Is there a way to change field order?

[Bilar Crais]

When playing back DVDs I have burned on the family TV, I am experiencing some flicker with the new PVR-250, and from what I've gathered in an exhaustive search of the web, this is commonly reported.
In addition, I am seeing computer graphics vibrate wildly..especially horizontal lines common in newscasts, or some fonts vibrate as well. I am also seeing some "mice teeth" in other material. I had the thought that maybe the '250 is recording the field order bass-ackwards. Is there a reg key that I can change to experiment?

Thanks for any help.

[Rich A]

Originally Posted by Bilar Crais

When playing back DVDs I have burned on the family TV, I am experiencing some flicker with the new PVR-250, and from what I've gathered in an exhaustive search of the web, this is commonly reported.
In addition, I am seeing computer graphics vibrate wildly..especially horizontal lines common in newscasts, or some fonts vibrate as well. I am also seeing some "mice teeth" in other material. I had the thought that maybe the '250 is recording the field order bass-ackwards. Is there a reg key that I can change to experiment?

Thanks for any help.

Can't help with the Reg Key information, but I do a lot of DVD creation from my PVR-x50. They all play back perfectly. Since I watch them only in a home theater played back with a stand alone DVD player I make sure to NOT use any de-interlacing. For TV playback I've always used interlaced source.

Are upi de-interlacing? If not what is the TV like? LCD, Plasma, CRT etc.?

[Bilar Crais]

Hi Rich...

It's just a 27" CRT. I am using more or less the default BTV DVD profile, and then authoring with TmpgEnc DVD Author.

I'm sure I'll come to something that I'll be satisfied with, but I've just tried WinDVD Recorder, and it gives markedly better results than BTV. I am fairly certain that it is offloading to the hardware encoder, because CPU usage is the same whether you are watching television, or capping full dvd resolution (25-35%). I wish there was a way to disable the preview.

[Rich A]

Originally Posted by Bilar Crais

Hi Rich...

It's just a 27" CRT. I am using more or less the default BTV DVD profile, and then authoring with TmpgEnc DVD Author.

I'm sure I'll come to something that I'll be satisfied with, but I've just tried WinDVD Recorder, and it gives markedly better results than BTV. I am fairly certain that it is offloading to the hardware encoder, because CPU usage is the same whether you are watching television, or capping full dvd resolution (25-35%). I wish there was a way to disable the preview.

There's an amount of customization you can do with the BTV stock default profiles. You can make the mpeg better suited for your needs by copying the dvd profile and then adjusting that newly created profile to fit your application.

Here's what I use.

Audio: 48 khz @ 224000 kb/s sampling
Frame Rate: 29.97 fps
Size: 720x480
Video bit rate: 7,000,000
B-frames per group: 2
P-Frames per group: 5
Noise reduction enabled @ 10 percent
Motion Est. set for 10 percent
Mpeg Stream Type DVD
Variable Bit Rate encoding turned on ..
Base BR = 4,500,000
Peak = 8,800,000

That should give you a minimum of 90 minutes or more per DVD. I generally cut out commercials from one hour shows which leaves around 43 minutes each. So I burn two episodes to a disc and have plenty room left over.

I use DVD-Lab for my DVD authoring. Quite a program. It has advanced features like an NTSC safe color filter that makes sure the colors don't cause problems like bleeding and shimmering etc. It's a wonderful program IMHO.

By the way, I've checked my own BTV environment during recording at the above settings, and my CPU is actually quite a bit lower than yours. Around 3 to 4 percent. I'll have to double check that though cuz it does seem very low. Been a while since I last checked. <Edit> .. oh wait, my system check was with no preview going or anything else running. That could be the diff. <Edit off>

I've also gotten great results from using a 1/2 D1 Frame size, with the over-all bit rates at about half of the full D1 frame. Quality is really pretty decent (if you have a good source) and I can fit about 5 or 6 TV shows per disc.

Let us know if you find any reg. edits that might help. I'd be curious about that myself.

[Bilar Crais]

Thanks Rich. I meant that WinDVD Recorder was showing 25-35% cpu usage. BTV is more like 3-9%.

