This part of IEC 62447 specifies the content, format, and recording method of the data blocks containing video, audio, and associated data which form the helical records on 6,35-mm tape in cassettes as specified in SMPTE 307M. In addition, this standard specifies the content, format, and recording method for longitudinal cue and control tracks. One compressed video channel, eight independent audio channels and subcode data are recorded on tape in the digital form. Each of these channels is capable of independent editing. On the following digital video formats, the helical recordings are synchronized to: – 1080 line/59,94 Hz field frequency; – 1080 line/50 Hz field frequency; – 720 line/59,94 Hz frame frequency. These are hereafter referred to as the 1080/60i, 1080/50i,and 720/60p systems, respectively. Similarly, in this standard, the 60 Hz system nomenclature refers to both 1080/60i and 720/60p systems, whereas, the 50 Hz system refers only to the 1080/50i system. Nomenclature 1080 line system refers to both 1080/60i and 1080/50i systems, while the 720 line system refers only to the 720/60p system. The recorded digital video signal shall be compressed according to the DV-based 100 Mb/s specification. The recorded digital video signal, eight audio channels and subcode data shall be defined by the data structure according to the DV-based 100 Mb/s specification.