how are you playing these videos back?

progressive is the 'native' format for PC monitors so that may be why it looks better to you. Media Player is not good for MPEG-2 so make sure you are previewing with something decent like Cyberlink PowerDVD. you should get much better results especially with interlaced MPEG-2 footage.

if your source material is recorded progressive (I know Canon has that option) then you should stick with progressive MPEG-2. if your source is interlaced, you may want to stick with interlaced as your destination format. 'Lower field first' is the proper setting.

a frame of interlaced video is composed of two sub-frames or 'fields' which are recorded 1/60th of a second apart so they don't usually combine into a single picture very well and can produce a comb effect when viewed on progressive equipment like a PC monitor, but make for very smooth motion since there are 60 samples per second. on the other hand, a frame of progressive video is a complete picture unto itself much like the way film works, but today's cameras take only 30 frames per second so the motion is not as smooth as interlaced.

I prefer to shoot edit and render in progressive mode exclusively. sometimes I shoot in interlaced mode if I know I'm going to do some slow motion effects because the 60 samples per second makes for much better slow motion compared to 30.

you should look into this further (read up on the subject) because it is fundamental to the way video works.

Hi,

Thanks for the feedback, but I am still a little bit confused.
I actually use a Matrox G400 MAX Dual Head card.
So the image is output to both my monitor and a TV.

The jittery effect appears on the TV screen if I encode with
upper or lower field. When using progressive it works perfectly.
Well almost! I have just tried rendering out to MPEG2 a 2 hour and 20
minute movie I filmed.
The Mainconcept codec seems to be unable to deal with this amount of data.
There is "skipping" occuring throughout the movie, at irregular times.
Can anybody recommend a good reliable MPEG2 encoder?
Also, can anyone tell me if an MPEG2 movie rendered as "progressive" will
work correctly when transferred to DVD?

Thanks.

organism_seven

>>>The jittery effect appears on the TV screen if I encode with
upper or lower field. When using progressive it works perfectly.

you can't judge it based on the output of a dual head card to a TV. this set up does not reflect what will happen in the real world. the best way to preview your work on a TV is through a 1394 port to a DV camcorder (or DV converter) and then to a TV. the jittery results are most likely due to your set up, not the video itself.

>>>The Mainconcept codec seems to be unable to deal with this amount of data.
There is "skipping" occuring throughout the movie, at irregular times.
Can anybody recommend a good reliable MPEG2 encoder?

TMPGEnc (Tsunami MPEG Encoder). it's really good but you have to render to an intermediary file from Vegas and then use TMPGEnc to compress the avi to mpeg.

>>>Also, can anyone tell me if an MPEG2 movie rendered as "progressive" will
work correctly when transferred to DVD?

Yes. any interlaced equipment will just display it as interlaced and any progressive equipment like a PC DVD-ROM or progressive DVD player will read it as progressive. but if your source is interlaced, you might be better off rendering to interlaced MPEG-2. just make sure if you do any tests to determine which one to use that you test on *real world* equipment.

Hi,

Thanks, I'm getting educated a little bit more every time I visit here.
Can you tell me how to find out what my source footage is?
i.e. Progressive, Upper, or Lower.
As mentioned I have an analog Sony Hi-8 Camcorder and a digital Canon XM-1.
What "field" do they capture in?
Sorry to appear dumb, but most of this is new to me.

Thanks

As a general rule DV will be bottom field first & analogue will depend on your capture device. If you are unsure about your capture device you can always download a free little utility called "bitrate viewer" from this link, load your captured file and it will display all the details of your file (i.e. field order,resolution,compression & graphs showing bitrate flow & quantization employed). It works on MPEG & AVI files. For a reasonable fee you can buy the full version which allows you to edit MPEG streams if you were having problems with spikes etc in your stream.

http://www.tecoltd.com/bitratev.htm

cheese, you hit the nail on the head there. Interlaced output from a dual-head VGA card is not synced at all to the display of images on it. So, even if we are painting images designed for interlaced output on it, the field order is not going to be synced with the painting of those lines on your TV and you are going to get all kinds of temporal artifacts.
///d@

If you have a few extra bucks to spend, an MPEG decoder card is an excellent way to check MPEG files on a TV monitor in a real-world setting immediately. It can be quite frustrating to burn a DVD and then find out you need to tweak the field order or something. But a decoder card lets you see right away.

They are available in the $50 range now. Highly recommended.

MainConcept Tech Support

>>>Can you tell me how to find out what my source footage is?
i.e. Progressive, Upper, or Lower.

open your clip in Vegas and switch to the Media Pool. right-click on the clip in the media pool and hit properties. the field order will be listed.

sometimes I capture clips that were recorded in progressive mode, but Vegas lists them as "lower field first" so it isn't guaranteed to be correct, but I think that's only a problem with short clips a few seconds long.

>>>As mentioned I have an analog Sony Hi-8 Camcorder and a digital Canon XM-1.
What "field" do they capture in?

if you are capturing via a DV device then the field order will be "lower first". (if you aren't capturing over Firewire, I highly suggest doing so) but check the documentation with your capture card if it's an analog capture card.

your Canon XM-1 can record in interlaced mode (Normal) or progressive mode (Frame). there is a switch on the back (Normal/Frame). experiment with both and see what a difference it makes. when shooting in progressive, you'll end up with 30 complete pictures per second, rather than 60 half pictures per second.