I am going to give your profile a try, and I think I'll try DVD Lab out as well.

Also, I am curious as to why you went with 10% ME? Most of the suggested profiles have ME at 100%. I'm going to try it...

Cheers,

CF

[Rich A]

Originally Posted by Bilar Crais

Thanks Rich. I meant that WinDVD Recorder was showing 25-35% cpu usage. BTV is more like 3-9%.

I am going to give your profile a try, and I think I'll try DVD Lab out as well.

Also, I am curious as to why you went with 10% ME? Most of the suggested profiles have ME at 100%. I'm going to try it...

Cheers,

CF

Generally if you think back to the "old days" with the ATI software type encoder, it was the general rule to bump up their motion estimation as far as you could, given the speed of your processor. The higher the ME, the better the quality would be. To a point. The problem was that with larger frames and higher bit rates, the CPU was usually over-taxed somewhat. For example encoding the same source with two different CPUs would mean different MEs for each. If one CPU was say a 1K clock then the ME might only go as high as 50 to 60 percent before the CPU became over-taxed. But a 2K CPU might be able to handle 90 percent without a problem.

When the CPU WAS being over-taxed, other areas became problematic. Dropped frames, corruption and out of sync audio could occur if you set your ME too high for your own CPU's speed.

Now as for the Hauppauge PVR-x50s, well they don't use hardly any CPU. The encoder is like it's own CPU and does all the mpeg creation. (and that's ALL it has to do) So it's pretty hard to over-tax it. But theoretically you might be able to. I guess it all depends where the engineers who designed that encoder set the limits. I see you can't do better than 720x480, or higher than 12 Mb/s. So I guess HD mpeg encoding would be out of the question.

Given those high end limits, I would imagine you should be able to set the ME at 100 percent and see no ill effects. Regardless of what CPU you were using. So why am I using 10 percent? Frankly I never saw enough difference to make it relevant. At 90 to 100, my mpegs look as good as 10 to 20. Actually the reason it's still at 10 percent is because after recording a dozen or so shows with both 10 and 100 percent I think the last test WAS 10 percent and I just never changed it. Hmmm.

[Bilar Crais]

Originally Posted by Rich A

I think the last test WAS 10 percent and I just never changed it. Hmmm.

I've done that on numerous occasions.

Well I have to say, that's a great all purpose profile you have there. Lots of quality in a little package. I just saved the same profile but changed it to half DVD res. I don't know if it's my imagination, but 1/2 res captures seem to look a good deal better than full DVD caps on the ol' CRT.

I've also tried DVD Lab...quite an impressive product. I'm not sure, but I think it also took care of a flickering problem I was having!

[Rich A]

Yes DVD-Lab is quite something. He let's you play for 30 days with the full product .. no nags etc. I forgot to mention on the compile screen he has options for not only the color thing but also something he calls "remove jitter". If you had that checked, that may have helped.

It is really a "lab" for dvd creators. It's cool to do menus that have motion and transitions between menus and stuff. Of course it can also be as simple as you need.

I only have the "standard" version as frankly it does everything I need to do and then some.

Oh check on the forum page. He is one of the few authors I see who actually spends a lot of time in the user forum. You might want to check there for updates and such. He just added a new "record" to his program. This one recognises most of the modern DVD and CDR burners. It's nice that you don't even need a burning program .. (like Roxio or Nero) .. it even does the burn for you if you select that option.

[kd5dea]

Hi,

I was wondering if you could point out where these profile files are stored. Are they INI files or what? Do you just edit them with any editor?

TIA,
Rob

[Rich A]

Originally Posted by kd5dea

Hi,

I was wondering if you could point out where these profile files are stored. Are they INI files or what? Do you just edit them with any editor?

TIA,
Rob

It's simplier than that. You do all the creation or editing in the Web Admin. screen. In the "recording" section you can make copies or edit the profiles listed. There are quite a few "stock" profiles that are part of the SS install. I choose to first edit one then save as a NEW COPY. Thus leaving the originals intact.

