Virtualdub creates unusable files using Blackmagic codec

[Kristian Lam]

Hi Uku,
c.

I tested this here and it worked fine with VirtualDub so I’m not sure what is going on.

Can you elaborate more about what you’re doing? We also need more information before we can try and troubleshoot. For example, what kind of files you’re starting with, what formats you’re compressing it to? What version of drivers do you have installed? What version of VirtualDub was used?

regards

Kristian Lam
Blackmagic Design

[Uku Toomet]

Hi Kristian,

The sources have been different avi files with 720×576, 25 fps ,any codec, including BM coded files.
The destination will be BM mjpg avi file or 10bit uncompressed.
The symptoms occur with any version of Virtual Dub, including latest beta VirtualDub-1.7.1 experimental.
It has been tested on two Decklink Extreme Machines with all the previous drivers and with the latest 5.9.2.
Same applies to 4.9 soft codecs.

If you try to seek the file, or the jump to the end, the following message is displayed at the bottom bar of Virtualdub:
Decoding frame 415, Preloading frame 415
Longer file will give better impression.

File properties in Virtualdub shows Number of keyframes: 1

The BM 10-bit uncompressed soft encoded 4.9 files generated in Premiere work fine though.

Regards,
Uku

p.s. Another thing: could be really nice if the stand alone software codecs will allow to compress to BM mjpg and BM DV as well. Will this be possible? By this far we are generating microsoft uncompressed files in Premiere machines with no Decklink hardware. The resulting files will be used in BM hardware machines. The sources of those projects have been DV, so uncompressed is real overkill.

[Kristian Lam]

Hi Uku,

It’s weird but I can’t reproduce this. The files created scrubbed fine in VirtualDub and shows the correct properties as well.

All I did was to load a clip in VirtualDub, choose the option in Compression, then do a Save AVI. I also did one where I selected the range to compress (I used 100 frames) and it was still ok.

[Uku Toomet] “Another thing: could be really nice if the stand alone software codecs will allow to compress to BM mjpg and BM DV as well.”

There is no Blackmagic DV codec. We use the Microsoft DV codec for the compression work. I’ll log mjpg as a feature request though.

regards

Kristian Lam
Blackmagic Design

[Uku Toomet]

Hi Kristian,

I tried the Virtualdub in all possible ways. The only possibility to get more than one keyframe at the output was to set the compression to DIrect Stream Copy, which repeats the source without recompression.
All the switches of the Virtualdub were set to default.

Could you please comment.

Regards,
Uku

[Chris Borjis]

Pardon me for intervening, but as a virtual dub user I’d like to recommend you both post what version you are using as there are different versions that may be causing the issues.

[Uku Toomet]

Hi Boris,

Do you get normal files with more, than 1 keyframe?
The symptoms occur with any version of Virtual Dub, including latest beta VirtualDub-1.7.1 experimental.
It has been tested on two Decklink Extreme Machines with all the previous drivers and with the latest 5.9.2.
Same applies to 4.9 soft codecs.

Regards,
Uku

[Shyam Mistry]

My problem with Virtual Dub is that when i record with virtual dub my video has a blackmagic codecc which then when i try to import to Sony Vegas it doesn’t see to work and makes sony just shut down.