video bit rates for DVD

[jparnold]

I'm sure that I can remember reading a discussion (or two) regarding video bit rates for rendering to DVD somewhere here but have used 'search' without finding it.
I found that the maximum for variable is best at 8000. I also remember the article I read explaining that there is a maximum bit rate which a DVD can be (including the audio) and that the type of audio compression (mpeg. lcpm etc) used affects the maximum VIDEO bit rate.
Can anyone point me to that article or if in fact it doesn't exist here then point me to another web site which does explain it all.

Lastly is there a method of searching for an EXACT phrase. I have found that if I search for say bit rate then I get results for not only the exact phrase but also every post which contains bit AND rate
Thanks

[skier-hughes]

I have found using a max of 8000 for both audio and video works best.
So, my audio is 256 ac3, my video is 7500, I fit nicely under the 8000.
The max is 9800.

If this doesn't answer your techincal queries, you're going to deep

http://www.videohelp.com/dvd

[jparnold]

Thanks Graham for the super fast response.

I normally use LPCM audio compression. I also remember reading something about AC3 compatibility (for DVD players) but can't remember exactly - is AC3 as compatible as LPCM? And is AC3 the same as MPEG audio (I don't see AC3 which creating a make movie template)?

[Ken Berry]

John -- just to jump in on your last post, AC3 is not the same as mpeg layer two audio, but uses similar rates of compression and produces similar (high quality) output.

And we in Australia (and Skier too) are lucky in that for PAL countries, both AC-3 and mpeg layer two, as well as LPCM are part of the DVD standard and all DVD stand-alone players can play any of them. In NTSC countries, mpeg layer two is not part of the DVD standard, though in practice these days just about every stand-alone player will play it nonetheless.

BTW, the total permissible combined video + audio bitrate is 10,000 kbps, so Skier's comment about 9800 is the maximum video bitrate, which would allow an audio max of another 200 kbps. But in practice, most stand-alone DVD players have difficulty with video bitrates above 8000 kbps. So try to keep it at that or a bit below.

[jparnold]

Thanks Ken
That begs the question though is what audio compression do I choose when creating a template to render to DVD (MPEG or DOLBY) as that is all I see in the drop down apart of course from LPCM or do I have a problem? Should I stick with LPCM and if so how many kbs does it 'occupy' compared with the others?

[skier-hughes]

Dolby, smaller file for similar quality to lpcm.

[Trevor Andrew]

Hi John

LPCM, Digital Dolby or Mpeg Audio.

Its just a personal decision, which is the correct one? Which-ever you choose is correct.
I use Digital Dolby.
As mentioned earlier, LPCM uses more memory than Mpeg Audio.
LPMC about 1300kbps whereas DD/Mpeg Audio 256kbps

Bit Rates.
A while back I did a test on file sizes, relating Variable/Constant/DD/LPCM.
See my guides, / Bit Rates and File Sizes.
It gives you a comparison with sizes.

I generally use a bit rate of 6000 kbps constant.
Again a personal choice, allows me up to 90 minutes of video per disc.

So forgetting everything that has been said:-

Using

8000kbps will allow 60 minutes of video per disc
6000kbps will allow 90 minutes of video per disc
4000kbps will allow 120 minutes of video per disc.

It boils down to how long your movie is.

[jparnold]

Thanks Trevor and everyone else

The reason I mentioned audio compression was because I have a video which is just over one hour and I was trying to render in the highest (video) bit rate (using 2 pass variable) and remembered that using LPCM resulted in a larger rendered file than when using other audio compression.

I have rendered my movie using DOLBY and the resulting file will 'fit' on a single sided dvd HOWEVER when I attempt to play the rendered file on my PC Windows Player just sits there displaying ACQUIRING CODEC - why then does VS render to a file which cannot be played with some (unknown to me) codec?

Maybe I should just use LPCM and drop the video bit rate - what do you think?

[Ron P.]

Do you have any other media player installed? I would try another media player to see if it plays ok. I seldom use WMP, instead I use Windows Media Player Classic. With WMP, I've found it hit and miss when playing some video files. It should be able to play an audio/video file that is using Dolby, however sometimes it refuses to, complaining about codecs. I've only had the Classic WMP do this a couple of times.

There's others such as VLC player, that will play numerous video file formats..

[jparnold]

Thanks Ron

Yeh the Classic WMP plays my rendered file ok. It just worried me a bit that if WMP couldn't play the file then an authored DVD might not play on a DVD player either.

What (audio compression) do you use normally? Do you think it is better to use Dolby than LPCM so that video bitrate can be increased (when trying to fit a large movie on a DVD) or do you consider lowering the video bitrate (and using LPCM) would not be noticeable during viewing on a LARGE flat panel TV?
I guess I'm talking about the difference between Variable 8000 max and Variable 7300 (approx) max?

[Ken Berry]

Personally, I would go for the higher video bitrate if you are displaying it on a large HDTV... From my own experience with a 46 inch HDTV, it is fairly unforgiving when it comes to the quality of home-made DVDs... (even when they are played on my Sony PS3 which upscales them close to high def standards). So the better the quality, the better the playback will be on a screen where the least fault will stand out like dogs' b*lls!!

[sjj1805]

I'm sure that I can remember reading a discussion (or two) regarding video bit rates for rendering to DVD somewhere here but have used 'search' without finding it.......

I think this is the link you saw previously:
What Bit Rate Settings etc Should I use?

[jparnold]

Thanks Steve

I had found that post (What Bit Rate Settings etc Should I use?) but had thought that I once saw a post which also had the difference in size (in Kbps) between the various audio compressions (I realise that with Dolby that this can vary by quality of sound required but LPCM is fixed) as well explaining that the max kbps for the entire video and therefore what the maximum video rate could be with each of the different audio types eg 'max DVD rate - 256kbs (Dolby at 256) = xxxx for the video bit rate.
Thanks again

[Trevor Andrew]

Hi John

There are calculators that will help in assessing the bit rates.
http://dvd-hq.info/bitrate_calculator.php

This one has plenty of reading to go with it explaining a lot about the process.

Basically you use the highest bit rate you can to produce a video file below 4.3 Gb.
Aiming for 4 Gb (a nice round figure), will allow ample spare capacity for the menu structure.
I would round the bit rate down to the nearest 500.

After rendering check the final file size, it will give you an idea as how far to push the bit rate.
At 4.4Gb the video won¡¦t fit to disc, and you would have to re-render to reduce the size.

And the difference between 8000 and 7300, I doubt if you will see any difference in quality at all.
What you have produced (without knowing the properties) is probably as good as it gets.
Other than using constant bit rate, but that starts another discussion.------Good luck

[jparnold]

Thanks Trevor
That is a great link (and calculator).

Does anyone know what VS sets 'average' and 'minimum' bit rate to when using VBR? I know that using TmpGenc these parameters can be set.

Does TmpGenc have a better 'rendering engine' than VS? I used to use it all the time when I first started out as I had to render to SVCD (in 2001 when still using VS v 6).