FFmpeg Failed to update header问题解决

场景

        nginx集成nginx-rtmp-module模块，使用FFmpeg动态库推送视频到nginx时报错，

[flv @ 031E5CE0] Failed to update header with correct duration.
[flv @ 031E5CE0] Failed to update header with correct filesize.

解决

       在写文件头的时候，指定 -flvflags no_duration_filesize 参数

      AVDictionary * opts = nullptr;

     av_dict_set(&opts, "flvflags", "no_duration_filesize", 0);

      int e = avformat_write_header(m_oFmtCtx, opts ? &opts : NULL);