rebuilder lower bit rate than clonedvd2

pazzini · Apr 8, 2006

I did 2 copys of Harry Potter 4 1 with Rebuilder with HC Encoder and the other with clonedvd2 2.8.9.2.

Could someone explain why clonedvd2 got an average bitrate of 4.11 while rebuilder got an average of 3.70 surely as clonedvd2 got a higher average bitrate surely the picture quality would be better?

I used nero recode to get the average bitrate.

Please give me your opinions

Thanks

Pazz

Jigen · Apr 9, 2006

Simply, the encoders that rebuilder uses actually recreate the video from scratch, and as a result can optimize the picture for the lower bitrate, but it takes a long time. Clone or Shrink are compressed domain transcoders which do not recreate the video, and so they produce a lower quality image, but they are much faster.

arniebear · Apr 9, 2006

Newer "one click" programs have made backing up a DVD a fairly simple process... but there is a significant trade-off. The quality that can be attained by even the best of these programs is poor in comparison to original techniques that used Cinemacraft Encoder, HC Encoder, QuEnc, or other top-notch encoders. The reason is simple. When using one of these encoders the picture is rebuilt from scratch and optimized for the resulting bitrate
Click to expand...

Transcoding or more specifically Compressed-domain Transcoding means normally a re-encoding process that changes the video or audio features, such as resolution or bitrate, by changing parts of the a/v content, but not by reconstructing the content again (which is the case in encoding process). Compressed-domain transcoding also maintains the format of the file same as in the original file. Transcoding doesn't encode it takes out small bits of detail to make the DVD video smaller. Faster then encoding.
Click to expand...

http://forum.digital-digest.com/showthread.php?t=55302

L8ter · Apr 9, 2006

ummm watch the two??
I would think average is due to the original p&b frames being used and all the compression taking place in the i frames showing higher bitrate average just simply means that the average bitrate of the entire maybe 2hr movie had a higher average.

I would think this more reason to use rebuilder that just mean's that a smaller portion of the video actually suffered the compression.

look @ your low's & high's maybe bitrateviewer.

but the final judgement is in the eye's

another point I'm not that familiar w/ recode but is this the bitrate of the source or what it would have to be compressed to?

pazzini · Apr 18, 2006

I have got 3 pictures with the bitrate test how can I upload them?

The film was Chronicles of narnia movie only

1)HC encoder avg: 3.88mb/sec
2)CCE basic encoder avg: 3.90mb/sec
3)Clonedvd2 transcoder avg: 4.68mb/sec

I used bitrate14 (freeware)

I always thought the higher the bitrate the better the picture.

L8ter · Apr 18, 2006

bitrate is nothing more than a measurement determining quality by bitrate is a very hard thing as they are only minutely related.

use urls to wrapped in img tags there is no uplaoding for ad due to some half million users that would mean a tremendous amount of server space.
and would make things extremely slow.

higher bitrate would indicate more action or more detail but can just mean there was more empty pixels or similar which is all in the original authoring, I'm interested more in what my eye's tell me about the picture by far this may be only my opinion but I'm sticking w/ it.
I've been reading on quantisation if you'd like a better means of determination try googling that.

arniebear · Apr 18, 2006

Following a trend of minimalist video editing applications, lower end DVD authoring packages produce DVDs with the minimum of user input. Although fantastic for the beginner, this design feature can to take far too much away from the more demanding end user. Two cases in point are opposite ends of an extreme: the user wanting to create the best possible image quality; and the user aiming to cram in as much video as possible on to a single DVD.

Despite these limitations, DVD authoring applications combined with more powerful MPEG2 encoders give far more flexibilty to the budding videographer. Be warned that your DVD authoring application should be capable of importing MPEGs – and author the DVD without re-encoding your expertly encoded video. This issue is addressed later with a list of applications meeting this criteria.

