DVD to DivX Conversion - Recommended File Sizes

[DakotaThrice]

I've recently begun converting my DVD collection so that I can store it in the loft and free up some space in my room. I'm using DVD Decrypter to rip the data from the DVDs and autogk to encode them.

I'm outputting the files at 1.36GB with 192 kbps VBR MP3 audio and using the auto width setting. I'm using 1.36GB rather than the standard 700MB as the quality this gives me is perfectly acceptable when viewed on my 32" screen, the larger file size also allows me to use the 192 kbps audio rather than 128 kbps which isn't feasible with a 700MB file.

So at present I'm currently fitting three films to a disc which will free up quite a bit of space but what I wanted to know was what file sizes should I look at using for ripping and encoding special features.

As an example I have one film that I've already encoded that has the following special features.

Deleted Scenes (10:09), Alternate Ending (6:37), Making Of (21:16), Music Video (3:50), Trailer (2:16) and Trailer (0:58) - what file size should I be aiming for to match the quality of the file I have for the actual film.

Also if I want to create a multiplexed .avi that includes commentary tracks as well as the original audio what would be my best options for sizes. For films with just one additional audio track I was thinking of staying with the 1.36GB file size and using 128 kbps for both audio tracks, however I'm unsure what to aim for when additional tracks are involved as I would like to maintain some consistency in file size accross my collection as well as an acceptable video quality.

When I get to encoding series I was considering using the 550MB file size that is sometimes used for slightly longer shows rather than the standard 350 MB which should hopefully allow for the use of 192 kbps audio and the inclusion of audio commentaries as well which would give me 10 rather than 12 episodes per DVD.


I'd appreciate any input you have on my choice of file sezes or any other recommendations you may have. Thanks in advance, Dakota.

[Baldrick]

Do you really need a specific size? If not then I would probably use constant/target quality encoding mode instead.

Another Output Size possibility is Target Quality (in Percentage). If, for example, you keep your movies on your hard drive, or run an HTPC, or plan to burn them to DVD-R and not to CD-R, then the final file size may not be important to you. A Quality encode will give you even quality throughout the movie at your designated percentage. The default is 75%, which will give you very good quality (but for DivX6 default is 60%). Good quality percentages begin at about 67% (Quantizer 3). I don't think there's much point in going above about 80% because then you'll lose some of the benefits of MPEG4's compression abilities. That's up to you, though. But remember, if you use a Percentage output, you'll lose control over file size. A Quality Percentage rip won't be split. The horizontal width will always be input source width, unless you set a fixed/maximum/minimum width in the Advanced Settings. Note: "Target Quality" mode performs 1-pass encoding while "Target Size" performs 2-passes encoding. (1 pass can speed up encoding considerably, but its not two times faster as you may expect.)

[redwudz]

That's about 45 minutes of 'extras'. Most times they aren't the same video and audio quality as the main movie. Sometimes stereo instead of 5.1 Dolby and the video may be encoded at a lower bitrate/quality. That's done to save space. If you use a bitrate calculator, it would tell you how much space they would use, depending on the desired bitrate.

At about 1000Kb/s, 45 minutes would give you a file size of about 400MB. 500MB would be about 1300Kb/s. You could test either of those bitrates to see if they are acceptable. You might also check the average bitrate of your main movie for comparison. A two hour Divx/Xvid movie at 1.36GB would also be about 1300kb/s. Shorter movies would be higher bitrates.

Personally I wouldn't use VBR audio for anything. I've spent too much time trying to convert it and it's difficult to edit. You gain some space savings, but I've never found it worth the problems. JMO.

I think if you add in all the extras and still want to keep the same quality as you have been, you would end up with two videos per DVD. But you can play around with a bitrate calculator and it will tell you size, or bitrate, depending on how you use it. The VH calculator is easy to use. Select Divx and Advanced and you can plug in values in several of the boxes to evaluate the results. https://www.videohelp.com/calc.htm

And welcome to our forums.

[DakotaThrice]

Do you really need a specific size?

There's nothing forcing me to use specific file sizes but as I said I'm trying to free up space so the consistency of knowing I can fit 3 films or 10 ~45 minute episodes on a disc helps.

Thanks for the welcome Redwudz, that calculator is pretty much what I was looking for. In general I won't be keeping all the extras, I just listed them all so people could see the durations.

As for VBR, the two video's I've done so far give me audio sizes of ~129MB for videos that are ~ 1h42m - what sort of file size should I expect to get using CBR instead?

And thanks again to both of you for your input