Sorry man, but this seems to be a related thread about mp4 video playback issues. I have a question and would you guys mind my asking here and I really need an answer right now? Recently I download a software as you can see "http://www.videoconverterfactory.com/tips/repair-mp4-file.html" (I hope somebody can help me check it when it's at your convenience) to fix one of my broken MP4 file. The file did not have audio output so I tried fixing it by converting it to another format. The conversion was successful and there was audio output again. But I could not figure why after conversion, the video size got much bigger, did you ever meet such a kind of issue or anyone ever heard about it?