Using VLC to debug video problem

[alan.campagna]

This is a presentation of a problem I am having with burned DVDs which play perfectly with VLC but have an audio desync on a standalone DVD player.

I have posted this problem on other video blogs, and searched as many blogs as I can find, with no success.

The problem is this:

>I have some .avi files which I am attempting to use to create a DVD.
>I use several good video converters, and I have ffmpeg available to check results.
>I create the DVD and check the audio sync at every step. The sync is perfect.
>The source .avi, the intermediate .mpeg files, and the resulting DVD all play perfectly in VLC (and other PC players).
>Taking the same DVD which I just checked, I play it in a standalone DVD player, and after a short while, audio is lagging the video.
>The player is an inexpensive Toshiba progressive scan player (Toshiba SD-K770).
>My research on progressive scan players indicates that the chipset used in the DVD player may be at fault, and I do not doubt that.
>However, before I run out and buy another player, I want to note that I have created many DVD discs, and most play well in the player, as well as all commercial discs.
>Moreover, what is very frustrating is that on the desync-ed discs, the sync can be re-established by using the 'back' button briefly, and restarting the video. It then desyncs again after some time.
>I note that the sync problem usually shows up after a video fade-out or abrupt change of scene.
>Therefore, I attempted to analyze the differences between the VOB files on the discs which play well, and those which don't. I've used ffmpeg and other analysis programs (I'm trying to avoid using names here), and I can determine no difference - there are certainly bitrate differences in both the audio and video, but mimicking those settings that work on the files that don't work has not produced results.
>I was hoping that VLC might be able to help me, by logging file decoding information, or by 'simulating' the behavior of the DVD player, so I can determine how to code these files so that the audio is properly sync'd.

Most of the blogs online these days are populated by blind-leading-the-blind conversations; "I use [favorite converter] and I never have a problem", as well as sheer guessing about stream mux/demuxing, and such. I suppose if I must become much more expert in video processing, I shall have to do that.

I note that some people have written about the same problem I just described, and I have not yet seen any purported solution which has worked. Most people seem to think it is a constant shift desync, or that it comes from the original source file, which is not true in either case.

I would appreciate any thoughts on this matter. As I said, I wouldn't be opposed to buying a better DVD player, except for the fact that it plays many of my burned DVDs well, and that there is obviously syncing information available, since it can be re-synched with the 'back' button.

Thanks in advance.

[ivoire]

Did you looked at VLC logs when playing the DVD. Maybe the file is a bit malformated but VLC can handle it but not your DVD player ?