FFmpeg4/libavfilter/split.c

/*
 * Copyright (c) 2007 Bobby Bingham
 *
 * 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
 */

/**
 * @file
 * audio and video splitter
 */

#include <stdio.h>

#include "libavutil/attributes.h"
#include "libavutil/avstring.h"
#include "libavutil/internal.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"

#include "avfilter.h"
#include "audio.h"
#include "filters.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

typedef struct SplitContext {
    const AVClass *class;
    int nb_outputs;
} SplitContext;

static av_cold int split_init(AVFilterContext *ctx)
{
    SplitContext *s = ctx->priv;
    int i, ret;

    for (i = 0; i < s->nb_outputs; i++) {
        AVFilterPad pad = { 0 };

        pad.type = ctx->filter->inputs[0].type;
        pad.name = av_asprintf("output%d", i);
        if (!pad.name)
            return AVERROR(ENOMEM);

        if ((ret = ff_insert_outpad(ctx, i, &pad)) < 0) {
            av_freep(&pad.name);
            return ret;
        }
    }

    return 0;
}

static av_cold void split_uninit(AVFilterContext *ctx)
{
    int i;

    for (i = 0; i < ctx->nb_outputs; i++)
        av_freep(&ctx->output_pads[i].name);
}

static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
    AVFilterContext *ctx = inlink->dst;
    int i, ret = AVERROR_EOF;

    for (i = 0; i < ctx->nb_outputs; i++) {
        AVFrame *buf_out;

        if (ff_outlink_get_status(ctx->outputs[i]))
            continue;
        buf_out = av_frame_clone(frame);
        if (!buf_out) {
            ret = AVERROR(ENOMEM);
            break;
        }

        ret = ff_filter_frame(ctx->outputs[i], buf_out);
        if (ret < 0)
            break;
    }
    av_frame_free(&frame);
    return ret;
}

#define OFFSET(x) offsetof(SplitContext, x)
#define FLAGS (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM)
static const AVOption options[] = {
    { "outputs", "set number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, FLAGS },
    { NULL }
};

#define split_options options
AVFILTER_DEFINE_CLASS(split);

#define asplit_options options
AVFILTER_DEFINE_CLASS(asplit);

static const AVFilterPad avfilter_vf_split_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
    },
    { NULL }
};

AVFilter ff_vf_split = {
    .name        = "split",
    .description = NULL_IF_CONFIG_SMALL("Pass on the input to N video outputs."),
    .priv_size   = sizeof(SplitContext),
    .priv_class  = &split_class,
    .init        = split_init,
    .uninit      = split_uninit,
    .inputs      = avfilter_vf_split_inputs,
    .outputs     = NULL,
    .flags       = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
};

static const AVFilterPad avfilter_af_asplit_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_AUDIO,
        .filter_frame = filter_frame,
    },
    { NULL }
};

AVFilter ff_af_asplit = {
    .name        = "asplit",
    .description = NULL_IF_CONFIG_SMALL("Pass on the audio input to N audio outputs."),
    .priv_size   = sizeof(SplitContext),
    .priv_class  = &asplit_class,
    .init        = split_init,
    .uninit      = split_uninit,
    .inputs      = avfilter_af_asplit_inputs,
    .outputs     = NULL,
    .flags       = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
};