N810 as a PMP
 

I'm looking at getting the N810 (from Dynamism) and while I'm going to use it primarily to browse the internet, I will also be using it extensively as a video player.

I'm currently using an old, but powerful, Dell Axim X30H with a 624 MHz XScale CPU. I've encoded most of my TV recordings and DVDs at the "typical" Internet format, 640x360 XviD with B-frames, 25fps at approx 1000kbps with 128kbps MP3. The X30 is able to play back these files perfectly using TCPMP.

Can the N810 with Mplayer (or any other playback software) play these files? I certainly not going to re-encode all my videos... this is the main reason why I didn't bother getting the iPod Touch.

Re: N810 as a PMP
 

Although I'm impressed by how well it can keep up with those vids, since you are coming from more powerful pmp you might not appreciate the occasional/frequent hitching during high motion scenes. I'd say 70% of the time it appears full speed, 15% of time drop frames, 15% completely frozen vid... the audio always seems to stay true though.

I frequently play videos encoded in those (internet xvid) resolutions, usually 350mb for tv shows and 700mb for movies and they play pretty well enough for me although they hitch as mentioned during high motion.

What software do you use to encode (efficiently) at those resolutions? My attempts to reencode to those resolutions using agk left me with much larger files than internet sources.

Re: N810 as a PMP
 

Couple of things.

More than likely, if you want to pay less that a grand for a device, you may have to re encode. Why you say you "certainly" wouldn't do so doesn't make a lot of sense to me. Find an encoder with drop folders and come back in a few days. (I do encoding for a living for ABC News, so I love any chance to encode, finding the smallest file size with the highest quality - of course with the 18 encoding nodes we have between our two farms, I could likely do your entire collection in the format of your choice in an hour or so, so perhaps I am not feeling your pain).

Why don't you post a link to one of your shorter videos and one of us can download it and test it for you to let you know about playback across a number of the media players? I can also take your existing xvid and convert it into a couple of test encodes using lower bitrates. At the very least, it will identify if you can transcode instead of re encode. Depends on how many B frames per I frame. MPEGs are always the worst to transcode, in my experience.

Re: N810 as a PMP
 

Two farms and 18 encoding nodes... Why hello there dubiousmike, friend, chum, life-long buddy, etc :D

Re: N810 as a PMP
 

We are mostly made up of Anystream with a smattering of Telestream. Plus at the times we do Cable VOD, Cox likes one while Comcast likes the other...

Re: N810 as a PMP
 

That's -- wrong (I wanted to write another word there, but decided to try politeness for a change). My Pepper Pad3 plays just about any Divx/Xvid video file without transcoding and it certainly doesn't cost a grand in whatever money you've got.

Re: N810 as a PMP
 

350mb for a tv show is insane waste of precious memory space..

Re: N810 as a PMP
 

Where? On my hard drive? Or on the memory card of my Itablet?

Re: N810 as a PMP
 

Is your point that 350megs for 45minutes is waste or that its tv show? And is that a waste on desktop as well?

Why compromise quality, i've got 24gigs to work with on that device and tv shows are just temporary.

The only waste is that n800 can't keep up and drops frames sometimes... but that 350megs seems pretty standard 'internet' size.

Re: N810 as a PMP
 

To clarify, I was speaking more in terms of pushing the bitrate he mentioned through a portable device.

I don't know, so I'll ask, does the Pepper Pad play an xvid file at 1128 kbps and at the resolution he mentioned without chugging? If so, I'm happy to say I am wrong. But I suspected that his bitrate was too high for most devices that will play xvid files. Thus the need for transcoding.

Re: N810 as a PMP
 

I have to admit that I'm really confused about the whole kbps thing. Different sources give me different numbers for -- seemingly -- identical files.

So here's the info Windows gave me on a movie:
Evil Dead 3 - Army of Darkness (what can I say, I love pulp)
624x368, audio: MP3, 160kbps, video: DivX, 23fps, data 127kbps, 24 bits (I have no idea what those last two numbers mean, but VirtualDub tells me the "data rate" of the file is 882kbps with 0.52% overhead, and those numbers appear to have absolutely nothing to do with the Windows numbers).

This movie plays flawlessly on my Pad3, no hicking, no jumping no desynching, just Bruce Campbell doing his stuff. May I add that the Pad3 has mplayer as its video player and runs an AMD Geode 800 MHz processor with 256 MB RAM, but it appears Hanbit went through the trouble of actually activating the graphics possibilities of their chip.

About all the bits thing: All my movies are encoded to a size of around 700 MB; this just felt like the best compromise between quality and storage space (meaning that my gellifying eyes can't see much difference between those DivX and Xvid files and the real DVD), so maybe I'm just lucky in that they play on the Pad. In any case, I no longer try to play these un-transcoded files on my Itablet, because it doesn't work. I might as well take a series of stills of the movie and run a slideshow (in fact, that might give even slightly bètter fps results).

Re: N810 as a PMP
 

30% hitches.... that doesn't sound very encouraging!

