View Full Version : Mobile Media


Stan64
4th May 2004, 21:47
I have a 3g phone, nec e808 and I want to encode anime and transfer it to the phone and watch on the subway. How should I do?

What is it encoded in and so on?

This is a sample movie recorded with the phone.
http://www.nintendo-next.se/stan64/nec_e808.mp4

bond
5th May 2004, 11:35
are you sure that the nec phone outputs .mp4 files? or does it output .3gp files and you renamed it to .mp4?

the easiest way to encode a file for your mobile, might maybe be if there some sort of encoding tool from nec itself available which could do the job
if not you will have to do the encoding "by hand"

analysing your .mp4 the file contains a MPEG-4 SP@L3 video stream with 176x144 resolution and is variable framerate (good stuff ^^) and doesnt use b-frames
your audio stream is AMR, which is basically a speech codec and not officially specified in .mp4, but only in .3gp files (which are basically very similar to .mp4)

so this leads to the following conclusions:
video:
to encode the video stream you can use any mpeg-4 video codec you want (xvid, divx5, 3ivx aso...), i am pretty sure that the phone will not handle advanced stuff, like qpel or gmc and i assume also not b-frames (you will have to test this out yourself)
i would recommend you to use 176x144 too for the res, of course you can also test if it handles higher ones, but 176x144 should work
as it seems to handle vfr i would recommend you to use a smart encoder like 3ivx or xvid and mux them as described here (http://forum.doom9.org/showthread.php?s=&threadid=73633), as this will create vfr streams which will help you to save bandwidth (brings more quality)
a problem maybe causes the framerate, you will have to test out if the phones handles up to 25fps or the maximum is 15fps...
your sample used on average ~4.6fps which is very low. if you use the xvid encoder with a higher framedrop ratio it will possibly output a stream below 15fps anyways

audio:
the phone itself encodes with amr it seems, but from what i read it also supports playback of aac, which would make things much easier
you should be able to encode with every aac encoder available (ie itunes/quicktime, nero, faac aso...) make sure that you use the lc profile, which should be default in every encoder anyways (maybe the phone also handles he-aac like some from nokia do already i think ^^)
if it only supports amr you can encode the audio with this tool (http://www.audiocoding.com/phorum/read.php?f=2&i=42&t=42), maybe quicktime pro also supports amr encoding

muxing:
quicktime can mux into .3gp (if you have to use amr for audio)
for .mp4 you can also use the .mp4 file outputted by 3ivx or mp4box diretly (yeah a standardised container is a nice thing :D )