Wrong .VOB duration in Avidemux 2.6

[owlbrudder]

I am having the same issue as reported under Windows in post http://avidemux.org/smuf/index.php?topic=14246.0, but I am using Linux 32 bit. My trusty old TV recorder records to DVD, which means the files I transfer from it are in VOB format. On two occasions recently, I have found Avidemux not "seeing" a large part of one of these transferred files. On one occasion, it 'saw' only the first 11 or so minutes of a 28 minute segment and the other occasion it 'saw' only the first five minutes. Both files could be played in their entirety by VLC, so the files were not obviously corrupted. As the errant files were over 1Gb in size, I have not tried to post them and, indeed, they no longer exist. I have not seen this happening with smaller files (yet).

As I have changed to using a different recorder (the old one ruined a couple of DVD-RWs I fed it), this is not an urgent problem for me, but I thought it worth posting in support of the other post referenced above.

Fedora 19 32 bit
Avidemux 2.6.7

[Jan Gruuthuse]

Perhaps you did let avidemux auto index the sequential .vob files? Remove the .idx2 files. Load vob part 1, answer no when avidemux asks to add the other parts. Append now each remaining vob part in sequence with the append from menu. An .idx2 file should been created for each .vob part. When finished loading the complete recorded video the total running time should been shown in the Avidemux Navigation bar.

update: vob loaded part1 and appended manually remaining parts:

[AQUAR]

Just a curious observation on the vobduration.png:
The audio lenght isn't matching the video lenght.

Is the audio lenght shown matching that in the first VOB?

[Jan Gruuthuse]

Did not look for audio issues. Just @ total playtime.
Anyway did now save the vob1 + appended vob's and audio is present for full length of saved video.
Looks like audio only gives info on 1st vob loaded.
If mean does find some spare time and could perhaps look at this beauty issue.

[ericzutter]

I tested again with the latest Windows version 2.6.8v2 but the problem is not solved. When opening and saving only one VOB file, the video and audio duration are the same but they both have the wrong duration.

I updated my post: http://avidemux.org/smuf/index.php/topic,14246.0.html

[AQUAR]

I think this has more to do with the VOB's being part of the DVD structure.
There is more to a VOB than just multiplexed video audio and subtitles.

Probably better off demuxing the streams of interest inside these VOB's and remuxing them into MKV.
As there often is some audio delay with respect to the video you may need to allow for that.

Just my 2 cents worth.   

[Jan Gruuthuse]

Done some more testing:
- playing zeitgeist VTS_01_1.VOB with vlc, it plays only for 0:14:12.
- mkv merge extracts the correct video time as does avidemux 2.5.6: 0:37:54:640.
- Did test some more VTS_01_1.VOB and some did load correctly in avidemux 2.6.8 and these did also play correctly in vlc.

So for mpeg video (dvd) best to use avidemux 2.5.6. or remux to mkv (mkv merge) see also AQUAR remarks here
The avidemux 2.6.8 vob indexing getting it wrong is most likely (perhaps partialy) external to, seeing the same issues in vlc.
Don't expect a soon fix for 2.6.* branch ...

[owlbrudder]

Perhaps you did let avidemux auto index the sequential .vob files?

Hi Jan - thanks for replying. I had tried all that you suggest. Yes, I initially let Avidemux auto-load the sequential parts and saw the problem, so I deleted the indices and manually loaded them in sequence - same problem. I even deleted the indices and manually loaded just the troublesome segment, but still had the same problem. No matter what I did, avidemux missed a large part of the troublesome segment. Always, the break occurred at the same place, so I suspect something in the structure of the file was upsetting avidemux - that is why I was surprised when vlc was able to play it without problems.

I have seen comments here and at the other problem report I referenced above, indicating this problem does not occur in avidemux 2.5 versions. It has me curious and, if I encounter the problem again, I will try reverting to an earlier version and see what happens. I am only using avidemux to trim off excess TV recording time from the beginning and end of a movie, prior to burning to DVD-R using mytharchive, so am not using any of the more powerful/arcane features of the software and reverting to an earlier version will not inconvenience me.

[Jan Gruuthuse]

Best to keep 2.5.6 and 2.6.x installed alongside.
2.5.6 for dvd and SD recordings in old dvb-s/c/t format.
2.6.x for SD/HD for the newer formats (dvb-s2/c2/t2, ...) not handled by 2.5.6.

[owlbrudder]

Best to keep 2.5.6 and 2.6.x installed alongside.

Thanks Jan, I'll do that. The old machine I was recording on was SD, so 2.5 should work fine for me.

[VanillaMozilla]

I have additional information, and I think this reply does belong in this topic.

I think I have exactly the same problem.  The video I'm working on is a multi-title DVD that was made with a Philips DVD recorder.  I simply copied the .VOB files from the DVD.  The first title of the DVD (not counting the menu) lasts about 5 minutes of a 2-hour video.  File VTS_01_1.VOB lasts 30-minutes, but version 2.6.8v2 for Windows will play back only the first title (not counting the menu, which is not displayed).  That makes about 25 minutes of video that is inaccessible.  Also, unlike previous versions, 2.6.8v2 does not save an index file (unless there is a temporary file in another directory).

VLC and Movie Player (Totem) play the whole 25 minutes without any problem.  The problem also does not occur in Avidemux version 2.6.1 for Windows or 2.5.4 for Linux.  I would use one of those versions, except the seemingly insurmountable synchronization problems.  That would be a subject for another discussion.

[Jan Gruuthuse]

make sure to
- delete .idx2 files for the used .vob
- don't let avidemux 2.6.8 to auto append other parts
- load 1st vob and append remaining parts manually. Press these keys together [Ctrl][A]

you should see a difference in .idx2 file sizes. manually appended should be bigger in size then the auto appended one.

[AQUAR]

I think we have said this a few times before:
For video streams with older codecs like MPEG-2 in VOB containers its better to use avidemux V2.5.6.

Like to know what the work flow is for these insurmountable synchronisation problems, with the frame based avidemux?

Just note that audio may be shifted relative to video in these DVD VOB's, and these shifts are not necessarily constant across the VOB parts for the video stream.
Simply put - video in DVD's are not just about sequentially appending component VOB's.
Luckily most are formulated so that this simple appending works fine, especially with V2.5.6.
   

[Jan Gruuthuse]

I hardly have issues with region 2 (PAL) dvd's in 2.6.8. Have no need to frame edit beyond the up/down key selectable editing point in 2.6.8.
If 2.5.6 provides a same size index .idx (auto appended versus manually appended) then this should be fine.

[VanillaMozilla]

make sure to
- delete .idx2 files for the used .vob
- don't let avidemux 2.6.8 to auto append other parts
- load 1st vob and append remaining parts manually. Press these keys together [Ctrl][A]

you should see a difference in .idx2 file sizes. manually appended should be bigger in size then the auto appended one.

1. I was mistaken.  It does create .idx2 files.  I don't know, I may have searched for .idx files.

2. I have never used autoappend.  If I just load VTS_01_1.VOB, I can only see the first 5 minutes of it.  If I append the other four files in correct sequence with ^a, I can see more of that file, but large parts of it are still unreachable.  This is reproducible.  I tested with another DVD, and have the same problem.  The second title is unreachable.  VLC Player and Avidemux 2.5.4 have no such problem.

3. On the bright side, the audio sync problem seems to be gone with 2.6.8.