audio offset?

[t_tringle]

--- In ExtractStream@y..., "J. Scott Dorr" <merlin@f...> wrote:
> Also, while playing with TMPGenc, I'm supposed to put in the audio 
offset that
> splitstream gave me. I don't know if there was something wrong 
with my
> stream, or what, but this was the first little bit of the input I 
got from
> splitstream:
> 
> E:\tivo> e:\utils\splitstream b2b-2002.ty b2b-2001.m2a b2b-2001.m2v
> badblocks1.ty
> 
> Bad chunk (header?) 0, skipping
> Warning: large sequence mismatch. Expecting 0:0, got 
15d:6cc0423e in chunk 1
> record 0 last audio time 00:00:00.0 last video time 00:00:00.0
> estimated audio delay from first video -287.300000 ms
> estimated audio delay from earliest video -220.555556 ms
> Warning: found even earlier Video frame, add 100.100000 to min 
audio delay
> chunk 1
> Warning: found even earlier Video frame, add 66.733333 to min 
audio delay
> chunk 1
> Warning: second byte in chunk 4095 is non-zero 1e:ff
> 
> So... do I use the audio delay from first video? Or from earliest 
video?
> And what about the Warnings that say I should add xxx.xxxxxx to min
> audio delay?
> 
> - scott

Scott,

Not sure if this helps, but when I was first learning about 
extractstream and all of the fun involved with getting a stream off 
the tivo and onto a pc I learned one thing that has made my audio 
synch problems go away.

first a few things. I use "sendstream" to get the ty stream onto my 
PC using NC for windows 2000. I can send you links to the documents I 
used to gather all of the commands necessary to do this.

After getting the complete stream over to my pc I use "convertstream" 
to turn it into an mpg file. !Note, this mpg file has an audio 
offset, if you use splitstream it does give you an offset but i have 
found it to be faulty most of the time, or at least I have never 
gotten it to work the same way twice.

What I do next, is that I simply use DVD2AVI to create a DV2 project 
file, at the same time it creates an MPA file. Now here is the good 
part, I don't think I have seen anybody mention this on this forum or 
anywhere else that I have seen, but at this point the name of the mpa 
file contains the audio offset from the video, you will see a number 
or a negative number in the name of this file. I have done this a few 
times now and every time, it has been perfect. I then use winamp to 
create a 48bit/192Khz wave file of the mpa, and use that file for any 
encoding I do.

You can use the offset in a few different ways. After using 
VFAPIConv.exe to create an avi that programs like TMPEG, or avidub 
can use, you can.

1. Use avidub to create an avi file (using the huffyuv lossless 
codec) that you can then encode, Just make sure you set "Audio - 
Interleaving" in the menu. In the dialog that shows up there is a 
place for offset or something to that effect. Place the exact number 
from the mpa that dvd2avi created in that spot.

2. In TMPEG, you simply put the offset in the appropriate spot, 
however the offset has to be entered in the opposite range, meaning 
if you have an offset of -66 listed in the dvd2avi conversion audio 
file, then you need to tell tmpeg to use an offset of "66" as a 
positive value. This will correct the audio.

Hope this helps, Roger Merchberger has a great web page that explains 
alot, but he uses splitstream and as I said I found that solution to 
not work for me alot of the time. For me sendstream has a lot less 
problems than extractstream or any other program I have tried, 
extracting the video with. It has almost never gotten bad blocks or 
bad chunks etc.

Hope this helps and feel free to e-mail me if you have any othe 
questions, It may take a little bit for me to respond as most of my 
systems are torn down right now while I rebuild my video 
editing/capture/tivorip system.

Good Luck

Tim