Optimal Video Bitrate and target DVD size

[src2206]

Hello there

I have started authoring DVDs for last few months (with a lot of help from my friends here). So I still consider myself as a newbie in this particular area.

There are some doubts in my mind which I would appreciate if some experienced users may clear up.

I generally use DLP for authoring. Though I convert/ encode the main video file generally using HEnc to MPEG2. I use VirtualDub to demux the audio and save that to wave format. After that in DLP I feed both video and audio to compile the final result. Now while using DLP, I found that I have to preset the target size of the DVD eg, DVD5. Depending on this target size I also calculate the video bit rate to be used in the HEnc (using bitrate calculator available at this site).

Now instead of using DVD5 (which I mostly use) if I use DVD9 as the target size, take the DLP output as folder (AUDIO_TS and VIDEO_TS), make an ISO of that folder using ImgBurn and then using softwares like DVDFab if I cut it down in to teo parts, suitable for 2 DVD5 sizes, will not I get a much better quality? What really is a good video bitrate for DVD movies (non HD, standard)?

I hope this question is not that dumb.

Thank you.

[tinker]

Anything between 6000 and 9000 kbs is good. Higher kbs better. If you want good bitrate and reasonable file, encode as VBR set at 8000kbs max, spikes will go higher.
With your wav file you have to be careful, because it is too big and max bitrate including Audio is 1080.
Why do not use AC3?

[guns1inger]

Actually, the combined size of two DVD5 is larger than that of a single DVD9. So if you are going to split it, you are better off splitting it into two when you encode, and authoring two discs, than splitting it afterwards with DVDFab.

All you need to do is add a Trim() statement to the avisynth scripts you use to feed HCEnc to split your video.

[src2206]

@tinker
Thank you for your reply.

Sorry, mate, forgot to mention that. I do change it back to AC3. So while authoring I use the MPEG2 video and AC3 audio.

@guns1inger

Hello mate. Thanks for your reply.
So if I follow your path, while encoding the MPEG2 will get divided in to two parts and I have to author twice- right?

But

i) as I'm demuxing Audio and Video, won't there be a out of sync audio for the second part?
ii) and what about the Menu? How am I supposed to tackle that?

Though I understand your point regarding the size, but DVDFab will take care of the Menu and Audio and Video both.

Please let me know your opinion.

[guns1inger]

Audio sync should not be a problem, and neither should the menu. My preference would be to split and author two separate discs, rather than use an automated tool to just split it down the middle.

[src2206]

Audio sync should not be a problem, and neither should the menu. My preference would be to split and author two separate discs, rather than use an automated tool to just split it down the middle.

I agree with you. I would love to do that too. But as I've never done it before, how exactly can I do it...I mean taking care of the two problems (that you said should not be a problem) that I mentioned in my last post?

[guns1inger]

The Trim() statement in avisynth will allow you to split the video and audio for encoding. As you are using HCEnc, you must have at least a passing familiarity with avisynth. Create a script and call it movie_part_1. Copy it and call it movie_part_2. Add Trim(0,nnn) to the end of script 1, where nnn is the frame you want to split the video on. Add Trim(nnn+1,0) to the end of script 2.

You can now use these two scripts to create the two halves of your video by encoding them with HCEnc. You can also use these scripts and DAudioK to create AC3 audio files to match. There will by no sync problems if you use the same scripts for video and audio encoding. Use the shorter running times to work out the bitrates to encode to based on DVD5 size discs. Once you have your assets, it is a simple matter of authoring each into it's own disc and burning it.

[src2206]

Thank you guns1inger

Quite clear. But I do not use HEnc/ CCE to encode audio. I can use DAudioK for the job as you describe, but I use another method described in this forum to encode the two channel audio in to 5.1 using Vegas. In Vegas only I encode the Audio to AC3.
Now is it possible to

Either

split the wave file into two without taking the output in AC3 using DAudioK? I understand that I have to do everything twice in Vegas though.

Or

splitting the AC3 output from Vegas using DAudioK?

I am accustomed with AVISynth scripts (Thanks to other members of this forum like Manono), but I am not even a average user of it. Generally I use FitCD to create a script and feed that directly to the encoder.

Regards....

[manono]

Yes, it's possible to split the audio either way. I use HeadAc3he for the job. Maybe split the finished AC3. Open it in HeadAC3he, set the Destination Format for Source, name the Destination File as, maybe, Part1, and in the middle of the GUI set the start or end frame, depending on if you're making Part1 or Part2. Before starting find the exact time that part 1 ends, from your AviSynth script opened in VDub(Mod) and taking note of the time of the last frame, or maybe the length of your Part1 in File->File Informatio.

