[FFmpeg-devel] [PATCH] avfilter: add anoisesrc

Nicolas George george at nsup.org
Wed Nov 4 19:30:15 CET 2015


Thanks for the updated patch, see comments below.

Le quartidi 14 brumaire, an CCXXIV, Kyle Swanson a écrit :
> Signed-off-by: Kyle Swanson <k at ylo.ph>
> ---
>  Changelog                    |   1 +
>  doc/filters.texi             |  36 +++++++
>  libavfilter/Makefile         |   1 +
>  libavfilter/allfilters.c     |   1 +
>  libavfilter/asrc_anoisesrc.c | 222 +++++++++++++++++++++++++++++++++++++++++++
>  libavfilter/version.h        |   4 +-
>  6 files changed, 263 insertions(+), 2 deletions(-)
>  create mode 100644 libavfilter/asrc_anoisesrc.c
> 
> diff --git a/Changelog b/Changelog
> index 91955da..ca477de 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -30,6 +30,7 @@ version <next>:
>  - innoHeim/Rsupport Screen Capture Codec decoder
>  - ADPCM AICA decoder
>  - Interplay ACM demuxer and audio decoder
> +- anoisesrc audio source
>  
>  
>  version 2.8:
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 15ea77a..620d787 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -3193,6 +3193,42 @@ ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
>  For more information about libflite, check:
>  @url{http://www.speech.cs.cmu.edu/flite/}
>  
> + at section anoisesrc
> +
> +Generate a noise audio signal.
> +
> +The filter accepts the following options:
> +
> + at table @option
> +
> + at item color, colour, c
> +Specify the color of noise. Available noise colors are white, pink, and brown. Default color is white.
> +
> + at item sample_rate, r
> +Specify the sample rate. Default value is 48000 Hz.
> +
> + at item duration, d
> +Specify the duration of the generated audio stream. Not specifying this option results in noise with an infinite length. 
> +
> + at item amplitude, a
> +Specify the amplitude (0.0 - 1.0) of the generated audio stream. Default value is 1.0.
> +
> + at item seed, s
> +Specify a value used to seed the PRNG. Default value is 0.
> +
> + at end table
> +
> + at subsection Examples
> +
> + at itemize
> +
> + at item
> +Generate 60 seconds of pink noise, with a 44.1 kHz sampling rate and an amplitude of 0.5:
> + at example
> +anoisesrc=d=60:c=pink:r=44100:a=0.5
> + at end example
> + at end itemize
> +
>  @section sine
>  
>  Generate an audio signal made of a sine wave with amplitude 1/8.
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 1b23085..5f60e15 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -93,6 +93,7 @@ OBJS-$(CONFIG_VOLUMEDETECT_FILTER)           += af_volumedetect.o
>  OBJS-$(CONFIG_AEVALSRC_FILTER)               += aeval.o
>  OBJS-$(CONFIG_ANULLSRC_FILTER)               += asrc_anullsrc.o

>  OBJS-$(CONFIG_FLITE_FILTER)                  += asrc_flite.o
> +OBJS-$(CONFIG_ANOISESRC_FILTER)              += asrc_anoisesrc.o
>  OBJS-$(CONFIG_SINE_FILTER)                   += asrc_sine.o

Alphabetic order after renaming the filter.

