Settings for extremely low bitrate and very low resolutions?

[junglemike]

Hi, since TCPMP can now decode avc video on PALM OS either - I would like to know the optimal (quality/size -wise) settings for extremely low bitrate (200-400kbps video) and low resolutions: (maximum 480x320 - which is resloltion of Palm PDA)
Encoding time is not a problem. don't think i have any good pc - I have 5 PC's. Best of them is Celeron 1700, than PIII-1000mhz, than 750mhz....) With recommended settngs i get smth like 2fps - but that's fine. I have plenty of time to prepare my episodes when i have time to watch them on pda.

[Sharktooth]

:search:

[foxyshadis]

Sharktooth's HQ profiles in MeGUI will point you in the right direction. (I always use more b-frames though.) They make for watchable looking 25kbps video, I'm sure they'd look great at 250. :p

[shon3i]

Probably is best to use HQ-Insane.

[BetaBoy]

I asked CruNcher to postabout his decoding profile for X264 for CorePlayer/TCPMP.

[Chainmax]

Very slightly on topic:

BetaBoy, do you think TCPMP could be ported to the GP2X sometime in the future?

[BetaBoy]

ATM no... BetaPlayer however is coming to the PSP.

[Chainmax]

Does BetaPlayer have the CoreAVC decoder?

[check]

Back onto low bitrate encoding, the best advice is that simply the highest settings will give the best quality. Exhaustive search is probably a waste though :P You should also look at reducing the resolution, just because your screen is 320x240 doesnt mean you should encode at 320x240 - a 240x160 encode may look far better.

[DarkZell666]

Hmm, 200-400Kbps isn't too low a bitrate anyway, we indeed are talking about H264 right ? ;)

At such bitrate, 320x240 should be watchable, considering anime can be VERY watchable in 576*432/512*384 @ 230kbps ... :)

[junglemike]

just because your screen is 320x240 doesnt mean you should encode at 320x240 - a 240x160 encode may look far better.
Screen of my palm is actually 480x320. I've tried encoding at 480x256 AVC - and NO WAY Tcpmp can play it back on Palm, (even overclocked to 600mhz) - But maybe that's because there is still no CoreAvc in Tcpmp (for Palm OS) - So I have no way of knowing if Palm can decode 480xXXX in realtime even when CoreAvc comes out.
So reducing resolution might be good idea.

Than i have another question - what settings require highest cpu usage - and thus should be avoided when coding for mobile devices?

[cbarroso]

I tried x264 + vorbis (MKV) in my PPC Axim X51 with TCPMP .72RC1 and it did not work. Do I have to install another direcshow decoder for AVC? I already googled it a lot and found nothing.

[check]

"did not work" ?
Be aware that pocket PCs can't really play back h264 video on anything higher than 'apple' spec, ie baseline + 1 bframe. I tend to use baseline + more refs and all partitions, which plays back fine at ~100kbits.
I ususally use xvid ~q8-12 for PPC playback, because h264 still drops frames unless you are using very low settings. I'd recommend you use HE-AAC too, which will let you reduce the filesize even more. The plugin is here: http://rarewares.org/aac.html

[aurora-glacialis]

Maybe it's dumb but what is "Sharktooth's HQ profiles in MeGUI"? I use MENCODER in Linux and hava a set of options :

-x264encopts bitrate=400:subq=6:partitions=all:8x8dct:me=umh:frameref=5:bframes=3:b_pyramid:weight_b:pass=2

This gives a reasonable quality at about 180MB fpr 45 minute episodes of TV Series. The Quality is probably ok for Palm and CRT-TVs. But I would like to optimize this even more. The Video has excellent fast moving scenes, but has weaknesses in slow moves (like panoramas) and sometimes in portrait scenes. Meaning that a camera move (like a very slow zoom) might not show fluently. And in some scenes where a constant background exists and a face of a person is slightly moving in front of it (like a reporter in front of a building), I get a very blurry face but a crystal clear background.

Can anyone help me with one or both of these optimizing problem???

Ciao
Aurora