr)
c->linear = avr->linear_interp;
c->factor = factor;
c->filter_length = FFMAX((int)ceil(avr->filter_size / factor), 1);
c->filter_type = avr->filter_type;
c->kaiser_beta = avr->kaiser_beta;
c->filter_bank = av_mallocz(c->filter_length * (phase_count + 1) * sizeof(FELEM));
if (!c->filter_bank)
goto error;
if (build_filter(c->filter_bank, factor, c->filter_length, phase_count,
1 << FILTER_SHIFT, WINDOW_TYPE) < 0)
1 << FILTER_SHIFT, c->filter_type, c->kaiser_beta) < 0)
goto error;
memcpy(&c->filter_bank[c->filter_length * phase_count + 1],