>  
>  OBJS-$(CONFIG_ANULLSINK_FILTER)              += asink_anullsink.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index a538b81..e716174 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -115,6 +115,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER(AEVALSRC,       aevalsrc,       asrc);
>      REGISTER_FILTER(ANULLSRC,       anullsrc,       asrc);
>      REGISTER_FILTER(FLITE,          flite,          asrc);
> +    REGISTER_FILTER(ANOISESRC,      anoisesrc,      asrc);
>      REGISTER_FILTER(SINE,           sine,           asrc);
>  
>      REGISTER_FILTER(ANULLSINK,      anullsink,      asink);
> diff --git a/libavfilter/asrc_anoisesrc.c b/libavfilter/asrc_anoisesrc.c
> new file mode 100644
> index 0000000..d008d67
> --- /dev/null
> +++ b/libavfilter/asrc_anoisesrc.c
> @@ -0,0 +1,222 @@
> +/*
> + * Copyright (c) 2015 Kyle Swanson <k at ylo.ph>.
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public License
> + * as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public License
> + * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include <float.h>
> +
> +#include "libavutil/opt.h"
> +#include "audio.h"
> +#include "avfilter.h"
> +#include "internal.h"
> +#include "libavutil/lfg.h"
> +
> +typedef struct {
> +    const AVClass *class;
> +    int sample_rate;
> +    double amplitude;
> +    int64_t dur;
> +    char *color;
> +    int seed;
> +
> +    int infinite;
> +    double (*filter)(double white, double *buf);
> +    double* buf;
> +    int buf_size;
> +    AVLFG c;
> +} ANoiseSrcContext;
> +
> +#define OFFSET(x) offsetof(ANoiseSrcContext, x)
> +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
> +
> +static const AVOption anoisesrc_options[] = {
> +    { "sample_rate",  "set sample rate",  OFFSET(sample_rate),  AV_OPT_TYPE_INT,       {.i64 = 48000},    15,        INT_MAX,   FLAGS },
> +    { "r",            "set sample rate",  OFFSET(sample_rate),  AV_OPT_TYPE_INT,       {.i64 = 48000},    15,        INT_MAX,   FLAGS },
> +    { "amplitude",    "set amplitude",    OFFSET(amplitude),    AV_OPT_TYPE_DOUBLE,    {.dbl = 1.},       0.,        1.,        FLAGS },
> +    { "a",            "set amplitude",    OFFSET(amplitude),    AV_OPT_TYPE_DOUBLE,    {.dbl = 1.},       0.,        1.,        FLAGS },
> +    { "duration",     "set duration",     OFFSET(dur),          AV_OPT_TYPE_DURATION,  {.i64 = 0},       0,         INT64_MAX, FLAGS },
> +    { "d",            "set duration",     OFFSET(dur),          AV_OPT_TYPE_DURATION,  {.i64 = 0},       0,         INT64_MAX, FLAGS },
> +    { "color",        "set noise color",  OFFSET(color),        AV_OPT_TYPE_STRING,    {.str = "white"},  CHAR_MIN,  CHAR_MAX,  FLAGS },
> +    { "colour",       "set noise color",  OFFSET(color),        AV_OPT_TYPE_STRING,    {.str = "white"},  CHAR_MIN,  CHAR_MAX,  FLAGS },
> +    { "c",            "set noise color",  OFFSET(color),        AV_OPT_TYPE_STRING,    {.str = "white"},  CHAR_MIN,  CHAR_MAX,  FLAGS },
> +    { "seed",         "set random seed",  OFFSET(seed),         AV_OPT_TYPE_INT,       {.i64 = 0},        0,         UINT_MAX,   FLAGS },
> +    { "s",            "set random seed",  OFFSET(seed),         AV_OPT_TYPE_INT,       {.i64 = 0},        0,         UINT_MAX,   FLAGS },
> +    {NULL}
> +};
> +
> +AVFILTER_DEFINE_CLASS(anoisesrc);
> +
> +static av_cold int query_formats(AVFilterContext *ctx)
> +{
> +    ANoiseSrcContext *s = ctx->priv;
> +    static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
> +    int sample_rates[] = { s->sample_rate, -1 };

> +    static const enum AVSampleFormat sample_fmts[] = {
> +        AV_SAMPLE_FMT_DBL,
> +        AV_SAMPLE_FMT_NONE
> +    };

I already commented on that: please avoid floating-point computations unless
they are absolutely necessary.

> +
> +    AVFilterFormats *formats;
> +    AVFilterChannelLayouts *layouts;
> +    int ret;
> +
> +    formats = ff_make_format_list(sample_fmts);
> +    if (!formats)
> +        return AVERROR(ENOMEM);
> +    ret = ff_set_common_formats (ctx, formats);
> +    if (ret < 0)
> +        return ret;
> +
> +    layouts = avfilter_make_format64_list(chlayouts);
> +    if (!layouts)
> +        return AVERROR(ENOMEM);
> +    ret = ff_set_common_channel_layouts(ctx, layouts);
> +    if (ret < 0)
> +        return ret;
> +
> +    formats = ff_make_format_list(sample_rates);
> +    if (!formats)
> +        return AVERROR(ENOMEM);
> +    return ff_set_common_samplerates(ctx, formats);
> +}
> +
> +static double white_filter(double white, double *buf) {
> +    return white;
> +};
> +
> +static double pink_filter(double white, double *buf) {
> +    double pink;
> +
> +    /* http://www.musicdsp.org/files/pink.txt */
> +    buf[0] = 0.99886 * buf[0] + white * 0.0555179;
> +    buf[1] = 0.99332 * buf[1] + white * 0.0750759;
> +    buf[2] = 0.96900 * buf[2] + white * 0.1538520;
> +    buf[3] = 0.86650 * buf[3] + white * 0.3104856;
> +    buf[4] = 0.55000 * buf[4] + white * 0.5329522;
> +    buf[5] = -0.7616 * buf[5] - white * 0.0168980;
> +    pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
> +    buf[6] = white * 0.115926;
> +    return pink * 0.11;
> +}
> +
> +static double brown_filter(double white, double *buf) {
> +    double brown;
> +
> +    brown = ((0.02 * white) + buf[0]) / 1.02;
> +    buf[0] = brown;
> +    return brown * 3.5;
> +}
> +
> +static av_cold int config_props(AVFilterLink *outlink)
> +{
> +    AVFilterContext *ctx = outlink->src;
> +    ANoiseSrcContext *s = ctx->priv;
> +    if (s->dur == 0) {
> +        s->infinite = 1;
> +    } else {
> +        s->dur = av_rescale(s->dur, s->sample_rate, AV_TIME_BASE);
> +    }
> +    return 0;
> +}
> +
> +static av_cold int init(AVFilterContext *ctx) {
> +    ANoiseSrcContext *s = ctx->priv;
> +
> +    av_lfg_init(&s->c, s->seed);
> +

