Blu-Ray to DVD File Sizes

[jim9977]

Hi, I've just done my first conversion of Blu-Ray to DVD and the resulting DVD file size is smaller than I expected. Converted the main movie only (1h 40min, 25gb ) to DVD9 and it came out as 1.8gb with a average video bitrate of 2.3Mbps. Is this normal or do I need to change some settings? Thanks.

[LoveRenee]

I get the same results,no matter what. I would expect that it would be much closer to whatever filesize I select. I read some other discussions, resolution discussions, however I agree that it should be MUCH larger/higher bitrates. Anyone?

[Claire]

And if you convert to DVD 5? How many audio and subtitle tracks are you including?

[jim9977]

And if you convert to DVD 5? How many audio and subtitle tracks are you including?

Same result when converting to DVD 5. I am converting only 1 audio track and no subtitles. I did the exact same conversion to DVD 5 in a different program (which I won't mention) and the result was a 4.3gb file, bitrate 6Mbps. That is much more like what I would expect.

It seems that there is a problem with your software not giving the maximum bitrate (quality) possible for the chosen media. i.e. not using the full capacity of the media. I hope this can be addressed in a future update because I really like the interface and ease of use of the VSO software.

[Claire]

What is the output size when converting to DVD5?

[jim9977]

What is the output size when converting to DVD5?

Same as before, 1.8gb. It seems to want to reduce the file size as much as possible rather than tailoring it to the chosen media/output. Maybe that is by design?

[LoveRenee]

Agree with jim - always the same 1.8GB file size. 1 audio track, 1 subtitle. Both movies (done separetely) were at least 1:40.

[jim9977]

Agree with jim - always the same 1.8GB file size. 1 audio track, 1 subtitle. Both movies (done separetely) were at least 1:40.

Just sent you a private message LoveRenee

[JJ]

Before you go any further: bigger bitrate does NOT equal better quality.
There are many other factors involved.
Sure, there are programs that always fill DVD, they simply pad the file.

[Claire]

What version are you using? I have launched a test to try and reproduce

[LoveRenee]

[quote="Claire"]What version are you using? I have launched a test to try and reproduce[/quote]
2.1.1.27

[jim9977]

Before you go any further: bigger bitrate does NOT equal better quality.
There are many other factors involved.
Sure, there are programs that always fill DVD, they simply pad the file.

True, the VSO software produces quite a good result despite the lower file size and lower average bitrate. I still think it could be better though by utilizing that extra space available on the DVD.

ps. I have since noticed a more serious problem with the picture breaking up every so often on playback but I'll try a few other Blu-rays and different settings before giving up.

[Claire]

ps. I have since noticed a more serious problem with the picture breaking up every so often on playback but I'll try a few other Blu-rays and different settings before giving up.

Are you burning the disks to DVD? Have you ruled out the problem could be from the disk playback or disk quality, rather than the file conversion itself?

[Claire]

I tested and got the same results 2.06gb for both conversions. This size is normal it depends on length in time of the movie (for my case 1h44).

As JJ said, other companies may produce bigger output size but that doesn't mean visually you have better quality.

[LoveRenee]

[quote="Claire"]I tested and got the same results 2.06gb for both conversions. This size is normal it depends on length in time of the movie (for my case 1h44).

As JJ said, other companies may produce bigger output size but that doesn't mean visually you have better quality.[/quote]
I find that hard to believe as most commercial 1h44 min DVD's are at least DVD5 size. Additionally, as someone else posted, the action scenes are more likely to be pixelated. I appreciate the information and your testing. Also jim9977, thanks for the pm info.

[Claire]

Please let us know if you have any quality or pixalized problems.

[JJ]

I find that hard to believe as most commercial 1h44 min DVD's are at least DVD5 size. Additionally, as someone else posted, the action scenes are more likely to be pixelated. I appreciate the information and your testing. Also jim9977, thanks for the pm info.

Most commercial DVDs are made to be more than DVD5 size just to prevent simple copying.
You can and should check conversion result before burning, then you see if there is pixelation or not.

