How important is Mbps in a rendered video

[lata]

We would recommend that the video data rate is used for the project settings.
Where you use 50P then the higher rate would be used and for the 50i aka 25fps the lower rate od 18000kbps would be used
Of course the show messages when first starting our project should take care of that.
For me more importantly the frame rate should be correct.

Then we can consider the format we are going to use for our final output, Share options, I know you were testing 50P v 25fps for playback on the TV, which format did you finally choose for your output files
Remember where you chose the 25000kbps option you probably also increased the frame rate from 25 to 50P
It’s a bit like “cannot make a silk purse out of a sows ear”, not that your 18000kbps is poor quality, the quality of your video was set during recording.
Using the original 18000kbps video and increasing the data rate is not gonna significantly improve quality.

Yes we could use a variety of filters to enhance the video, but a straight increase in the data rate is not going to improve much.

[jparnold]

Thanks Trevor.

What I am doing is just taking the 'defaults'.

When I create a NEW project using .mts clips and allow the project properties to match the first video clip the project properties becomes AVCHD (as expected) with 'properties' as follows
MPEG Transport-Stream Files
24 bits, 1920 x 1080, 50 fps
Frame-based
(HDMV-PAL), 16:9
H.264 Video
Video data rate: Variable (Max. 25000 kbps)
Audio data rate: 384 kbps
Dolby Digital Audio, 48 KHz, 3/2(L,C,R,SL,SR)

BUT if I import an existing OLD project containing .mts video clips which has project properties of (say) DVD (remember I only recently started to allow the project properties to match the first video clip) AND then I CHANGE the project properties to AVCHD then the properties become -
as above BUT with
Video data rate: Variable (Max. 18000 kbps)
NOTHING within the project has changed (still using .mts video clips)

I am wondering WHY it 'defaults' to a max of 18000 and not 25000 and more importantly what the difference is for the video data rate. I have searched the internet and found a few web sites including a video bitrate calculator but I still could not find what difference there would be visually eg if there is no visible difference using a variable with max bitrate of 18000 compared to 25000 why then render to a maximum 25000 with a resulting larger file?

The project contains the same .mts video clips which if I used with a new project would have had a project with a max 25000 yet because the properties were originally DVD and I change that to AVCHD then it 'defaults' to only 18000. This can be changed to 25000 but what improvement should there be.

[lata]

Hi John
Open the old project, right click the MTS clip for Properties, make a note of the Data Rate and Frame rate
I assume 50P and 25000Kbps
To manually set the Project Properties press Alt+ Enter or Settings Project Properties
1 / Project Format – choose AVCHD
2 / choose the top option 1920 x 1080, you are going to create a new template using these settings as a starting point
3 / Hit NEW
4 / modify the Profile Name to My AVCHD (1920 x 1080, 50P 25Mbps), assuming this is what you are aiming for.
5 / General Tab – Change the frame rate to use 50 fps – the Frame type will update to Frame Based aka P
6 / Compression Tab - change the data rate to 25000kbps
7 / Compression tab – I think the Video Format option should be H.264 Video, if that is greyed out, deselect the AVCHD box.

The new template is saved to the Project Properties AVCHD section and by adding the MY to the name is easily recognised as one of your templates.
Using your old project there should be no problems in rendering using the same settings as Same as First Clip could always be used.

Data rate 25000 re 18000, the latter is used with 25fps interlaced, increase the frame rate to 50fps and 25000kbps is used.
Recording at a higher frame rate 50P will / should improve quality especially with faster action video.

[asik1]

John, VS uses a templates for user/codec practical reasons.
So a 50fps HD video can go as high as 65Mb, but 25fps can reach up to 20M.
I never shoot that high as I see no point for my needs, our PAN does up to ~17Mb for 25i or ~28Mb for 50P so VS's templates are just enough.
** The lookup table can be manipulated and I've done so for years when needed, but if done wrongly it will crash VS completely (and for other reasons also I never publicized how to do so).

[Ken Berry]

Given that at the start of this thread you said your MTS clips had a bitrate of 18 to 20 Mbps, I personally cannot see any benefit in increasing the bitrate to 25 Mbps. As the old saying goes, you can't make a silk purse out of a sow's ear. Now of course I'm not really suggesting your original video is a sow's ear, but you can't simply improve the quality of video with an 18/20 Mbps bitrate by using a higher bitrate. As you have found, a higher bitrate using much the same format (MTS/AVCHD) will certainly increase the size of the resulting video, and the increase, as you have found, can be substantial. Original video using 18/20 Mbps should produce much the same quality if rendered in a similar format at 18/20 Mbps, and that appears to be the case where your eyes cannot detect any difference between the video using a lower bitrate and video using 25 Mbps. So stick with the original bitrate...

