View Full Version : Losing A/V sync after TYTool extraction

02-07-2003, 06:36 AM
I'm using TYTool5 under windows to extract (and split) tystreams from my SA Series 1 UK Thomson Tivo. The problem is that when i mux the streams using mplex, the audio and video slowly drift out of sync during the course of the programme. Is there any extraction/muxing method I can use to stop this from happening?


02-07-2003, 08:02 AM
Yes - use tydemux. This is available in the stick thread in this forum started by Olaf_sc.

You need the latest version 0.4.2

The problems you are seeing are due to errors in the ty stream. vsplit does not fix all of these errors, tydemux does.

02-08-2003, 07:43 PM
I tried that, but unfortunately it only extracts the first couple of seconds of the stream. It gets the whole of the video stream, but the audio stream is only about 52k. Looks like I've got a badly broken stream.

02-08-2003, 08:24 PM
as I don't have a uk tivo, this is just a guess, but ...;)

use tytool in "tystream" mode (extract raw .ty files)

then use jdiner's newest vsplitmux2b


...to get the elementals. (mpa/mpv)

then mux and edit using tmpegenc. this will give you a synced mpeg that most dvd authoring tools are happy with.

If your not looking to burn disks, you can us the built-in muxer in vsplitmux2b. It'll give you a nice, quick mpeg, but as the tool is still a work in progress, there are still some issues with the muxed mpeg output.

02-08-2003, 08:53 PM
another thought....

If there's a spot in the ty that's hosing the audio, try skipping past it.

As a test, use vsplitmux2b's muxer output to find the spot where the audio glitch happens. Try jumping in at say 10 chunks, then 20 chunks, then 30 chunks.... untill you find the spot where everything goes ok.

here's the command:

vsplitmux2b -m -j10 -l200 badfile.ty badfile.mpg trash.mpa

...where -m tells vsplitmux2b to output a muxed mpeg, the -jxx tells vsplitmux2b how many chunks to skip before processing and the -lxxx tells vsplitmux2b how many chunks of the file to process. (figure you'd just want to do enough to tell where the bad spot is)

Once you know the spot where the glitch is, (for instance, you find that you still have a problem when you jump in 34 chunks, but it does fine when you jump in at 35 chunks) you can use that point to jump in past it when processing normally.

vsplitmux2b -j35 badfile.ty badfile.mpv badfile.mpa

there's a good chance that you'll find some spots where the output will really freak out.... just jump a couple of chunks after that point and keep going.

Good Luck!!