[FFmpeg-devel] [PATCH] lavfi: add showvolume filter
Michael Niedermayer
michaelni at gmx.at
Fri Feb 20 23:49:12 CET 2015
On Fri, Feb 20, 2015 at 02:28:21PM +0000, Paul B Mahol wrote:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
> libavfilter/Makefile | 1 +
> libavfilter/allfilters.c | 1 +
> libavfilter/avf_showvolume.c | 197 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 199 insertions(+)
> create mode 100644 libavfilter/avf_showvolume.c
>
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 289c63b..7e64a20 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -234,6 +234,7 @@ OBJS-$(CONFIG_AVECTORSCOPE_FILTER) += avf_avectorscope.o
> OBJS-$(CONFIG_CONCAT_FILTER) += avf_concat.o
> OBJS-$(CONFIG_SHOWCQT_FILTER) += avf_showcqt.o
> OBJS-$(CONFIG_SHOWSPECTRUM_FILTER) += avf_showspectrum.o
> +OBJS-$(CONFIG_SHOWVOLUME_FILTER) += avf_showvolume.o
> OBJS-$(CONFIG_SHOWWAVES_FILTER) += avf_showwaves.o
>
> # multimedia sources
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 55de154..e236d05 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -249,6 +249,7 @@ void avfilter_register_all(void)
> REGISTER_FILTER(CONCAT, concat, avf);
> REGISTER_FILTER(SHOWCQT, showcqt, avf);
> REGISTER_FILTER(SHOWSPECTRUM, showspectrum, avf);
> + REGISTER_FILTER(SHOWVOLUME, showvolume, avf);
> REGISTER_FILTER(SHOWWAVES, showwaves, avf);
>
> /* multimedia sources */
> diff --git a/libavfilter/avf_showvolume.c b/libavfilter/avf_showvolume.c
> new file mode 100644
> index 0000000..5ab9410
> --- /dev/null
> +++ b/libavfilter/avf_showvolume.c
> @@ -0,0 +1,197 @@
> +/*
> + * Copyright (c) 2015 Paul B Mahol
> + *
> + * 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 "libavutil/parseutils.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "audio.h"
> +#include "video.h"
> +#include "internal.h"
> +
> +typedef struct ShowVolumeContext {
> + const AVClass *class;
> + AVFrame *outpicref;
> + int w, h;
> + int f;
> + AVRational frame_rate;
> +} ShowVolumeContext;
> +
> +#define OFFSET(x) offsetof(ShowVolumeContext, x)
> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
> +
> +static const AVOption showvolume_options[] = {
> + { "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, 0, FLAGS },
> + { "r", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, 0, FLAGS },
> + { "w", "set channel width", OFFSET(w), AV_OPT_TYPE_INT, {.i64=400}, 40, 1080, FLAGS },
> + { "h", "set channel height", OFFSET(h), AV_OPT_TYPE_INT, {.i64=20}, 1, 100, FLAGS },
> + { "f", "set fade", OFFSET(f), AV_OPT_TYPE_INT, {.i64=20}, 1, 255, FLAGS },
> + { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(showvolume);
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> + AVFilterFormats *formats = NULL;
> + AVFilterChannelLayouts *layouts = NULL;
> + AVFilterLink *inlink = ctx->inputs[0];
> + AVFilterLink *outlink = ctx->outputs[0];
> + static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
> + static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
> +
> + formats = ff_make_format_list(sample_fmts);
> + if (!formats)
> + return AVERROR(ENOMEM);
> + ff_formats_ref(formats, &inlink->out_formats);
> +
> + layouts = ff_all_channel_layouts();
> + if (!layouts)
> + return AVERROR(ENOMEM);
> + ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
> +
> + formats = ff_all_samplerates();
> + if (!formats)
> + return AVERROR(ENOMEM);
> + ff_formats_ref(formats, &inlink->out_samplerates);
> +
> + formats = ff_make_format_list(pix_fmts);
> + if (!formats)
> + return AVERROR(ENOMEM);
> + ff_formats_ref(formats, &outlink->in_formats);
> +
> + return 0;
> +}
> +
> +static int config_input(AVFilterLink *inlink)
> +{
> + AVFilterContext *ctx = inlink->dst;
> + ShowVolumeContext *s = ctx->priv;
> + int nb_samples;
> +
> + nb_samples = FFMAX(1024, ((double)inlink->sample_rate / av_q2d(s->frame_rate)) + 0.5);
> + inlink->partial_buf_size =
> + inlink->min_samples =
> + inlink->max_samples = nb_samples;
> +
> + return 0;
> +}
> +
> +static int config_output(AVFilterLink *outlink)
> +{
> + ShowVolumeContext *s = outlink->src->priv;
> + AVFilterLink *inlink = outlink->src->inputs[0];
> +
> + outlink->w = s->w;
> + outlink->h = s->h * inlink->channels;
> + outlink->sample_aspect_ratio = (AVRational){1,1};
> + outlink->frame_rate = s->frame_rate;
> +
> + return 0;
> +}
> +
> +static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
> +{
> + AVFilterContext *ctx = inlink->dst;
> + AVFilterLink *outlink = ctx->outputs[0];
> + ShowVolumeContext *s = ctx->priv;
> + int c, i, j, k;
> +
> + if (!s->outpicref || s->outpicref->width != outlink->w ||
> + s->outpicref->height != outlink->h) {
> + av_frame_free(&s->outpicref);
> + s->outpicref = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> + if (!s->outpicref) {
> + av_frame_free(&insamples);
> + return AVERROR(ENOMEM);
> + }
> +
> + for (i = 0; i < outlink->h; i++)
> + memset(s->outpicref->data[0] + i * s->outpicref->linesize[0], 0, outlink->w * 4);
> + }
> + s->outpicref->pts = insamples->pts;
> +
> + for (j = 0; j < s->h * inlink->channels; j++) {
> + uint8_t *dst = s->outpicref->data[0] + j * s->outpicref->linesize[0];
> + for (k = 0; k < s->w; k++) {
> + dst[k * 4 + 1] = FFMAX(dst[k * 4 + 1] - s->f, 0);
> + }
> + }
> +
> + for (c = 0; c < inlink->channels; c++) {
> + float *src = (float *)insamples->extended_data[c];
> + float max = 0;
> +
> + for (i = 0; i < insamples->nb_samples; i++)
> + max = FFMAX(max, src[i]);
i think some users will want more a sophisticated volume calculation
but that can be added in future patches/commits
> +
> + max = av_clipf(max, 0, 1);
> +
> + for (j = 0; j < s->h; j++) {
> + uint8_t *dst = s->outpicref->data[0] + (c * s->h + j) * s->outpicref->linesize[0];
> +
> + for (k = 0; k < s->w * max; k++) {
> + dst[k * 4 + 1] = 255;
> + }
the max calculation should be done in integers to avoid potential
float inaccuracies leading to out of array writes
patch LGTM otherwise
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
During times of universal deceit, telling the truth becomes a
revolutionary act. -- George Orwell
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