[vlc] [VLC 2.0.3]

[dE .]

On 12/03/12 03:06, Petar Koretic' wrote:
> I wrote that on the line above. In this case, with mpeg2 codec ffmpeg 
> uses more resources per one stream, and since we have 50-100 live 
> channels transcoding this ends up being pretty big difference.
> On the other hand, If there is an obvious option, why is not working? 
> Maybe I should file a  bug report?
>
> On Sun, Dec 2, 2012 at 1:45 PM, dE . <de.techno at gmail.com 
> <mailto:de.techno at gmail.com>> wrote:
>
>     I'm not a webserver expert and I think I don't understand your
>     requirements, but you can use ffmpeg for this.
>
>
>     ---------------------------------
>     Support software for non profit, buy Android phones.
>     On Dec 2, 2012 12:13 AM, "Petar Koretic'" <petar.koretic at gmail.com
>     <mailto:petar.koretic at gmail.com>> wrote:
>
>         I'm doing real time transcoding on our servers. Gui is not an
>         option. There is already web gui fronted for transcoding.
>
>         On Sat, Dec 1, 2012 at 7:01 PM, dE . <de.techno at gmail.com
>         <mailto:de.techno at gmail.com>> wrote:
>
>             Why dont you use the force aspect ratio line in vlc GUI
>             settings?
>             ---------------------------------
>             Support software for non profit, buy Android phones.
>
>             On Nov 30, 2012 3:23 AM, "Petar Koretic'"
>             <petar.koretic at gmail.com <mailto:petar.koretic at gmail.com>>
>             wrote:
>
>                 This is ffmpeg line ( I have removed other parameters
>                 as it would be too long) which works, it sets aspect
>                 ratio to what I want (checked with mediainfo, and seen
>                 on the system)
>
>                 ffmpeg -i $1 -vcodec mpeg2video -aspect "16:9" -vf
>                 scale=$width:$height -an -f mpegts udp://@$2
>
>                 for vlc I use this
>
>                 vlc -I dummy -vvv $1 --sout
>                 "#transcode{vcodec=mpeg2v,width=$width,height=$height,acodec=none}
>
>                 Here I tried putting aspect ratio settings on four
>                 different places with different names as found over
>                 the internet and vlc wiki (aspect, canvas-aspect,
>                 canvas-ratio,aspect-ratio) but I just cannot get it to
>                 work.
>
>                 In vlc help I can see
>                 --aspect-ratio <string> Source aspect ratio
>
>                 but setting that (--aspect-ratio="16:9") haven't
>                 changed output aspect ratio.
>
>                 I wan't to have it over vlc since cpu usage with 20
>                 channels transcoded and streamed over the network in
>                 realtime is 20% difference on the server.
>
>                 Thanks in advance.
>
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But VLC uses ffmpeg libraries itself, so the inefficiency of the codec 
will persist. Also it may 'appear' to be faster cause the aspect ratio 
is not enforced.

I'd suggest you compile ffmpeg from GIT and use custom CFLAGS optimised 
for your server.

Constant bitrate also helps, and maybe you can you filters instead of 
-aspect to improve performance.
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