FFMPEG, Mencoder (or not) conversion.

[Rashkae]

Jordon Bedwell wrote:

> 
> 1.) What does this mean: muxing overhead 1.251961%  that was outputted
> with some other stuff after my last failed attempt to try and figure out
> FFMPEG (which mind you was horribly failed.) ~ If it's to do with
> filesize I don't care.  Storage is near limitless ~ even on the go since
> I can stream.


I don't know for certain in this case, but muxing is the process of 
combining the video and other streams (such as audio/subtitles, etc) 
into a container format (such as mkv).... so I would assume muxing 
overhead means filesize overhead for the chosen container format.

> 
> 2.) Can somebody give me an example of converting [random codec] to
> H.264, I heard H.264 does support 1080P HD, if this is not true,
> suggestions and facts to break the myth's I've heard?

H.264 is currently the most widely used video codec, and is, in fact, 
the native codec used by BD discs and digital HD television.  (so yes, 
it does support 1080p,, or whatever resolution you want to crank it at.

Here's an old mencoder example:

mencoder -oac copy -ovc x264  -vf pullup,softskip -ofps 24000/1001 
-x264encopts crf=16:threads=2 3.vob -o 3.avi

Note that mencoder options are a little arcane and need to be customized 
for the source.  (In this case, I'm applying a reverse telecine filter 
to an anime source.).  Reading and understanding Mencoder documentation 
is a must, and there is, to my knowledge, no magic incantation that just 
works for all sources.  However, I now use Handbrake for this job (which 
you have not mentioned in your OP), which does, for the vast majority of 
video I've thrown at it, do the right thing with a single set of options.

It's also worth mentioning that while it is still widely used, Mencoder 
is considered by it's developers to be deprecated and unsupported.

> 
> 3.) Do I need mencoder to do all this or can I simply rely on FFMPEG?
> Usually when I setup a client server and they do media, they ask me to
> install FFMPEG + Mencoder.  Now, I know how to setup all this stuff, and
> get it to work, but I certainly don't know how to actually work it for
> real.  Never needed to utilize it before now.


You can use either.  Mencoder (part of MPlayer) includes it's own copy 
of ffmpeg (which is what actually does the work) and provides a well 
documented set of options to interface with ffmpeg.  As mentioned 
earlier, however, Mencoder is considered 'depricated.'  However, since 
it has been the 'go-to' program for so long, it is well supported by 
many people.  While ffmpeg does the encoding, mencoder lets you use all 
other mplayer options and filters as well.  (Like the inverse telecine 
in my example).  If I wanted to do something like that with only ffmpeg, 
I would first have to process the video in mplayer and output to raw or 
some such for encoding.

> 
> 4.) Can I thread FFMPEG (and Mencoder if needed) across all my CPUs? I
> have 2 Xeons and 2 graphics card in this rig, seems like a major waste
> with two 5870's and dual Xeons if can't thread across all the power to
> cut the time by a 10th.
> 

Encoding is fully threaded and will work across your CPU's (but not 
GPU's).  You'll actually be able to cut the time by almost a complete half.