Ok the HP hx4705 pocketPc isn't exactly cheap, but it has some pretty impressive video specs: 4" True VGA screen powered by an ATI Imageon graphics chip. I decided to try and figure out what this hardware combination could really achieve in the mobile video department...
Now I've tried playing video on my pocketPc's before. It made for a pretty impressive demo on my original Ipaq, and I've done a little bit on my Dell Axim x5, but overall these machines didn't really have the horsepower to do anything fancy. If you wanted to get video to work you needed to encode your sources down to a very low resolution with a low framerate. That was a lot of work for not so impressive results. Boy how things change.
Lets start with the video app: BetaPlayer. In the begining there was pocketDivx based on the open Divx code. This projected stalled out and was picked up as pocketMVP. This also stalled and was ported to what is now betaPlayer. Betaplayer handles most mp4 video including Divx and Xvid. There are also plugins for wmv and other formats. The latest (unstable) versions of BetaPlayer support the accelerated ATI chipset found in the VGA Ipaq 47xx and Intel chipset in the Dell x50v. The claim on both these devices is the ability to play full resolution / framerate and bitrate Divx files! Imagine the possibilities.
So now for the test. I installed the latest unstable BetaPlayer build on an hx4705. I verified in the options that the ATI Imageon chip was detected and enabled. Then I tried a sample clip downloaded from their site at 640x480 24fps 1500kbit/s 2-pass Xvid. It was amazing! I could rotate it and play it full screen. The video was perfectly smooth without a single dropped frame. Now for the real test, how would it handle a homemade Divx encode of a full movie? To find out I copied a full Divx backup CD (700Mb) to a CF microdrive and gave it a go. The results simply amazing! I watched about 30min of a 100min movie with no skips stutters or sync problems. The quality of the image on the VGA screen was very impressive.
Summary: If you have the hardware you no longer need to transcode down in order to play Divx movies on the small screen I've discovered a use for my older Divx backups, Betaplayer is pretty full featured, it will even scale the image in real time so you can force a wide screen movie to fill the screen for example. The file size of a full Divx movie may be an issue for some, but those 1g flash cards are getting very cheap these days. Or here's one for you, if you are around the house why not skip the memory altogether and just stream the movie via wifi? I tried just that, I popped in a disk, shared the drive and fired it up. Your mileage may vary depending on the strength of your wifi connection and the bitrate of the movie, but I was able to play a typical bitrate movie no problems. Not bad.
I started laughing at the point you said, "... I installed the latest unstable BetaPlayer..." imagining what was going to come next: "... and then all the power in my house went out...".
Well you know how personal dev projects are.. you get things working up to a certain point and never bother to go through remaining 10% of work required to do a proper test / release cycle. In all honesty, the 'unstable' version of BetaPlayer is much much more stable than the 'released' version of PocketMVP I used to use.
This is cool, since my iPaq stylus holder (finally) broke today so I'm going to be in the market for a new PPC. Watching video on the shuttle would be really cool. I could divxify all my futurama DVDs...
Heh, coincidentally, I also installed BetaPlayer this weekend on my ancient Toshiba e355. I'm still transcoding my old Divx files using a super one-button program called PocketDivx Encoder.
http://divx.ppccool.com/
But the results are awesome! It's real easy to do and now I've got my flash card full of cartoons for the kids to watch on the long flight home.
Cool stuff! My old overclocked celeron 300A can't even play that stuff! What do you think battery life is like? I wonder if a flash drive would use less power than a microdrive? Batteries seem like the biggest bottleneck, given that we have the handheld storage and horsepower. In the car or airport, you could plug it in, but on airplanes, power is still hard to come by.
A guy over on the pocketpcthoughts forum says he gets 2 hours 15 minutes of microdrive video with the bluetooth headphones going on a single battery. That's not bad. He always carries a second battery with him though. I agree about the flash. I orderd up a 1m 60x sd. The microdrive is great for music where it can spin down while the song plays but video is another story. Battery life will also depend on the brightness of the display.
There's a pretty slick way to deal with the battery life issue when traveling. 4 AA rechargable batteries in a holder wired to a barrel connector can be used to recharge and/or power your pda. Here's a review of one such device:
http://www.the-gadgeteer.com/ipowerpak-review.html
I built my own using stuff I had on hand but the parts would be about $5.00 at Radio Shack (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=270-409 + a little wire + connector). Before you build your own, a little googling is recommended as a few devices require slightly less voltage. For those devices I believe a diode can be wired in series to provide the necessary voltage drop.
I use this setup when I travel as I always carry a few sets of recharable batteries and a small travel charger for my digital camera. I don't even bother to bring a real AC adapter for my PDA.