关于OpenEdx用户类型的说明

这个内容实在stackoverflow网站上找到的
Users are automatically enrolled as “honor”. Honor code certificates are free of charge to all students and are available for all except a few specific courses.
An honor code certificate of achievement certifies that you have successfully completed a course, but does not verify your identity (ref).

继续阅读关于OpenEdx用户类型的说明

ffmpeg音视频合成

Merging video and audio, with audio re-encoding

See this example, taken from this blog entry but updated for newer syntax. It should be something to the effect of:
ffmpeg -i video.mp4 -i audio.wav \
-c:v copy -c:a aac -strict experimental output.mp4
Here, we assume that the video file does not contain any audio stream yet, and that you want to have the same output format (here, MP4) as the input format.
The above command transcodes the audio, since MP4s cannot carry PCM audio streams. You can use any other desired audio codec if you want. See the AAC Encoding Guide for more info.

继续阅读ffmpeg音视频合成