<edit>

Just got home .. and thought I'd post the step by step for you. The options for the profiles are going to be different depending on whether you have a hardware encoder or software encoder. At the bottom of the list, you should see an "Advanced" option to click on. This will give you the ability to set Variable Bit rate options (if your encoder is capable) plus other things like GOP frame sizes etc. Follow this route:

Web Admin:
Configuration
Recording Pref.
Next to "Default Quality" click on "List all Quals"
Find one near to what you want and then:
Click on "Edit"
Lastly, when done .. choose either Save Changes (modifies the original) or
"Save as new" (creates a new profile using your newly modified original with the changes)

I would only putz with the various registry settings and any INI's etc. if I were aware of the potential consequences. Everything you "really" need is available to the users via the route as listed above.

<end edit>

[kd5dea]

Thanks Rich!

Rob

[Rich A]

Here's something I found, that you may be interested in.

Before burnable DVDs were available I was doing a lot of "mini-DVDs". That is a normal DVD Title Set with full menus, chapters etc., but burned onto CD-R. I purposefully bought a Sampo stand alone DVD player that was touted as being able to play anything on anything. CD-RW, DVD-R/W etc. With VCD SVCD and of course DVD and MP3 etc. I still have it and works fine.

I found I could use the 1/2 D1 DVD format with just the right bit rates etc. and could fit about 45 minutes onto a 700 Mb CDR (with a little over-burning) Between 45 and 42 minutes is what's left of a network one hour show after you get rid of the commercials. So this worked great for archiving all those Star Trek shows and such.

DVD Lab has an option to burn a "mini-DVD" rather than a DVD. It's burning application does it all automatically, and burns the DVD Title Set straight to a CDR if you so choose. Back in the day, we had to do other things to get this to work.

Another thing that DVD-Lab will do is to accept SVCD proper Video to be used for DVD burning.

I made up my own special profile using SVCD frame size (480x480) and higher than normal variable video bit rates AND set the audio to 48 kHz instead of the normal SVCD 44.1. Then burned my "hybrid SVCD DVD". Well I have to say, the resulting video was in a word .. outstanding. People watching it all thought it was a store bought commercial DVD. In fact the most common question was, "Where the heck did you get a DVD of THAT show?"

Although my 1/2 D1 (or 352x480) was pretty darn good, the SCUD frame size (with DVD parameters) just blew it away. I "think" the extra res of 480 vs 352 plus the higher bit rates I was using probably made the difference. I did that for some time .. It was very cool as by using DVD-Lab to author this "Hybrid SVCD DVD" I could still have a normal playing and looking playback with menus, buttons, chapters and such.

Of course you had to have a DVD player that would decode SVCD that was written on a CDR or DVDR. That's why I bought the Sampo 620. Then the cost of DVD-Rs and the burners came down to a point where it was just as economical to burn a "real" DVD. And that's what I've been doing since.

As an experiment you might try making a custom profile using variable bit rate with SVCD sized frames and 48 KHz audio. Then use DVD-lab to burn it as a "hybrid DVD". You'll use less megabytes and the quality will surprise you. If I recall I used a target video bit rate of around 3.2 Mb/s.

Well .. there I go again .. Digressing all over the place. Well this is sorta all about various video types and fields etc. .. sorta eh?

[kd5dea]

Rich,

I asked this in another post but have'nt got an answer yet. I see you have variable bit rate enabled. I've seen where others have it off. What are the advantages/disadvantages of variable versus a constant bit rate?

Thanks for all your great info! It's not digressing to me.

Rob

[Bilar Crais]

Yes...very interesting! My Pioneer standalone plays SVCD's, but they can be a bit dodgy at times, playing 3/4 of the way through and then locking up.
I download SVCD's from Usenet frequently, so it's nice to know they can be made burned to DVD.

Before I bought the BTV/PVR-250 and a DVD burner, I had an 8500DV. I found my captures to be much better at 352x480 than 480x480, and I burned them as SVCD's using VCDEasy. I don't think I would want to return to the 8500 now though.

[Rich A]

Hi Rob,

I hope you don't mind reading. This is long, but I've tried to give you the important points based on my own real world experiance with Mpeg encoding.

