How important is Mbps in a rendered video

Post Reply
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

How important is Mbps in a rendered video

Post by jparnold »

I have just noticed that my input (.mts) video files (from my Panasonic XC920 video camera) are around 18-20 Mbps but my rendered video file (MPEG-4 AVC 1920 x 1080 25p 15Mbps) are around 13.5 Mbps. I view my rendered video on a large screen LED TV.

I notice that with VS10 it is possible to render to XAVC S MP4 HD, 50p, 20Mbps (I am now using VS10 and this was not possible with my older VS).

What difference can I expect to see with video rendered at a higher Mbps? I read somewhere that this affect the level of detail (I think that is what I saw) but will I notice much difference especially as the rendered files are quite a bit larger in size.

Thanks
John
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
tletter
Posts: 772
Joined: Thu Jul 16, 2015 12:23 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
processor: i7-3632QM 2.2 GHz
ram: 16GB
Hard_Drive_Capacity: 1TB
Corel programs: X4, X5, X6, X7, X8, X9, X10, 2018, 2019
Location: Canada

Re: How important is Mbps in a rendered video

Post by tletter »

jparnold wrote:What difference can I expect to see with video rendered at a higher Mbps?
The data rate can be important depending on what is happening in the clips.  If the captured scene is very detailed then rendering at the same data rate as the source is important assuming that you're able to view the output's detail, e.g. you're not viewing on a low res or tiny screen.

You should try rendering at different data rates and test whether you can see any difference when viewing.

tletter
https://www.youtube.com/user/tletter
User avatar
lata
Site Admin
Posts: 12135
Joined: Thu Jan 19, 2012 6:21 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: ASUSTeK COMPUTER INC A88XM-A USB 3 1 Rev X 0x
processor: 4 10 gigahertz AMD A10-7890K Radeon R7
ram: 16 gb
Video Card: on board
sound_card: Realtek High Definition Audio
Hard_Drive_Capacity: 500 SSD
Monitor/Display Make & Model: LG W2242 [Monitor]
Corel programs: CVSX10, 18, 19, 20, PSP, PI, MS3D
Location: UK
Contact:

Re: How important is Mbps in a rendered video

Post by lata »

Hi John
Are you comparing MTS to Mpeg4

My Pana 900 uses 16800 kbps when recording video at 25fps, if I use the 50fps it increased to 26000kbps, I assume the 920 uses a similar rate.
That is the recording rate to produce the best quality.
Or does your 920 camcorder record to Mpeg4?

As an aside--- at 20000 kbps for MTS the file size will be approx. 8 Gb.

Using Video Studio you have the option to render Same as First Clip which will use the original video files settings and retain the original quality, at least that is how I understand it.
So increasing the data rate to render MTS is not gonna improve quality although the file size will increase.
I have to admit I do not know the equivalent data rate when converting the MTS to Mpeg4 and like “tletter” you should try a few tests using different rates to check quality.
Also take into account that your MTS 25fps probably uses Upper Field Interlacing where as Mpeg4 may be progressive.

Frame Rates
If your original video uses 25P there is little point in rendering to 50P, the program will simply create duplicate frames, playback will look the same.

If your camcorder records to Mpeg4 then ignore the above and from Share use Same as First Clip.
Regards Trevor
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

Re: How important is Mbps in a rendered video

Post by jparnold »

Hi Trevor,

Sorry I have misled my readers.

No I do NOT record to MPEG with my Pana 920 but I render to MPEG.

So I start with MTS files from my Pana (with camera set to highest recording ie 1080/50p) and render to MPEG for portability (eg I can play them on my LED TV).

After noticing that I can render to different Mbps (using VS10 - something I didn't have with VS6) I checked my rendered file using MEDIAINFO (app) to check exactly what Mbps I achieved with my rendered video and it displays 13.5 (I though it would be closer to 15 since that the output I selected for rendering).

I then wondered what my input (.MTS) files from my Pana were and MEDIAINFO displayed a varying value which appeared to be related to the 'complexity' (detail as tletter mentions above) of the image in that video clip. The highest Mbps from the selection I chose was 19.4 which is higher than the 13.5 I ended up with in my rendered video - am I loosing detail?

I then wondered what I should expect to 'see' with video rendered to a higher Mbps hence this thread. I was particularly concerned that using MPEG-4 AVC 1920 x 1080 25p 15Mbps might result in a noticable loss since it is lower than what my input (.MTS from Pana) files are. Tletter suggests that perhaps I might notice a diffeernce when not viewing on a small screen which I don't.

I guess tletter sums it up by stating that rate affects the detail. My LED TV is 65" (165cm) and is capable of 4K and supposedly UPSCALES to 4K so it seems I need to select a short video clip with HEAPS of detail and render at 15 and 20 and see if I can notice any difference. At least I now understand more about 'rate'.

