MP4 container: problems with navigation

[alexVS]

I used AVIDemux to cut fragments from MP4-file (h264+AAC). I cutted it on key frames, then joined cutted fragments together with YAMB.

New file can be played from begin to end without errors, but I can't navigate in it both in MPC and The KMPlayer. Navigation works fine in the original MP4 file, but with the NEW MP4 file all players hang or stuck when I try to navigate.

I tried to demux/remux NEW MP4 with YAMB. Remuxing went fine, but nothing changed.

What can be wrong and what can be done to fix navigation problem?

***
one more question. Is there a program, that can THOROUGHLY analyse MP4-file with AVC? That can tell me all about errors/warnings, ISO compatibility of this file and about compatibility with hard and soft(like Quicktime) players? (I'm not sure about some options I set during mp4 encoding, and now I want to check the MP4 on errors/compatibility)

[alexVS]

nobody?
may be because of my bad english

By "navigation" I mean that I can't play MP4 file from random position. I can play it only from the beginning.

[Inspector.Gadget]

By "navigation", you mean what most people call "seeking". There are a number of reasons your MP4 file might be broken, and the one that pops to mind immediately is that you didn't make one of the cuts on a keyframe. Please post a sample of a non-working file.

[alexVS]

Here are two files: 10Mb samples
1. BAD - seeking in KMPlayers and Media Player Classic takes very much time
http://www.sendspace.com/file/icgob0
2. GOOD - sample of original file. Seeking is very fast. Playback begins from any moment without delay.
http://www.sendspace.com/file/yd0oyb

[Inspector.Gadget]

OK, I was able to reproduce your seeking error in MPC-HC using both the internal MP4 splitter and Haali's splitter on your bad sample. Re-muxing to MKV didn't solve the problem. I guess something is getting corrupted in the video stream by the splitting process - either GOPs are getting cut or something similar.

When I took your good sample and split it by size in YAMB, I didn't experience the problem in the splitted files. Did you split it by size, by time, or by something else? In any case, I would report it to Kurtnoise, who develops YAMB, in the YAMB thread in the containers forum. He can help you figure out whether it's an mp4box bug or a YAMB bug. Good luck.

[alexVS]

I think the problem is in AVIDemux, not in YAMB
YAMB can split/join files alright, without errors.
My errors appeared after splitting by AVIDemux.
I'm not sure if AVIDemux damages video stream or container.
If YAMB can fix errors it'll be great :) But from now I'll use only YAMB for splitting MP4 to avoid errors.

[Reimar]

Here are two files: 10Mb samples
1. BAD - seeking in KMPlayers and Media Player Classic takes very much time
http://www.sendspace.com/file/icgob0


MPlayer can seek very fast, but plays several broken frames. So the issue is that keyframes are not marked correctly, the DirectShow decoder you use just does not output anything until it reaches a keyframe whereas libavcodec (which MPlayer uses) tries error concealment, which results in a picture but a very ugly one.