Combine h264 mp4s without re-encoding- Who knows how?

[jeepsterryan]

I purchased some software from alloksoft.com that will join videos without re-encoding (as long both cilps share identical encoding properties). However, it will only join h264 files using the baseline profile. Videos encoded with the Main or High profiles suffer from jittery playback. I'm sure it has to do with I frames vs. B frames.

Does anyone know how to combine (Concatenate) two h264 mp4 files without a re-encode?

 

[JeganRX]

I purchased some software from alloksoft.com that will join videos without re-encoding (as long both cilps share identical encoding properties). However, it will only join h264 files using the baseline profile. Videos encoded with the Main or High profiles suffer from jittery playback. I'm sure it has to do with I frames vs. B frames.

Does anyone know how to combine (Concatenate) two h264 mp4 files without a re-encode?

B-frames are not exclusive to Main profile H264. Do these files (MP or HP) play fine on their own, before joining?

I haven't tried this, but I'm pretty sure MP4Box (and most likely through its GUI, YAMB) can cut and join H264 streams into MP4s. It's quite a nice tool for a few purposes (demuxing, setting framerate, changing aspect ratio, labeling the tracks, etc), but it might be good for you. I'm also gonna say that you should probably have streams with identical encoding settings. Changes in reference frames, b-frames, vbv buffers, etc, would probably not work with this.

 

[jeepsterryan]

The clips play beautifully on their own. They are of identical encoding settings. I've tried MP4 box. When I add the files in the YAMB Gui under the "join supported files" option, the result is hard to explain in writing. If clip 1 is 5 seconds and clip 2 is 30 seconds and I combine them I get a clip that is 30 seconds long. The audio for both clips is merged and starts at zero. Visually, you see the video from clip 1 for the full 5 seconds, then you see the video from clip 2 from the 5 second mark on. Below are links to some clips so you can see what I mean:

Original Clip 1 (h264 High Profile Level 1 720x480 widescreen progressive)
Original Clip 2 (same settings as above)
Output from YAMB

Here is a screen shot of YAMB after I add the files to the Join queue.

Any suggestions? Is there a setting in YAMB I am missing?

 

[PDR]

Certain mp4box builds can be buggy

Anyways, you can do it in avidemux

1) Open the 1st file, when it gives you a warning b-frames, say yes to using that mode. Don't worry about the green screen preview, it will work fine

2) File=>append=>open the 2nd file

3) Set the video & audio sidebar to "copy" , format to "mp4"

4) File=>save video (enter name with extension e.g. "myjoinedvideo.mp4" )

I'm using r5869 svn build which can be found here
http://avidemux.razorbyte.com.au/

 

[jeepsterryan]

I found a thread on the doom9 forum where the problem was acknowledged and solved, but it wasn't clear how.

@PDR - you are my hero! Avidemux did the trick. Quick and easy. Thanks!

@RX782 - you can be my hero too - thanks for the help.

 

[JeganRX]

I found a thread on the doom9 forum where the problem was acknowledged and solved, but it wasn't clear how.

@PDR - you are my hero! Avidemux did the trick. Quick and easy. Thanks!

@RX782 - you can be my hero too - thanks for the help.

Hah, no problem in any case. Glad PDR had a working solution, as I might have to do this at some point. I never use Avidemux actually, most of my encoding work is on Staxrip these days.