Extract sound from video

I'm currently doing my Multimedia assignment where I have to create a new video using one video as a foreground and another as a background. OpenCV allows me to do just that: extracting images from each frame in video, processing them and putting the results back into a video format. However, OpenCV is only a computer vision library. Is there a library that allows me to do the same for sound? I'd like to extract sound (music, actually) from a video开发者_C百科 I'm using and put it into the final video.

You can use libavcodec library used in FFmpeg.

Try Tuna Audio Extracter (http://github.com/tuna74/TunaAudioExtracter). You can use the extracter part from that program.