[MEncoder-users] Using vqscale with vrc_maxrate under lavc gets sloooooooow

tripp eliared at yahoo.com
Thu Jul 10 20:42:30 CEST 2008


hi,

--- On Wed, 7/9/08, David Smith <dcsmith2 at gmail.com> wrote:

> I need to convert to flv.  So what's the best way to do "crf"
> using libavcodec options?  

it's not a libavcodec option.
it's an x264 option.
as in -ovc x264enc

> I am trying to find the perfect command line 

gl with that!

> Btw, I only care about converting to Flash so I can only use *lavc.*

no,
you can also use vfw vp6,
with mencoder's vfw2menc.exe tool
needs flash 8 for playback
or use x264, which you can put in the flv container if your 
mencoder uses a recent enough libavformat.
or just x264 in mp4.
needs flash 9 for playback


> Basically I want to encode both kind of files to a relative quality without
> having to worry about bitrates, 
> So I am working with vqscale 

good

> I am using the params below, but my encoder bogs down to  the point where it
> is only encoding about 1 frame PER SECOND and I'm not  exactly sure why. 

buffer underflows?

get in the habbit of providing full output of the command you use.

remove the bitrate restrictions...
or increase maxrate,
or set a higher qscale.

> I have a state-of-the-art desktop.

you mean it was, yesterday :)

> 
> I have read that vqscale will end up wasting lots of bits on complex scenes
> and producing a bitstream that requires way too much cpu power to decode and
> if I don't have proper constraints and a long complex scene eats all the
> bits, then lavc makes subsequent simple scenes look like crap trying to
> recover from its excessive bit usage.

??
qscale encodes to a constant quality based on texture complexity.
it's your constraints that are choking it.
 
> I thougth I was adding a constraint by enforcing maxrate,
> but perhaps it's still too much?

it was
 


gl
tripp


      



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