Hi,

I have an ADVC-100 for capturing my Hi-8 footage, which is routed
through my Adaptec Firewire card.
My Canon XM-1 goes through the firewire card directly.

Thanks for that tip about about the normal/frame switch, I will check that out.
30fps? Would that only be applicable to the American version (GL1) or does it
also apply to the UK version (XM1)? PAL DV is 25fps isn't it?

Also, considering the reply from Mainconcept Tech Support, am I right in thinking
that their MPEG2 software codec is not up to the job of encoding 2 hours of DV?
I'm not giving Mainconcept a bad time, in fact if that is the case, I appreciate them being honest in recommending a hardware MPEG card.
But my system is already fairly stacked out with hardware, is there a good reliable
MPEG2 software solution, for producing DVD compliant files?
I am producing wedding videos, and more and more people are asking for DVD discs.
I want to be able to produce just the one file that I can output to VHS tape, and transfer over to a DVD disc if required.
I am using a dual processor 1.8AMD machine with 512MB Ram and a 120GB Hard disk for video capture, so I would have thought that my hardware was up to the "grunt" task.
Any more help would be appreciated.

Regards

organism7@blueyonder.co.uk

Actually MainConcept's MPEG card suggestion is for a playback card, not an encoding card. I have one that came with my Creative Labs DVD drive, the DXR-3. When using CL's playback software, it unloads the decoding job to the card instead of bogging down the processor. The card also delivers real NTSC composite and S-Video signals to drive a television. It's very handy for viewing DVDs and MPEG files (oddly enough it won't play AVI files though).

This particular card has an unfortunate bug in that the software refuses to play the last 4 seconds of a file.

As Chienworks said, my recommendation was for a playback card -- a fast, easy way to immediately check MPEG files.

Our encoder is certainly up to the task you mentioned. Bear in mind that a hardware encoder is simply a software encoder that's embedded into hardware. There is no quality gain -- the goal is to achieve better speed. However, with today's processor speeds, that advantage is disappearing FAST.

It was definitely a misunderstanding -- our encoder is designed for tasks like yours!

MainConcept Tech Support

Hmm.... Thanks for the feedback, again.

After reading the Mainconcept Tech Support reply, I can only assume that I must be doing something wrong somewhere. Human error strikes again!.
I was so disappointed when my attempt to render my 2 hour video into an MPEG2 file, using the Mainconcept codec, failed to work properly.
I have rendered other DV files using the Mainconcept codec, about 60 minutes in length, and I have to say that I thought the quality was perfect.
In fact the animations and titles as well as the video were pixel perfect!
When rendered as just plain DV files the text and animations tended to develop stray artifacts around the edges, particulary on text.

So, I would like to continue using the Mainconcept codec.
I am using the default settings in Vegas (Version 3.0c) for making the MPEG2 files.

Save as Type: Mainconcept MPEG-2
Template: DVD PAL

The only thing I have modified in this is to change the Field Order to Progressive.
This has worked perfectly with 60 minute movies, so why not 120 minute ones?
Do I need more RAM, or should 512MB be enough?
This is driving me mad.
Any more ideas appreciated.
Thanks.

Regards

organism7@blueyonder.co.uk

organism seven, differences in source material will make more difference in the quality of the output than most people realize. Scenes with softer, blended colors will encode much better than scenes with harsh and sharp edges. Light scenes will often look smoother, but require higher bitrates than dark scenes. Fast action will often break up on playback. So what you have in your video is probably more responsible for any problems you are seeing than the length of it.

If you've got the time to experiment, try encoding your project as two separate 60 minute files and you'll see that they will probably be just as objectionable as the full 120 minute file.

Hi Again,

When you say that the two-hour render failed to work properly, do you mean that there was an error which prevented the encode from finishing? Or do you mean that it finished but you are commenting on the quality?

Hi,

The rendering completed successfully, but when played back I noticed
that skipping was occuring. Very brief, but very noticeable.
The audio was also affected at these points.
The only way I can describe this, without providing a sample, is like this:
It is as if the encoding process got exhausted at certain (irregular) points and frames were missed out or mistimed (for a duration of about a half to one second), but it then seems to recover itself only to get tired again and repeat this glitch at other points further along.
I hope you can visualise this. Does that help explain my problem?
Thanks.

Regards

organism7@blueyonder.co.uk

Where are you seeing the skipping -- when playing back on a computer or a standalone DVD player?

It's my understanding the PowerDVD displays fields properly on a computer monitor, showing a full 60 fields per second. True? I know of no other software players that do this. It might be the next best thing to an external monitor.

Luxo

>>>It's my understanding the PowerDVD displays fields properly on a computer monitor, showing a full 60 fields per second.

that has been my experience. I have watched countless DVDs using PowerDVD connected to an Infocus LP350 projector and never see any interlace artifacts. load up an MPEG-2 file into PowerDVD and no interlacing artifacts are evident. play the same MPEG-2 file in Windows Media Player and it's comb city. :D