Variable Bit rate video encoding can make the video better AND also smaller. You might ask how the heck can making the total size of the mpeg smaller, result in better video? First you have to understand what variable bit rate does.

As it's encoding, it examines the video and adjusts the video bit rate accordingly depending on the scene content. If you had something like a "static" scene, like a news reporter just reading the news, and the background and everything else (except for his face) was more or less not moving, then whether the bit rate was 1 Mb/s or 9 Mb/s .. the playback would be the same. I'm not talking about "quality" in the sense of picture quality ... but more about the playback quality. By that I mean a lack of motion artifacts. Motion artifacts show up as "blocks" in the video and jerkiness, or stuttering. (Note . there IS also an actual picture quality improvement by going to a higher bit rate, but it is not usually noticable, unless you were being very critical)

The reason for raising the bit rate in mpeg encoding is mostly to reduce those problems during playback. Given the same source material, if I were to make a ten minute video of something like a painted picture .. it could be done at 1 Mb/s or 9 Mb/s and the thing would play the same quality but the 9 Mb/s version would be MUCH larger in file size.

Now the problem with Mpeg encoding at CBR (constant bit rate) is that you have to fix the bit rate at the highest level dependant on the highest motion scene. So maybe 45 minutes of your one hour video is nothing but "talking heads" with minimal "action" scenes and 15 minutes are comprised of scenes of high motion .. like a car chase or explosions. 45 minutes of that video is being recorded at a MUCH higher bit rate than it needs to be. The result is you are sure to see the high motion scenes play back smoothly without error, BUT the over-all video will be much larger than it really needs to be.

Some people swear they get better results by using CBR. But I'm going to suggest that they just haven't set the VBR parameters correctly. Given the proper environment and settings, I bet they would see no difference between the two (other than one being smaller MB wise) Most likely they are over-taxing the encoder .. (read setting vbr parameters higher than a "software / CPU" based encoder can handle) More on that later.

Of course where VBR really shines and saves you a lot of file size space, is if you have a video that has lots of high motion scenes as well as low motion scenes. Like an action adventure flick.

To do VBR correctly you have to find out the best parameters to use. These can vary from show to show based on the motion in those shows. But you can find an overall average that will work out for all of them. Things to work on are the "base" video rate and the "maximum" rate.

Some encoders work differently than others, but I believe the PVR-x50's use the base rate as the starting point and of course make the max rate just what it is. During the "swings" up and down there can be minor excursions above the maximum and large excursions below the base. So if you are doing something that is going to be used to make a "compliant" medium (like a DVD) you should take that into account. The DVD max rate is around 9 Mb/s. Some players can handle short burps slightly above that without problems. Some can't. It's why I set my max at 8.8 Mb/s. After examining the video I very seldom see high end rates over 9 mb/s at that setting.

So let's say you have the average set for 4.5 mb/s and the max at 8.8. Here's what will happen. The thing will encode at 4.5 (on average) .. If it senses a very static scene it will drop even lower. I've seen my videos drop to as low as 1.1 MB/s. If there is a fast action scene it will raise the bit rate. In my experience the Hauppauge hardware encoders are very "aggressive". That is a good thing. That means they do a good job swinging the bit rate to match the scene. This is hard to do with real time encoding. The advantage the PVR-x50s have is that they are using their own processing hardware engine. Sort of like a 2nd CPU that is dedicated to only mpeg encoding. This results in your actual PC CPU just loafing along like nothing else is running.

Let's take a fast action scene show. You might have to set your CBR as high as 6 mb/s to insure those fast action scenes will be error free. Even at 6 mb/s there might be some areas where it really needs to be higher. But it's only a few fractions of a second during playback and you mostly don't notice it. Because of CBR you are wasting a tremendous amount of disk space in that you are ALSO encoding even the lowest action scenes at the 6 mb/s. Where guys make the most common mistake is that when they switch to VBR they use the same parameters as their old CBR. Like maybe a max of 6 mb/s. They've narrowed the "window" of swing for VBR which hinders it's aggressivness. They would be better off setting the max to 8 or 9 mb/s instead of 6 mb/s.

