[MPlayer-users] encoding at faster speed

[Nico Sabbi]

Il Thursday 05 June 2008 03:59:24 Art ha scritto:
> On Mon, Jun 2, 2008 at 12:10 AM, Nico Sabbi <Nicola.Sabbi at poste.it> wrote:
> > Il Monday 02 June 2008 08:48:57 Art ha scritto:
> >> I would like to encode a video lecture downloaded from the web to play
> >> at about 1.5 times the speed. The device I playback on has no way to
> >> change the speed of playback, as with mplayer -speed, which works
> >> perfectly for fast playback on my work desktop. Is there a way to do
> >> this with mencoder? Or other software? These lectures are painful to
> >> watch at regular speed.
> >
> > mencoder -ofps N -af lavcresample=M ...
> > when N = fps*speed and M=original samplerate * speed
> > but be aware that basically very few  audio codecs accept
> > arbitrary sample rates (pcm being the only one I can think of)
> >
> 
> I couldn't get this to work. I think it is the problem you described
> about arbitrary sample rates (like lame doesnt work with 76800). Also,
> this is over my head so if I get a better understanding, I may do
> better.
> 
> Is there a way to do this in two steps? There is blog post:
> 
> http://mark.santaniello.com/archives/260

I still have to find a better way, but as is mentioned in that thread
-speed 1.5 -af scaletempo is a much more straightforward way
to tell mplayer how to accelerate playback


> 
> for pitch corrected playback (I actually haven't gotten the pitch part
> working). Could I use mplayer and output the fast audio to a separate
> file and use this file as an input to mencoder along with fast video
> with  -ofps x1.6?

-ao pcm:file=out.wav will generate an accelerated wav file that mencoder can read