[jparnold]

Thanks everyone

It seems I have not explained or expressed myself correctly.

The main reason why I resurrected this thread (and now I am sure I should have started a new thread so that previous posts were not taken into consideration) was to ask what I should achieve by changing the video data rate from 18000kbps to 25000kbps. My camera 'shoots' higher than 18000kbps (1920x1920p 50fps) and as such my clips are all (type) mts. I was NOT attempting to increase the video characteristics from the maximum they could be (making a silk purse out of a sow's ear).
It just had me scratching my head when I changed the project properties on a project I created a few years ago (and which ONLY contained video clips all of which are 1820x1080p 50fps) from DVD to AVCHD.

Maybe if I understood exactly what project properties does I would better understand. I always thought that when you chose the output file type before rendering (after selecting 'share') that all characteristics were set at that point and as such could never understand the importance of project settings and that it was only so that smart render could take place.
Does the project properties change the properties of every video clip in the project?

I will retain 18000kbps as Ken suggests.

I NOW realise that in the past by not setting project properties to AVCHD (as it should be to get the best out of my video camera) and rendering also to AVCHD that by choosing MP4 that I lost the benefits of 1080p 50fps in my output file. My ONLY excuse is that as I only found out recently that the output file could be renamed from .m2t to .mp4 so that my blu-ray player would recognise them and play them.

[Ken Berry]

Maybe if I understood exactly what project properties does I would better understand. I always thought that when you chose the output file type before rendering (after selecting 'share') that all characteristics were set at that point and as such could never understand the importance of project settings and that it was only so that smart render could take place.

You are right in thinking that the settings chosen just before rendering are the important ones. As far as I have always been concerned, Project Properties while editing have little by way of importance -- although if you have selected high bitrate etc properties, you can get a better quality image from a project in Project mode while editing! After that, though, Project Properties are only important when you get to Share and want to output a new video with those same properties as the project -- so of course in Share you then choose "Same As Project Settings".

Does the project properties change the properties of every video clip in the project?

Choosing "Same As Project Settings" then affects all videos in the project regardless of their original formats. But then again, whatever output format you choose in Share affects everything in the project -- though with SmartRender enabled, anything in the project with those properties and which have not been edited, will not be rendered afresh.

But in Edit mode, applying a set of properties to the project/timeline does not mean anything is changed in reality. Remember you are using an NLE -- a non-linear editing program, and nothing is changed in reality: it is all virtual. Even after you have rendered a new video, all the original material in the project is still there in your computer untouched, and can be used again over and over in other projects if you wish.

[jparnold]

Thanks Ken.

Thanks for clearing it up for me about what project properties does (not a lot for me other than allowing smart render to work).

I have noticed though that when I change the project properties project format there is a pronounced delay (seemingly proportional to number if individual video clips) with the hard disk activity light flashing continually which makes me think that VS is writing data for every video clip. Anyway I digress.

I am still scratching my head though that if I set the project properties (for a project containing my .mts video clips) to something other than AVCHD and save then when I reload and then change the project properties to AVCHD VS defaults to a (variable) maximum of 18000kbps when it is 25000kbps if I create my original project using AVCHD. I hope I described that meaningfully.

Exactly where would I best notice the difference (in the output video) between 18000kbps and 25000kbps? In scenes of rapid movement? In highly detailed scenes eg a old tv test pattern with varying thickness of the black and white lines? Very small text characters? I would like to do a test to see for myself.

[lata]

Hi John
Manually setting Project Properties from the Settings menu for AVCHD gives us 3 default templates, I guess Corel could provide all templates but the list would be endless, and yes the 1920 x 1080 option does default to using 18.000kbps.
The Show Messages overcomes the short fall in templates automatically setting the properties.
However for any existing project a manual approach can be used, I believe your older projects were set to DVD, I assume at the time you were burning DVD Discs.
For existing projects we have the option to either Edit or create a New template, I gave details to do that in an earlier post for your 1920 x 1080 x 50P x 25000kbps, I believe this is the format that the camera records to.

To retain the original quality you should render using the original video files settings (1920 x1080 x 50P x 25000kbps)
If you wish to reduce the data rate to 18000kbps then the quality will be reduced, whether that is noticeable is a matter of testing, the size of the video file will also be reduced.
In changing the render settings make sure you retain the 50P frame rate and not set 25fps the latter will impact on “scenes of rapid movement”

Creating Movie Profiles, may help in testing.

