[MEncoder-users] Mencoder params

[Raimund Berger]

RC <cooleyr at gmail.com> writes:

> On Thu, 22 May 2008 10:27:38 +0200
> "Raimund Berger" <raimund.berger at gmail.com> wrote:
>
>> Renders it pretty much unusable for that kind of 2 pass encodings I'd
>> say.
>
> I fail to see why.  It isn't ideal, of course.

Well, apart from burning considerable cpu time for nothing, with the
knowledge that video is synced not to a time line, but rather to the
audio stream - including the particular choice of audio encoder - and
likely vice versa, let me ask the following question:

how would you then proceed if, when performing a high quality dvd
backup, you would like to save 2 or more audio streams into your
backup?

With all I learned from you, it'd be pretty much idle to even attempt
this with mencoder and hope to get a sane result. Moreover, even if
you were aiming only for a simple style one shot a/v encoding, if you
found out something was wrong with the audio (not downmixed or
normalized the way you wanted, maybe the bitrate was wrong etc) you
could start over with a full a/v encoding right away. Which after all
might take serious hours in case of a high profile encoding.

Sorry, but calling that "not ideal" appears to be kind of an
understatement to me. Unusable with respect to AVC/AAC encoding seems
more to the point. Safe the simplest use cases maybe.

>
>> >> Again, it'd be helpful if you pointed to the exact section where
>> >this > requirement is supposedly made explicit.
>> >
>> > My mistake.  It's in the HTML docs, not the man page.
>> 
>> Still didn't find it. Link?
>
> Hmmm...  
>
> See -lavcopts vglobal / aglobal in the man page.  That should
> help explain -faacopts raw and -x264opts global_header .
>
> aglobal / vglobal are also briefly mentioned in the HTML docs 13.4.

OK, from "it's in the man page" we now got down to "there's some info
spread over the docs, and albeit the docs never explicitly mentioning
the faac 'raw' requirement for lavf mp4 muxing, if you read through
all of it and properly memorized every line, you might be able to
infer that you need it". Just to put it into perspective.

Apart from that, I still tend to consider the lavf mp4 muxer requiring
raw aac and not allowing e.g. adts - well, limiting, if you will.