There are other ways to do this, I'm sure, like splitting the WAV file in an WAV Editor, but HeadAC3he has always worked well for me. I've never used DAudioK, so I don't know if it splits or not.

[guns1inger]

DAudioK can upsample 2 channels to 5.1. I haven't tried it, so I don't know how good it is. I use it to convert 6 channel AAC to AC3 using an avisynth script to re-order the channels.

[src2206]

Thank you manono and gunsl1inger

So DAudioK can not be used for splitting right?

manono, basically if the same AVISynth can be used to split the Audio and the Video (though separately) chances of human error is completely minimized- isn't it? I understand your process, but the only spot of worry is that if there is even a small difference in the Audio and Video introduced while noting down the 'cut- time', then Audio and Video will be out of sync. So can't the AVISynth script be used to split in HeadAc3he?

One more thing gunsl1inger, I do not convert 6 channel from one version to other, rather, I convert 2channel audio to 6channel and then encode that in AC3. It give quite a good result. I found it out here: https://forum.videohelp.com/topic322664.html

[guns1inger]

It looks like you are using my guide to create a pseudo- 6 channel audio mix. Since that was written, a few programs have tried to automate the process. Soopafresh has a script that does it, and DaudioK has a function built in. You lose nothing by giving it a try to see how good it is.

[src2206]

Oh yes, I am very sorry guns1nger for not acknowledging that, I should not have missed it.

Basically, I have nearly memorized the process and hardly go back to that thread, I just refer to the guide you have written which I have saved in PDF.

As I do not have a 6 channel Audio, I really can not understand the difference. Would it be possible for you to give a verdict regarding the new ones? It will be immensely helpful for me.

I could not find Soopafresh while googling, could you please post the link here?

Regards

[thecoalman]

I could not find Soopafresh while googling, could you please post the link here?

Regards

https://forum.videohelp.com/member94129.html

[guns1inger]

And Soopafresh's upmixer script thread : https://forum.videohelp.com/topic326127.html

[src2206]

Thanks thecoalman and guns1inger. I never really thought that he is a distinguished member (or dismember), though I recognized the avatar instantly.

Though it does not seem that the script will be able to handle AVISynth script which DAudioK can.

You have told me to use the trim() command. Could you please tell me how can I ascertain the frame numbers?

[manono]

Open the script in VDub(Mod) and scroll to the place where you want to split it. Take note of the frame number.

If you decide to split at frame 100000 (100000 being the last frame of part1):

Trim(0,100000)

And the Trim for part 2:

Trim(100001,0)

I wouldn't do it that way, by the way, but since you asked...

[src2206]

How would you do manono...? Please share. You know I'm rather inexperienced in comparison with you and other esteemed members here.

[manono]

I'd encode the whole thing at once and split it when done, perhaps after muxing in the audio, or even perhaps after making the DVD and using VobBlanker for the split.

The reason I wouldn't split it in half before the encode is that, unless you do some testing before hand to find the best place to split it, you'll wind up with 2 halves of differing quality, perhaps a lot different quality. For example, a lot of movies have a lot of the action - the fights, explosions, chases, etc. - in the second half of the movie. If you split it in half and give each half an equal bitrate, for those movies the part2 quality will suffer because the more complex scenes need a higher bitrate for the same quality.

[src2206]

Thats what I thought at the first place, though instead of using VOBBlanker, I proposed DVDFab Platinum (I know its not free, and I never used VobBlanker). The only problem is setting the target size in the DVD authoring program. Setting DVD9 is not a good idea, as (correctly pointed out by guns1inger) 2 DVD5 > 1 DVD 9. But I don't think I can set 2DVD5 as target size in the DVD Authoring Program.

How do you tackle that? Please suggest.

Regards

[manono]

How do you tackle that? Please suggest.

Use an authoring program that doesn't care how big the result will be. What the heck is an authoring program doing anyway, telling you how big you can make your project? Muxman doesn't care. You set the target size in the encoder, not in the authoring app - not, that is, unless you're inviting it to reencode it and ruin all your hard work, and waste more of your time. But I don't use DLP anyway, so what do I know?

This whole thread is kind of bogus anyway. There is no one-size-fits-all "Optimal Video Bitrate", and the "target DVD size" is however much space you have available.

[guns1inger]

DLP will let you go oversize. It will warn you, but it shouldn't stop you.

[src2206]

Thank you manono (sans your last comment).

Thank you very much guns1inger.
I shall surely try DAudioK and let you know. In the mean time I thing Encore CS3 also does not care and the target size can also be set to custom.