Author Topic: Video Conversion?  (Read 6561 times)

vidapura

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Video Conversion?
« on: October 01, 2008, 12:11:08 PM »
I'm realy dissapointed that the video playback is so dismal...

Anyone tried converting a divx to the native format for the ONEt to see does it improve?

oldgrumpyman

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Re: Video Conversion?
« Reply #1 on: October 03, 2008, 01:43:24 AM »
Use the free program "Super" to convert DivX to avi.
Of course you'll need a PC to do this, don't expect to do it on the ONEt.
(It's not much of a stretch like some other video conversions,  because DivX is a particular extension of avi)

It shouldn't have escaped your notice that in the manufacturer's own words "The Ingenic Jz4730 is a multimedia application processor targeting for mobile and general embedded devices." 
Little MP4 players with QVGA screens (320x240 pixels) have been the main use of such a processor. Specification:

http://www.ingenic.cn/eng/productServ/App/JZ4730/pfCustomPage.aspx

So when this 336MHz processor (not 400MHz, as being used in the notebook descriptions) is working an 800x480 pixel display and running extra things that you wouldn't get on a pocket MP4 player, it's busting a gut. It simply isn't capable of displaying a full 800x480 video. The Elonex web-page advice is:

Q. I cant view video clips properly.
A. The ONEt does not have powerful graphics decoding hardware so can only play small video clips. You should only play videos at 350x288 pixels at less than 129kbps to avoid jumpy graphics.

When you start up the video player it says:
video size <=350*288
video fps <=25 fps
video bitrate <= 129 kbps
video bpp <= 24 bpp
audio sample <=22.5 KHZ
audio bit rate <= 128 kbps

While 350x288 is the design maximum, it doesn't conform to standard sizes, so choosing less is the first option.
QVGA 340x240 is probably wisest choice for standard aspect ratio  and 320x180 is a good choice for wide-screen.

You can reduce video files a bit further and make the processing load easier for the MPU by choosing mono-sound rather than stereo which you should note must not exceed 128kbps.  (Although certainly use stereo for MP3 only audio files)

Finally, you have to reduce the frame rate.  In the UK we are used to 25fps (PAL TV), but the ONEt struggles with this.
When you are doing the conversion choose to convert to 15fps (or possibly 12.5 fps)
Because the display is progressive, you don't see the flickering that you might experience with shuttered systems, e.g. conventional cinema film projectors would be unacceptable at these frame rates.

I took a near two hour DVD 9GB video (Roger Water's - The Wall Live in Berlin) and converted it to 340x240 15fps with stereo sound at 128kbps.  It came out to 469MB. There are JPEG artefacts in the picture some of the time, such as the plain red background which is very "blocky" during first number by The Scorpions, but the singer is rendered without artefacts,  and it's all completely OK on the next number.  On a 4GB SDHC card you will get 16 hours of such video, enough for many a TV series.

vidapura

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Re: Video Conversion?
« Reply #2 on: October 03, 2008, 12:01:50 PM »
Wow,
thats a seriously comprehensive answer to my question.
I really appreciate it, thanks very much!

I searched for Super and found this page (in case anyone else wants to do this) which has a good bit of info about how to convert the video...
http://www.gersbo.dk/2007/09/use-super-to-convert-divx-video-for-your-mobile.html

Thanks again oldgrumpyman,

Vida

nspur

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Re: Video Conversion?
« Reply #3 on: October 26, 2008, 11:17:38 AM »
I must say that following oldgrumpyman's advice at least the video was visible but very very small except at full screen when it was blocky and full of artefacts. If there was a way of increasing the size of the output to larger but less than full screen then that would be OK but I think for videos that I'll stick to my Archos

Leven2e

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Re: Video Conversion?
« Reply #4 on: October 26, 2008, 07:01:11 PM »
I didnt experience difference on quality when enlarged it to full-screen.
The Hun.

nspur

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Re: Video Conversion?
« Reply #5 on: October 27, 2008, 11:10:04 AM »
I didnt experience difference on quality when enlarged it to full-screen.
Could you give me your recipe for obtaining working video? I'm recording TV on my laptop using Pinnacle TV Center Pro (very good reception). If I use Super to processs it to 320 x 176 16:9 25 fps 128 kb/sec I get a tiny picture (can't really see it) which if enlarged to full screen is just unacceptable. Maybe you have the magic settings in which case please do share!

nspur

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Re: Video Conversion?
« Reply #6 on: November 01, 2008, 07:35:01 PM »
To reply to my own post, after a lot of experimentation I have come to what I think are the optimum settings for converting DivX Video at 720x576, 3982 kbps, 25 fps to the miniBook. I'm using AVS Video To Go which I already use to convert anything to run on my Archos 605. These settings for the miniBook may surprise you. The are

Video bit rate 303 kbps
Frame size 512 x 384
Frame rate 10 fps
Video output compression MPEG-4 DivX
Audo bitrate 64 kbps
Audio channels 1 (mono)
Audio frequency 32000 Hz (I would prefer 20500 but the program won't set it)
Audio output MPEG-1 Layer 3

The miniBook doesn't barf at the throughput in unzoomed state and the output is large enough to see well and the low quality sound is acceptable even when amplified. Zooming to full screen still produces a good picture but the processor can't handle the throughput and it's rather jerky but at least now I can watch a video clip (maybe even a feature film) on the miniBook but I'd still much rather use my Archos 605 for that.

bill

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Re: Video Conversion?
« Reply #7 on: January 08, 2009, 10:02:45 AM »
Excellent NSPUR

Thanks for posting your findings. I'm sure this will save everyone a lot of work.


I'm off to try these abd will convert a film on my Mac - i'll probably use ffmpegX on the mac to do this.