Some encoders are better at VBR than others. Some are severely hampered because they are not using a dedicated hardware encoder. The ATI mpeg encoder is really a very good CPU based encoder. (it uses your CPU and has no hardware encoding) I have found that if you have the CPU horsepower it can do an incredible job. But when you have a weaker CPU, it can easily become over-taxed and a VBR encoding can be worse than CBR. Remember, with CBR there is no adjustments being made to the video bit rate. Therefore with a software / CPU based encoder, it would be easer to do a CBR of say 6 mb/s as opposed to VBR with a max of 9 mb/s It all depends on your CPU and overall system power in general. FWIW, I HAVE recorded with video bit rates up to 15 Mb/s with my old ATI AIW Radeon 9000 with excellent quality and no dropped frames. But that was with a highly optimized 3.2 gHz computer that I mainly use for video editing.

Just an additional note .. commercial DVDs are of course not using real time encoders. They use software encoders that do multiple passes. Because these encoders are not limted to having to work in "real time" they have all the time in the world to examine and adjust bit rates .. and then do so in multiple passes. Therefore the high bit rates are really high, and the lows really low. But they don't stop there. Usually they add the "human" factor. They have a guy (called a compressionist) who examines the video where things are really hairy .. like multiple explosions or where scenes are really static .. like a 60 second view of a street sign or something. Then he makes further adjustments. That's why those store bought DVDs always look good.

More on other VBR engines: Those appliance boxes like ReplayTV and TIVO also use VBR encoding. However the engineers have set the parameters to be very conservative. They use VBR just to insure the high action scenes record okay and gain a little space saving on the low motion scenes. But the max and average set bit rate are very close to each other. So there is NOT a lot of bit rate swinging. You can see this if you examine the mpeg produced by them closely (I've off-loaded their mpegs and actually ran all kinds of tests etc. on them) Find a really high action scene that was recorded with ReplayTV's highest quality and if you look frame by frame you can almost always see motion artifacts. These are hard to see when viewing them normally. Where they do show up is when you are looking at the video in your home theater projected to an 8 foot screen.

You will notice that because the VBR settings are so conservative that most of the shows recorded are almost exactly the same size. This is one of the reasons they use such "conservative" VBR settings. Those devices work in a human environment where the amount of space left for recordings is based on time. Ie, you have 4 hours of recording available at high quality. Now if they had set the parameters to really be aggressive, then the hourly size of each video would vary too much and they could not accurately compute the amount of free hours left for recording.

I've recorded the same show from both my ReplayTV and the BTV (PVR-350) at the same time. The ReplayTV mpeg was 2.3 GB. The BTV mpeg was 1.2 GB. And the BTV was far better quality and playback. That's why a properly set up VBR (with a hardware based encoder) is the way to go.

The Hauppauge PVR-x50s have a great VBR encoding engine. You can't over-tax it as it's set upper limits are 12 Mb/s. You have a lot of area to play with.

Software (PC CPU) based encoders are very dependant on the CPU's power. You have to be careful not to go beyond your system's capabilities when setting VBR paramenters. VBR takes much more processing than CBR. Because of this, sometimes you will get better results using CBR at a higher bit rate than VBR (when dealing with a software based encoder). But the trade off will be disk space. Of course if you have a wiz bang 3 gHz CPU, some of the software based encoders can do surprisingly well.

Last tidbit .. Mpeg-1 encoders are optimized for low bit rate CBR recording. Mostly below 2 mb/s. Mpeg-2 encoders are optimized for high bit rate VBR recording, mostly above 2 mb/s. Generally a well encoded Mpeg-1 CBR video at VCD rates ( 1.1 mb/s) will look better than the same thing encoded with MPeg-2 at CBR or VBR with the same bit rate. The "encoding" algorythms for Mpeg-2 are designed specifically to take advange of variable bit rate encoding at higher bit rates. When you use an mpeg-2 encoder at very low bit rates, it can't make use of it's advantages. It's not optimised for that low a bit it. Mpeg-1 however is optimised for the best CBR encoding it can do at under 2 mb/s

Sorry for the long winded dissertation. You asked .. and I just can't ignore a good question.