How do you forcefully change video resolution/buffer dimensions?.

F3low · 27th January 2020, 00:42

Hi, first I'm sorry if this isn't the right place to post this.

I usually encode my videos to HEVC 1920x1080p using Vidcoder and then I cut and merge them using Avidemux, now the problem is from time to time I come across videos that have Buffer Dimensions of 1920x1088 and Video Resolution of 1920x1080 sometimes after encoding them the VR and BD change to 1920x1080 (this is what I want and set Vidcoder to do) other times the VR changes to 1920x1078 or nothing changes and the videos keep the original VR and BD.. now this is a big problem for me because if I try merging videos with different VR or BD I get a messed up output where only the first part of the video plays correctly and as soon as the second part starts I get a static image with or without artifacts and only the sound plays.
At first I didn't know what caused that problem since I encode my videos with the same settings and resolution so I started doing some research and found that on VLC the buffer dimensions are different from video resolution.

Sorry for the long post but I tried to explain as best as I can.

Thanks.

sneaker_ger · 27th January 2020, 08:53

If you have --min-cu 16 pixels then x265 will have to encode 1088 rows (because 1080 is not mod16) and then add metadata for the player to crop away the excess 8 pixels. So try to have all your parts encoded with the same --min-cu value.

F3low · 27th January 2020, 13:44

Quote:

Originally Posted by sneaker_ger

If you have --min-cu 16 pixels then x265 will have to encode 1088 rows (because 1080 is not mod16) and then add metadata for the player to crop away the excess 8 pixels. So try to have all your parts encoded with the same --min-cu value.

HI, I don't know if I have --min-cu 16 but can you tell me how to set the same --min-cu value for my future encodes on Vidcoder?.

benwaggoner · 27th January 2020, 19:50

--min-cu-size 8 is the parameter you want to use. Have you set the preset to "ultrafast" - that's the only one that defaults to min-cu-size of 16. And isn't going to give you great results, and might not be that much faster given source decoding and other operations. At least try superfast and keep going until encoding gets too slow for you.

F3low · 27th January 2020, 22:20

Quote:

Originally Posted by benwaggoner

--min-cu-size 8 is the parameter you want to use. Have you set the preset to "ultrafast" - that's the only one that defaults to min-cu-size of 16. And isn't going to give you great results, and might not be that much faster given source decoding and other operations. At least try superfast and keep going until encoding gets too slow for you.

I always use the slow preset, I added --min-cu-size 8 but I still got 1920x1078 resolution instead of 1920x1080, please take a look and tell me where I did go wrong https://imgur.com/a/ljit5Dq.

sneaker_ger · 27th January 2020, 23:04

I thought the 1078 was a typo at first. I think your problem may be VidCoder doing some auto-cropping. (Irregardless of that you would set "min-cu-size=8" in VidCoder, not "--min-cu-size 8".)

F3low · 28th January 2020, 01:12

Quote:

Originally Posted by sneaker_ger

I thought the 1078 was a typo at first. I think your problem may be VidCoder doing some auto-cropping. (Irregardless of that you would set "min-cu-size=8" in VidCoder, not "--min-cu-size 8".)

It worked! thanks guys.

27th January 2020, 00:42	#1 \| Link
F3low Registered User Join Date: Jan 2020 Posts: 21	How do you forcefully change video resolution/buffer dimensions?. Hi, first I'm sorry if this isn't the right place to post this. I usually encode my videos to HEVC 1920x1080p using Vidcoder and then I cut and merge them using Avidemux, now the problem is from time to time I come across videos that have Buffer Dimensions of 1920x1088 and Video Resolution of 1920x1080 sometimes after encoding them the VR and BD change to 1920x1080 (this is what I want and set Vidcoder to do) other times the VR changes to 1920x1078 or nothing changes and the videos keep the original VR and BD.. now this is a big problem for me because if I try merging videos with different VR or BD I get a messed up output where only the first part of the video plays correctly and as soon as the second part starts I get a static image with or without artifacts and only the sound plays. At first I didn't know what caused that problem since I encode my videos with the same settings and resolution so I started doing some research and found that on VLC the buffer dimensions are different from video resolution. Sorry for the long post but I tried to explain as best as I can. Thanks. Last edited by F3low; 27th January 2020 at 00:45.

27th January 2020, 19:50	#4 \| Link
benwaggoner Moderator Join Date: Jan 2006 Location: Portland, OR Posts: 4,438	--min-cu-size 8 is the parameter you want to use. Have you set the preset to "ultrafast" - that's the only one that defaults to min-cu-size of 16. And isn't going to give you great results, and might not be that much faster given source decoding and other operations. At least try superfast and keep going until encoding gets too slow for you. __________________ Ben Waggoner Principal Video Specialist, Amazon Prime Video My Compression Book

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

27th January 2020, 08:53	#2 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	If you have --min-cu 16 pixels then x265 will have to encode 1088 rows (because 1080 is not mod16) and then add metadata for the player to crop away the excess 8 pixels. So try to have all your parts encoded with the same --min-cu value.

27th January 2020, 23:04	#6 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	I thought the 1078 was a typo at first. I think your problem may be VidCoder doing some auto-cropping. (Irregardless of that you would set "min-cu-size=8" in VidCoder, not "--min-cu-size 8".)