Bitrate Setting

[Gillou]

Im converting from .avi to Mpeg a 348 MB file.
Im not understanding why the Bitrate Setting Wizard changes the same file to 2578 MB, more than 7 times its original size.



I know I can change that setting but what difference would it make? How low can I go?
Thanks everyone.

[paglamon]

The length of ur video is 42 min 16 sec. File size=time x bitrate.In this case it is 2536sec x 8383(7999+384) kbits/sec .Do not be fooled by the small size of ur avi.It is probably highly compressed using a low bitrate and encoding with XviD or DivX.

[ed klein]

Also, look at all the remaining room you have on your DVD-5 up to 4.7gb as shown on the doted red vertical line.

The lower you go on the compressed mb's and bitrate settings the picture quality will be bad. Let TMPGEnc Plus at the mpeg 2 level do its thing on the automatic settings for a DVD-5 at 4.7gb.

There is no compression on that existing m2v video file now, so your picture quality should be great. Take that output TMPGEnc Plus m2v video file, along with the audio, subtitles, chapters and author and then burn VIDEO TS folder to a blank DVD-5, you should have great picture quality.

[Gillou]

Thank u for ur answers everyone.
Now, am I to understand that 2578 MB is the file uncompressed?

[ed klein]

Yes, and the file size will not start to be compressed until it reaches 4.7gb or larger, 4.7gb is the max that a DVD-5 will hold anything more in mb's will have to be compress down to 4.7gb.


If you use a DVD-9 (single sided dual layer) disk you can go as high as 8.5gb before any compression will be needed.

[LT. Columbo]

i've read that some players may give playback problems with such a high bitrate, but that is the best way to maintain quality. if you had two files like that i'd set each one up like you have, then author together, then use dvd shrink with quality settings - will turn out beautiful.

even if you dropped it down to 7000, quality is still extremely good.

[anonymez]

Now, am I to understand that 2578 MB is the file uncompressed?

no, it's still compressed, just as mpeg2

[fwienk]

Just a little question....
Isn't it true, that making the bitrate bigger, that at some point it doesn't do anything for the quality anymore? I guess you can't make the quality better than the original, so why go beyond that point if it only makes the filesize grow?

Thanx.....

[anonymez]

Isn't it true, that making the bitrate bigger, that at some point it doesn't do anything for the quality anymore?

correct

[ed klein]

@ anonymez

My understanding that the origional AVI file at 348mb was not compressed. TMPGEnc Plus changing the file to mpeg2 still should not have any compression on the file.

[LT. Columbo]

technically converting to mpeg-2 is always lossy i believe.

[paglamon]

My understanding that the origional AVI file at 348mb was not compressed.

I cannot think of a 42min uncompressed avi to have a size of 348MB.

[anonymez]

My understanding that the origional AVI file at 348mb was not compressed. TMPGEnc Plus changing the file to mpeg2 still should not have any compression on the file

uncompressed video is like a sequence of windows bitmaps; they're huge and file size increases with resolution. take 1 minute of an mpeg2 in virtualdub, set video compression to uncompressed, save as avi. note the file size

[ed klein]

OK, thanks for the information, seems I have a lot to learn about AVI files.

[aussiealan]

change the settings

Hi, can somebody please tell me how to change the bitrate setting in DVD Author? thanks ALan.