DGIndex is NOT showing delay in AC3 file when video has delay

[laserfan]

Originally Posted by holygamer

Hasn't anyone else who's edited a video and saved a project in DGIndex reported this sync problem before or do most people just encode first and then make their cuts?

I've not followed this thread very closely but have used VRD a few times w/o the problems you've reported. It seems to me iirc that what I've done is

- edited a recorded (TiVo in my case) HDTV program in VRD

- saved that edited program as Elementary Streams

- converted the Video ES using DGtools/x264

- converted also the CC of the TV program to text with ccextractor and made a BD sub from it

- muxed the converted video, original audio es, and new sub w/tsMuxeR

- it works

Dunno about out-of-sync in your case unless as neuron2 said up-front maybe your VRD cuts have in some cases not been made retaining only original audio. IOW if you have a TV show that is DD5.1, and then it transitions to a commercial break which is only mono or stereo non-Dolby, and include some frames from That, then that could be an issue I suppose. I have VRD set to show a different color waveform for diff audio tracks so I don't make this mistake.

[VideoFanatic]

I thought I already did explain in my last post? I just enabled multiple audio stream support in VideoRedo and saved the video as an MPEG2. I then demuxed that video with TSMuxer and remuxed and the audio was in sync. However if I take the MPEG2 saved from VidoeRedo and "Save Project and Demux Video" with DGIndex and then remux the DGindex files then the audio is out of sync!

[Guest]

Please compare the audio and video elementary streams demuxed by tsmuxer to those demuxed by DGIndex. Are they different? Meanwhile, I await completion of downloading for this new sample.

[VideoFanatic]

OK but what do you mean by compare?

[Guest]

I demuxed the new stream with both DGIndex and tsmuxer. I then remuxed both with tsmuxer. Both play in sync at the end of the file. So you appear to be misleading us again. Also, the demuxed files are again the same, so that result is expected. The reported 2ms delay is present in the source file.

So what exactly are you saying is wrong here?

(When I say "compare" two files I mean to check if they have the same content. If the elementary streams are the same then you would expect the same result when they are muxed.)

[VideoFanatic]

What I was saying was that DGindex is causing a delay but it seems that isn't true. For the video sample I uploaded, I created it by saving the video in VideoRedo and then demuxed and remuxed with TSMuxer. I played the video and it seemed to be in sync at the end of the video. I also took the VideoRedo video and saved a project with DGindex and I saw a 2ms delay mentioned in the AC3 file. I didn't play the video to see if it was in sync or not because I assumed it wouldn't be due to the delay mentioned in the file name. I played it just now and it was in sync despite the 2ms delay. So whether I use TSMuxer or DGindex makes no difference to the sync. Is 2ms too little of a delay to be able to see any sync problems in the video? How much of a delay do I need for me to be able to see it? I tried saving a project of a different video and got a 14ms delay and I couldn't see any sync problems when playing back the video!

I don't suppose you have a test file that has a large delay when saving a project in DGindex? That way I can test it.

[Guest]

The DirecTV spec for sync is <= 20 milliseconds. Exactly where it becomes noticable is different for different people, some are very sensitive to it and others don't even notice 100 milliseconds. I would not expect a 14 millisecond delay to be noticable by anyone but there may be freakish outlier people.

I don't suppose you have a test file that has a large delay when saving a project in DGindex? That way I can test it.

Of course I have such files. What do you want to test? The point of reporting the delay in the filename is so that you can shift the audio as needed in your script to eliminate the delay. For 2 milliseconds, it's too small to bother but you could correct it.

Just get a VOB and cut a piece out of the middle. Likely you will have some delay in the demuxed audio due to the open GOPs. You also see delays quite often in transport streams.

[VideoFanatic]

So I tried 3 different methods:

1. In VideoRedo I enabled multiple audio stream support and saved the video. I got a 2ms delay when using DGIndex and remuxing or if I demuxed first using TSMuxer then used DGindex and muxed the DGIndex video with the TSmuxer AC3 file. However I can't see a delay in either video. I also tried lots of other files and the largest delay I got was 29ms but again I couldn't see a delay at the start or end of the video.

