[MEncoder-users] improving performance - general questions

[James Hastings-Trew]

On 12-08-18 8:44 PM, The Wanderer wrote:
> On 08/18/2012 04:16 PM, Rossana Guerra wrote:
>
>> 2012/8/18 Reimar Döffinger <Reimar.Doeffinger at gmx.de>
>>
>>> On Sat, Aug 18, 2012 at 04:56:45PM -0300, Rossana Guerra wrote:
>
>>>> So the only output is the command mencoder console output.
>>>>
>>>> I noticed add subtitles takes time, any tip.
>>>>
>>>> This is the command:
>>>>
>>>> mencoder /carpeta_X/pelicula.avi -sub /carpeta_X/pelicula.srt -oac 
>>>> copy
>>>> -ovc lavc -o /tmp/pelicula_final.avi -subcp latin1 -font
>>>> /usr/share/fonts/msttcore/arial.ttf -subfont-text-scale 2.8
>>>
>>> Is the problem that this is slow whether you encode subtitles or 
>>> not, or
>>> that specifically removing the -sub option (and only that, possibly 
>>> replacing it with -nosub) makes it much faster.
>>> Anyway try with -lavcopts vcodec=mpeg4:mbd=0:turbo=yes:vqscale=2
>>
>> Sorry, I didn'y understand very well, maybe is my english and because 
>> I am
>> totally new with mencoder.
>>
>> I need to add subtitles, sio why to use nosub?
>
> To find out whether it's specifically the subtitles that are making it 
> slow, or
> whether the encoding itself is the slow part.
>
> If the subtitles themselves are slowing down the encoding process more 
> than
> minimally, then that might be a problem (even a bug) in need of 
> fixing. If the
> encoding itself is slow, that may well just be the nature of the 
> transcoding
> process.
>
>> As I posted before, this is the command I am using:
>>
>> mencoder /carpeta_X/pelicula.avi -sub /carpeta_X/pelicula.srt -oac 
>> copy -ovc
>> lavc -o /tmp/pelicula_final.avi -subcp latin1 -font
>> /usr/share/fonts/msttcore/arial.ttf -subfont-text-scale 2.8
>
> And he was suggesting that you add the '-lavcopts' option, with a 
> particular set
> of suboptions, to possibly help speed up the encoding process.
>
I repeat what Reimar asked earlier. Why not skip transcoding entirely, 
and use VLC to display the srt subtitles at playback time? Is there some 
specific reason you want the subtitles burned into the video (since that 
requires re-encoding the video, which is something of a hard job for a 
single processor machine)?