From Settings – Movie Profile Manager allows us to create a variety of templates
Select the format as AVC/h.264
Now choose the Add option
Give the template a name “ My 1920 x 1080 x 50 x 25000”
Selecting the three little dots to the right of the file path will allow you to browse your hard drive for one of your MTS Video Files
OK to close that panel, the properties now showing in the lower panel should reflect the MTS settings.

Create another profile by using NEW – name “ my 1920 x 1080 x 50 x 18000” this time modify the data rate to 18000kbps (Compression Tab)
Ok and close

From Share AVCHD the Profile drop down panel will list your new templates at the top
You can now render your project by selecting your 18000 and then 25000 to compare quality.
At least you no longer have to change settings before rendering, just a matter of selecting the new profile

[jparnold]

Thanks Trevor
For a while I was thinking that VS wrote data to the project with reference to the project format and as such because my older projects which were set to DVD (yes for burning DVDs as you thought) that be changing to AVCHD I had somehow lost quality (18000kbps max). With the last few posts from you and Ken and Asik1 I have learned otherwise.
I note that you stated that there are a multitude of 'templates' and as such I CAN set the video rate up to 25000kbps and I will do to ensure I get the best possible outcome regardless of whether I visually notice the difference or not. I have a camera capable of up to 25000kbps and so why degrade that during editing regardless of file size since external storage devices are so cheap and large these days.
Thanks again. If we ever meet I will buy you or Ken a Newcastle Brown (I have already offered asik1 something else in another post (color balance) so I guess I will have to up that to two ).
John

[Ken Berry]

I have never tried a Newcastle Brown, but love dark and dark brown beers (though don't like Guinness!) I particularly like a Speckled Hen... So I'll happily take you up on your kind offer if ever we do meet...

[jparnold]

It's a deal. If the borders open by March 9 we will tour both islands for 14 days with APT but unfortunately Levin is not on the itinerary.Wellington is the closest. If you like Speckled Hen you will like Newcastle Brown (maybe Trevor will agree?)

[lata]

Newkie Brown, long time since I had one of those, very nice ale, and Guinness also goes down well, completely different drinks of course.
Hopefully the borders will be open especially if the new vaccination works as well as expected

So enjoy the vacation

[TroyTheTech]

Sorry to resurrect this thread but there is another (last?) question and that is regarding the Video Data Rate which can be adjusted in Project Properties.
As a result of what I have learned with this thread I have decided to 'redo' all my 'holiday' videos which I still have the original video clips stored on my hard drive(s).
I note that after loading a project and then change the Project Format to AVCHD it defaults (in the 'compression' tab) to 'variable' max 18000kbps whereas if I start from scratch it defaults to 25000kbps.
Is there any thing to gain by INCREASING this to say 25000kbps. I did a test a a short video clip which has movement of a person walking across the scene rendering to AVCHD at 18000kbps and also at 25000kbps and I could not detect any difference when I 'played' each although the file size increased from 12.9Mb to 19.4Mb.

If I may pop in to answer this one part, there is no real benefit to increasing the Bitrate (unless you are increasing the Resolution or adding Overlays/Clips on top/into your video, which is more 'things to keep track of on the screen') – eg. If you are not adding anything to the video. Just taking a video of someone walking at 15000kbps and rendering it out to 25000kbps will mostly just increase the size of the file (especially if NOT using VBR or Variable Bit Rate – more on that below).

If you want to keep your files smaller (if it is possible for them to be), choosing VBR (Variable Bit Rate) in beneficial – I mention this as you are stating you are looking at that above – as Variable Bitrate will allow the renderer to ‘only use as much Bitrate as needed for the action that is going on in the video’ data stream.
For example, if there is a few seconds where nothing is moving (eg. a sidewalk) then the Bitrate will (should) lower, being able to only 'keep the changes on the screen' (of which there is little) with a small “data per second” going through. Then, when more action (changes) occur on the screen (eg. People start walking by), the Bitrate will (should) increase, as the codec (the compressor/renderer) is now trying to keep all the details and changes going on between the frames (kept as data/size within the video file). This is a simplified example of how the “variable” version works.