Before explaining the process of DVD creation it's worth explaining the fundamentals of DVDs. The typical commercial DVD contains over two hours of high quality video on a dual layered DVD. You may have noticed a slight "jump" in the middle of a film - this is where the laser jumps from reading the first layer of data to a second. Alas, this method is not available to the home user and DVDs created on home PCs are limited to the physical data limit of a single layered DVD (approximately 4.37Gb).

So how does this affect the amount of video on a DVD? Well, video encoding coverts the picture into data and then compresses this data by using a technique of comparing one frame of video (frame A) to the next (frame B), discarding any data duplicated in frame B. More specifically, MPEG files have a "Group of Pictures" (GOP) structure, consisting of complete (intra) frames "I", predicted frames "P", and bidirectional frames "B". Predicted frames are based on past frames, bidirectional based on past and future frames. Secondly, the amount of data consumed every second by is known as the video bitrate: the higher the bitrate, the more data per second and the higher the quality - you get less video on a DVD the higher the quality of the picture.

The maximum bitrate under the DVD standard is 9800kbits/sec (this includes both video and audio). It’s important to adhere to this standard to ensure the created DVD plays in standalone players. At this constant maximum bitrate, you’ll get 60mins of video on your DVD. As we know, the lower the bitrate, the lower the image quality but the more video we can fit on a DVD. So if we reduce the bitrate by half, we can get 120mins of video on a disc. A maximum Constant bitate should be used to encode videos less than 60mins long - this will maximise video quality by ensuring no space is wasted on the DVD.

Notice the use of the word “constant” above. This is important: an alternative to constant bitrate (CBR) is variable bitrate (VBR). When you’re encoding more than 60mins, 2-pass VBR should be the preferred alternative. The encoder runs through the video twice, the first “pass” analyses the data, the second actually encodes the video, using a higher bitrate in scenes with high motion. This will then “smooth” your video and should achieve better quality video compared to CBR for videos greater than 60mins.

If you do the maths, you’ll see that these bitrates don’t quite add up – and that’s because the audio is treated separately to the video. Another DVD standard is PCM audio, this is uncompressed audio with a datarate of 1536kbits/sec. This may seem high – and it is. Although not part of the DVD standard, you can compress the audio to squeeze more video onto your disc! If we use MPEG layer II audio at a bitrate of 224kbits/sec, we can either slightly increase the video bitrate or fit an extra 12 more minutes of video onto the disc. AC3 audio would work in a similar vain.

So there you have it: we can alter the constant bitrate of the video to control either quality and the amount of video we fit on a DVD. We can also use a variable bitrate to maximise overall quality when using a lower average bitrate and we can then compress the audio to further control the amount of video we can fit into a DVD.
Click to expand...

http://www.videoforums.co.uk/reviews/features/p2_articleid/78

Ergo, the difference would be in CBR vs. VBR, or I could be wrong.

pazzini · Apr 18, 2006

I have seen alot of tests where the person crops in on the image to compare how good each transcoder / encoder is, for example the spiderman test in the doom9 forum. What software can I use so I can compare for myself?

I have:

1click dvd copy pro
Clonedvd2
dvd-rebuilder pro with HC and CCE basic
dvd shrink
Nero recode 2
Dvd2one
1click dvd copy

L8ter · Apr 19, 2006

I personally like to use the zoom function on my player I know that's not what you want to hear but my monitor is not a huge plasma and the actual viewing of the movie will be done on my t.v. so that's where I do a final judgement.

most any dvd playing software could be used to pause zoom wmp mpc windvd.etc.etc.etc

Log in or Sign up

rebuilder lower bit rate than clonedvd2

pazzini Guest

Jigen Regular member

arniebear Active member

L8ter Guest

pazzini Guest

L8ter Guest

arniebear Active member

pazzini Guest

L8ter Guest

Share This Page

Log in or Sign up

rebuilder lower bit rate than clonedvd2

pazzini Guest

Jigen Regular member

arniebear Active member

L8ter Guest

pazzini Guest

L8ter Guest

arniebear Active member

pazzini Guest

L8ter Guest

Share This Page

Useful Searches