FFmpeg/libavformat/options.c

/*
 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "libavutil/opt.h"

/**
 * @file
 * Options definition for AVFormatContext.
 */

#include "options_table.h"

static const char* format_to_name(void* ptr)
{
    AVFormatContext* fc = (AVFormatContext*) ptr;
    if(fc->iformat) return fc->iformat->name;
    else if(fc->oformat) return fc->oformat->name;
    else return "NULL";
}

static void *format_child_next(void *obj, void *prev)
{
    AVFormatContext *s = obj;
    if (!prev && s->priv_data &&
        ((s->iformat && s->iformat->priv_class) ||
          s->oformat && s->oformat->priv_class))
        return s->priv_data;
    if (s->pb && s->pb->av_class && prev != s->pb)
        return s->pb;
    return NULL;
}

static const AVClass *format_child_class_next(const AVClass *prev)
{
    AVInputFormat  *ifmt = NULL;
    AVOutputFormat *ofmt = NULL;

    if (!prev)
        return &ff_avio_class;

    while ((ifmt = av_iformat_next(ifmt)))
        if (ifmt->priv_class == prev)
            break;

    if (!ifmt)
        while ((ofmt = av_oformat_next(ofmt)))
            if (ofmt->priv_class == prev)
                break;
    if (!ofmt)
        while (ifmt = av_iformat_next(ifmt))
            if (ifmt->priv_class)
                return ifmt->priv_class;

    while (ofmt = av_oformat_next(ofmt))
        if (ofmt->priv_class)
            return ofmt->priv_class;

    return NULL;
}

static const AVClass av_format_context_class = {
    .class_name     = "AVFormatContext",
    .item_name      = format_to_name,
    .option         = avformat_options,
    .version        = LIBAVUTIL_VERSION_INT,
    .child_next     = format_child_next,
    .child_class_next = format_child_class_next,
};

static void avformat_get_context_defaults(AVFormatContext *s)
{
    memset(s, 0, sizeof(AVFormatContext));

    s->av_class = &av_format_context_class;

    av_opt_set_defaults(s);
}

AVFormatContext *avformat_alloc_context(void)
{
    AVFormatContext *ic;
    ic = av_malloc(sizeof(AVFormatContext));
    if (!ic) return ic;
    avformat_get_context_defaults(ic);

    ic->internal = av_mallocz(sizeof(*ic->internal));
    if (!ic->internal) {
        avformat_free_context(ic);
        return NULL;
    }
    ic->internal->offset = AV_NOPTS_VALUE;

    return ic;
}

const AVClass *avformat_get_class(void)
{
    return &av_format_context_class;
}