AVBitStreamFilterContext *av_bitstream_filter_init(const char *name)
{
    AVBitStreamFilter *bsf = first_bitstream_filter;

    while (bsf) {
        if (!strcmp(name, bsf->name)) {
            AVBitStreamFilterContext *bsfc =
                av_mallocz(sizeof(AVBitStreamFilterContext));
            bsfc->filter    = bsf;
            bsfc->priv_data =
                bsf->priv_data_size ? av_mallocz(bsf->priv_data_size) : NULL;
            return bsfc;
        }
        bsf = bsf->next;
    }
    return NULL;
}