[FFmpeg-user] Concat MOV files from Camcorder to h.264 mp4

[Roman Smolkin]

Hello,

We recently purchased a JVC GY-HM650U Camcorder, primarily because it can
record to HD and Web-ready (supposedly H.264 MP4 files, for some reason
with .mov extension) onto two different SD cards at the same time.

However we ran into a little problem, for lonter videos (like over 30
minutes) it splits the video into several MOV files.  It does it at the
points where the HD file reaches 4GB limit, but the web files are only
about 700MB each.  So we need to merge the 3 MOV files it the camera
created into 1 mp4 file.

I've found this
http://stackoverflow.com/questions/7333232/concatenate-two-mp4-files-using-ffmpegand
tried both the demuxer and protocol methods.  I was able to create a
merged MOV that plays fine.  However, if I try to convert that to mp4 I
lose the audio.

We are trying to prevent having to re-encode the videos, as that would
defeat the whole point of the camera producing web-ready files.

I wish there was an easy way for me to provide you a sample file, not sure
exactly how I could do that.

This should be easy, and I tried several pieces of software that supposedly
can do this without having to re-encode, but without success.