Whats keyframe interval?

[applesuxD]

Whats keyframe interval and which number is better for quality,more or less

[ALwin]

Whats keyframe interval and which number is better for quality,more or less

 

Keyframe interval, if you're talking about videos, means that a keyframe will be set at every X number of frames.  It helps when videos are encoded into lossy compressed formats, where only incremental changes of data for most frames are saved.

 

As for choosing the right value:

http://www.streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval-.html

http://foscam.us/forum/key-frame-interval-t4416.html

 

You can set every frame to be a keyframe, in which case the video file will be very large, or you can set every 1000 frames or a frame ever 10 minutes to be a keyframe which will make the video file smaller to a certain degree with the risk of losing quality.  You have to base it on how the scenes in the video are changing.  If you are filming a scene with very little change (e.g. a video of pouring water from a bottle into a cup, with a very clean static background) you can set a longer interval, but if you were filming a scene that's very dynamic then a shorter interval is better.

[applesuxD]

Keyframe interval, if you're talking about videos, means that a keyframe will be set at every X number of frames. It helps when videos are encoded into lossy compressed formats, where only incremental changes of data for most frames are saved.

As for choosing the right value:

http://www.streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval-.html

http://foscam.us/forum/key-frame-interval-t4416.html

You can set every frame to be a keyframe, in which case the video file will be very large, or you can set every 1000 frames or a frame ever 10 minutes to be a keyframe which will make the video file smaller to a certain degree with the risk of losing quality. You have to base it on how the scenes in the video are changing. If you are filming a scene with very little change (e.g. a video of pouring water from a bottle into a cup, with a very clean static background) you can set a longer interval, but if you were filming a scene that's very dynamic then a shorter interval is better.

Mm ok,for 15000 bitrate,should i use constant quality or VBR

[applesuxD]

Keyframe interval, if you're talking about videos, means that a keyframe will be set at every X number of frames. It helps when videos are encoded into lossy compressed formats, where only incremental changes of data for most frames are saved.

As for choosing the right value:

http://www.streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval-.html

http://foscam.us/forum/key-frame-interval-t4416.html

You can set every frame to be a keyframe, in which case the video file will be very large, or you can set every 1000 frames or a frame ever 10 minutes to be a keyframe which will make the video file smaller to a certain degree with the risk of losing quality. You have to base it on how the scenes in the video are changing. If you are filming a scene with very little change (e.g. a video of pouring water from a bottle into a cup, with a very clean static background) you can set a longer interval, but if you were filming a scene that's very dynamic then a shorter interval is better.

Looking for 1080p 60fps

[ALwin]

Mm ok,for 15000 bitrate,should i use constant quality or VBR

 

Do you mean CBR (Constant Bit Rate) or VBR (Variable Bit Rate)?

 

Generally I would say VBR is better, however for some cases CBR can provide better quality.  Again I would use my example of a simple video of pouring water into a cup, CBR could be enough.  However with dynamic scenes where there is a lot of changes VBR will be better.

 

Good discussion here.

https://forums.creativecow.net/thread/24/893298

 

Quote:

Variable Bit Rate means that you can vary the amount of bits used to represent a frame so that the overall average amount of bits-per-frame is achieved. It does this by stealing bits from frames with less information to encode (that don't need them) and giving them to frames that have more information to encode (and does need them).

Constant Bit Rate means that each frame uses the same amount of bits regardless of whether it needs them or not.

If you encode a video at 6Mbit CBR and 6Mbit VBR the VBR can have better quality. This is because it will vary the bitrate perhaps giving some frames as much as 8 or 9Mbit while others only 3 or 4Mbit but in the end it will average out to 6Mbit. CBR, on the other hand, will never give any frame more that 6Mbit. If there are frames that need more than 6Mbit to encode, CBR will look worse than VBR.

[ALwin]

Looking for 1080p 60fps

 

Can you explain what you mean?  What are you trying to record, what camera or software (e.g. ShadowPlay) are you using, for what purpose?

[applesuxD]

Can you explain what you mean? What are you trying to record, what camera or software (e.g. ShadowPlay) are you using, for what purpose?

obs

[applesuxD]

Do you mean CBR (Constant Bit Rate) or VBR (Variable Bit Rate)?

Generally I would say VBR is better, however for some cases CBR can provide better quality. Again I would use my example of a simple video of pouring water into a cup, CBR could be enough. However with dynamic scenes where there is a lot of changes VBR will be better.

Good discussion here.

https://forums.creativecow.net/thread/24/893298

Quote:

Variable Bit Rate means that you can vary the amount of bits used to represent a frame so that the overall average amount of bits-per-frame is achieved. It does this by stealing bits from frames with less information to encode (that don't need them) and giving them to frames that have more information to encode (and does need them).

Constant Bit Rate means that each frame uses the same amount of bits regardless of whether it needs them or not.

If you encode a video at 6Mbit CBR and 6Mbit VBR the VBR can have better quality. This is because it will vary the bitrate perhaps giving some frames as much as 8 or 9Mbit while others only 3 or 4Mbit but in the end it will average out to 6Mbit. CBR, on the other hand, will never give any frame more that 6Mbit. If there are frames that need more than 6Mbit to encode, CBR will look worse than VBR.

Theres this constant quality option,i know that vbr is generally better for quality and my pc can handle it but i wanna know if constant quality is better

[ALwin]

Theres this constant quality option,i know that vbr is generally better for quality and my pc can handle it but i wanna know if constant quality is better

What exactly is the label of the setting you are curious about?

 

Are you talking about this?

http://slhck.info/articles/crf

 

Here's a guide for OBS settings

https://obsproject.com/forum/threads/technical-explanation-of-obs-settings.642/

[applesuxD]

What exactly is the label of the setting you are curious about?

Are you talking about this?

http://slhck.info/articles/crf

Here's a guide for OBS settings

https://obsproject.com/forum/threads/technical-explanation-of-obs-settings.642/

Obs multiplatform

Under advanced

Record

Keyframe interval seconds and Rate control

3 options cbr vbr and cqp

[.spider.]

With x264 you can set your Keyframe intervals as long as you want.

Benefit; better quality at lower bitrate

Drawback; slower to edit

But x264 has a scenecut detection which sets Keyframe automatically so it won't produce long GOPs if they aren't necessary

The Keyframe decision is based on this simple formula [1 - (bit size of P-frame) / (bit size of I-frame) ] < [(scenecut / 100) * (distance from previous keyframe) / keyint]

As you can see raising the scenecut value could be a good idea.

If you are recording to file you only want to use rate control.

[applesuxD]

With x264 you can set your Keyframe intervals as long as you want.

Benefit; better quality at lower bitrate

Drawback; slower to edit

But x264 has a scenecut detection which sets Keyframe automatically so it won't produce long GOPs if they aren't necessary

The Keyframe decision is based on this simple formula [1 - (bit size of P-frame) / (bit size of I-frame) ] < [(scenecut / 100) * (distance from previous keyframe) / keyint]

As you can see raising the scenecut value could be a good idea.

If you are recording to file you only want to use rate control.

To file