Question about After Effects

H.264 was removed from the Render Cue/Output Module because H.264 is a MPEG format that uses IPB compression. After Effects renders one frame at a time. To do a good job rendering IPB compression the software needs to render an I-frame (keyframe) by compressing the color and luminance values from the original pixels, then a P frame (Predicted Picture) is calculated by looking at the previous frame and calculating which pixels changed, then a B-frame (bidirectional predicted picture) is calculated from the previous and the next frame before the sequence repeats. The Render Cue and the Output Module cannot do that because After Effects renders one frame at a time and then starts on the next frame. There was no way to give users high-quality compression without completely engineering the way After Effects calculates pixels from layers. 

The other codecs were removed because of expiring license agreements and lack of support from other parties. There is not much any company can do if a supplier drops support or fails to keep their product up to date. Adobe may have dropped some formats, but they gave us others. Using the Media Encoder also allows you to keep working while a comp is rendering. In the long run, almost all users can be more productive and deliver a better product.

Because Adobe removed a lot of important codecs and containers from the render manager...for me it's XDCAM HD in MXFOP1a for a broadcast standard workflow. God knows why, I'd suspect to push the usage of AME and remove the neccessity to maintain both encoders.

If you need H.264 the only way (I know) is to export via AME: