SVCD Standard

[delicious]

Hi... I would like to start making some SVCD's (I have experience making VCD's and DiVX's) and would like a little help with one thing.

I've read that a SVCD disc remains compliant until the MPEG file exceeds a bitrate of around 2600. So, if the resolution remains at 480x480, and nothing else changes, save lowering the bitrate to maybe fit a movie on 2 discs instead of 3, will my SVCDS still be compliant?

I hope my question makes sense....

Thanks for any help.

[adam]

The video stream cannot exceed 2600kbits.
The audio stream cannot exceed 384kbits.
The total bitrate (video+audio+subs+some overhead) cannot exceed 2778kbits.

Factoring in a typical audio bitrate of 224kbits, that leaves you with a safe max bitrate for video of about 2500kbits. You can go as low as you want, you just cannot exceed the set maximums, and in fact, few dvd players are completely strict regarding the standards.

The typical way to make SVCDs is to set a minumum bitrate of around 0-300kbits and a max bitrate of about 2500kbits depending on how high your audio bitrate is. From there you can simply use a bitrate calculator and multipass encoding to set the average bitrate to fit your movie exactly on 1, 2, or 3 cdrs. As an alternative you can use 1-pass encoding, however it is not possible to completely predict the filesize but there are some tests you can run to achieve a better prediction. DVD2SVCD has a built in function for this and there is a script available at the kvcd.net forums for the same purpose. Personally, I recommend multipass encoding, at the very least it just simplifies things.

[delicious]

muchas gracias, adam

[fingers]

Question about the minimum bit rate.

Adam you're saying to use 300, but in reading many messages from this forum users state that many players choke if the datastream is below 500... Is there a minimum bit rate that would be recommended to be more widely compatible... ie I don't want to have to go back and re-encode things later if I get a new player that can't handle such a low bit rate.... If it helps I have a Pioneer DV333, which plays SVCD's but doesn't read the menus, I want to make sure that whatever I encode today will be widely accepted in the future.... I know we can't predict the future, but I would think that a higher minimum bit rate of say 900 would be more widely compatible... or am I just wasting bits by going so high?

[adam]

Well you are wasing bits by using 900kbits, that's for sure but this would generally be more compatible. Actually, from my experience, if you set your min bitrate to 300, it will probably never get below 500 anyway. The point is that you never want to set your min higher than you think you will need for any given scene. The fact is that dvd players that choke on low bitrate are definitely the exception to the rule. I always use 300 and I have tested my SVCDs on every dvd I could find, and none of them had any problems. There's a tradeoff to everything but personally I wouldn't worry about compatibility in this regard since problems are so rare. I'd say anywhere between 0-500 is good.

[Bstansbury]

Adam,...

What guide do your use or recommend for making good SVCD's

Thanks in advance.

[energy80s]

Or you could just use CBR at 2496kbps and get 40 mins on each disc guaranteed, at excellent quality and quick encoding times.

[patsym1]

Regarding Maximum Bitrate we did a test on 3 stand alone DVD Players.
Philips,Grundig,and Nec, The maximum bitrate we could use was 2300,anything higher and you end up with a disc that will freeze every minute or so for a couple of seconds. that was for SVCD'S. Obviously there are other makes of standalone players which will go higher than that. Which makes me wonder why most Encoders default settings are 2500 bitrates or above for Svcd's ,I know you can of course reduce the bitrate level but not all programmes allow you to do this ,Easyvcd to name but one.


regards patsym1

[sterno]

Which makes me wonder why most Encoders default settings are 2500 bitrates or above for Svcd's

Probably because the accepted SVCD standard specifies the maximum bitrate, and with the 224k audio that is typically used the maximum bitrate for video is about 2500k. If you can't play anything over 2300k on those players then they probably either do not correctly support SVCD or your encoder allowed the bitrate to go too much higher than you specified.