Opinions on DigiTV Advice Please

[Anonymous]

I am the (relatively) impressed owner of a DigiTV PCI card from Nebula Electronics (www.nebula-electronics.com) but, along with many other owners, have a bit of a job creating DVDs from the files it creates (MPEG2 Transport Stream). I know they are including support for converting them to DVD compliant files in updated software to be released later this year but I already have 200GB of recordings I want to get off my hard drives!

Anyway, I contacted their customer support who advised me to use VideoReDo in the meantime to edit the files (cut out commericals, etc) and then run them through PVAStrumento v2.0.30 (specifically that version) to make a PS with a packet size of 2048. While they didn't explain the reasons for using both programs I assume that the instructions are 1) use VRD to cut bits out of the original file but otherwise leave as is and then 2) use PVAS to fix the bitrate based on the max/avg found in the file (and perhaps some a/v sync issues).

I'm not exactly up to speed with all this (know just enough to be dangerous!) but I have some specific questions:

1) Why use both programs - can't I just use VRD and make sure I set the packet size and change the bitrate to a nominal value (say 8)?

2) Why does VRD have a default packet size of 2028 for DVD and PVAS use 2048? Does it even matter?

3) Is the bitrate option in VRD the whole bitrate or just for the video stream? I believe that 10 is the maximum whole bitrate for a DVD.

I have successfully created a DVD simply using VRD and TMPG DVD Author so I assume I don't need PVAS but I want to clear up these issues before I get rid of the original source files and then run into a snag!

BTW I'm impressed with VRD and will more than likely purchase it once I'm happy I can create DVD compliant files from my DigiTV files. I'm confident Nebula will release decent support for this sort of thing but if I already have a tool I can trust to do the job quickly and easily then I'm not waiting on the edge of my seat am I?

[DanR]

I'm not a DigiTV user since it isn't available here in the US, but I'll try my best to answer your questions.Anyway, I contacted their customer support who advised me to use VideoReDo in the meantime to edit the files (cut out commericals, etc) and then run them through PVAStrumento v2.0.30 (specifically that version) to make a PS with a packet size of 2048. While they didn't explain the reasons for using both programs I assume that the instructions are 1) use VRD to cut bits out of the original file but otherwise leave as is and then 2) use PVAS to fix the bitrate based on the max/avg found in the file (and perhaps some a/v sync issues).The current version of VideoReDo only accepts program streams as input. If you can open the file in VideoReDo, its a program stream.
1) Why use both programs - can't I just use VRD and make sure I set the packet size and change the bitrate to a nominal value (say 8)
2) Why does VRD have a default packet size of 2028 for DVD and PVAS use 2048? Does it even matter?
You can. Actually you don't need to worry much about the packet size. All the popular DVD authoring programs will demux the stream and author the DVD with the correct packet size. For the very few programs that really care about packet size, the VideoReDo packet size is correct. In VideoReDo, the PES packet is preceeded by a system header packet. When VideoReDo is set to 2028, the combined length of the PES packet and the system packet is 2048, the DVD standard. Regarding the bit rate, set it to any value that is greater than the actual bitrate. Most DVB broadcasts I've seen are 5-6 Mbps. If you set it too low VideoReDo will warn you with a PTS underflow messages. Also, VideoReDo will inform you of the actual bitrate after you've output a file. You might want to output just a small section of a file to quickly determine the actual bitrate.
) Is the bitrate option in VRD the whole bitrate or just for the video stream? I believe that 10 is the maximum whole bitrate for a DVD.Its the video bitrate. Remember, that rate is not the actual bitrate, but the bitrate value that appears in the header field of the MPEG2 stream. As long as its greater than the actual you're going to be fine. Most DVB broadcasts transmit with a 15Mbs bitrate which is about 3 times more than the actual video. A 2 channel audio stream bitrate is measured in Kbps, and isn't much of a factor in the overall bitrate.

One more thing. VideoReDo is excellent at preserving sync, so there shouldn't be any need for PVAStrumento for that either.

You might also want to visit the Usenet group: uk.tech.digital-tv. We have a pretty good following of users over there as well.