Create a video mosaic app using ffmpeg libraries.

Need to create a application using ffmpeg libraries which can merge multiple live streams and output single stream. Basically code will do equivalent work of using ffmpeg tool with complex filter example -filter_complex "nullsrc=size=640x480 [base]; [0:v] setpts=PTS-STARTPTS, scale=320x480 [left]; [1:v] setpts=PTS-STARTPTS, scale=320x480 [right]; [base][left] overlay=shortest=0:x=0 [tmp1]; [tmp1][right] overlay=shortest=0:x=320:y=0" The code should be able to handle adding and removing of input streams at runtime. ie for example if at start only one stream stream is active simply output that stream's data to a diff endpoint. Now if a new stream comes online app should be able to merge the two streams and use 50% of output video area for each stream and so on. Audio codecs support needed - SPEEX , AAC video codec - h264