jcodec

Codec is an open source pure java implementation of video and audio codecs and formats.

Features 

Roadmap 

H.264 ( AVC ) Main profile decoder 

MP3 decoder/encoder 

Apple ProRes decoder and encoder 

AAC encoder 

H264 Baseline profile encoder 

Matroska ( MKV ) demuxer and muxer 

MP4 ( ISO BMF, QuickTime ) demuxer/muxer and tools 

MPEG 1/2 decoder ( supports interlace ) 

MPEG PS/TS demuxer 

Java player applet 

VP8 encoder 

MXF demuxer

https://github.com/jcodec/jcodec