How do I create a lower quality DVD

[arrosen]

I am trying to put 3 hours of VHS cartoons on a DVD for my kids - 4 45 minute tapes. When I convert them to MPEG-2 (using the defaults) in either ProCoder or TMPGEnc, I get about 8 G worth of MPG files. What settings should I use to make the files smaller and still be DVD compliant?

[Bob W]

You could make the files into DVD files then just use DVDshrink to make them fit onto a single DVDR.

[holistic]

https://www.videohelp.com/calc.htm

Cartoons - I would try a bitrate of 3000+ and audio of perhaps 192

try the calc.

][

[LanEvo7]

If you are using TMPGEnc, do the following:

Load the DVD Template
Then load unlock so you can change the settings

Enter these values For Video:

Size: 352x480(NTSC) or 352x576(PAL)

Rate Control:
For faster conversion: CBR at 2861
For better quality: VBR with average of 2861, max of 5000, min 1000

Go to audio and change the bitrate to 192

You should get the files to be slightly under 4.3 gigs with these settings and itis fully dvd compliant.

[arrosen]

Thanks...I'll try a lower bitrate; but this raises 2 questions for me:

1. Is bitrate directly proportional to file size? In other words, If I use half the bit rate (assuming CBR) will the file be half the size?

2. Does CBR or VBR yield a smaller file size (regardless of video quality)?

Thanks!

[thayne]

Thanks...I'll try a lower bitrate; but this raises 2 questions for me:

1. Is bitrate directly proportional to file size? In other words, If I use half the bit rate (assuming CBR) will the file be half the size?

2. Does CBR or VBR yield a smaller file size (regardless of video quality)?

Thanks!

1) Yes

2) VBR will give you a lower files size with higher quality compared to CBR. VBR is also more acurate at detirmining final file size too.

[ImaWeTodd]

VBR is also more acurate at detirmining final file size too.

I don't use TMPGEnc, but that doesn't sound right. For a Constant BR, one would think there was little leeway in the calculation of the file size.

Arrosen:

I loved your topic title. I myself have become adept at creating low quality DVDs.

Here are some of my features:

• Interlace problems - Might just make you sea sick
• Audio Sync - But can you really tell on a cartoon ?
• Poor Colors - Wow to the oversaturated orange and red
• And sometimes they just don't play

[bugster]

VBR Vs CBR w.r.t fileseize.

Only two things affect the filesize of an mpeg file. These are Bitrate and playing time.

CBR and the AVERAGE value with VBR give identical filesizes, assuming the encoder is accurate in its use of these settings. As Thayne said, VBR will generally give a better quality result than the equivalent CBR, or you can reduce the VBR average slightly, for a smaller size at 'equivalent' quality.

[flaninacupboard]

Well 2-pass VBR with an average bit rate of (say) 4,000kbps is more likely to actually hit that target than CBR 4,000kbps. This is because of the differences in the predicted size of an encoded frame, and the actual size of the encoded frame. for anyone using TMPGenc, turn encode logging on next time you use it, and have a look at the figures, there's often a -big- difference here!
Consequently, the final file is not exactly the requested rate. doing a second pass allows the encoder to adjust the level of compression on the rogue frames, to get a more accurate bitrate.
So CBR is less accurate than 2-pass, which is less accurate than 3-pass, which is less accurate than 4-pass etc etc.

[ImaWeTodd]

Well 2-pass VBR with an average bit rate of (say) 4,000kbps is more likely to actually hit that target than CBR 4,000kbps. This is because of the differences in the predicted size of an encoded frame, and the actual size of the encoded frame.

Amazing. This blows away my assumption that CBR encodes each frame using a specific number of bits. I guess the proof is in the testing (as you say, you see it in the log).

Even on TMPGEnc.net they are being misleading:

How can we calculate the actual size of MPEG file which will be crated?
If you choose CBR, The following equation can be used to calculate. "2048/2018" stands for bitrate of system stream.

Filesize (Kb) = (Video+Audio) x (2048/2018) x sec/8

E.g. Video is 1150Kbps, audio is 224Kbps, 15 sec MPEG file would be "(1150+224) x (2048/2018) x 15/8" = 2614KB

This implies it would be exactly 2614kB.

I guess I could do some tests of my encoders, but this ends up being academic, because I usually use vbr, give a little pad when I calculate, and rarely ever fill the dvd-r anyway.

Thanks

[SquirrelDip]

DVD for my kids

I've done this many times... I've found that when dealing with the kids that video quality is not the most important thing - they could care less if there's a few artifacts or blocking.

I've encoded just over 5 hours on single dvdr's - used thes on longer car trips. Use half D1 and set your bitrates low (use the www.dvdrhelp.com/calc for estimating your bitrate), I've gone as low as 1200 and it's still acceptable for kids shows. I also tend to use film framerates (quality seems a little better) but that's when copying dvd's...

[flaninacupboard]

Ah well, this is where multi-pass CBR comes in. acts the same as multi pass VBR, but just corrects rogue frames to fit the CBR spec instead.