If your Hardware that you are playing your media back on can support it. HEVC or ‘version h.265’ can also be smaller than AVC or ‘version h.264’ media can, while looking comparatively the same to human eyes. The reason is that HEVC/h.265 divides up the screen into much smaller ‘boxes to keep track of the changes on the screen’, as it keeps the video data in the file, than AVC/h.264.
VideoStudio seems to handle HEVC/h.265 well too, as I took a 15second clip of just a tree, and rendered it out to a file, testing both of these codecs (AVC/h.264 and HEVC/h.265) in VS2020 and this was the outcome:

AVC/h.264 file = 15s with ~8000kbps average Bitrate in the file (Max 20000kbps in Preset) = 17 MB output file size
HEVC/h.265 files = 15x with ~2000kbps average Bitrate in the file (Max 20000kbps in Preset) = 2.5 MB output file size

The HEVC file was a lot smaller, but looked the same (to my eyes). As with any video editing or programs, no matter what you are using, be sure to make a couple of short renders/tests of your material, testing to see what ‘looks good enough for you’ on what you mostly watch your video playback on – make sure it looks good to you (and get some second opinions if you desire).

As a note, the ‘not-variable’ version of video compression, called CBR or Constant Bit Rate is the version where it does not change the Bitrate ‘as needed’ (increasing when there is more ‘changes on the screen’) but it actually tries to keep the same Bitrate throughout the entire video. This results in much larger file sizes in the end, but someone might choose this if they wanted to be more sure of the resultant file size they will end up with (eg. to make sure it fits on a disc, etc). It still follows the same limitations as VBR – as they both can only ‘go as high as the maximum’ that is set, such as 15000kbps or 25000kbps, whatever it was set to.
With both VBR and CBR video, if the Maximum Bitrate is set too low, if there are many things going on in the video (lots of action or ‘changes’ on the screen), then the detail/crispness will be lost – if limited by a max bitrate that is too low. Variable Bitrate allows the range to go up and down as needed (if things aren’t moving much on the screen, then the Bitrate will go down [and the overall filesize will be smaller in the end] and if things are moving around and there is a lot of action/changes in the screen, then the Bitrate will go up as needed) – but then the resulting filesize is harder to calculate, with VBR. IF this doesn’t matter to you, then feel free to use Variable all the time!

[There are also programs that can allocate a specific filesize limit, while using VBR, to try to fit a home movie into say, one disc; but that is outside the scope of my now-already-super-long-posting, heh – (I believe that VideoStudio does this in the Disc Mode, where is tries to ‘squish’ the video into one disc of size, changing the Bitrate as needed, but I have not tested this, sorry)]

I’m going to stop for now, but I hope that helps a little bit more – adding to the already helpful information that is already in this Thread! ~T

Edit:
I see that some of this is repeating what other helpful people have already said; sorry about that, I really should read the entire Thread before adding to it haha

Edit 2:
If I may Reply to this part

<snip>
The project contains the same .mts video clips which if I used with a new project would have had a project with a max 25000 yet because the properties were originally DVD and I change that to AVCHD then it 'defaults' to only 18000. This can be changed to 25000 but what improvement should there be.

The reason why the Bitrate seems to 'go down' is because DVD video is normally kept in the format of MPEG-2 (that is the version of the video compressor used to create the output file).
AVCHD is normally kept in the format of MPEG-4.
That shows that the AVCHD format is 'newer' (version 4 as opposed to version 2) and uses different kinds of compression to render the file and store it as an output file.
These new methods (such as dividing up the screen into smaller areas [called Macroblocks] and using better compression techniques) do not require such as high a bitrate to still 'look as good to human eyes'.
There are a lot of 'tricks' that computers can use, to lose a bit of detail in video and make the file smaller, while still making it so that 'human eyes cant really tell as much' (eg. losing more detail in darker or flatter areas that are all the came colour). These 'tricks' allow the newer formats of video to use less Bitrate - much of these changes was researched or had their research funded by Network and Broadcast companies (to save them space/money in utilizing the formats)!
HTH

[jparnold]

Thanks HTH
In deed a lot of information. Very interesting that codec H.265 results in noticably smaller file sizes.Not sure if I will bother with it after reading that it was developed mainly for bluray and probably to decrease file sizes for 4 times the number of pixels.
I have learned heaps since creating this thread.

I have my video camera set to 1920x1080 50p (the highest video recording setting) and I understood that it could record at up to 24000 or even 25000kbps. When I use MediaInfo app to display characteristics o many video clips from my camera the video rate certainly shows that it does. As such I don't wont to compromise that quality just to have a smaller rendered file - AVCHD 1920x1080 50p H.264. I also have 'compression' set to the far right for quality rather than speed.

Here is a web site which I found the other day to be very interesting especially the part about video rendered at VBR (variable bit rate) is usually better quality that at CBR (constant).
https://help.encoding.com/knowledge-bas ... deo-files/