七牛 avconcat视频拼接无效？

Question

请帮我看看，我的需求是音视频合并，试了无数次，都高不成功，文档也写的不详细，请给指导一下。
已经差多官方文档，但是写的很模糊，解决问题全靠猜

async combineVideoAndAudio(videoKey, audioKey, targetKey, pipeline) {

    //已经上传到bucket
    const videoUrl = `${videoKey}`;//01z001d15tddduokaj00mtsczd0023hi.mp4
    const audioUrl = `${audioKey}`;//01z001d15tddduokaj00mtsczd0023he.mp4
    
    const videoUrlSafeBase64 = qiniu.util.urlsafeBase64Encode(videoUrl);
    const audioUrlSafeBase64 = qiniu.util.urlsafeBase64Encode(audioUrl);
    const saveasKey = qiniu.util.urlsafeBase64Encode(`${targetKey}`);

    const fops = `avconcat/1/format/mp4/${videoUrlSafeBase64}/${audioUrlSafeBase64}`;

    try {
        const result = await this.executePfop(this.bucket, videoKey, encodeURIComponent(fops), pipeline);
        if (result.statusCode === 200) {
            return `http://${this.domain}/${targetKey}`;
        } else {
            throw new Error(`Failed to combine video and audio: ${result.statusCode}, ${JSON.stringify(result)}`);
        }
    } catch (error) {
        throw error;
    }
}