[MEncoder-users] Video iPod

[Guillaume POIRIER]

Hi,

On 11/10/05, Andrea Gelmini <dislessico at gmail.com> wrote:
> Hi all,
>         I've got a new iPod and I would like to upload videos, but I
> dunno how to encode it in the right way (by the way, I haven't apple
> computers/microsoft OS, so I cannot use iTunes). So, thanks a lot in
> advance for your time/clues.

Please do yourself a favour and read the encoding guide in order to
get yourself started on using mencoder and getting decent results.

>         From the specs I read I have to choose to encode between:
>
>          -> H.264 video: up to 768 Kbps, 320 x 240, 30 frames per
> sec., Baseline Profile up to Level 1.3 with AAC-LC up to 160 Kbps, 48
> Khz, stereo audio in .m4v, .mp4 and .mov file formats
>
>          -> MPEG-4 video: up to 2.5 mbps, 480 x 480, 30 frames per
> sec., Simple Profile with AAC-LC up to 160 Kbps, 48 Khz, stereo audio
> in .m4v, .mp4 and .mov file formats
>
>          Yesterday and today I've googled a lot, but I found only a
> lot of front ends (of mplayer/mencode) for OSX, not the simple command
> line of mencoder (well, I also found a lot of things l do not care,
> such encoding in raw, and so on).
>
>          At the end you can find the output of a file I can play on iPod.

A simple encoding line would be something such as :

mencoder input.divx -ovc x264 -x264encopts psnr:bitrate=$video_bitrate -o \
output.h264 -oac faac -vf scale=$Width:$Height,harddup -faacopts
br=$audio_bitrate

to for example convert your old divx to H.264 files.

Note that you'll have to replace input.divx, output.h264,
$video_bitrate, $audio_bitrate, $Width and
$Height by the appropriate value.

In order to compute the video bitrate edequatly, you can use the
following formula:

                 $bpp * $width * $height * $fps
$videobitrate = --------------------------------
                            1000

I found that $bpp = 0.13 (best quality) to 0.09 (decent but not too
good) were mostly okay for dvd size encodes.

I hope the resulting file will work fine on your IPOD. You may have to
do further black magic in order to remux the file to the mp4
container, in which case, mp4box is your friend.

If you need further details, you can send me an IPOD, that would allow
me to write a nice official howto about it :-P.

Guillaume
--
Reading doesn't hurt, really!
  -- Dominik 'Rathann' Mierzejewski