int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
                               AVCodecContext *avctx, const char *args,
                               uint8_t **poutbuf, int *poutbuf_size,
                               const uint8_t *buf, int buf_size, int keyframe)
{
    BSFCompatContext *priv = bsfc->priv_data;
    AVPacket pkt = { 0 };
    int ret;

    if (!priv->ctx) {
        ret = av_bsf_alloc(bsfc->filter, &priv->ctx);
        if (ret < 0)
            return ret;

        ret = avcodec_parameters_from_context(priv->ctx->par_in, avctx);
        if (ret < 0)
            return ret;

        priv->ctx->time_base_in = avctx->time_base;

        if (bsfc->args && bsfc->filter->priv_class) {
            const AVOption *opt = av_opt_next(priv->ctx->priv_data, NULL);
            const char * shorthand[2] = {NULL};

            if (opt)
                shorthand[0] = opt->name;

            ret = av_opt_set_from_string(priv->ctx->priv_data, bsfc->args, shorthand, "=", ":");
        }

        ret = av_bsf_init(priv->ctx);
        if (ret < 0)
            return ret;
    }

    pkt.data = buf;
    pkt.size = buf_size;

    ret = av_bsf_send_packet(priv->ctx, &pkt);
    if (ret < 0)
        return ret;

    *poutbuf      = NULL;
    *poutbuf_size = 0;

    ret = av_bsf_receive_packet(priv->ctx, &pkt);
    if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
        return 0;
    else if (ret < 0)
        return ret;

    *poutbuf = av_malloc(pkt.size + AV_INPUT_BUFFER_PADDING_SIZE);
    if (!*poutbuf) {
        av_packet_unref(&pkt);
        return AVERROR(ENOMEM);
    }

    *poutbuf_size = pkt.size;
    memcpy(*poutbuf, pkt.data, pkt.size);

    av_packet_unref(&pkt);

    /* drain all the remaining packets we cannot return */
    while (ret >= 0) {
        ret = av_bsf_receive_packet(priv->ctx, &pkt);
        av_packet_unref(&pkt);
    }

    if (!priv->extradata_updated) {
        /* update extradata in avctx from the output codec parameters */
        if (priv->ctx->par_out->extradata_size && (!args || !strstr(args, "private_spspps_buf"))) {
            av_freep(&avctx->extradata);
            avctx->extradata_size = 0;
            avctx->extradata = av_mallocz(priv->ctx->par_out->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
            if (!avctx->extradata)
                return AVERROR(ENOMEM);
            memcpy(avctx->extradata, priv->ctx->par_out->extradata, priv->ctx->par_out->extradata_size);
            avctx->extradata_size = priv->ctx->par_out->extradata_size;
        }

        priv->extradata_updated = 1;
    }

    return 1;
}