MVP and AVIs

[Spartan]

SUCCESS!!! I finally got my AVI playing with audio that is not out of sync. And It can be done with Auto GK. My video was encoded at 29.97 fps, with XVID as the video codec and MP3 audio. If your using Auto GK you need to press F9 (In the current beta release) and specify the frame rate. As well as check some other settings to make sure they are correct for your country. I'm going to re-encode my collection of AVI's so I get proper playback on the MVP. Now my son can watch Thomas the Tank Engine out on our playroom/porch. I'm really impressed with GBPvr, the MVP, and the users of this forum. Thanks for the feed back, suggestions, and help. I could not have fixed my AVI issues without your help.

Awesome -- I have been working on this off and on myself for a bit now, with little success. Care to put together a cheatsheet?

I am mostly interested in making my own divx conversions of both mpeg2 broadcasts and raw avi (dv home movies).

Thanks!

(By the way, just when do you hit F9? I can't seem to figure that one out)

EDIT: I see that it's CTRL-F9

[LilY0da]

What settings did you use for XVid? I'm not used to it, so any clue appreciated...

[dgeezer]

LilY0da, you da man!!!

I have tried for months to get the avi movies that I have on my laptop to play over the MVP. I've tried converting to mpeg using diko and mainconcept but no luck with either one. Resizing thru virtualdub is simple enough for even me to do.

So far everything I have converted has played perfectly. Now my daughter won't have to watch her old disney movies on the laptop anymore.

Thanks again.

I've used divx 6.0 "home theatre setting" as my codec choice with good results so far. I am going to try one using xvid and compare my results. I'll let you know which works best for me.

[A_Brass]

(By the way, just when do you hit F9? I can't seem to figure that one out)

EDIT: I see that it's CTRL-F9

Yeah sorry I was typing so fast that I didn't put the correct shortcut in my post.

If you still need the cheat sheet I'll try to write it up tonight. (At work now). It's not too hard but if you use Auto GK it's going to make lots of assumptions. (I think). Because you can reduce by size, it will automaticly drop fps, quality, size, or other things to achive deisred file size. I'm not sure what the effect of forcing different settings will be. ie: forcing 29.97 fps might cause larger then desired file size.


Something that bothers me. I thought for the human eye/brain to perceive fluid motion, you needed close to 30 fps. Why does 23.xx look just as good? Do I need a new pair of eyes?

[Spartan]

Yeah sorry I was typing so fast that I didn't put the correct shortcut in my post.

If you still need the cheat sheet I'll try to write it up tonight. (At work now). It's not too hard but if you use Auto GK it's going to make lots of assumptions. (I think). Because you can reduce by size, it will automaticly drop fps, quality, size, or other things to achive deisred file size. I'm not sure what the effect of forcing different settings will be. ie: forcing 29.97 fps might cause larger then desired file size.


Something that bothers me. I thought for the human eye/brain to perceive fluid motion, you needed close to 30 fps. Why does 23.xx look just as good? Do I need a new pair of eyes?

Yea, a cheatsheet would be great. I let AutoGK convert a couple of movie MPEGs that were created via DVD2MPEG, and the results were much less than stellar (audio & video off by 5 sec, odd aspect ratio, etc).

I guess what I am looking for is:

- Settings in AutoGK to create XviD files (fps, resolution, anything else?)
- Codecs you use to display the XviDs on the MVP (and how to determine which ones are used -- I just can't seem to get my arms around this). I've checked out GSpot & graphedit a little and really don't understand what I am looking at.
- Do you use FFDshow or not? If so, do you use the settings specified in the hyperlink a few posts up?
- Any other good info!

Thanks!

[groover km]

Regarding framerate (and IIRC)...

Movies (film) were/ are shot at 24fps; this was an original specification tied to the reaction speed of the film, the mechanical operation of the camera/ projector, and the fact that 24 is a number easily divisible/ multiplied (the same way that time is 24hrs, 60 mins, 60secs). Bonus - the human brain retains the image at this 24fps and sees a seamless progression without flickering.

Semi-related trivia for fellow sad folk
Incidentally, all films pre-1952(? The release of "The Robe") were shot in 3:4 ratio which was the standard ratio for 35mm film; also the reason why television adopted 3:4 for compatibility. Widescreen (think: panavision, cinemascope, etc) was a gimmick adopted by the studios in the same way as 3-D, etc., who were fearful of tv killing movies (some things don't change) and hoping to put bums on cinema seats. The film used was still 35mm 3:4, but a matte was used either in front of the camera or projector to crop the image. studies actually show that an image of 3:4 is actually more pleasing (the golden third rule) than 16:9. So next time the sales assistant at the local electronics store says widescreen is more natural, you can point out that actually, no, it's a carry over of a 1950's marketing ploy and has nothing whatsoever to do with image perception, and he might as well try and sell you cardboard 3-D glasses made out of sweetie wrappers)
(while your wife sinks into the ground in embarrassment next to you)
(or maybe that's just me)

Anyhoo, back to fps...

