Optimal conversion for handheld

[santosx]

hello forum

lately im converting a lot of stuff to be watchable on my phone (Samsung Wave GT S8500). It supports mkv and a lot of codecs, but it seems mpeg-4 runs most smooth (not h264). one of the limitations is that b-frames arent supported, which requires to basicaly reconvert everything.

converting to mpeg-4 does give pretty good results, but looking very closely, there is still that little freeze now and then. as if the cpu spiked to 100% for a millisecond, or as if a frame would be skipped.

now i am wondering if maybe using mpeg-4/h.264, which has a lot more options as it seems, could give a better endresult by making sure everything is set to minimize cpu load for the mediaplayer used in the phone.

this is supported:
MP3, AAC, AAC+, e-AAC+, WMA, AMR, WAV, MP4, MPEG4, H.263, H.264, WMV, DivX, XviD, MKV

on a sidenote, strangely an mkv runs less smooth then an mp4 even if all used codecs are the same.

any suggestions for optimizing the movies in order to minimize the cpu load for the decoder?

edit: i'm using the xmedia recoder atm (without the s8500 preset). standard setting for me is mpeg4 with ac3 (cause the phone doesnt support 5.1 aac, so i use 5.1 ac3 in order to benefit from the virtual 5.1 feature of the phone).

[Baldrick]

I guess you have tried lower resolution and lower video bitrate? It might help a lot. And Divx/xvid is usually better if you want to minimize cpu load.

[santosx]

most things are already below the 800x480 resolution that the phone has, and it doesnt make a difference if the resolution is lower, identical or higher. everything up to 720p basicaly runs the same. same goes for bitrate, i mostly use about 1000 to 2000, but also 6000 and more isnt a problem (except for the space the movies need at high bitrates).

going to try xvid, thanks. i dont see divx in xmedia, does it require a certain container other then mp4?

[Baldrick]

Nope, xvid in a mp4 should work fine. But you can also try put in an avi.

[santosx]

in zoomplayer xvid seems to have the same cpu usage as mpeg4, but mpeg4/h264 is a good bit higher (converted a 2 min full hd for testing).

unfortunately xmedia crashes when trying to encode with divx. will it be considerably lower cpu usage then xvid?

[santosx]

i'm having trouble converting to divx, which tool would be easiest to try that codec? do you think using a constant bitrate instead of variable might help to even out spikes?

[yoda313]

format factory is a good one. I use it quite frequently with good results.

[santosx]

are you sure it handles divx? it doesnt say so in the list. and there is a warning about messing up the codecs of other encoders.

[yoda313]

It does xvid.

I have it and a ton of other codecs without any obvious side effects.

[santosx]

i need divx, all encoders i tried can do xvid.

[yoda313]

then checkout super or xvid4psp (I think it does actual divx as well).

[santosx]

super works, thanks

there is a problem though. the wave only supports 5.1 as ac3.

until now i reencoded the things as mpeg4 codec with ac3 5.1. Zoomplayer plays that without sound, but the phone plays it fine and can use the 5.1.

in super though, if i use avi container, divx codec and ac3 5.1, its extremely choppy on the phone, and zoomplayer complains about "not prepared for sequential reading" and "reinterleaving recommended". any way to fix this or divx and ac3 5.1 are incompatible?

[santosx]

what has the lowest cpu usage, mp3, aac or ac3?