2. In VideoRedo I could disable multiple audio stream support and choose the "Resync - Insert Extra Video Frames" then save the video twice. On the 2nd save it inserts a several video frames. If I then demux and remux with DGindex or TSmuxer then I don't get a delay.

This is VideoRedo's description of Resync - Insert Extra Video Frames: If the video starts to lags behind the audio, VideoReDo will insert extra replicated frames into the GOP in order to maintain sync. This setting is useful when the source material is digitized from old or noisy video tapes. Often these tapes create multiple video drop outs, yet the audio is perfect. By inserting the extra frames into the output stream, the audio track as well as sync is preserved.

3. In VideoRedo I tried disabling multiple audio stream support then saved the video. I then saved project in DGIndex and got no delay in the file name but after I remuxed the DGindex files I could see a delay! Of course the same things happens if before using DGIndex I demuxed using TSMuxer then remuxed the TSMuxer AC3 and the DGindex video file.

How do you shift the audio in a script to remove the delay reported with DGIndex ( I'm only encoding video not audio)?. Also if I did option 3 then I wouldn't be able to do that because DGIndex does not mention a delay in the file name even though their is one!

So basically DGIndex isn't causing any problems and I could do option 1 however I'm reluctant as I may get a visible delay in future. I could do option 2 however "the disable multiple audio stream support" option may be removed in future versions of VideoRedo. I could try AvsPmod like you suggested but it isn't much good to me because there's no audio in it. I watch my videos in a video editor and edit them at the same time.

[Guest]

Originally Posted by holygamer

So I tried 3 different methods:

1. In VideoRedo I enabled multiple audio stream support and saved the video. I got a 2ms delay when using DGIndex and remuxing or if I demuxed first using TSMuxer then used DGindex and muxed the DGIndex video with the TSmuxer AC3 file. However I can't see a delay in either video. I also tried lots of other files and the largest delay I got was 29ms but again I couldn't see a delay at the start or end of the video.

OK, that is consistent with most people, but DirectTV would not accept it.

3. In VideoRedo I tried disabling multiple audio stream support then saved the video. I then saved project in DGIndex and got no delay in the file name but after I remuxed the DGindex files I could see a delay! Of course the same things happens if before using DGIndex I demuxed using TSMuxer then remuxed the TSMuxer AC3 and the DGindex video file.

Yes, and I explained why all this occurs.

How do you shift the audio in a script to remove the delay reported with DGIndex ( I'm only encoding video not audio)?.

If you are processing audio in your script, you use DelayAudio(). If not, you use an external tool like DelayCut. But this won't help you if you have created progressive desync by inappropriate editing.

Also if I did option 3 then I wouldn't be able to do that because DGIndex does not mention a delay in the file name even though their is one!

I explained why this is so, but you are unable to comprehend it.

So basically DGIndex isn't causing any problems

Halleluhah, you've seen the light.

and I could do option 1 however I'm reluctant as I may get a visible delay in future. I could do option 2 however "the disable multiple audio stream support" option may be removed in future versions of VideoRedo. I could try AvsPmod like you suggested but it isn't much good to me because there's no audio in it.

That's because you did not include it in your script.

Look, DGIndex is operating rationally and sensibly and as designed. You have lots of options for processing, and other tools are also involved. If you hose up your process don't blame it on some specific tool without knowing what is going on. Get to the bottom of things. Everything you need to know to do that is here in this thread.

If you do editing at transport stream level and then demux, you can run into issues, depending on how the editing is done. This isn't the fault of DGIndex, it doesn't know how you may have mangled your transport stream. Why aren't you whining about tsmuxer? After all, you can demux with it, remux, and have audio desync. Why isn't your thread title "tsmuxer is screwing up my audio sync"? You screwed it up with your editing!

[VideoFanatic]

Also if I did option 3 then I wouldn't be able to do that because DGIndex does not mention a delay in the file name even though their is one!

How do you know there is a delay? Where is your demonstartion of this? Or should we assume you don't really understand what is going on and you are misleading us again?

