Green Flashes on Just Playback.

[Debbie]

Hi,

I have not been using the hardware MJPEG codec for a long while (green flash issue). However on a clip captured with the above codec it appears that the green flashes are not on the clip but are trigerd during playback.(at least in my case).

I loaded the clip on UMSP 6.5 timeline and inspected the frames and the clip was "clean".

Any ideas. Could I view Matrox MJPEG clips using another codec?

Regards to all,

Debbie

[Dr Mordrid]

Green flashes are often caused by a bus contention, that is another device is hogging the bus while the capture card is trying to play the video. The green is the background behind the video overlay showing through when the playback is interrupted.

What mainboard/CPU are you using and what cards do you have in your system?

Dr. Mordrid

[Debbie]

Hi Doc,

I am using Marvel (well known for this issue).

My motherboard is the Tyan Trinity 400 Via Cipset.

OS. Win98SE, PIII 1Ghz.

BIOS on both Motherboard and Video card updated to most recent.

Regards,

Debbie

NB.

I have just uninstalled video tools and installed Morgan M-JPEG. No "green flashes" on playback.

[Dr Mordrid]

Yup, I have Marvels here by the case. It's MJPeg codec is more sensitive to this than Morgan or PICVideo's MJPeg.

Terry

[Debbie]

Hi again Terry,

If I use the avi.exe application, is it possible to use the PicVideo codec and if in the affermative what sistem.ini and registry statments will I rquire ?

Regards,

Debbie

[Sciascia]

The only thing that you will need to do is determine what the FourCC is for PicVideo. The Marvel HW created MJPEG files have a FourCC of dmb1. You can find this in the driver32 section of you system32.ini, it will be an entry like "vidc.MJPG=Pvmjpg20.dll" if Pvmjpg20.dll is the dll for Picvideo (I can't remember). So basically just open the avi file in avi.exe and change the FourCC field to whatever you need it to be like "mjpg" and it will use the PicVideo MJPEG codec for decoding, and you will still be able to capture using the Marel HW MJPEG codec.

Sorry if this is hard to read, but I just woke up.

Good Luck! © (it works here too!)

[Debbie]

Hi Sciascia,

So if I understand correctly, The application has been set to use the Moegan codec, and if I am using the PicVideo codec I should leave everything
as it is ?

Regards,

Debbie

[LvR]

Hi guys

I may be totally wrong here, but I have always been under the impression that the Marvel G400 uses a software playback codec rather than a hw codec.

On top of that, I have also been under the impression that the particular Matrox software codec is somehow tied up with/based on some version of the Picvideo codec.

If all of that is the case, then the act of forcing Picvideo for playback would really achieve very little if anything

[Debbie]

Hi LvR,

Matrox Marvel and RRS have hardware compression, but thanks to the Flyingdutchman's patch which reactivates YUY2 it is possible to apply software compression (eg. PicVideo) in the G200 and G400.

Regards,

Debbie

[LvR]

Hi Debbie

Yes - Marvel has hardware compression (Zoran codec) - but as far as I know the playback process (decompression) is done via a software solution and not via the Zoran chipset (even for Hardware codec captured avis).

As I said - my understanding may in fact be up to maggots.

If you wanna experiment try this: (I have seen this on quite a few systems but suspect that results may vary with driver revisions)

1. With Windows installed on your system with no VTs and no Picvideo present.
2. Install you registered Picvideo codec - take careful note of your registered username and registration numbers for both the encoder and the decoder sections.
3. Install your VTs for your card.
4. Go and check out the properties for your just installed Picvideo codec - You will now have a username "Matrox user" registered with a totally different set of registration numbers for the decoder and the encoder.
5. Now uninstall your VTs, and you will find your own Picvideo codec is no longer registered even though your correct username is once again entered on the Picvideo property page - there will also not be any registration numbers entered on that page, and if you try to register it by using your own registration numbers you cant - you have to reinstall the codec from scratch!

I have seen comments on both MURC and Matrox forums confirming the use of the VTs built-in sw decoder for playback of Matrox Mjpeg files - If you can confirm the results form the above experiment, one would have to come to the same conclusion as I have posted above .

[daniele greco]

Hi,
the codec discussio was very interesting: I am curious to make the trial with PICvideo and Matrox. Anyway, back to the green flashes again. Debbie, my videos were affected by green flashes too, and I succeeded to eliminate them by optimizing my system configuration.

My system is old but it works honestly ;-) and well :

MSI 6160 Mobo
Celeron 466 - 192 MB RAM
Win 98SE
marvel G400TV
HD 1xSystem Seagate 30 GB 5400 gg
HD 1 x Video MAxtor 30 GB 5400 gg on Promise controller
Both disks have DMA active
Audio SB 64V PCI - ISA Legacy emulation disabled

The important change is about the swap file usage, by inserting the following line in System.ini:

[386Enh]
ConservativeSwapFileUsage = 1
This limits the usage of swap file by Winsozz, and so limit the traffic on the bus, which can be a cause of green flashes, as Dr Mordrid suggested.
Since this change I had no more green flashes.

More, I have put this:

[vcache]
MinFileCache=32768
MaxFileCache=32768
ChunkSize=512

Of course, swap file has fixed size (300MB) and is defragmented and put at the beginning of system disk.

Hope this helps.

daniele

[Dr Mordrid]

The PICVideo MJPeg uses the "normal" fourCC of MJPG for MJPeg, but will also intercept and play files with the Matrox dmb1 fourCC if you set it up to do so.

It performs VERY well with either its own encoded material or Matrox's, which is why I always use it for capture/edit/export with my G-card and the eTV MJPeg projects.

Dr. Mordrid