Thanks
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
User avatar
lata
Site Admin
Posts: 12135
Joined: Thu Jan 19, 2012 6:21 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: ASUSTeK COMPUTER INC A88XM-A USB 3 1 Rev X 0x
processor: 4 10 gigahertz AMD A10-7890K Radeon R7
ram: 16 gb
Video Card: on board
sound_card: Realtek High Definition Audio
Hard_Drive_Capacity: 500 SSD
Monitor/Display Make & Model: LG W2242 [Monitor]
Corel programs: CVSX10, 18, 19, 20, PSP, PI, MS3D
Location: UK
Contact:

Re: How important is Mbps in a rendered video

Post by lata »

Hi John
As your camera records to 1920 x 1080 x 50P.MTS then any change to Mpeg4 should also use 50P
If you change to Mpeg4 25p then you are removing 50% of the frames and that would impact on quality.
I assume as you are going to this trouble to re-code the video as you are experiencing problems when playing the MTS on your TV.

When you render using Same as first Clip the resultant video will be/ should be the same as the original but have a file extension of m2t.
If that video does not play on your tv, try renaming the file to use .mpg
You can try this on a short sample, if that plays then you would not have to convert to Mpeg4.
Otherwise converting to Mpeg4 should use the 50P frame rate and 1920 x 1080.
Regards Trevor
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

Re: How important is Mbps in a rendered video

Post by jparnold »

Thanks Trevor,
Sorry for the delay in responding.

Anyway I encoded a very short video clip with 'profile' MPEG-4 (1920x1080 25p 15Mbps) and also with 'profile' AVC (1920x1080 50p 28Mbps) which produced an m2t file - maybe I should have selected render using the same as the first clip ie render same as project settings (which is the same as the first video clip).

I use a blue ray player to play videos on usb memory sticks as it is easier to plug into than the back of the tv and also have a more user friendly menu system to select files on the usb memory stick.
I had to rename the from .mt2 to mpg as the blue ray player did not recognise .m2t as you suggested.
Both my wife and I watched the video clip rendered at 15Mbps and also 28Mbps and neither of us could see any difference - my wife actually preferred the one rendered at 15Mbps - strange!

I looked up the specs for both my blue ray player and tv.

The blue ray player did not mention file format' .m2t HOWEVER the tv did include file format m2ts as well as .mts. Maybe I should check both rendered files plugged directly into the tv, although it is difficult to find the usb socket on the back of the tv without pulling the tv out from the wall.
If the .m2t file renames as .mpg plays on the blue ray player would the blue ray player alter anything eg play it but with a reduced frame rate and Mbps I wonder?

Regards John
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
User avatar
lata
Site Admin
Posts: 12135
Joined: Thu Jan 19, 2012 6:21 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: ASUSTeK COMPUTER INC A88XM-A USB 3 1 Rev X 0x
processor: 4 10 gigahertz AMD A10-7890K Radeon R7
ram: 16 gb
Video Card: on board
sound_card: Realtek High Definition Audio
Hard_Drive_Capacity: 500 SSD
Monitor/Display Make & Model: LG W2242 [Monitor]
Corel programs: CVSX10, 18, 19, 20, PSP, PI, MS3D
Location: UK
Contact:

Re: How important is Mbps in a rendered video

Post by lata »

Hi John
The 50P original video should look better when viewing fast video or panning video
The original video converted from 50P to 25P may show lower quality when viewing fast video or panning video
I think it’s a matter of trial and error to see which plays best for you.
Renaming the files from m2t to mpg should not alter the data rate of frame rate, renaming was for me just a means for the player / TV to recognise the video.
You could also try renaming to m2ts, I have not tried that so unsure of the results.

As for Motion Transport Stream files
Your camera records using a MTS extension (Motion Transport Stream)
Render that to “same as first clip” or the avchd options and the m2t extension files will be used.
Burn a Bluray folder or disc and we can view the files used, they will be using m2ts
You can view these in the BDMV – Stream folder.
Regards Trevor
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

Re: How important is Mbps in a rendered video

Post by jparnold »

Thanks Trevor

Ok now I see that the 'benefits' of 50p would be seen in fast motion/panning BUT what about 28Mbps compared to 15Mbps? From what I read the higher the bit rate the more 'crisp' and detailed an image should be. When my wife and I compared the same video clip rendered at 15 and also at 28 we couldn't see any difference with our aging eyes. Even at 15 Mbps we are extremely happy with the quality of the video and it appears to us to be as good as anything we see on purchased DVDs or broadcasted TV shows on the HD channels.

I will seek a clip containing fast motion and do the test as suggested.

