avi to mpeg2 too big

[younso]

I have 3 seasons of a comedy show in avi format that I want to convert to mpeg2 and then burn as a dvd. Each season has 6, 9 and 7 episodes each and each episode is 30 minutes long I am using TMPGenc to convert to mpeg2 and TMPG DVD Author to author my dvd. Everything works fine. But I have a questions regarding how many episodes per dvd compilation.
For instance I could put 5 episodes on one disc but the size of the final compilation in DVD Author exceeds 4.5 GB. Would it be better to adjust the size of each mpeg2 file in TMPGEnc to 20 % of a dvd disc when convertng from avi or would it be better to convert the final dvd compilation (VIDEO_TS and AUDIO_TS folders) with dvd2one? Which method is quicker? I notice that if you shrink the mpeg2 file size too much it goes from 720x to 352x. Should I have this as a minimum ie do not go under 720x?

[andyp1]

If you are happy with the 5 episodes per disc and they come to 4.5GB , thats fine. Use TMPGenc DVD Author to author the DVD ,you will be given a warning about too big a file just click ingnore or continue anyway .
Once you have your VIDEO-TS folder , open it with DVD Shrink and let it squeeze it slightly to fit on a DVD-R.

[daamon]

Hi younso,

Use AVICodec to get details of the AVIs (I'm gonna presume they're all the same in terms of resolution). I ask because, if the resolution is is not (or not near) full D1 (720 x 480 / 576 = 720 x NTSC / PAL), then you can encode with TMPGEnc at 1/2 D1 (352 x 480 / 576).

This means that you can use a lower bitrate (say, around 3,000kbps - use the DVDRHelp Bitrate Calculator to get an exact rate) and so meaning that you can get a lot more on a single DVD (assuming you're also gonna use compressed audio - AC3 etc.). You should aim for around 4 - 4.5 hours max. at 1/2 D1 on a DVD. You can go for more, but common consensus is the quality degrades too much.

"Will it affect the quality?" I hear you ask - Well, given that (for example) VHS is 352 x 240 then, if it's from VHS you won't affect the quality. The higher the AVIs are away from 1/2 D1 the more you'll lose sharpness. But, that said, even if they are full D1 resolution the loss in sharpness shouldn't be too bad.

Try it out on a sample and burn to a re-writeable DVD to see if you like what you get.

Hope that helps....

[younso]

OK, I got the whole D1 thing, but if the files are D1 quality I guess I should not go under 720x576.
Most likely the 5 episodes will result in a much larger compilation than 4.5 GB, more like 5-6 GB.
When it comes to shrinking the files/video_ts folders what I was thinking was this: lets say it takes 3 hrs to convert the avi at full resolution does it take longer or shorter to convert to a percentage that still retains the D1 quality ie does the compression take longer or shorter? If it takes longer then I might as well convert all of the files first at 100% and then use dvd2one to compress the whole thing.
Or?

[daamon]

Hi younso,

If the AVIs are at full D1, and you wanna stay that way, then IMO (based on logic and not experience as I've not done this) I'd say that it'd be quicker to use the DVDRHelp Bitrate Calculator to figure out a bitrate for the amount of time you want to put on to a DVD.

Then, encode your AVIs at that bitrate to MPEG2 ready for burning and no need to shrink. If you go for slightly bigger MPEG2s, it's gonna take longer to create them initially then, using something like DVD2ONE or DVD Shrink, they'll have to be transcoded (re-encoding MPEG2 to a smaller MPEG2) which will also take time - the total of which is longer than just encdoing to MPEG2s at the correct size.

Using 2 hours (4 episodes @ 1/2 hour each) gives a bitrate of just under 5,000. This assumes you're using compressed audio @ around 192 - 256kbps, and not PCM / WAV @ 1,536kbps.

Experiment with short clips (say 10 - 15 mins) with different bitrates to see where your quality starts to degrade beyond what you find acceptable.

Good luck.

[Shudder]

I don't get it, you want to set the bitrate incorrectly so you get a larger than 4.3G DVD, then use Shrink/DVD2One on it? You would be MUCH better in just setting the Bitrate so it's exactly 4.3, that's all there is to it.

If you don't want half d1 and it barely goes under the threshhold (I think Tmpgenc has it at 4mbps), then just change it back to 720x and you'll be fine.

