I'm trying to export an mp4 file from fcp (as this format is most compatible with our clients). However, i'm getting a really bad fuzziness and bad blending in tone.
I've created an animation in cinema 4d (a mov file with h264 compression) and ive edited it in fcp adding video transitions and still jpgs. I've matched the sequence settings with the main animation clip, Although i have tried exporting mp4's and mov files using a number of compressor codecs in the sequence settings and i think i have narrowed it down to being an issue with the h264 compression in the sequence settings as any mov file i export using a different sequence codec seems to be fine.
It gets especially bad where there are transparencies in my animation clip where i have faded objects in.
problem seems to be when i have both h264 as the codec in sequence settings combined with exporting mp4's. export settings are set to current and both the source clip and the sequence and export settings are 1920x1080. Data rate is 5120 kbps. audio/video settings are set to DV NTSC
Your first mistake is having exported from Cinema 4D with a code that is not for production an that is not supported by FC (h264).
if you don't want to start again exporting from Cinema4D with to a proper codec (Prores would be the best option), try changing your sequence codec (Prores would be the best option again) and in the render options, set to render in 8bYUV, or better in High Precision.
Export a self contained movie and then convert to MP4/h264.