AME produces tiny h264 file even though its set to CBR 120Mbps

[andyschon]

I am trying to encode an mp4/h.264 of a slowly changing gradient background with text overlays (generated in AE). With a 2min clip, 3840x1620px, encoder set to CBR 120Mbps, AME says it will produce a file about 1.7GB, it actually produces a file of 92.6MB that is riddled with banding and compression artefacts.

This is an example source frame. I've tried encoding directly from the AE composition or exporting a tiff sequence from AE and encoding that. I've tried a variety of VBR/CBR and bit rate settings. All with no change. It comes out as 92.6MB whatever I do.

[SAFEHARBOR11]

First off, I've seen posts suggesting that perhaps best not to encode .mp4 direct from AE. Perhaps export to an intermediate codec, then use Media Encoder for the H.264 encode.

Second, highly compressed formats have issues with large areas of solid color, doesn't compress well. Blocks/banding. Might help to add some "grain" meaning "video noise" to give the compressor something to work with.

Thanks

Jeff

[andyschon]

I've had no problems encoding from an AE comp in the past, and as mentioned above, I've tried exporting uncompressed from AE and encoding from that, which produced an identical file down to the byte.

Adding a little noise is a very good idea. Not ideal as this is destined for a 20ft wide 4k display. The player can only handle h264 though so needs must.

Thanks Jeff.