[younso]

Great, now I understand. I have not messed around with the bitrate before, but know I understand how this is much better and quicker.

Hi younso,

If the AVIs are at full D1, and you wanna stay that way, then IMO (based on logic and not experience as I've not done this) I'd say that it'd be quicker to use the DVDRHelp Bitrate Calculator to figure out a bitrate for the amount of time you want to put on to a DVD.

Then, encode your AVIs at that bitrate to MPEG2 ready for burning and no need to shrink. If you go for slightly bigger MPEG2s, it's gonna take longer to create them initially then, using something like DVD2ONE or DVD Shrink, they'll have to be transcoded (re-encoding MPEG2 to a smaller MPEG2) which will also take time - the total of which is longer than just encdoing to MPEG2s at the correct size.

Using 2 hours (4 episodes @ 1/2 hour each) gives a bitrate of just under 5,000. This assumes you're using compressed audio @ around 192 - 256kbps, and not PCM / WAV @ 1,536kbps.

Experiment with short clips (say 10 - 15 mins) with different bitrates to see where your quality starts to degrade beyond what you find acceptable.

Good luck.

[daamon]

Great, now I understand. I have not messed around with the bitrate before, but know I understand how this is much better and quicker.

OK, well done - it's a good feeling when you start cracking this stuff, eh?.

Now, if encoding time is not an issue (I leave mine running overnight), look into 2-Pass VBR (VBR = Variable BitRate).

Why? Well, because with 2-Pass VBR you set a min., average and max. bitrate. The benefit of this is that it can (read as "may") improve the quality of the picture over a CBR (Constant BitRate) encode at the same bitrate as the average. I'd suggest the following settings:

Min = 2,000kbps
Average = What the bitrate calculator gives you
Max = 8,500kbps (again, assuming compressed audio)

How? Well, let's say you identify that, to reach a certain quality level that you desire, you have to encode at 7,000kbps. If you do this at CBR it means that every single frame will be encoded at 7,000kbps - even if some frames don't need that high a bitrate.

When encoding with VBR, because you set the min, average, and max, the tool can look at each frame and decide how much bitrate to apply - down to the minimum for frames that don't need much, up to the max for frames that do need it. It then does this in accordance with the overall bitrate being the average that you specify.

In short, it means that you can still get your 4 episodes (4 x 1/2 hour) on a DVD at an avergae of 5,000kbps, but the tool has been allowed the flexibility to drop the bitrate where it doesn't need it and use it where it does need it - or, put another way, put the quality into frames (high bitrate) where it's needed without doing it all the way through and so not resulting in an unneccessarily large file.

Because of this, 2-Pass VBR can often be used to provide better quality for longer footage without going over a desired file size. When the footage goes below a certain duration (around 100 mins I think) then CBR might as well be used as the resultant filesize at the highest bitrate (around 9,000kbps) produces a file that will still fit on to one DVD disc.

Hope that helps. Good luck...

[younso]

Wow, thanks a lot. The series I am trying to convert is Coupling, so not a show that will probably need the higher bitrate since there is no action involved, but you never know. I was already thinking of trying CBR and the way that you previously descibed to get everything right and then try it with VBR to increase the quality. With your description I am half way there already.

[flaninacupboard]

i agree with what daamon says, except minimum bitrate. i'd use 0 as the minimum, there's nothing in the DVD spec that forbids it, and you don't need 2mbps for a black screen. the extra bits will come in handy with the amount you're trying to squeeze on a disc.

The official DVD's have all 7 eps of series three on one disc :P

[daamon]

Wow, thanks a lot ... With your description I am half way there already.

No problem. I'm glad you're making progress...

i agree with what daamon says, except minimum bitrate. i'd use 0 as the minimum.

Fair enough. I've not been doing this long and am still learning.

[teegee420]

i agree with what daamon says, except minimum bitrate. i'd use 0 as the minimum.

Fair enough. I've not been doing this long and am still learning.

I would go with 300kpbs just for compatibility reasons. Some players might not be able to handle a minimum bitrate of 0.

[flaninacupboard]

well that is what TMPGenc reccomends, and i don't honestly see a stream going as low as 0, but i see nothing in the DVD spec to say you can't have 0kbps video with whatever audio.