Generally I use VirtualDub in 2-pass mode with XviD. You can use the bitrate calculator in XviD to get whatever file size you want.

I believe the Axim was cheaper than the N810 and it has no problems with these files! :)

Having to re-encode means having an entire new set of video files just for a device that can't cope. I'm looking to upgrade, not downgrade!

I will encode a short video (say 2 minutes) recorded from TV. Is there somewhere to upload it in this forum?

It should. The Raon Vega which has the same LX800 CPU and cS5536 companion chip can decode up to 2 Mbps DivX and XviD files according to the UMPCPortal review.

I think Windows gives the data rate for the entire file in kilobytes/sec.

VirtualDub breaks it down to video bitrate (in kilobits/sec) and audio bitrate (also in kilobits/sec).

Also is mplayer optimised to run on the OMAP2420? Does it make full use of the hardware video decoding features?

Re: N810 as a PMP
 

The issue is not the CPU decoding, it's the low bandwidth to the LCD controller.

Because of this, neither the N810 nor the N800 make really good media players (though I use my N800 as a media player and absolutely love it). Wait for the next generation maemo tablet within the next 6-10 months (probably the N900), as it will most likely be using the new TI OMAP3 CPUs and will be able to decode 720p with ease. ;)

Re: N810 as a PMP
 

Yeah. I've got a Cowon A2 PMP. It cost me less than £300 and it plays almost any xvid/divx I throw at it (Flac too which is nice). The A3 supports even more formats.

Re: N810 as a PMP
 

But the A2 has "only" a 480x272 screen, while the Pad 3 has the same resolution as the N800 (800x480). Wouldn't that make a difference?

Re: N810 as a PMP
 

Low res is what killed the ipod touch for me. That and no bluetooth.

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I have a 770 (which had decent video abilities) and a Cowon A2. I wanted to use the Nokia 770 to watch videos but the Cowon was so much better. I am not complaining - love my 770, but just want to note that the NITs can't compare to a dedicated PMP such as Archos or Cowon A2. Why? because the image is better (screen just looks better), and for me the ability to zoom in on the fly means I can watch videos larger when some cropping doesn't matter (like in dialog scenes). I was thinking if the OP will mostly be watching videos, he should get a PMP because the experience is much better. (I am not a N810 user, but I believe video on N810 is not that much better that a 770).

Re: N810 as a PMP
 

Hmmm.. if it's the low bandwidth to the LCD controller, wouldn't it be dropping frames 100% of the time? Dropping frames in high-motion scenes suggests to me that the CPU or DSP doesn't have the horsepower to decode the MPEG4 video.

If the iPod Touch had bluetooth (with DUN), I would buy one in an instant! I'd even overlook its pathetic video support.

Re: N810 as a PMP
 

It's a combination of both, mostly the LCD controller is to blame. The CPU is sometimes the culprit for larger stuff (it plays MPEG4 stuff at 400x240 with a bitrate of about 800-1200Kbps and MP3 audio 100% everytime, so it certainly has the horsepower to decode MPEG4), but the LCD controller is the true bottleneck (as we'd have hardware video decoding from the OMAP2420 if we could use the built-in decoder).

Re: N810 as a PMP
 

Actually this strengthens my views that it is the CPU/DSP to blame. MPEG4-ASP is more CPU intensive to decode when you increase the resolution. Higher bitrates will also increase the CPU processing required but not to the same extent.

When the device plays 400x240 MPEG4 files, wouldn't the CPU/DSP have scaled the video to the LCD's native resolution (800x480) before it gets to the LCD controller? This would mean that the LCD controller wouldn't know the difference between the 400x240 and 800x480 files.

Also I've just tested my Axim X30H and it was able to play a 624x352 file at approximately 126% normal speed using TCPMP. Since the Axim is in theory much faster (although its hard to compare with a different ARM architecture, DSP, OS and player), it seems likely that the N8x0's OMAP2420 is right on the border of being able to play back this file without a hitch.

Re: N810 as a PMP
 

No, pixel doubling is done on the controller.

Trust me here, the LCD controller is the major bottleneck, not the CPU. :)

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I have an older USB EyeTV I use on my Mac to record TV, which encodes to mpeg1, but 320x240 and at 1.5Mbps and they play quite well. The mp4/m4v files I use for the iPod seem to be a bit more stressful.

650 Mb for one hour of video in the higher rez mode.

Re: N810 as a PMP
 

That's VBR, too, I believe (EyeTV 200 and 500 over here).

I wish they would let you customize the automated output a little more finely. As MPEG4 also has AAC which wont be decoded by the DSP.

Re: N810 as a PMP
 

Even if the video bandwith is a limitating factor it is possibel to watch video in fairly good quality on n770/n800/n810. The video properties are a more complex problem. For instance, XVid encoded material does not run smoothly for certain constellations with B-Frames. I found this after a lot of experiments: http://www.internettablettalk.com/fo...8&postcount=13