Regards John
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
User avatar
lata
Site Admin
Posts: 12135
Joined: Thu Jan 19, 2012 6:21 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: ASUSTeK COMPUTER INC A88XM-A USB 3 1 Rev X 0x
processor: 4 10 gigahertz AMD A10-7890K Radeon R7
ram: 16 gb
Video Card: on board
sound_card: Realtek High Definition Audio
Hard_Drive_Capacity: 500 SSD
Monitor/Display Make & Model: LG W2242 [Monitor]
Corel programs: CVSX10, 18, 19, 20, PSP, PI, MS3D
Location: UK
Contact:

Re: How important is Mbps in a rendered video

Post by lata »

Hi John
I don’t know why the 15mb video should show better than the original at 28Mb
The conversion to Mpeg4 has not only reduced the data rate but reduced the frame rate from 50 to 25 fps, that has removed 50% of your frames.
Even so you see the video as better quality.
If you feel the Mpeg 4 options show better quality for you then you should use those.
There is an option to render to Mpeg4 using 50fps, give that a test.
XAVC S MP4 HD (1920 x 1080, 50p, 20Mbps)

If you are going to convert the original 50fps video to 25fps I do not think there is any point in recording to 50fps

There is of course the TV upscaling to consider, that in itself should improve playback, maybe it does a better job on the Mpeg4 files?

Good exercise though
Regards Trevor
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

Re: How important is Mbps in a rendered video

Post by jparnold »

Hi Trevor
I had edited my previous post and it didn't seem to update as I am looking at it as I type this and it is not there.
This is what it should be showing
I selected a clip with panning and rendered it at 25p and also at 50p (same as first clip) and it was MUCH smoother and as such I will in future render the same as my input video from camera (ie AVCHD 50p).
I still don't really notice much difference between 15Mbps and 28Mbps but then again my eye sight is not nearly as good as it used to be. Maybe I should show my 40 something year old son and see what he thinks. Maybe I am not using a video clip with enough detail? Any suggestions? Use an image with various size text characters down to very small?

Yes my 4K tv might be upscaling very well.

I'll do another test using XAVC S MP4 HD (1920 x 1080, 50p, 20Mbps)

Regards
John
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
tletter
Posts: 772
Joined: Thu Jul 16, 2015 12:23 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
processor: i7-3632QM 2.2 GHz
ram: 16GB
Hard_Drive_Capacity: 1TB
Corel programs: X4, X5, X6, X7, X8, X9, X10, 2018, 2019
Location: Canada

Re: How important is Mbps in a rendered video

Post by tletter »

jparnold wrote:I still don't really notice much difference between 15Mbps and 28Mbps
You can't divorce frame rate from data rate if you want to maintain a good looking video. For example if you boost the frame rate from 25 to 50 but keep the data rate unchanged, then the detail will suffer as each frame will have only half the number of kilobytes per frame. As well, your panel refresh rate must support the input frame rate.

tletter
https://www.youtube.com/user/tletter
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

Re: How important is Mbps in a rendered video

Post by jparnold »

Thanks tletter

I see looking at the 'profiles' available fps and data rate seem to go 'hand in hand' EXCEPT a slight difference in maximum video rate between when I select to render same as first clip (in my case 1920x1080 50fps frame based video data rate variable MAX 25 Mbps) OR AVC 1920x1080 50fps frame based video data rate variable MAX 28 Mbps (all the same except it could produce up to 28 instead of 25 Mbps). I guess using the former and smart render it would then render faster?

At least I now understand more how Mbps works and it seems to me that video rate would be higher at 50fps than 25 as there are twice as many frames per second.
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
tletter
Posts: 772
Joined: Thu Jul 16, 2015 12:23 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
processor: i7-3632QM 2.2 GHz
ram: 16GB
Hard_Drive_Capacity: 1TB
Corel programs: X4, X5, X6, X7, X8, X9, X10, 2018, 2019
Location: Canada

Re: How important is Mbps in a rendered video

Post by tletter »

jparnold wrote:it seems to me that video rate would be higher at 50fps than 25 as there are twice as many frames per second.
As your camera has a say in the question of data rate, I'd suggest that you record a clip at 25fps and another at 50fps and then compare the data rates of both clips. VS can't meaningfully increase the data rate in post-production.

tletter
https://www.youtube.com/user/tletter
User avatar
jparnold
Advisor
Posts: 965
Joined: Sat Dec 17, 2005 10:45 am
operating_system: Windows 10
System_Drive: C
32bit or 64bit: 64 Bit
motherboard: Gigabyte Z390 UD
processor: Intel Pentium i7-9700 3.6Ghz
ram: 16GB DDR3
Video Card: Gigabyte RTX2060 OC 6GB
sound_card: Onboard Realtec ALC887
Hard_Drive_Capacity: 2048Gb mix
Monitor/Display Make & Model: Samsung S27C450B
Corel programs: Videostudio X10, Paint Shop Pro X8
Location: Blue Mountains, NSW, Australia

Re: How important is Mbps in a rendered video

Post by jparnold »

I always have my camera set to 1920 x1080p 50fps (for 'top' setting which I always use) and so there is no need for me to increase it. Therefore I am NOT trying to increase fps.
It seems I have been decreasing it (fps and Mbps) without realising I can do better (by choosing to render at MPEG-4 25fps 15Mbps) but will now always choose the properties of the first video clip even though that means I will need to rename the output file from M2T to MPG (and end up with a larger file) which is no big deal.
John a
VS X10 Ultimate, Paint Shop Pro X8, Audacity, Panasonic HC-X920M, Canon SX50 HS
Post Reply