video encoding from uploaded files

[dragonBoy]

hi all

we need to set up a system where users can upload movies in some format (avi, wmv, mpeg, mov, etc or can be limited i guess)
which we would need to be converted server side to mp4 video files (not streaming atm)
the movies will be 2MB or less (so really short videos taken on phones or digital cameras)
now i have a lot of questions about this cos i have no idea what i need to do

is this a reasonable situation, would the video conversion take up too many system resources
our site is pretty busy and it already gets a bit slow at times, would video encoding of uploaded video files slow it down even more?

we are using apache 2 with php 4.3.9
red hat 9, dual xeon cpu, 2GB ram
72GB HDD
is there an application we can use where we just call exec(/usr/local/videoencoder $filein $fileout $encoding);?

does anyone know of a tutorial or resource site where i can find this information?

also, is there a way to get a frame, or series of frames so that we can create a thumbnail for the movie?

thanks a lot
any help is greatly appreciated
dave

[wmcbrine]

is there an application we can use where we just call exec(/usr/local/videoencoder $filein $fileout $encoding);?

Sure, mencoder.

does anyone know of a tutorial or resource site where i can find this information?

man mencoder

but that's not the best. This is actually a weak point IMHO. There's a lot of scattered info on the Net, but I haven't really seen a proper tutorial. (Maybe there is, by now?)

also, is there a way to get a frame, or series of frames so that we can create a thumbnail for the movie?

"mplayer -vo png" or "mplayer -vo jpg" would be one way, combined with options to limit the number of frames processed.

[dragonBoy]

hey thanks for your reply
i've just finished installing ffmpeg
is it better to use ffmpeg on it's own or use mencoder instead?
i am having trouble converting a .mov to .mp4 or any other format except mpg
saying unkown video codec
and converting to images, saying unknown image format jpeg

thanks again
dave

[mats.hogberg]

Take a look at transcode too. Properly setup, it can convert pretty much anything to anything.
But seriously, this work should not be done by the web server. Video encoding has a tendency to take all resources it can find. Better set up an application server that does the encoding, leaving the web server to serve the web!

/Mats

[dragonBoy]

i'm not sure if i have the codecs, is there any way to find out, and where can i download them from and how to install?
sorry for not knowing anything
when i try -vcodec mpeg4 or -acodec aac
it says either "unknown video/audio codec"
or "error while opening codec for output stream, maybe incorrect parameters for bitrate", even if i do not have bitrate flag
i have looked at the -formats option and all the codecs are there, so just don't know how to actually know which codecs are on my computer

for some reason i can only output to mpg files with no codecs set
i basically just downloaded ffmpeg from http://mplayerhq.hu/MPlayer/cvs/
the latest ffmpeg version, and just installed with configure, make, make install
that's it, did i need to do more?

[update]
i can do conversions with something basic like
ffmpeg -i videos/jk2.mpg -b 50 videos/jk2.wmv
can't do to mp4, mov, etc.
just wmv, avi, mpg
but avi's, wmv's can't be viewed by media player
but i can't put any other flags in like vcodec, audio codec, time duration, format, image format etc.

any help
dave

[dragonBoy]

just in case this happens for someone else
the issue was seemingly because i didn't have the audio codecs set up properly

need to install faad, faac to get it going, hopefully i can do that and it will work