[MEncoder-users] Flash rotation help

[Sean Brady]

Thanks for the quick response Corey!

On Wed, 2006-05-24 at 11:33 -0700, Corey Hickey wrote:
> Sean Brady wrote:
> > Hi. Okay, so I have a flv file that was created using mencoder.  The
> > command was something like so:
> > 
> > mencoder -of lavf -oac mp3lame -ovc lavc -lavcopts
> > vcodec=flv:acodec=mp3:abitrate=64:vbitrate=400 -srate 22050 -ofps 15 -vf
> 

> If you use -oac mp3lame, then -lavcopts acodec=mp3:abitrate=64 has no 
> effect. Either use -lameopts to tune lame's parameters or use -oac lavc 
> to use lavc audio encoding.

Ahhhh, that makes sense.... I'll make the changes.


> 
> > scale=400:300 a4e7c2ab298ffdfad27d568cc675b4a9.wmv -o test.flv
> > 
> > I've also added -rotate to the -vf list...  like so:  
> > 
> > -vf scale=400:300, rotate=1
> > 
> > which works great.... now here's the dilemma.  I need to make this work
> > off of the .flv file, so instead of running this on the .wmv file and
> > encoding it to .flv, I need to run it on a .flv file, and encode it to a
> > new .flv file... basically trying to rotate the .flv file 90 degrees.  
> > 
> > I'm sure it's simple, but I just can't get anything to work!
> 
> Next time please tell us what you tried. Anyway, there are a few things:
> 
> 1. You're using a build of mencoder that is at least somewhat old. You 
> should upgrade to recent CVS. Actually, the CVS server is down at the 
> moment (hardware failure), but you can get a snapshot here:
> http://www.mplayerhq.hu/~rtogni/snapshots/
> 
> 2. Re-encoding multiple times is a bad idea. I'm not sure if that's what 
> you want to do, but your description sort of indicates that you're 
> trying to encode wmv-->flv-->flv(rotated). When you re-encode using a 
> lossy codec, information is lost, and doing so more than once compounds 
> the difference. If you're talking about rotating and re-encoding files 
> that were already flv by the time you got them, then you don't have any 
> choice, but it's always best to use as close to the original as you can 
> get. If you want to have one normal flv and one rotated flv, then do two 
> encodes: wmv-->flv and wmv-->flv(rotated).
> 
> 3. All that aside, this should work well enough to get you started:
> $ mencoder flv.flv -vf rotate -oac copy -ovc lavc -lavcopts vcodec=flv \
> -o rotated.flv -of lavf -lavfopts \
> format=flv:i_certify_that_my_video_stream_does_not_use_b_frames
> 
> -Corey

I tried your suggestion.... here's what I got:

/home/sbrady/p4/tech1/VirV/bin/mencoder_32
af71553950feea9afc64fab063e34b5e.flv -vf rotate -oac copy -ovc lavc -
lavcopts vcodec=flv -o rotated.flv -of lavf -lavfopts
format=flv:i_certify_that_my_video_stream_does_not_use_b_frames
MEncoder dev-CVS-050805-21:00-3.4.3 (C) 2000-2005 MPlayer Team
CPU: Intel  (Family: 6, Stepping: 8)
Detected cache-line size is 64 bytes
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2

File not found: 'frameno.avi'
Failed to open frameno.avi
Option lavfopts: Unknown suboption
i_certify_that_my_video_stream_does_not_use_b_frames

Exiting... (error parsing cmdline)

I'm guessing I need to upgrade to a newer version that supports the
option i_certify_that_my_video_stream_does_not_use_b_frames

Thanks,
Sean