Resolution/bitrate for small LCD

[jkleslie]

I've been encoding DVDs for a number of years now for display on the old tube to my current 50in+ plasma and LCD, but I've never actually encoded for something as small as an 8in LCD screen.

My son has grown bored of the few DVD copies I have made that aren't scratched beyond being playable and I refuse to make anymore copies for my wife. She doesn't take care of them and end up in the floor or under a seat, so I started thinking of an alternative (this is for an 8in. LCD mounted in a Chevy Suburban, btw).

I decided to get an inexpensive Tvisto Lite 2.5" media player. I already have the 3.5" version and know that it's good enough to suit the purpose. What I need to do now is find out what resolution and bitrate would be suitable for an 8in screen (std resolution) encoded in XviD with 64-96kbit MP3 audio? I already have a 2.5" 60GB drive for it, so I want to be able to fit as much on their while maintaining decent enough quality.

The only reason I'm asking is because I'd like to go ahead and start encoding so that when it arrives, all I have to do is load it up. I've just never done anything on that small of a screen before.

Thanks!

Jon

[redwudz]

Apparently it can use these formats:

Video:
MPEG-1 (AVI, MPG)
MPEG-2 (AVI, VOB),
MPEG-4 (AVI, DivX, XviD)

Audio:
MP3

Photo:
JPG baseline and progressive up to 8 mega pixel

I would try Xvid with MP3 audio. The resolution would depend on the specifications of your playback device and the desired filesize. It would be the same with any storage unit that outputs video. You could use MPEG-2 at DVD quality and 5.1 Dolby audio. But that would take up a lot of space.

For Xvids, try AutoGK to do DVD conversions. The resolution doesn't make much difference with the file size, but bitrate does. Try a few test encodes and see how far you can drop down the bitrate before it becomes 'unwatchable'.

Easiest would be to rip the DVDs to your computer hard drive, extract the MPEGs with VOB2MPG and use that. You won't get a lot of videos on there, but it would be quick.

[cd090580]

Try to encode your videos at the native resolution of your screen.

I do that for my portable video player and they look great on the screen (of course, they will look like crap when viewed on a normal tv)

[jkleslie]

Apparently it can use these formats:

Video:
MPEG-1 (AVI, MPG)
MPEG-2 (AVI, VOB),
MPEG-4 (AVI, DivX, XviD)

Audio:
MP3

Photo:
JPG baseline and progressive up to 8 mega pixel

I would try Xvid with MP3 audio. The resolution would depend on the specifications of your playback device and the desired filesize. It would be the same with any storage unit that outputs video. You could use MPEG-2 at DVD quality and 5.1 Dolby audio. But that would take up a lot of space.

For Xvids, try AutoGK to do DVD conversions. The resolution doesn't make much difference with the file size, but bitrate does. Try a few test encodes and see how far you can drop down the bitrate before it becomes 'unwatchable'.

Easiest would be to rip the DVDs to your computer hard drive, extract the MPEGs with VOB2MPG and use that. You won't get a lot of videos on there, but it would be quick.

So what you're saying is that a 1h15m movie at 400Kbps w/64Kbps MP3 @ 320x240 is going to look just as crappy on a 8" LCD as it would on a 37" LCD?

All this is for is to keep a 3 year old entertained while he's on the road (most every day for a couple hours, at least. He's not going to be real picky , but he's not going to be happy watching a bunch of colorful blocks that only sound like his favorite cartoon characters, lol.

What I'm doing right now is loading a dozen or so that I had already converted for my Media Centers at home into Dr. DivX, using the mobile profile (320x240/64Kbps MP3/400Kbps DivX). I'm just wondering if they'll be passable on a standard 640x480 8" LCD.

I'd like to encode at the screen's native display, but I want to keep the file sizes low. 400-500Kbps is going to look horrible at 640x480. Then again, blowing up 320x240 to that resolution may not be any better. I think there's still something for me to learn in there somewhere.

[jman98]

While I understand why you wanted to ask for advice, the truth is that what one person thinks is unacceptable may be OK to you or even a 3 year old kid. Try various settings and see what you think. I would suggest using a size close to 640x480 with a video bit rate of 700 Kbps and use CBR audio for MP3. I like 128 Kbps myself. VBR audio barely saves any space and can just cause sync problems over using CBR. You should get something roughly equivalent to VCD quality, which may be fine for all concerned.

[jkleslie]

The more I think about it, the more I think you're probably right, jman.

I want to cut too many corners to really be able to tell if one thing is going to be worth it or not. As far as audio goes, I'm pretty well set there. I can go 64Kbps 24Hz and save a lot of space. The car stereo is playing it back, so it's not that big a deal. I'm just going to have to do some encodes and wait for the device to arrive so I can see how they'll turn out. I may even try and hook the 3.5" Tvisto I have up and test it that way. That would probably be my best option if I'm actually going to put this much effort into it, lol.

Thanks for all the advice. I appreciate it.

[cd090580]

No, I was saying that an encode for a portable/mobile device will lokke great on a small screen but look crap on a normal tv.

i.e: Mobile 320*240 => very good on the mobile/portable device but crappy on a big tv screen