That was the first video I uploaded which you checked and we both confirmed that the delay was in the AC3 file whether demuxed by TSMuxer or DGindex.

AvsPmod only plays a video when you hold the right arrow key. I said before that I watch a video while I edit it. I don't want to hold the arrow key all the time. I want to be able to play it without holding any keys down then pause it and make my cuts. AvsPmod also doesn't show the video in the correct aspect ratio.

I think I'll just try the 1st option along with DelayCut. Here's a screenshot of the options I selected if I have a delay of 6ms. Are these the correct options I should select?

[Guest]

Originally Posted by holygamer

Also if I did option 3 then I wouldn't be able to do that because DGIndex does not mention a delay in the file name even though their is one!

You made a progressive desync by your edits. DGIndex reports only the delay at the start. There is no delay at the start. It occurs at the point of your first edit and gets worse with each subsequent one. This is seen only when you demux. I told you all this. Why do you continually fail to comprehend what I tell you?

I think I'll just try the 1st option along with DelayCut. Here's a screenshot of the options I selected if I have a delay of 6ms. Are these the correct options I should select?

It won't help if you made a progressive desync. DelayCut addresses only the fixed offset at the start. And why bother for 6ms? Didn't you absorb our discussion about perceptible delays?

I have really reached the end of my rope, because you fail to understand what I say. You don't seem to even understand the difference between a fixed offset delay and a progressive one.

[VideoFanatic]

If you are processing audio in your script, you use DelayAudio(). If not, you use an external tool like DelayCut. But this won't help you if you have created progressive desync by inappropriate editing.

I didn't think my editing was inappropriate! I was just make some simple cuts but I understand what you're saying now about progressive desync. I'm basically screwed sync-wise if I edit a video before I process it with Avisynth and there's no way to fix the sync in the Ac3 file. Thanks for your help and I'm sorry I'm a bit slow when it comes to absorbing information.

[Guest]

You're not screwed if you choose the right option in VideRedo. You showed that yourself.

I don't know why you are winding yourself up in all these knots. Use the appropriate option in VideoRedo to retain sync and be happy. They are not going to remove it as it has an essential function, as you have learned. Use that option and then, if the resulting project reports a delay greater than 20ms, you can correct it with DelayCut.

I have to head to a swim meet, I'll check back later.

[VideoFanatic]

VideoRedo has an enable support for multiple audio streams option. You can set it to disable. I can then save a video and I don't get a delay or any sync problems in DGIndex. That is the option that will be removed in future versions.

The default setting of enable support for multiple audio streams = yes, will not be removed in future versions but that shows a delay in the AC3 file via DGindex. While I haven't seen a delay in the video, it doesn't fill me with confidence that I won't see one in future!

[Guest]

What makes you think an important option is going to be removed?

[VideoFanatic]

Originally Posted by neuron2

You're not screwed if you choose the right option in VideRedo. You showed that yourself.

I don't know why you are winding yourself up in all these knots. Use the appropriate option in VideoRedo to retain sync and be happy. They are not going to remove it as it has an essential function, as you have learned. Use that option and then, if the resulting project reports a delay greater than 20ms, you can correct it with DelayCut.

What I mean is that the default setting of enable support for multiple audio streams defaults to yes but that shows a delay in the AC3 file via DGindex. The option to set it to no results in no delay but that setting WILL be removed in future versions. I thought you said before that I can NOT use DelayCut because the cuts I made in the video result in a progressive desync video?

[Guest]

Again I ask, what makes you think an important option is going to be removed?

[VideoFanatic]

Did you read what I said? Also the developers told me that the option to disable multiple audio stream support will be removed in future versions. I said that several posts ago.

You moaned at me for not listening to you when you said I can't use DelayCut because when you edit a video you make it progressive desync so DelayCut won't work so why did you suggest me to use it again?

[Guest]

Now you're getting pissy so I'll leave you to your own devices. Good luck!

[VideoFanatic]

My comment was perfectly reasonable considering that you're the one who got pissy with me for not listening to you. Not so nice being on the other end of it, is it?