Conflicting info on Video Data Rate

[RickMen]

I'm experimenting with 4K video and I'm getting conflicting data with regards to video data rate. The raw file has the following settings:

raw file

rawfiledata.PNG (8.18 KiB) Viewed 2102 times

I want to render the file using the same settings as the source clip. When I go to share/render it I was unable to create a custom template with the exact same settings as the raw file under Movie Manager so I had to use the 'Add' option to select a clip with those same settings.

Movie Profile

I then rendered the project.

When I look at the rendered clip's properties using VS I get the following:-

Properties via VS

rendered_clip_usingVS2.PNG (8.18 KiB) Viewed 2102 times

When I look at the rendered clip's properties using Windows right click properties I get the following:

rendered clip using windows

So in summary the video data rate on the rendered clip is:-

using VS 99,999 Kbps
using windows 64,935 kbps

Which one should I reply upon?

[Ken Berry]

It would be useful if you installed and used a freeware program called MediaInfo which you can download from https://mediaarea.net/en/MediaInfo/Download/Windows That will give you more info than you will ever need about your video, but it should include an accurate report of the datarate.

[RickMen]

Thanks Ken.

I took your suggestion. MediaInfo is reporting the following. So, if I'm reading it correctly the video data rate is 64.2 Mbs which doesn't match the data rate in the Personal Profile of 100Mbs. Am I reading it correctly? If so, why doesn't the data rates match?

[aljimenez]

I think the answer is encoding is not going to be identical. the original source video was probably encoded by a camera, and VS re-encodes it with a different encoder. I am guessing you will never get the exact same data rate for the rendered project. Especially if you do any editing on the original video.

The key is how good is the quality of the two video files. Are you seeing different quality? I wouldn't worry about the numbers, rather the quality you get.

[lata]

I want to render the file using the same settings as the source clip. When I go to share/render it I was unable to create a custom template with the exact same settings as the raw file under Movie Manager so I had to use the 'Add' option to select a clip with those same settings.

There is an option from Share to use same as first clip, that should use the original clips properties.

From your other posts regarding max data rates this option may revert to Video Studios max rate for your files???
worth a try...

click image for larger view.

[RickMen]

Hi aljimenez,

Will try out your suggestion later on my UHD TV and let you know the results.

Hi lata / Trevor,

I tried both the "Share using same as first clip" and "same as project settings" and had the same outcome, ie bit rate of 64Mbps.

So the conclusion I draw from this is that the maximum bit rate that VS2018 can handle for XAVC-S format encoding/rendering is 65Mbps. Pity that my Sony AX53 can record at 100Mbps. Oh well, maybe Corel will come to the party in a future release of VS. In the meantime, I now know not to rely on the properties info within VS as that is misleading and I have new tool in the toolbox (MediaInfo - Thanks Ken).

[aljimenez]

One thing I want to make sure you are aware is that most current encoders data rates are variable. For example, your camera's 100 data rate is maximum, and it seldom is actually that amount. Video has to be of a scene with very fast motion, light change, color gradients, etc. In other words, if your camera is capturing a very static scene, the data rate will not need to be 100. I don't know your camera, but it is possible its encoder is not very efficient and ends up using more data rate than the scene you captured. It is entirely possible that VS encoder is more efficient and needs a smaller data rate to encode your clip.

[RickMen]

Thanks aljimenez, I'll keep that in mind. It's either that the VS encoder is more efficient or the encoder can only handle a maximum bit rate of 65 Mbps. I'm leaning towards that later but I will keep an open mind.

BTW - I finally reviewed the rendered clip on my UHD TV and to be honest I couldn't tell the difference between it (4K) and a FHD clip, but I wasn't comparing 'like for like' clips. Will do that later when I get some free time. I was expecting the 4K clip to stand out but not the case.