I've been reading the threads below on AC3 delay (as extracted by DVD2AVI) with interest.
I'm converting a section of a concert DVD to XviD with the original 5.1-channel AC3 audio. The AC3 file as demuxed by DVD2AVI contains "DELAY 867 ms" in its title.
Ok, simple enough. What I'd like to know is: If I correct the delay with BeSweet or any other tool,
will BeSweet in fact re-encode the whole file (??) In other words, in order to add in the delay, will it be necessary for BeSweet to un-encode, add in the delay (I presume it would add in 867 msec of silence at the beginning), and then
re-encode the AC3?
What I'd like to know is whether my Ac3 file will be of the exact same quality as it was before I added the delay. I obviously want to maintain the 5.1-channel sound. Simply put: Will BeSweet process the whole file,
or will it simply add 867 msec of silence at the beginning and do
nothing else?
If the latter is the case, would this command line do the trick?:
Code:
"C:\path_to_besweet\besweet.exe" -core( -input "C:\path_to_my_file\myfile_with_DELAY_867_ms.ac3" -output "C:\path_info\myfile_postprocessing.ac3" ) -ota ( -d 867)
. . . or is the "ac3enc" parameter needed?
Wizards and GUIs for BeSweet make me nervous because they don't seem to allow you to
not use certain switches.
If in fact BeSweet
will reprocess the whole file, I've considered just trimming the AVI file instead. I'm thinking if my file moves at 29.97 fps and I have a 867 msec delay, then 29.97*0.867 = 25.98399 ... could I not just delete the first 26 frames of my AVI with VirtualDub and get a good result?
So that's that. Part 2 of my question regards something
Incredible said in another thread about the delay information being in the IFO file. First, I'm wondering: which IFO file (the VIDEO_TS or the VTS_01), and where can I find that info?
Lastly, I'd like to know, if anyone else knows, whether DVD rippers rip the IFO info exactly from the disc, or whether they change it in respect to the user's reauthoring specifications. I guess that sort of answers itself since obviously the rippers remove Macrovision, region coding, etc. But in my case, I used DVD Shrink's start/end frame feature and selected only the
portion of the program chapter I wanted to rip (i.e. I only ripped about 37 minutes of a concert lasting probably twice that long). So basically I'm just wondering whether the delay information that is supposed to be in the
ripped IFO file (i.e. the one now on my hard drive) is accurate in regards to: a) what is on the DVD,
or b) the newly reauthored VOB on my hard drive.
Did that last bit make sense?
Thanks,
-abs