[MEncoder-users] How concatenate several MPEG2 clips

[Nico Sabbi]

Gennady Ovcharov wrote:

> Hi Ladies and Gentlemen!
>
> I want concatenate several MPEG2 clips in one MPEG2 file
> mencoder version: MEncoder 1.0rc1-3.3.3
>
> I prepared 10 clips as:
> mencoder [1..10].avi -o [1..10].mpg \
>    -vf softskip,scale=352:576,harddup,smartblur=0.3:1:0 \
>    -of mpeg -mpegopts format=dvd -srate 48000 -af lavcresample=48000 
> -ofps 25 \
>    -ovc lavc -oac lavc \
>    -lavcopts 
> vcodec=mpeg2video:aspect=4/3:vrc_buf_size=1835:vrc_maxrate=9800:\
>        
> vbitrate=2000:keyint=15:acodec=ac3:abitrate=192:trell:mbd=2:dc=10:cbp:mv0:vstrict=1 
>
>
> ... and make:
> cat *.mpg | mencoder -of mpeg -ovc copy -oac copy -o ../big.mpg -
>
> O-o-p-s :(
>
> on stdout i see:
> ...
>
> BUFFER UNDEFLOW at stream 1, raising muxrate to 2898 kb/s, delta_scr: 
> 152597
> ERROR: scr 15.597, dts 0.000, pts 15.472
> ERROR: scr 15.636, dts 15.480, pts 15.520
> Pos:  15.9s    390f ( 0%)  0.00fps Trem:   0min   0mb  A-V:-0.063 
> [1249:192]
> ...


specify the :format option in -mpegopts (e.g. format=dvd:tsaf)

>
> In result I have big.mpg. On border between clips - boxing artifacts 
> and disalignment A/V :(
>
> I attempt
>    cat *.mpg | mencoder -of mpeg -mpegopts -format=dvd -ovc copy -oac 
> copy -o ../big.mpg -
> and
>    cat *.mpg | mencoder -of mpeg -ovc copy -oac copy -forceidx -o 
> ../big.mpg -
>
don't. rather use
mencoder -of mpeg -ovc copy -oac copy -mpegopts format=dvd:tsaf -o 
final.mpg file1.mpg file2.mpg...