ffmpeg 写mp4 header
- copy from c - avformat_write_header fails with error "invalid argument - Stack Overflow
- test for Android ndk .
AVFormatContext* pOutFormatContext;
AVOutputFormat* avOutputFormat;
if ((avOutputFormat = av_guess_format(NULL, "mp4", "video/mp4")) == NULL) {
cerr << "Could not guess output format" << endl;
return -1;
}