A system for characterizing a relative offset in time between audio and video signals, the system comprising: a frame storage configured to: receive, from a television origination facility, a sequence of frames including video and audio signals as well as in-band characterization data associated with each scanline of each frame in the sequence of frames, said characterization data including a checksum for the video data in a scanline of a video signal and a checksum for the audio signal corresponding to the same scanline, wherein each frame includes: (i) a visible frame space storing the video signals of the respective frame; (ii) a vertical ancillary (VANC) space storing the checksums for the video signal and corresponding audio signal of the respective frame, said checksums being encoded in the VANC space at the television origination facility; and (iii) a horizontal ancillary (HANC) space storing the audio signals of the respective frame; and store at least a portion of the frames in the sequence of frames; a checksum receiver coupled to the frame storage and configured to: extract the encoded checksums from the VANC space in the sequence of frames; capture checksums for each scanline of each frame in the sequence of frames based on the video signals for the same scanline in the visible frame space for each frame in the sequence of frames and the audio signals in the HANC space in the sequence of frames; and compare the checksums captured for each scanline of each frame of the sequence of frames with the extracted checksums to determine the relative offset in time between the audio and video signals of the sequence of frames. a frame storage configured to: receive, from a television origination facility, a sequence of frames including video and audio signals as well as in-band characterization data associated with each scanline of each frame in the sequence of frames, said characterization data including a checksum for the video data in a scanline of a video signal and a checksum for the audio signal corresponding to the same scanline, wherein each frame includes: (i) a visible frame space storing the video signals of the respective frame; (ii) a vertical ancillary (VANC) space storing the checksums for the video signal and corresponding audio signal of the respective frame, said checksums being encoded in the VANC space at the television origination facility; and (iii) a horizontal ancillary (HANC) space storing the audio signals of the respective frame; and store at least a portion of the frames in the sequence of frames; receive, from a television origination facility, a sequence of frames including video and audio signals as well as in-band characterization data associated with each scanline of each frame in the sequence of frames, said characterization data including a checksum for the video data in a scanline of a video signal and a checksum for the audio signal corresponding to the same scanline, wherein each frame includes: (i) a visible frame space storing the video signals of the respective frame; (ii) a vertical ancillary (VANC) space storing the checksums for the video signal and corresponding audio signal of the respective frame, said checksums being encoded in the VANC space at the television origination facility; and (iii) a horizontal ancillary (HANC) space storing the audio signals of the respective frame; and store at least a portion of the frames in the sequence of frames; a checksum receiver coupled to the frame storage and configured to: extract the encoded checksums from the VANC space in the sequence of frames; capture checksums for each scanline of each frame in the sequence of frames based on the video signals for the same scanline in the visible frame space for each frame in the sequence of frames and the audio signals in the HANC space in the sequence of frames; and compare the checksums captured for each scanline of each frame of the sequence of frames with the extracted checksums to determine the relative offset in time between the audio and video signals of the sequence of frames. extract the encoded checksums from the VANC space in the sequence of frames; capture checksums for each scanline of each frame in the sequence of frames based on the video signals for the same scanline in the visible frame space for each frame in the sequence of frames and the audio signals in the HANC space in the sequence of frames; and compare the checksums captured for each scanline of each frame of the sequence of frames with the extracted checksums to determine the relative offset in time between the audio and video signals of the sequence of frames.