[MPlayer-users] Recoding to VCD Using MEncoder Only

[Nico Sabbi]

Gordan Bobic wrote:

>On Monday 10 May 2004 16:26, Nico Sabbi wrote:
>  
>
>>Gordan Bobic wrote:
>>    
>>
>>>Is there any reason why this cannot be done? I presume that it
>>>cannot be done, since I have found the mencvcd script in the TOOLS
>>>directory which seems to use an exceedingly long winded way of
>>>recoding files into VCD format, using mjpegtools.
>>>
>>>I think I have managed to get the mencoder setup almost right to
>>>achieve the same thing without the clutter of all the other
>>>seemingly inferior tools and overheads of doing the same job
>>>several times, but I am stuck in one last tiny detail.
>>>
>>>Here is the script I use:
>>>
>>>#!/bin/bash
>>>mencoder	-oac lavc	\
>>>		-ovc lavc	\
>>>		-ofps 25	\
>>>		-of mpeg	\
>>>		-lavcopts
>>>vcodec=mpeg1video:acodec=mp2:vbitrate=1150:abitrate=224:vrc_buf_size
>>>=327:vrc_maxrate=1150
>>>      
>>>
>>you missed keyint=12, but generally dvd players tolerate much longer
>>values;
>>    
>>
>
>Ah, OK. Is 12 really what the spec for VCD says? That sounds rather 
>small...
>  
>

yes it's tiny, and if I remember correctly it's the value stated in the 
specs,
but following the standard at the letter with modern players is quite 
useless.
In my opinion you can safely use a larger value.

>  
>
>>2 passes and mbd=2 are reccomended
>>    
>>
>
>OK, I'll try it with mbd=2 and see if it looks better...
>  
>


>  
>
>>>\
>>>		-vf scale=352:288,dsize=4/3	\
>>>		-af resample=44100:0:2	\
>>>		$1 -o $2
>>>
>>>This seems to work really well, except for one small problem - the
>>>"-af resample=44100:0:2" part doesn't seem to do what the
>>>documentation says it should (or maybe I am reading it wrong).
>>>      
>>>
>>-srate 44100 usually works well
>>    
>>
>
>Ah, excellent, thanks, that did the trick. :-)
>
>  
>
>>>I have videos encoded with varying frequencies other than 44100
>>>(e.g. 22050, 48000), and I have to make this into 44100 to make it
>>>VCD compliant. However, the files encoded using the above script
>>>still have the same audio frequency (confirmed using "mplayer
>>>-identify") as the source file. The video seems to be in the
>>>correct format, but the audio is not.
>>>
>>>What I am I doing wrong? I would really like to avoid using the
>>>mjpegtools script if at all possible because it takes much longer.
>>>      
>>>
>
>One last problem - the "dsize=4/3" (or "dsize=1.333333") parameter 
>doesn't seem to set the aspect ratio in the resulting file. I know that 
>this is being really pedantic, but I have heard that VCD MPEG video 
>should have it. Can anybody confirm or deny this, and if it is 
>required, how do I make it stick on the encoded file?
>
>Thanks.
>
>Gordan
>  
>

dsize is useless, instead add to lavcopts ...:aspect=4/3:...