Creating a Motion JPEG frame by frame with variable frame-rate

Question

I'm analyzing a number of solutions to the problem that I have in hand: I'm receiving images from a device and I need to make a video file out of it. However, the images arrive with a somewhat random delay between them and I'm looking for the best way to encode this. I have to create this video frame by frame, and after each frame I must have a new video file with the new frame, replacing the old video file.

I was thinking of fixating the frame-rate a little "faster" than the minimum delay that I might get and just repeat the last frame until a new one arrives, but I guess that this solution is not optimal.

Also, this project is made with Delphi (no, I cannot change that) and I need means to turn these frames into a video file after each frame. I was thinking about using mencoder as an external tool, but I'm reading the documentation and still haven't found an option to make it insert a frame in an already encoded Motion JPEG video file. As my images come in as JPEG, I thought that it would be reasonable to use Motion JPEG, but not even this is certain yet. Also, I don't know if mencoder can be used as a library. It would help a lot if it did.

What would you suggest?

Answer 1

There are some media container formats that support variable frame rate, but I don't think MJPEG is good choice because of the storage overhead. I believe the best way would be to transcode JPEG frames to MP4 format using both I-frames and P-frames.

You can use FFMPEG Delphi/FP header files for the transcoding.

Edit:

The most up to date version of FFMPEG headers can be found at GLScene repository on SourceForge.net. To view the files you can use this link