SVCD Quality

[Sakuya]

Hi, I was wondering. I am creating a XSVCD with a maximum bitrate of 2520 kbits/sec and a rate control mode of constant quality at 80%. The original AVI file is 540MB. And I have extracted the audio as an MP3 with CD quality that is 82.4MB! Now, after I change the volume via TMPGEnc's Audio Edit, the output file is 660MB. I want to do a re-convert because my subtitles were too low. At the same time, do you think I can raise the quality so it can fit with or without overburning to a 700MB/80 minute CD-R? If so, should I set the constant quality at 85% or maybe 90%?

[24seven]

increasing the quality isn't going to make your file size bigger.. move it to 100 percent.. it's the bitrate that is going to make it bigger.. you'll have to drop the bitrate if you want a smaller file.. But at 660mb you will have no problem fitting on a 700 or 650mb cd.. you can fit up to 803mb or so on a 700mb cd (in svcd) so i'm assuming 660 will still fit on a 650mb cd.. so quality at 100 ALWAYS and bitrate should be fine still at 2520

[johns0]

Not true,changing the percentage in quality makes a big difference,do some test files at 1 minute each during 6 different passes and figure out the average size the file will come to and increase or decrease the constant quality and keep the bitrate at 2530 max and 300 min.

[ZippyP.]

I think 24seven doesn't understand CQ mode (or missed the reference).

CQ is a one-pass VBR encoding process, you pick the min and max values and a quality level. The encoder maintains the quality while encoding but the output size is unpredictable. The amount of action and scene changes vs. static camera shots can greatly affect the bitrate required to maintain quality thereby affecting the final size.

johns0 has a good idea for estimating file size (6 tests of 1 minute each) but it will still be approximate. I prefer 2-pass VBR, you choose an average bitrate instead of a quality level. It takes almost twice as long but the size is predictable for filling up a CD.

24seven is correct, an 80 min. CD holds 800 MB in SVCD mode. The size of the avi (in bytes) is irrelevant to the mpeg size. The only thing that determines file size is the length of the clip (in seconds) and the average bitrate (in Kb/s). SVCD mpeg requires a higher bitrate than most avi compressions in order to maintain quality, and it will allow only about 50 minutes per disk for decent quality. Minutes per disk and bitrate/quality is personal choice however.

[Sakuya]

Thanks! My movie is 1 hour and 3 seconds.

[Sakuya]

I now set the quality at 85 and I'm worried that the output file size will be too large. Do you think it will fit?

[tenders]

drop the "x" and make an svcd,try this: https://www.videohelp.com/forum/userguides/119210.php

[Sakuya]

Sorry, my DVD player can't handle SVCDs. The video was fine but the audio was just screwed up. So I did a few tests and lowered the VBV Buffer Size and it kinda worked. So that's how I am making XSVCDs.