Aspect ratio question
Brought to you by:
baloan
Menu
▾
▴
#12 Aspect ratio question
Originally created by: fabtarr@…
I'm sorry about using this way but I have a problem with my sourceforge account.
I'm going to use your software for my movie convertion and I have a question.
My question is:
About aspect ratio, I have understood that your software looks for the sequence header and substitues the sequence with the right one.
But...
in case the payload or the other data (not the header) fits the same sequence... have you implemented a check in order to not damage the wrong part of the file?
Does the mpeg format permit that sequence (sequence header) in other places than the header itself?
Thanks in advance for replaying.
Regards
You are right: modcopy just searches for the sequence header signature $000001B3 and replaces one byte at offset. It does not parse the MPEG2 stream. And yes, if the signature is embedded - for example - in a GOP (group of pictures) it will change video data.
My source does not mention whether sequence header signatures are forbidden in video data.
Recently I started to convert the MOD files directly to AVI using avidemux. There I use different avidemux configuration files for 16:9 and 4:3 MOD files. The next release will contain this code.
Andreas