[0xdeadbeef]

This is a known VSO issue. It was the same with ConvertXtoDVD. Yet for some reason the VSO guys insist that their encoder delivers "constant quality" without using the best possible bitrate. Indeed their encoder seems to be a slightly modified constant bitrate encoder, even if you enable the 2nd pass (which neither improves the bitrate distribution nor image quality significantly). However, for some weird reason, they don't even use the possible average bitrate but limit it to something in the 2.x MBit/s range.

A proper MPEG2 encoder (e.g. the free QEnc) will use the 2nd pass to create true VBR encoding where complex scenes (e.g. with a lot of movement) get more bitrate and static scenes get much less bitrate while the average bitrate is close to the maximum possible and the end size is more or less exactly the limit you chose.

I annotated this years ago for ConvertXtoDVD but without any success. There were several VSO hardcore fanboys at that time that would not allow any other opinion than that this fancy "constant (bad) quality" encoder was the best idea since sliced bread. Even though of course VSO seems to be the only company in this world that believes so. Every quality encoder uses true VBR with multipass encoding for good reason.
Indeed, for quite some time, I re-encoded the video stream externally with e.g. TmpgEnc and re-muxed it in the final DVD to get best results. Funny enough, the high-quality two-pass encoding with TmpgEnc took about as long as the low-end encoding of ConvertXtoDVD. However, I gave up this approach some time ago as I convert only a few DVDs now and then for people with pretty low-end equipment and obviously they don't appreciate my efforts anyway.

I'd still hope VDO would give up that "constant quality" delusion for the common idea of "best quality" and implement a decent VBR encoder (or at least allow an external encoder like Qenc), but after all these years, I kinda lost hope that this will ever happen.

[JJ]

Oxdeadbeef: that is your opinion and you have every right to express your opinion.
Just don't try to impose it as absolute truth because it is not.

I have also used TMPGEnc for some time before I found CxD.
When I noticed that CxD produces same or even better quality with smaller filesize, it was easy decision for me as I store files on external hard drive. Even when burning to DVD I found it extremely useful to be able to squeeze more movies to one DVD with better quality.
Why would I use more space when it is not needed? Even single movies to one DVD, in most cases it is better to not fill DVD, as edges of burnable area are very prone to errors. Of course commercial pressed DVDs do not have this problem as they are not burned.


Converting video is very complicated issue. Original source file is biggest factor, then converter settings.
Sure, there most likely is some cases where program like TMPGEnc produces better quality than CxD, but in most cases CxD wins easily.
And CxD is much faster - unless you use TMPGEnc with correct format mpg2 files, then it does not re-encode and that is of course faster than re-encoding.


Only way to get really best quality is to use uncompressed video, all compressing methods are producing some sort of quality loss.
It is up to end-user to decide what he accepts.

[0xdeadbeef]

This is neither my opinion nor an opinion at all. Multipass VBR is an industry standard - and for a good reason. Every serious comparison of codec efficiency with quality comparison to the uncompressed video stream will (and did) show that a 2.5MBit/s CBR stream can never reach the quality of a 4MBit VBR multipass with a decent encoder. Maybe people who claim that only look at the I-frames and ignore the B- and P-frames. I dunno, it's really beyond me as this is like claiming a 2.5Mbit/s TV show produced with an on-the-fly encoder has the same quality as a double layer DVD with high (>=4MBit/s) bitrate which was encoded with a professional multi-pass encoder. Heck, I never even saw a commercial DVD5 with really good picture quality. Indeed even commercial double layer DVDs quite often show lots of artifacts since space was wasted for extras instead of using a higher bitrate.
MPG2 is such an inefficient codec that not a single bit should be wasted - and BD Converter easily wastes 1-2GB without even having a top notch encoder.
So I won't even argue on the "CxD wins over TmpgEnc quality wise" statement as it's really beyond any discussion. Neither CxD nor BD Converter could ever win against TmpgEnc in two pass VBR mode quality wise - not even against QEnc. Never ever.