Iris QC and SCC Caption Files

Background

• SCC is a frame-based format based on CEA-608 specification.

• SCC files are text files that can be opened in most text editors.

• SCC files contain lines of data where each line has a starting timecode followed by 2-byte

hexadecimal words.

• Each 2-byte hexadecimal word represents one frame worth of processing

• Only 29.97 fps drop frame, and 29.97 non-drop frame are technically supported.

Current use of SCC caption files

Since SCC caption files were the standard for many years in broadcast usage, the ecosystem for these files is large. As SD video made way for HD and the ability to use frame rates that approximate that of film (23.98 fps) and the greater need to localize, added PAL 25 fps many of the existing files have been converted to better match the current video.

However, in the conversion process files can be corrupted or more often timing issues can be introduced. The requirements for accessibility can also play a role as the timing reductions in conversion can make the readable screen time too short.

Here’s an in-depth look at .SCC captions (attached)