[Ffmpeg-devel] FFMPEG: How to encore audio and mix (merge) audio and video file

[Paul]

Hi all member,
i am using FFMPEG library (thank for free)
I have used this lib to record video file (MPEG1 codec). The video file call video.mpg

I can use directsound to get sound data buffer.
Now i want to use FFMPEG to encore the sound buffer, and then i can get encoded audio file (MPEG1 or any codec).
Can you show me how to do this? Assume i call the encoded audio file is audio.mp3 

And final, i would like to mix (merge) audio.mp3 and video.mpg, how can i do this????

These are urgent for me and many thank for your help.