我尝试使用libavcodec来编码h264视频，但avcodec_open2返回-22“无效参数”，我不知道为什么。下面是我的代码，它主要是从libavcodec的encode示例复制而来的。

/* find the mpeg1video encoder */
    const AVCodec* codec = avcodec_find_encoder(AV_CODEC_ID_H264);
    if (!codec) {
        fprintf(stderr, "Codec '%s' not found\n", "h.264");
        exit(1);
    }

    AVCodecContext* codecContext = avcodec_alloc_context3(codec);
    if (!codecContext) {
        fprintf(stderr, "Could not allocate video codec context\n");
        exit(1);
    }

    AVPacket* pkt = av_packet_alloc();
    if (!pkt)
        exit(1);

    /* put sample parameters */
    codecContext->bit_rate = 400000;
    /* resolution must be a multiple of two */
    codecContext->width = 1920;
    codecContext->height = 1080;
    /* frames per second */
    codecContext->time_base = { 1, 25 };
    codecContext->framerate = { 25, 1 };

    /* emit one intra frame every ten frames
     * check frame pict_type before passing frame
     * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
     * then gop_size is ignored and the output of encoder
     * will always be I frame irrespective to gop_size
     */
    codecContext->gop_size = 10;
    codecContext->max_b_frames = 1;
    codecContext->codec_type = AVMEDIA_TYPE_VIDEO;
    codecContext->pix_fmt = AV_PIX_FMT_YUV420P;

    if (codec->id == AV_CODEC_ID_H264)
        av_opt_set(codecContext->priv_data, "profile", "baseline", 0);

    /* open it */
    int ret = avcodec_open2(codecContext, codec, nullptr);
    if (ret < 0) {
        char eb[AV_ERROR_MAX_STRING_SIZE];
        fprintf(stderr, "Could not open codec: %s\n", av_make_error_string(eb, AV_ERROR_MAX_STRING_SIZE, ret));
        exit(1);
    }

有人知道我哪里做错了吗？