In a rather handy coincidence, the refresh rate of TVs is tied to the incoming frequency, so for PAL countries (again, IIRC):

50hz frequency with interlaced image = 25 full frames/ sec (approx)
(close enough to 24 fps to get away with, and the reason why you'll sometimes see a disparity between theatrical running times and PAL DVD running times of a few secs)

For NTSC...
60hz frequency with interlaced image = 30 full frames/ sec (approx)
(which is when you have to get into fancy 3:2 pulldown, repeating images, etc, to make it balance - you can sometimes see this, in horizontal pans or titles that come in from the side as a slight judder or jerkiness)

So there you go, you don't need new eyes, and that's (basically) the reason for the different framerates between PAL and NTSC.

(I'm not always, this boring, honest!)

[A_Brass]

Regarding framerate (and IIRC)...

Movies (film) were/ are shot at 24fps; this was an original specification tied to the reaction speed of the film, the mechanical operation of the camera/ projector, and the fact that 24 is a number easily divisible/ multiplied (the same way that time is 24hrs, 60 mins, 60secs). Bonus - the human brain retains the image at this 24fps and sees a seamless progression without flickering.

I hope you went to school for this? If you learned this on your own you either read too much or have way too much free time

So, if 24fps can be recognized by the eyes and brain as "seemless" why bother with more. For instance FPS (First Person Shooters not Frames Per Second) games. Everyone goes on and on about how many FPS they can run Doom3. Can you actually see more detail at higher frame rates?

To tie this back to the thread, why would GBPVR play a 23fps video fine on the server, audio in sync, no flickering looks great, but the GBPvr MVP transcode process cant get it right. Hauppauge has some way arround this issue with the stock MVP client. I know Sub has no internal working knowledge of the MVP transcode process, and I'm not trying to imply he should. I'm just wondering.

Actually while I'm wondering, I wonder if my AVI's that will be re-encoded to 29.97 fps will work better on other platforms. Such as a portable video player. I would expect they they might. Has anyone tried the same files that play nice with the MVP on other devices? Archos, Smartdisk, Creative?

Now I'm having a good idea. Lets try to cram GBPvr into a portable player. Sub can call it -- GBPvr-To-Go. As if we don't ask him for too much already.

Ok, I'll stop now. I'm just not right today. Sorry.

[A_Brass]

Ok quick run down on Using Auto GK to get a MVP playable AVI File.

Download and install Auto GK 2.15b (When I just ran the program it says a newer version is available). It includes everthing you need including Xvid. But you can use Divx if you have it installed.

Just follow the steps as it shows on the auto GK screen.

1. Select input file. I started with a Mpeg2 file in this case but Auto GK can accept DVD, AVI(DV), Mpeg, and some other input files. Name the output file.

2. Select the Audio and Subtitle if needed.

3. Select the target size or quality

4. Advanced options. -- I have decided to use the advanced menu to change the audio to MP3. I'm hopeing to use my AVI's on a portable player soon, and most of the ones I have seen don't support AC3. You may or may not want to change this. You can also specify the resolution. I have let Auto GK take care of this in the past but since MVP's need one of two resolutions to fill the screen it might make sence to change it.

Ok almost done.

Now hit CTRL F9 The Hidden options screen pop's up. This is where you can tell Auto GK your FPS as well as a host of other options. The only one I changed was FPS. For NTSC users you want 29.97fps. Hit "OK"

Click on "Add Job". now set up your next file and click Add Job when ready.

That's all I did. If you already have an AVI file that needs to changed to 29.97 fps you will need to use VirtualDub. I tried to use Auto GK to change the FPS on a previously converted AVI and it didn't work.


Playback on MVP:

The first few times I created AVI's with Auto GK It reduced the resolution to 5??x4?? (different for each video) So I use FFDshow with my GBPVR to get proper display on the MVP. I use the resize function, to get it to 640x480. But I set the "keep original aspect ratio" option. Set like this it looks great on the MVP and does not have any Letterboxing. Unless its a 16x9 video.

One word of caution, when I was using Auto GK with FFdshow configured as noted above, the tray Icon would appear while Auto GK did its thing. I'm not sure what affect it has so I stoped everything and disabled FFDshow.

I hope this helps anyone trying to use Auto GK to make there AVI's.

[Spartan]

Thanks for the write-up! I am converting a recording as we speak. I have one question about the target size / quality. I wasn't sure what to put here, so I told it to process at "75%" quality. What do you use?

[A_Brass]

I wasn't sure what to put here, so I told it to process at "75%" quality. What do you use?

I reduce by size. So a full lenth movie I try to get down to 1CD or so. In case I want to back it up later. For a 1hr of tv I use 1/2 CD and a Half hour TV I use 1/4 CD.

It seems to fit about right. Quality looks good but this was before I started to force the FPS and resolution. I'm not sure what effect that will have on my next convert. I'll let you know. I'm going re-convert the Increadables tonight and compare it to my previous AVI. I expect that if you force the fps and the resolution the only other place it can shrink file size is the quality. I hope it doesn't go down too much, or I'll have to start making bigger AVI's.