I have been hired as a freelancer to build a video splitting utility that's supposed to split video clips at certain points as indicated by the user. I am using ffmpeg as a library and it produces files that play OK in all the players I have. However, when my client tries to import the files in Final Cut Pro (which is an essential part of my client's workflow) the files do not play as intended, they have some kind of visual distortion.
I do not have access to FCP and even if I did I don't think I could fix ffmpeg bugs, if they're bugs in ffmpeg at all and not bugs in Final Cut Pro. I also don't know of any other video manipulation library that could get the job done with any kind of video file, and we are already way past the time estimate I gave my client.
This is a fixed bid project, I have been working for nearly a month (more than expected) fixing bugs and trying to solve my client's needs (which weren't well specified at the beginning), and I don't know what to do now. How do I handle this situation?