In Post-production, footage is sometimes converted with an intermediate codec to a format more appropriate for edition. Capture formats can be very computing-intensive, for example to render one H264 frame at the end of a long Group of Pictures can take one second, because all the previous frames need to be rendered too.
With an intermediate codec, rendering is very fast and quality is almost indistinguishable from the master clip.
Intermediate is the short name for Apple Intermediate Codec, a video codec designed to be an intermediate format for editing HDV media.
As it doesn't use temporal compression, so takes 3 to 4 times more space but is faster to decode.
(This codec doesn't come pre-installed in Mac computers.)
Intermediate is repaired without major problem.
How to repair a corrupt Intermediate movie
The easiest way is certainly to ask our Movie Repair Service to do it for you.
But for those who can program, here you have a few tips:
Techniques used are:
Video track has a 'icod' codec fourcc and is organized in frames.
Each frame starts with a pattern that is easy to find:
01 16 xx xx xx xx ww ww hh hh, where:
- xxxxxxx encodes the frame length (32 bits)
- wwww encodes the frame width in pixels
- hhhh encodes the frame height in pixels
The frame length varies, but the width and height are always the same in the movie.