ok, i've found this because sometimes i have a desynch when i convert de sound of my svcd to 48000 khz ( only with ntsc svcd )
demux the mpeg and don't use ssrc with tmpeg for convert the sound to 48000.Kill the .mp2 you will have with the demux, open flask version 6 or more, take the mpg original you have , in option, put the sound on 48000 and extract the sound to wav.after that, take your wav and convert to 224mgbit with tmpeg if your original sound is less than ( 128 or 192 )
your sound always synch after with the picture and you'll have a sound clear ( sometimes with ssrc your sound is to high and make when you've a lot of bass,some distorsion )
that's all
sorry for my bad english , i wish you'll understantd me