diff options
| -rw-r--r-- | Changelog | 1 | ||||
| -rw-r--r-- | doc/filters.texi | 27 | ||||
| -rw-r--r-- | libavfilter/Makefile | 1 | ||||
| -rw-r--r-- | libavfilter/af_stereowiden.c | 167 | ||||
| -rw-r--r-- | libavfilter/allfilters.c | 1 | ||||
| -rw-r--r-- | libavfilter/version.h | 2 |
6 files changed, 198 insertions, 1 deletions
@@ -6,6 +6,7 @@ version <next>: - extrastereo filter - ocr filter - alimiter filter +- stereowiden filter version 2.8: diff --git a/doc/filters.texi b/doc/filters.texi index 4958374edf..9b6e6ffd80 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -2394,6 +2394,33 @@ silenceremove=1:5:0.02 @end example @end itemize +@section stereowiden + +This filter enhance the stereo effect by suppressing signal common to both +channels and by delaying the signal of left into right and vice versa, +thereby widening the stereo effect. + +The filter accepts the following options: + +@table @option +@item delay +Time in milliseconds of the delay of left signal into right and vice versa. +Default is 20 milliseconds. + +@item feedback +Amount of gain in delayed signal into right and vice versa. Gives a delay +effect of left signal in right output and vice versa which gives widening +effect. Default is 0.3. + +@item crossfeed +Cross feed of left into right with inverted phase. This helps in suppressing +the mono. If the value is 1 it will cancel all the signal common to both +channels. Default is 0.3. + +@item drymix +Set level of input signal of original channel. Default is 0.8. +@end table + @section treble Boost or cut treble (upper) frequencies of the audio using a two-pole diff --git a/libavfilter/Makefile b/libavfilter/Makefile index b0a2a7af25..03e18d2da9 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -80,6 +80,7 @@ OBJS-$(CONFIG_RESAMPLE_FILTER) += af_resample.o OBJS-$(CONFIG_SIDECHAINCOMPRESS_FILTER) += af_sidechaincompress.o OBJS-$(CONFIG_SILENCEDETECT_FILTER) += af_silencedetect.o OBJS-$(CONFIG_SILENCEREMOVE_FILTER) += af_silenceremove.o +OBJS-$(CONFIG_STEREOWIDEN_FILTER) += af_stereowiden.o OBJS-$(CONFIG_TREBLE_FILTER) += af_biquads.o OBJS-$(CONFIG_VOLUME_FILTER) += af_volume.o OBJS-$(CONFIG_VOLUMEDETECT_FILTER) += af_volumedetect.o diff --git a/libavfilter/af_stereowiden.c b/libavfilter/af_stereowiden.c new file mode 100644 index 0000000000..30f8754c04 --- /dev/null +++ b/libavfilter/af_stereowiden.c @@ -0,0 +1,167 @@ +/* + * Copyright (C) 2012 VLC authors and VideoLAN + * Author : Sukrit Sangwan < sukritsangwan at gmail dot com > + * + * 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 "libavutil/channel_layout.h" +#include "libavutil/opt.h" +#include "avfilter.h" +#include "audio.h" +#include "formats.h" + +typedef struct StereoWidenContext { + const AVClass *class; + + float delay; + float feedback; + float crossfeed; + float drymix; + + float *buffer; + float *write; + int length; +} StereoWidenContext; + +#define OFFSET(x) offsetof(StereoWidenContext, x) +#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption stereowiden_options[] = { + { "delay", "set delay time", OFFSET(delay), AV_OPT_TYPE_FLOAT, {.dbl=20}, 1, 100, A }, + { "feedback", "set feedback gain", OFFSET(feedback), AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.9, A }, + { "crossfeed", "set cross feed", OFFSET(crossfeed), AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.8, A }, + { "drymix", "set dry-mix", OFFSET(drymix), AV_OPT_TYPE_FLOAT, {.dbl=.8}, 0, 1.0, A }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(stereowiden); + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterFormats *formats = NULL; + AVFilterChannelLayouts *layout = NULL; + + ff_add_format(&formats, AV_SAMPLE_FMT_FLT); + ff_set_common_formats(ctx, formats); + ff_add_channel_layout(&layout, AV_CH_LAYOUT_STEREO); + ff_set_common_channel_layouts(ctx, layout); + + formats = ff_all_samplerates(); + if (!formats) + return AVERROR(ENOMEM); + return ff_set_common_samplerates(ctx, formats); +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + StereoWidenContext *s = ctx->priv; + + s->length = 2 * s->delay * inlink->sample_rate / 1000; + s->buffer = av_calloc(s->length, sizeof(s->buffer)); + if (!s->buffer) + return AVERROR(ENOMEM); + s->write = s->buffer; + + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + StereoWidenContext *s = ctx->priv; + const float *src = (const float *)in->data[0]; + const float drymix = s->drymix; + const float crossfeed = s->crossfeed; + const float feedback = s->feedback; + AVFrame *out = NULL; + float *dst; + int n; + + if (av_frame_is_writable(in)) { + out = in; + } else { + AVFrame *out = ff_get_audio_buffer(inlink, in->nb_samples); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + av_frame_copy_props(out, in); + } + dst = (float *)out->data[0]; + + for (n = 0; n < in->nb_samples; n++, src += 2, dst += 2) { + const float left = src[0], right = src[1]; + float *read = s->write + 2; + + if (read > s->buffer + s->length) + read = s->buffer; + + dst[0] = drymix * left - crossfeed * right - feedback * read[1]; + dst[1] = drymix * right - crossfeed * left - feedback * read[0]; + + s->write[0] = left; + s->write[1] = right; + + if (s->write == s->buffer + s->length) + s->write = s->buffer; + else + s->write += 2; + } + + if (out != in) + av_frame_free(&in); + return ff_filter_frame(outlink, out); +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + StereoWidenContext *s = ctx->priv; + + av_freep(&s->buffer); +} + +static const AVFilterPad inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + .config_props = config_input, + }, + { NULL } +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + +AVFilter ff_af_stereowiden = { + .name = "stereowiden", + .description = NULL_IF_CONFIG_SMALL("Apply stereo widening effect."), + .query_formats = query_formats, + .priv_size = sizeof(StereoWidenContext), + .priv_class = &stereowiden_class, + .uninit = uninit, + .inputs = inputs, + .outputs = outputs, +}; diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index c78d79be9b..89390aaaa0 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -102,6 +102,7 @@ void avfilter_register_all(void) REGISTER_FILTER(SIDECHAINCOMPRESS, sidechaincompress, af); REGISTER_FILTER(SILENCEDETECT, silencedetect, af); REGISTER_FILTER(SILENCEREMOVE, silenceremove, af); + REGISTER_FILTER(STEREOWIDEN, stereowiden, af); REGISTER_FILTER(TREBLE, treble, af); REGISTER_FILTER(VOLUME, volume, af); REGISTER_FILTER(VOLUMEDETECT, volumedetect, af); diff --git a/libavfilter/version.h b/libavfilter/version.h index e7204bca7b..b3ad51a52a 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -30,7 +30,7 @@ #include "libavutil/version.h" #define LIBAVFILTER_VERSION_MAJOR 6 -#define LIBAVFILTER_VERSION_MINOR 3 +#define LIBAVFILTER_VERSION_MINOR 4 #define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ |