Author Topic: AV sync?  (Read 16000 times)

Offline Dmitry Vergeles

  • Administrator
  • Users
  • *****
  • Posts: 877
    • View Profile
Re: AV sync?
« Reply #10 on: March 07, 2010, 01:08:31 PM »
Hello Nologic,

Some notes.

>>1. This AVI file is broken. Seeking will not work correctly. Do you want to try to fix it? This might take a long time.

That is absolutely problem of VLC, as AVI files are created by Microsoft Muxer and AVI is Microsoft standard. WMP does not complain to such streams, only VLC does.
If you reject so-called fixing offer, VLC will play it back with no probs.

>>AVI: Stream 0 (video) has a non-zero start position of 30 samples (+1000 ms). VirtualDub does not currently support a non-zero start time and the stream will be interpreted as starting from zero.

Nonzero position at VIDEO is not a bug, but an attempt to keep video audio/synchronization. I don't know why Vdub does not like such streams, but that is absolutely valid situation.

As for out of sync, it would be helpfully to have a look at the stream you grab.


Regards,
Dmitry Vergeles
Solveig Multimedia

Offline Nologic

  • Users
  • *
  • Posts: 4
    • View Profile
Re: AV sync?
« Reply #9 on: March 01, 2010, 11:37:21 AM »
I can also confirm this issue. So far experienced it with both TSCC & FFV1 lossless encodes.

The original resulting file from HyperCam will play fine in VLC but will be out of sync in WMP.

VirtualDub gives me the following errors upon opening the file.

AVI: Stream 0 (video) has a non-zero start position of 30 samples (+1000 ms). VirtualDub does not currently support a non-zero start time and the stream will be interpreted as starting from zero.

AVI: Stream 1 (audio) has a non-zero start position of 1469 samples (+33 ms). VirtualDub does not currently support a non-zero start time and the stream will be interpreted as starting from zero.

VLC however does give the following error when opening the file.

This AVI file is broken. Seeking will not work correctly. Do you want to try to fix it? This might take a long time.

=========================================
== Update
=========================================

I'm going to have to retract my confirmation at this time, as I'm currently experiencing to a much lesser degree this same issue with other products.
« Last Edit: March 02, 2010, 09:54:52 AM by Nologic »

Offline cantoris

  • Users
  • *
  • Posts: 5
    • View Profile
Re: AV sync?
« Reply #8 on: January 24, 2010, 03:25:18 PM »
Hi,

That test video I uploaded for you is meant to be uncompressed (as that was how I told HyperCam to create it).
If I load it into GSpot, it says the video codec is "DIB (_RGB)" - a raw RGB Device Independent Bitmap.
The original material I recorded was also done "uncompressed".

Thanks.

Offline Dmitry Vergeles

  • Administrator
  • Users
  • *****
  • Posts: 877
    • View Profile
Re: AV sync?
« Reply #7 on: January 24, 2010, 01:46:33 PM »
Hello Cantorism,

Sorry for delayed answer.
Could you please ttry to record the same movie with video uncomressed just to check if there is any difference?
Regards,
Dmitry Vergeles
Solveig Multimedia

Offline cantoris

  • Users
  • *
  • Posts: 5
    • View Profile
Re: AV sync?
« Reply #6 on: December 26, 2009, 04:03:19 PM »
OK here's one:
http://www.megaupload.com/?d=1WIMC82K
5MB zipped.  Also uncompressed video straight off HyperCam.
It gives the same error in VirtualDub and plays out of sync if I load it into WMP as is.

Thanks for looking into this for me.

Offline cantoris

  • Users
  • *
  • Posts: 5
    • View Profile
Re: AV sync?
« Reply #5 on: December 26, 2009, 03:29:53 PM »
I'm afraid it's >6GB as I grabbed it uncompressed.  I'll try and find something else to make a little test capture with and see if I can make it do the same thing.

Offline Dmitry Vergeles

  • Administrator
  • Users
  • *****
  • Posts: 877
    • View Profile
Re: AV sync?
« Reply #4 on: December 26, 2009, 02:40:58 PM »
Hello cantorism

Is it possible to take a look at the clip we are talking about? If so please upload it to www.yousendit.com or any other file sharing service
Regards,
Dmitry Vergeles
Solveig Multimedia

Offline cantoris

  • Users
  • *
  • Posts: 5
    • View Profile
Re: AV sync?
« Reply #3 on: December 26, 2009, 02:20:41 PM »
Yes, the original captured file is out of sync by around a second and displays the error I quoted when I load it into VirtualDub.

I also discovered that when I had processed it in VirtualDub and inserted a skew value, the resulting file played OK in WMP but not in DivX Player (so whatever correction it used is not recognising universally).

Offline Dmitry Vergeles

  • Administrator
  • Users
  • *****
  • Posts: 877
    • View Profile
Re: AV sync?
« Reply #2 on: December 26, 2009, 12:52:36 PM »
Hello cantoris,

Thank you for your post.
It is difficult to say what happened after you edited the clip. Is there any our of sync issue with the original file made by HC3?
Regards,
Dmitry Vergeles
Solveig Multimedia

Offline cantoris

  • Users
  • *
  • Posts: 5
    • View Profile
AV sync?
« Reply #1 on: December 25, 2009, 05:16:09 PM »
Happy Christmas!

I tried capturing a video with HyperCam3 for the first time yesterday but on loading it into VirtualDub was warned that the AVI video stream "has a non-zero start position of 23 samples (+958 ms)".  To then edit the video in VirtualDub I had to enter an audio skew correction of 958 to get the audio and video to be in sync.  When I then uploaded the processed video (which now played correctly) to YouTube, the video was out of sync again online.
What's going on?

Thanks for any suggestions.