[FFmpeg-devel] [PATCH] swresample: allow double precision beta value for the Kaiser window
Paul B Mahol
onemda at gmail.com
Sat Nov 7 17:47:30 CET 2015
On 11/7/15, Ganesh Ajjanagadde <gajjanagadde at gmail.com> wrote:
> Kaiser windows inherently don't require beta to be an integer. This was
> an arbitrary restriction. Moreover, soxr does not require it, and in
> fact often estimates beta to a non-integral value.
>
> Thus, this patch allows greater flexibility for swresample clients.
>
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
> doc/resampler.texi | 2 +-
> libswresample/options.c | 2 +-
> libswresample/resample.c | 4 ++--
> libswresample/resample.h | 2 +-
> libswresample/soxr_resample.c | 2 +-
> libswresample/swresample_internal.h | 4 ++--
> 6 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/doc/resampler.texi b/doc/resampler.texi
> index 155230f..cb7d536 100644
> --- a/doc/resampler.texi
> +++ b/doc/resampler.texi
> @@ -220,7 +220,7 @@ select Kaiser windowed sinc
> @end table
>
> @item kaiser_beta
> -For swr only, set Kaiser window beta value. Must be an integer in the
> +For swr only, set Kaiser window beta value. Must be a double float value in
> the
> interval [2,16], default value is 9.
>
> @item output_sample_bits
> diff --git a/libswresample/options.c b/libswresample/options.c
> index 2bf8ab1..654102a 100644
> --- a/libswresample/options.c
> +++ b/libswresample/options.c
> @@ -120,7 +120,7 @@ static const AVOption options[]={
> { "blackman_nuttall", "select Blackman Nuttall windowed sinc", 0
> , AV_OPT_TYPE_CONST, { .i64 = SWR_FILTER_TYPE_BLACKMAN_NUTTALL },
> INT_MIN, INT_MAX, PARAM, "filter_type" },
> { "kaiser" , "select Kaiser windowed sinc" , 0
> , AV_OPT_TYPE_CONST, { .i64 = SWR_FILTER_TYPE_KAISER },
> INT_MIN, INT_MAX, PARAM, "filter_type" },
>
> -{ "kaiser_beta" , "set swr Kaiser window beta" ,
> OFFSET(kaiser_beta) , AV_OPT_TYPE_INT , {.i64=9 }, 2
> , 16 , PARAM },
> +{ "kaiser_beta" , "set swr Kaiser window beta" ,
> OFFSET(kaiser_beta) , AV_OPT_TYPE_DOUBLE , {.dbl=9
> }, 2 , 16 , PARAM },
>
> { "output_sample_bits" , "set swr number of output sample bits",
> OFFSET(dither.output_sample_bits), AV_OPT_TYPE_INT , {.i64=0 }, 0 ,
> 64 , PARAM },
> {0}
> diff --git a/libswresample/resample.c b/libswresample/resample.c
> index 1a0c369..9f5e10e 100644
> --- a/libswresample/resample.c
> +++ b/libswresample/resample.c
> @@ -142,7 +142,7 @@ static double bessel(double x) {
> * @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 filter_type, int kaiser_beta){
> + int filter_type, double kaiser_beta){
> int ph, i;
> double x, y, w, t;
> double *tab = av_malloc_array(tap_count+1, sizeof(*tab));
> @@ -283,7 +283,7 @@ static int build_filter(ResampleContext *c, void
> *filter, double factor, int tap
> }
>
> static ResampleContext *resample_init(ResampleContext *c, int out_rate, int
> in_rate, int filter_size, int phase_shift, int linear,
> - double cutoff0, enum AVSampleFormat
> format, enum SwrFilterType filter_type, int kaiser_beta,
> + double cutoff0, enum AVSampleFormat
> format, enum SwrFilterType filter_type, double kaiser_beta,
> double precision, int cheby)
> {
> double cutoff = cutoff0? cutoff0 : 0.97;
> diff --git a/libswresample/resample.h b/libswresample/resample.h
> index 99a89b7..a126b11 100644
> --- a/libswresample/resample.h
> +++ b/libswresample/resample.h
> @@ -44,7 +44,7 @@ typedef struct ResampleContext {
> int phase_mask;
> int linear;
> enum SwrFilterType filter_type;
> - int kaiser_beta;
> + double kaiser_beta;
> double factor;
> enum AVSampleFormat format;
> int felem_size;
> diff --git a/libswresample/soxr_resample.c b/libswresample/soxr_resample.c
> index 535e9ce..807f508 100644
> --- a/libswresample/soxr_resample.c
> +++ b/libswresample/soxr_resample.c
> @@ -30,7 +30,7 @@
> #include <soxr.h>
>
> static struct ResampleContext *create(struct 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 precision, int cheby){
> + double cutoff, enum AVSampleFormat format, enum SwrFilterType
> filter_type, double kaiser_beta, double precision, int cheby){
> soxr_error_t error;
>
> soxr_datatype_t type =
> diff --git a/libswresample/swresample_internal.h
> b/libswresample/swresample_internal.h
> index bf0cec7..5c46dda 100644
> --- a/libswresample/swresample_internal.h
> +++ b/libswresample/swresample_internal.h
> @@ -69,7 +69,7 @@ struct DitherContext {
> };
>
> typedef struct ResampleContext * (* resample_init_func)(struct
> 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 precision,
> int cheby);
> + double cutoff, enum AVSampleFormat
> format, enum SwrFilterType filter_type, double kaiser_beta, double
> precision, int cheby);
> typedef void (* resample_free_func)(struct ResampleContext **c);
> typedef int (* multiple_resample_func)(struct ResampleContext *c,
> AudioData *dst, int dst_size, AudioData *src, int src_size, int *consumed);
> typedef int (* resample_flush_func)(struct SwrContext *c);
> @@ -128,7 +128,7 @@ struct SwrContext {
> int linear_interp; /**< if 1 then the
> resampling FIR filter will be linearly interpolated */
> double cutoff; /**< resampling cutoff
> frequency (swr: 6dB point; soxr: 0dB point). 1.0 corresponds to half the
> output sample rate */
> int filter_type; /**< swr resampling
> filter type */
> - int kaiser_beta; /**< swr beta value for
> Kaiser window (only applicable if filter_type == AV_FILTER_TYPE_KAISER) */
> + double kaiser_beta; /**< swr beta value
> for Kaiser window (only applicable if filter_type == AV_FILTER_TYPE_KAISER)
> */
> double precision; /**< soxr resampling
> precision (in bits) */
> int cheby; /**< soxr: if 1 then
> passband rolloff will be none (Chebyshev) & irrational ratio approximation
> precision will be higher */
>
> --
> 2.6.2
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
I'm afraid that this can't be done this way.
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