Playing Captured Video in Windows

[Conroe]

I'm new to the world of video capture and I'm not exactly sure what's going on. I normally use the open source VLC media player. However, I have noticed that video that I capture using VirtualVCR will not always play in VLC. The captured video does play fine in the Windows Media Player, though.

I don't know if this is related, but when I load the VirtualVCR AVI into VirtualDub, I get a warning message. "Stream has a non-zero start position of x samples". But other than the message, everything looks fine.

Thanks!

[Baldrick]

What video and audio codec are you using?

[Conroe]

Hmmm ... I can't seem to find a codec option in VirtualVCR. It has a "color format" of YUY2 but I'm not certain if that is the codec. The audio compression was left blank in VirtualVCR.

Edit: I looked at the AVI File Information tab in VirtualDub. It says I have "Internal DIB Decoder (YUY2)" for video and "PCM (Uncompressed)" for audio.

[Baldrick]

You could identify the video codec in the captured using mediainfo.

If you resave the avi using virtualdub, be sure to use video->direct stream copy and audio->direct stream copy, does the new avi work in vlc then? Maybe just some video headers that are corrupt.

[Conroe]

MediaInfo shows YUV and PCM for the codecs.

Using the direct stream copy to resave the AVI did not resolve the problem with VLC. I did notice, though, that if I slow down the playback in VLC, I was able to get it to play. Albeit slowly. If I speed it back up, the image just sits there like it is paused. No audio at any speed.

The direct stream copy still plays just fine in Windows Media Player.

[jagabo]

It sounds like you are capturing uncompressed YUY2 video and uncompressed PCM audio. VLC should be able to play that but your hard drive may not be fast enough for it to play smoothly. Of course, that would also mean you are dropping frames while recording so the saved video won't be smooth anyway.

You need to compress the video. If you want lossless compression use HuffYUV (fast enough to use while capturing) or Lagarith (may not be fast enough to comrepess while capturing). I don't know VirtualVCR but it should have some way of specifying a codec for capturing.

If you want to compress what you already have with VirtualDub:

1) File -> Open Video File
2) Video -> Fast Recompress
3) Video -> Compression, pick codec and settings
4) File -> Save as AVI

[Conroe]

VLC should be able to play that but your hard drive may not be fast enough for it to play smoothly. Of course, that would also mean you are dropping frames while recording so the saved video won't be smooth anyway.

I have an ATA133 7200rpm hard drive that I picked up a couple of years ago. Its not as fast as some of today's SATA drives, of course, but it was one of the faster ones available a couple of years ago. VirtualVCR reported that I had zero dropped frames. In addition, when I use the "goto next dropped frame" option in VirtualDUB, it is not finding any.

If you want to compress what you already have with VirtualDub:

1) File -> Open Video File
2) Video -> Fast Recompress
3) Video -> Compression, pick codec and settings
4) File -> Save as AVI

I ran this option using the HuffyUV codec that you recommended. It still won't play the video in VLC, although it will now sporadically give me some audio. So a slight improvement.

Windows Media Player will also still play the AVI. However, it looks like there was a huge drop in quality. The compressed AVI now jumps or stutters (not sure how best to describe it). I'm assuming that is caused by the options that I selected. I used the 2 methods labeled "best". Unfortunately, I'm not sure what any of them mean without reading up on them first.

[jagabo]

What you're describing is very odd. Let's be sure we have known sources to begin with. Attached is a zip file with uncompressed YUY2 video and HuffYUV compressed YUY2 video (720x576, 25 fps PAL format but for our purposes here they should be fine). The video is mostly black except once a second there is a flash of test pattern and an accompanying beep. Do these play with VLC on your system? Other players?

yuy2.zip

[Conroe]

What you're describing is very odd.

Very odd, indeed! Until I started capturing my own video, I had never encountered a file that VLC couldn't play. Which is why I like it so much.

Do these play with VLC on your system? Other players?

The huffy one plays just fine. But the YUY one chokes. They both play fine in Windows Media Player. And just for grins, I went and downloaded MPlayer which is another open source media player. It plays both of them just fine, as well.

I also went out to the VideoLan website and downloaded the latest version of VLC. I had been using the d version, but I am having the same problems with the current i version.

At this point, I am coming to the conclusion that the problem isn't with the way that I am capturing. But rather a problem with VLC or maybe with the way VLC interacts with my hardware.

[jagabo]

If you can open your files in VirtualDub and they look ok they are fine.

Note that VirtualDub can only detect dropped frames if they are marked as such by including duplicate frames (an instruction to just repeat the last frame). Many (most?) capture programs will not do this. VirtualDub does when it captures. I don't know about VirtualVCR.

[Conroe]

Good to know! Thanks! VirtualVCR seems to be a pretty good program (from my limited experience). Unfortunately, VirtualDub doesn't seem to support my card. But it does open the captured AVI's just fine.

I really appreciate your help, Jagabo and Baldrick!

[jagabo]

Another capture program you might look at is AVI_IO. It's a little quirky but it works very well. I never had any trouble using HuffYUV with that program. I haven't used it in years though!