I'm just curious about how well bigger avi's work on the GP2X. For instance, 700MB avi's. My digital camera ouputs 640x480 MPEG-4 videos.

I read that alot of people like to re-encode the video to 320x240 for better playback (and battery life?) and smaller file size, but if I were to use a portable device for movies, I don't want to bother. I like the Zodiac for that reason.

What sort of bitrates are reasonable? I'm not looking for specs on paper here, just hoping for real world experience from owners of the GP2X. Thanks!

The scaler works fine, and except on one SD card that is ridiculously slow I haven't had any trouble with skipping video due to file sizes being too large. Battery may or not be an issue depending on the set of batteries you buy and how long you need it to last, I haven't done any benchmarks for battery life on high-res videos.

Thanks for your response but I also wonder about the bit rate as it pertains to the processor's capability to handle it and not so much about SD card transfer rates. I didn't even think about that. I just assumed the SD card could keep up!

Video playback has been very smooth for me at high bitrates, so I think the SD card read limit will kick in before the video decoder maxes out, at least on most SD cards...

I have to say that pocketdivx encoder does such an excellent job that I never hesitate to quickly reencode videos. I use settings that can encode whole movies in minutes (hint: single pass is fine). The benefits:

• smaller size
• no dropped frames
• no audio sync issues
• you could probably underclock the 2x and still have them play fine (more battery life).
• no noticeable degradation in quality

I know the benefit of the 2x is that you don't have to re-encode, but I've found lots of skipping and audio-sync issues when using "raw" content. It's totally worth it. Even if only for the size reduction. Nothing like 3 movies on a single 1GB SD.

I've had success with PDE as well... but would you please list the settings that you use, so that I can compare them to mine and possibly improve my results? I remember that I use the iRiver with a few tweaks. Thanks.

Here are the settings I use. The result would be: a typical hour show (40 minutes without commercial) would be about 150MB & look and sound fine on the little player.

My PDE Settings
Device = Archos AV400

Output Options
==============
Video Quality = 23 (bitrate 402)
Audio Quality = 6 (44100, stereo, 96kbps)
brightness = +6% (may not be necessary)
all other = 0%
output = 320 X 240 (for widescreen, keep width at 320 and have smaller height)

Advanced video & audio options
==============
EVERYTHING UNCHECKED, except:
VHQ
Audio Normalization (may not be necessary)

Notes:
There is a temptation to not reencode the audio (by selecting "direct audio stream copy"), but re-encoding audio has done wonders for audio-sync issues.

402kbps bitrate may seem low, but is perfectly acceptable on the small screen, except for real fast motion. If you want to improve quality and time isn't an issue, then go for 2-pass encoding instead of greatly increasing that number.

Setting audio to 7 will bump it to 128kbps. I don't mind 96 for tv shows etc and it saves some space.

The instruction set on the wiki for encoding video using avidemux is pretty good too. I've used this and also get files down to ~300 MB. the GP2X is 320x240 resolution, so it's not advantageous to watch movies with a higher resolution on it.
http://wiki.gp2x.org/wiki/Video_Encoding

What about if you're using TV out ?

Thanks for taking the time to write this out. In return, I whipped up a little Megaman avatar for you that's at a better resolution than the one you currently have. Enjoy.

Look at me! I'm running! I'm running!

Thanks



Depends on the TV. If it's a "TV" (big heavy tube thing 20-27"), you won't notice the difference. But if it's all fancy and really big with svideo in, then you you would notice the difference. But if you're SD card's too slow, and the video's choppy, that'll look worse than the downscaled, but smooth, version.

I prefer a divx-enabled dvd player for TV-based viewing personally. They're so dang cheap now.

The GP2x has a hardware decoder that seems pretty good for High Bitrate files, how high a bitrate are you thinking of?


No offense, but you must have bad eyesight :S I can fault any video under 768kbps, usually easily under 1Mbps, at 320*240. I have to stick to 512k for space restirctions though

1-2 Mbps

I'll do a few tests with mine tomorrow. Ill try a 1Mbps file at 640*480, and same for 1.5 and 2Mbps.

Oh wow. Thanks for going to the trouble! I appreciate it greatly!

Actually, for the record, I have ridiculously good eyesight. On a PC screen I can also notice lowbitrate really well. The size and "softness" of the little '2X screen makes the artifacts much harder to detect.

As an example, I watch "One Piece" a lot on it. The opening credits sequence has lots of panning and swooping motion. That looks kinda cruddy with blocking. The show proper is more static, even the action sequences, so I can hardly notice the artifacts. Same with ST-TNG or MST3K. Just saying.

Totally respect the idea of going higher. But if you haven't tried low-bit-rate on the GP2X, it's very forgiving, kind of like an old 13" TV.

I have tried it, but it's not barable. I used settings almost as high as yours on my GP32 . Anyway, One Piece is cell shaded. ST-TNG is live action, there would be a big difference in compression efficiency and quality.

Also, did my tests and the GP2x handles 2mbps @ 640*480 in "Full" mode, and I think thats just because at a lower clockrate the SD read speed is too slow for the files.

Thanks for testing this for me....now if I can find one going for cheap enough on Ebay, I think I might snap it up

Cool, always happy to help.