Choosing the right bitrate for DVD capture

[OS_Man]

Hello,

When I capture in mpeg-1 format, I use standard bitrate (1150 kbit/s) naturally. I think there is not a standard bitrate for mpeg-2 format. Because, it is said in https://www.videohelp.com/calc.htm that mpeg-2 bitrate varies as to the chosen capture time. According to it, if I intend to capture 120 minutes video in mpeg-2 format for a DVD5 (4.7GB), I have to set the maximum bitrate 4853 kbit /s.

These are the bitrates for several time lengthes according to https://www.videohelp.com/calc.htm :
Max bitrate for 120 mnts mpeg-2 must be 4853 kbit /s
Max bitrate for 90 mnts mpeg-2 must be 6548 kbit /s
Max bitrate for 60 mnts mpeg-2 must be 9570 kbit /s
Max bitrate for 40 mnts mpeg-2 must be 15000 kbit /s
What do you think about this?

Does it mean, I can only record 60 minutes mpeg-2 video on a DVD5 if I set the bitrate approximately 10 Mb/s ? Is it ouf of question to record 120 minutes mpeg-2 video on a DVD5 with high bitrates (higher than 5Mb/s)?

- Does the quality between expensive and cheap cards vary at the same bitrate? For exampe, If I capture at 5Mb/s with a 1000$ card and 200$ card. Will the quality be same?

- Is the mpeg-2 capture file SIZE equal at the same bitrate regardless if the card expensive or cheap?

Thank you very much for your help.

[Nelson37]

There is no standard bitrate for either MPEG-1 OR MPEG-2. There IS a standard bitrate for VCD, and MAX bitrates that cannot be exceeded for SVCD, CVD, and 1 or 2 on a DVD. 10 Mbit/s would exceed the DVD spec.

Using VBR, you can and will go BELOW the maximums the calc shows you, and you cannot EXCEED the spec maximums for the desired media.

Note that some players do indeed handle bitrates higher than spec, at least for some media. But there is no guarantee, and limited compatibility.

Bitrate determines filesize. However, various cards and software encoders will deviate from the specified bitrates, sometimes in dramatic fashion. As long as you don't go over the spec maximum, you can use whatever bitrate you desire, however you are limited by whether the resultant file will fit on a DVD.

A low-motion clip may average well below the specified bitrate, resulting in a file that will fit. The same length clip, with the same bitrate settings, but with lots of motion, may exceed the available size. It all depends on how your encoder decides to allocate those bits. The important point here is that you do NOT necessarily get what you asked for.

Have never used a $1000 card, but I have used several encoders, and different ATI cards on various PC's. Quality of encoding does vary quite a lot at the same settings. However, I would not buy a $1000 card unless it would do HDTV, and even in that case I would put the money into a different solution. Unless you have money to burn, NEVER buy the top of the line in PC peripherals. It will be half the price in a very short time, or the lower-priced alternative will be upgraded to very near the same capability.

Put the money into increasng the qualtiy of your available source.