Possible bug in latest version of GUI for dvdauthor

[boweng]

I've been using an old version (0.77) of GUI for dvdauthor to author a dvd of video I've captured during the year with my Sony TRV17 camcorder and Canon A710 digital camera. I downloaded the new version (1.04) just to stay current and discovered a possible bug in how it handles chapter timecodes. It appears the chapter timecodes are modified during the creation of the batch files, specifically in the file author.xml. For example, if I automatically create chapters every two minutes, the resulting author.xml file shows the chapters incrementing an additional 0.24 seconds at each chapter. Instead of

00:02:00.000, 00:04:00.000, 00:06:00.000, 00:08:00.000

The chapters in the author.xml file are:

00:02:00.240, 00:04:00.480, 00:06:00.721, 00:08:00.961

In a 40 minute video, the chapters drift forward several seconds. It happens consistently on the project I'm working on with the new version, but not the old. I just wanted to check if anyone else can reproduce the problem. Normally I would have sent an email to the author, but I couldn't find an email address.

I'm using 64 bit Windows Vista Business edition. That's probably not relevant because the old version works fine for what I'm doing.

Thanks

George in Denver

[borax]

That's not a bug (at least I have changed it by will). After testing a little bit around with NTSC and drop frame/non drop frame timecodes, I discovered this 'strange setting' in dvdauthor. After authoring, check in your favorite player if the chapters are set 'correct' or not. During my tests the 'new' timecodes fit better (20 minutes is 20 minutes, not only 19 minutes and some seconds)

[boweng]

Thanks Borax, but could you elaborate a little more on how to control the chapter time codes? I suspected it might be a setting in GUI for dvdauthor, but I cannot find it. Basically I want GUI for dvdauthor to not change the chapter time codes I specified when it creates the author.xml file. Currently the chapters are in the wrong place when I play the dvd. I can manually edit author.xml to put the chapters back the way I intended, but I shouldn't have to do that.

[borax]

Ok, I will create a selectable option for it. NTSC is kind of a problem concerning timecodes (i.e. drop frame/non drop frame; pulldown flags...). And I have only very few 'testing material', as I live in a PAL country and get my movies legal (maybe for download sources, NTSC is more common, but I don't know).

[SpaceNut]

I've experienced the same problem. The source video was an over the air ATSC standard defintion video recording that I re-encoded to DVD specs using ffmpeg.

I demultiplexed to ES to avoid and SCR to GOP timecode error when adding the video.

The file imports correctly using version 1.01 but has the chapter timcode problem in V1.04.

I look forward to the new version with a selectable option.

Can you suggest any sources of information about the mpeg content involved in this issue? I'm relatively new to video processing and would like to learn.

Thanks for a great tool.

[borax]

I hope to post it the next days... (probably only as 'development version).
Problems for correct timing of NTSC are drop frame/non drop frame timecodes and pulldown flags in the video (these are no errors or 'bad habit', but nevertheless complicate things...).
Just google for the keyword 'drop frame/non drop frame' and you will find a lot of infos (and problems)

[hech54]

I hope to post it the next days... (probably only as 'development version).
Problems for correct timing of NTSC are drop frame/non drop frame timecodes and pulldown flags in the video (these are no errors or 'bad habit', but nevertheless complicate things...).
Just google for the keyword 'drop frame/non drop frame' and you will find a lot of infos (and problems)

I have NO clue what you are talking about....but if you
need help with NTSC material let me know. I'm a Yank In Germany.

[borax]

Thanks for your offer! But I'm just tired about this topic (I have only PAL material myself and never any of this problems). I used a NTSC file from the net (trailer or something like this), set chapter timing by automatic (one chapter each minute) and found that my players show something about 9 minutes and some seconds if I jump to the chapter with the timecode 00:10:00.000 Therefore I changed the calculation according to the drop frame/non drop frame factor (1.010101).
Maybe your timecodes are already corrected (then the correction would be applied twice), or I just had 'bad luck' during my tests.

[boweng]

I did a some research and the drop frame concept is a little complicated. My understanding is that it comes into play when converting a movie at 24fps into NTSC video at 29.97 frames per second. Drop frames are used to keep the timecodes in the video the same as the timecodes in the movie. If you are trying to automatically compensate for the drop frames, then applying the drop frame correction of 1.01.01.01 is indeed correct.

However if your source video is NTSC to start with or you have reencoded the video which recalculates the timecodes, then the drop frame correction no longer applies.

I wouldn't call Borax's test video bad luck. I just think the NTSC drop frame correction applies to some source video, but not all.

Cheers, and keep up the good work.

[SpaceNut]

Was the development version with the selectable option for dropframe treatment ever posted? If so, where do I find it?

Thanks,

[borax]

Here it is:
https://forum.videohelp.com/topic310993-120.html#1821027

Sorry for the delay.