[MEncoder-users] x264 2-pass, FAAC, smearing

[Robert Ramiega]

On Thu, Jan 15, 2009 at 07:25:42PM +0200, GM wrote:
> It's not about bitrate.

 Of course not. It's about bitrate distribution.
 Still I don't see how omitting audio can screw video bitrate calculation 
(and thus bitrate distribution)

> It's what happens when you omit or copy the audio stream in the first
> pass and encode it in the second pass.
> Read the first message in the thread please.

 I did just now. I don't belive that bad bitrate distribution comes from
different audio options. You haven't written anything about constraints on
output file (bitrate etc) but normally you would use video bitrate of say
thousands of kbits and audio bitrate - hundreds of kbits. Maybe you've hit
some bug =o)

 It might be helpful when you post full command-line of both passes not just
some tidbits as in first message in the thread.

When i do some transcoding i use hand-crafted batch created by h264enc. This
batch encoded video and audio seperately later muxing them to mp4 or mkv
(-noaudio on both passes then dump audio to a pipe and encode from it - note
that i'm using neroaac for this not mencoder). Did you tried this approach?


 Please stop top-posing. It's annoying at best.

> On Thu, Jan 15, 2009 at 5:42 PM, Robert Ramiega <jedi at plukwa.net> wrote:
> > On Thu, Jan 15, 2009 at 03:40:06PM +0200, GM wrote:
> >> Using those options, you are messing up quality.
> >> This is because the first pass will have wrong bitrate distribution when
> >> applied to your second pass.
> >
> >  I think you've got it wrong. John might get A-V sync issues but I believe
> > audio bitrate does not influence video bitrate distribution in any way.
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-- 
Just a friendly Jedi Knight     | I find your lack of faith
Robert Ramiega jedi at plukwa.net  | disturbing
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