Abstract: A timecoding technique for determining and assigning timecodes for variable frame rate video. Content identified for timecode assignment is decoded, and for sequential frames of the content, portions of timestamps are compared to determine if the frames are from a same time period (e.g., from the same second in time). For a subsequent frame from the same time period, an index is atomically incremented, a timecode generated from a combination of the time period and the index, and the timecode assigned to the frame. For a subsequent frame from a different time period, the index is initialized, a timecode generated from a combination of the different time period and the initialized index, and the timecode assigned to the frame. Accumulated durations of frames may be used in place of timestamps, in some instances.