vf_format.c

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/*
 * 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
 * format and noformat video filters
 */

#include <string.h>

#include "libavutil/internal.h"
#include "libavutil/mem.h"
#include "libavutil/pixdesc.h"
#include "libavutil/opt.h"

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

typedef struct {
    const AVClass *class;
    char *pix_fmts;
    /**
     * List of flags telling if a given image format has been listed
     * as argument to the filter.
     */
    int listed_pix_fmt_flags[AV_PIX_FMT_NB];
} FormatContext;

#define AV_PIX_FMT_NAME_MAXSIZE 32

static av_cold int init(AVFilterContext *ctx)
{
    FormatContext *s = ctx->priv;
    const char *cur, *sep;
    char             pix_fmt_name[AV_PIX_FMT_NAME_MAXSIZE];
    int              pix_fmt_name_len, ret;
    enum AVPixelFormat pix_fmt;

    if (!s->pix_fmts)
        return AVERROR(EINVAL);

    /* parse the list of formats */
    for (cur = s->pix_fmts; cur; cur = sep ? sep + 1 : NULL) {
        if (!(sep = strchr(cur, '|')))
            pix_fmt_name_len = strlen(cur);
        else
            pix_fmt_name_len = sep - cur;
        if (pix_fmt_name_len >= AV_PIX_FMT_NAME_MAXSIZE) {
            av_log(ctx, AV_LOG_ERROR, "Format name too long\n");
            return -1;
        }

        memcpy(pix_fmt_name, cur, pix_fmt_name_len);
        pix_fmt_name[pix_fmt_name_len] = 0;

        if ((ret = ff_parse_pixel_format(&pix_fmt, pix_fmt_name, ctx)) < 0)
            return ret;

        s->listed_pix_fmt_flags[pix_fmt] = 1;
    }

    return 0;
}

static AVFilterFormats *make_format_list(FormatContext *s, int flag)
{
    AVFilterFormats *formats = NULL;
    enum AVPixelFormat pix_fmt;

    for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
        if (s->listed_pix_fmt_flags[pix_fmt] == flag) {
            int ret = ff_add_format(&formats, pix_fmt);
            if (ret < 0) {
                ff_formats_unref(&formats);
                return NULL;
            }
        }

    return formats;
}

#define OFFSET(x) offsetof(FormatContext, x)
static const AVOption options[] = {
    { "pix_fmts", "A '|'-separated list of pixel formats", OFFSET(pix_fmts), AV_OPT_TYPE_STRING, .flags = AV_OPT_FLAG_VIDEO_PARAM },
    { NULL }
};

#if CONFIG_FORMAT_FILTER
static int query_formats_format(AVFilterContext *ctx)
{
    ff_set_common_formats(ctx, make_format_list(ctx->priv, 1));
    return 0;
}

#define format_options options
AVFILTER_DEFINE_CLASS(format);

static const AVFilterPad avfilter_vf_format_inputs[] = {
    {
        .name             = "default",
        .type             = AVMEDIA_TYPE_VIDEO,
        .get_video_buffer = ff_null_get_video_buffer,
    },
    { NULL }
};

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

AVFilter avfilter_vf_format = {
    .name          = "format",
    .description   = NULL_IF_CONFIG_SMALL("Convert the input video to one of the specified pixel formats."),
    .init          = init,
    .query_formats = query_formats_format,
    .priv_size     = sizeof(FormatContext),
    .priv_class    = &format_class,
    .inputs        = avfilter_vf_format_inputs,
    .outputs       = avfilter_vf_format_outputs,
};
#endif /* CONFIG_FORMAT_FILTER */

#if CONFIG_NOFORMAT_FILTER
static int query_formats_noformat(AVFilterContext *ctx)
{
    ff_set_common_formats(ctx, make_format_list(ctx->priv, 0));
    return 0;
}

#define noformat_options options
AVFILTER_DEFINE_CLASS(noformat);

static const AVFilterPad avfilter_vf_noformat_inputs[] = {
    {
        .name             = "default",
        .type             = AVMEDIA_TYPE_VIDEO,
        .get_video_buffer = ff_null_get_video_buffer,
    },
    { NULL }
};

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

AVFilter avfilter_vf_noformat = {
    .name          = "noformat",
    .description   = NULL_IF_CONFIG_SMALL("Force libavfilter not to use any of the specified pixel formats for the input to the next filter."),
    .init          = init,
    .query_formats = query_formats_noformat,
    .priv_size     = sizeof(FormatContext),
    .priv_class    = &noformat_class,
    .inputs        = avfilter_vf_noformat_inputs,
    .outputs       = avfilter_vf_noformat_outputs,
};
#endif /* CONFIG_NOFORMAT_FILTER */