> +    if (!strcmp(s->color, "pink")) {
> +        s->filter = pink_filter;
> +        s->buf_size = 7;
> +    } else if(!strcmp(s->color, "brown")) {
> +        s->filter = brown_filter;
> +        s->buf_size = 1;
> +    } else if(!strcmp(s->color, "white")) {
> +        s->filter = white_filter;
> +        s->buf_size = 0;
> +    } else {
> +        av_log(ctx, AV_LOG_ERROR, "Invalid noise color: %s\n", s->color);
> +        return AVERROR_OPTION_NOT_FOUND;
> +    }

Better use AV_OPT_TYPE_FLAG for that.

> +
> +    if (s->buf_size > 0) {
> +        s->buf = av_malloc_array(s->buf_size, sizeof(double));

Unless I am mistaken, buf_size will be at most 7. I do not think allocating
it dynamically is worth it, just allocate it directly in the structure.

> +        if (!s->buf)
> +            return AVERROR(ENOMEM);
> +        for (int i = 0; i < s->buf_size; i++)
> +            s->buf[i] = 0;
> +    }
> +
> +    return 0;
> +}
> +
> +static int request_frame(AVFilterLink *outlink) {
> +    AVFilterContext *ctx = outlink->src;
> +    ANoiseSrcContext *s = ctx->priv;
> +    AVFrame *frame;
> +    int nb_samples, i;
> +    double *dst;
> +
> +    if (!s->infinite && s->dur <= 0) {
> +        return AVERROR_EOF;
> +    } else if (!s->infinite && s->dur < 1024) {
> +        nb_samples = s->dur;
> +    } else {
> +        nb_samples = 1024;
> +    }
> +
> +    if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
> +        return AVERROR(ENOMEM);
> +
> +    dst = (double *)frame->data[0];
> +    for (i = 0; i < nb_samples; i++) {
> +        double white;
> +        white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
> +        dst[i] = s->filter(white, s->buf);
> +    }
> +
> +    s->dur -= nb_samples;
> +    return ff_filter_frame(outlink, frame);
> +}
> +
> +static av_cold void uninit(AVFilterContext *ctx) {
> +    ANoiseSrcContext *s = ctx->priv;
> +    if (s->buf_size > 0)
> +        av_freep(&s->buf);
> +}
> +
> +static const AVFilterPad anoisesrc_outputs[] = {
> +    {
> +        .name          = "default",
> +        .type          = AVMEDIA_TYPE_AUDIO,
> +        .request_frame = request_frame,
> +        .config_props  = config_props,
> +    },
> +    { NULL }
> +};
> +
> +AVFilter ff_asrc_anoisesrc = {
> +    .name          = "anoisesrc",
> +    .description   = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
> +    .init          = init,
> +    .uninit        = uninit,
> +    .query_formats = query_formats,
> +    .priv_size     = sizeof(ANoiseSrcContext),
> +    .inputs        = NULL,
> +    .outputs       = anoisesrc_outputs,
> +    .priv_class    = &anoisesrc_class,
> +};
> diff --git a/libavfilter/version.h b/libavfilter/version.h
> index c3ecf91..ed3b642 100644
> --- a/libavfilter/version.h
> +++ b/libavfilter/version.h
> @@ -30,8 +30,8 @@
>  #include "libavutil/version.h"
>  
>  #define LIBAVFILTER_VERSION_MAJOR   6
> -#define LIBAVFILTER_VERSION_MINOR  14
> -#define LIBAVFILTER_VERSION_MICRO 101
> +#define LIBAVFILTER_VERSION_MINOR  15
> +#define LIBAVFILTER_VERSION_MICRO 100
>  
>  #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
>                                                 LIBAVFILTER_VERSION_MINOR, \

Regards,

-- 
  Nicolas George
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