Rendering H.264 with 2 consecutive B frames

[JervisFilmz]

Hello,

I want to render an H.264 project for youtube.

YouTube recommends "2 consecutive B frames" in the exports.

my project is 60fps so what setting i need to type in the "keyframe distance" to get this 2 consecutive B frames?

[Dave_LaRonde · Accepted solution]

Well, this is pretty easy. Open Adobe Media Encoder. There's a command to open an AE comp. Navigate to the project file, pick the right comp, and then use the YouTube compression preset. Hit the start button. AME takes care of it for you. 

[JervisFilmz]

I understand tha you believe that the YT preset is using the correct "keyframe distance" value to output

2 consecutive B frames. I would like to learn more about it and want know how to calculate it.

[Rick Gerard]

Dave hit the nail on the head. Until you completely understand video compression and video formats you really have no business messing with the presets. They are all set up and they will give you the best results almost all projects. It's pretty hard to improve on anything.

[JervisFilmz]

I understand tha you believe that the YT preset is using the correct "keyframe distance" value to output

2 consecutive B frames. I would like to learn more about it and want know how to calculate it.

[Rick Gerard]

You need to check the official documentation to study up on h.264 specifications. Do not rely on amateurs and enthusiasts to give you advice. Most of the encoding advice on the net is just plain wrong. You have to vet the sources to make sure they know what they are talking about. 

The AME Help will take you to the User Guide. That's where you learn how to manipulate the controls and what they do. The AME is setup for standard distribution and rendering of video and things like setting up the IBP frames are hidden because there are standards that must be followed if the video is going to be viewable on standard devices and delivery systems. 

Specialized encoders are required for things like big LED displays and multi-screen presentation systems. If you have to produce specialized media you need specialized encoders. The AME is not designed or intended for that kind of work because each specialized system has its own requirements and it is not a good idea to give the average user access to controls that will screw up the render.

[JervisFilmz]

My dear friend,

5+5 is 10 right?

there is no discussion about it.

the advanced render setting "keyframe distance" for h.264 is there to set the video structure right?

so what is the calculation to have a video at 2 consecutive B frames

[Rick Gerard]

The keyframe distance does not set the arrangement of the IBP frames. You are not clearly understanding the way the Media Encoder works or the purpose of the keyframes. Both the YouTube and the Vimeo presets produce perfectly compatible files for YouTube and Vimeo according to their standards. Their standards are pretty universal to all streaming services. YouTube and Vimeo both re-compress every video that is sent to them to prepare them for multiple data rate playback. Sending them a video that matches their recommendations does not mean that your original will be served up to users, it means that their system will do the least amount of damage to the file when they re-compress the file. Following their recommendations also will help your video be ready for distribution in less time.

Keyframes in the media encoder have nothing at all to do with the IBP compression. They are automatically set based on the frame rate and you should not mess with them unless you are trying to do something custom with the frame rate. Custom frame rates are not a good idea so that setting should not be messed with unless you are following a template for some kind of specialized media player. The frame rate also has nothing at all to do with IBP frames or their arrangement. IBBP is going to be the same for 23.976 or 24, or 25 or 29.97 or any other frame rate. You will get an intraframe compressed frame (the only one with all of the pixel and color data) then a pair of bi-directional predicted data (color predictions and luminance predictions) and then a predicted frame that is nothing more than a software prediction of where the colors are and where the detail has moved using the AME and there is nothing you can do to change that setting.

Let me say this one more time. The presets in the AME already send the right format video to the streaming services. There is nothing you can do in the AME to change the IBP cadence. That option does not exist. You are obsessing about a setting that you cannot change in the AME.

Check the User Guide. 

[JervisFilmz]

alright ,

thank you