Tape copy should be submitted on Digital Betacam format.

Tape copy should be sent to the following address :
Channel Four Server Operations, 124 Horseferry Road, London SW1P 2TX

The recorded video must be a compatible 625 line 25 frame standard, conforming to CCIR 601.

Vision should be legal such that in the RGB domain all the R, G, B signals are within the range 0 to 100% of peak luminance. Please note that we will automatically clip levels to this range. Vision which does not comply may be affected by the process.

The aspect ratio must be 16:9 full height anamorphic and protected for 14:9 transmission. The widescreen 16:9 full height commercial copy supplied will be presented on widescreen services in 16:9 anamorphic format and on non-widescreen services in a 14:9 slight letterbox format, matching the format of many existing programmes. It is essential that delivered widescreen copy is produced to the UK Broadcasters specification for 16:9 shoot & protect 14:9 as outlined in Appendix A.

Stereo sound is standard for all Channel Four transmissions, including commercials. Any commercial that is not stereo should be delivered with phase coherent mono sound on both audio tracks.

Format should have the transmission audio on tracks 1 and 2.

There should be 6 frames of audio silence at the start and end of the commercial and the duration should not exceed the stated length. At the end of the commercial there should be a 10 second hold on vision followed by 30 seconds of black. ( No ‘Living Freezes’ )

The Channel’s commercial transmission system allows subtitles to be received by the hard of hearing. Subtitles should be recorded on television line 335 and conform to the “World System Teletext” standard. The clock should state “Teletext 888” if subtitles are present. The subtitling of commercials for the hard of hearing is encouraged by the Channel.

Tapes must start with a line-up signal consisting of at least 1 min of line-up reference comprising:

• Video: 100% colour bars
• Audio: reference tone on each track, comprising 1 kHz tone at 0dBu (-18 dBFS, PPM 4), phase coherent, on tracks 1 and 2.

Line-up test signals should be followed by a countdown clock for at least 20 seconds duration. The clock should identify:

• Product name
• Agency copy number (clock number)
• Commercial duration
• ‘Teletext 888’ if subtitles are present
• Stereo or mono audio

Black should exist between –3 on the clock and the first frame of picture.

It is not Channel Four policy to return door copy.

The use of digital recording will ensure that the necessary copying processes are transparent and commercials are transmitted to the highest technical standards. Any technical defect which is apparent in the source master tapes, copy delivered by linefeed, or in digitally delivered copy will be referred to the agency or supplying company for correction and re-submission.

Any breach of Ofcom/ASA guidelines will similarly be referred for correction and re-supply.

Legally required captions which are outside the designated 14:9 safe caption area, do not meet the Ofcom guideline requirements, or are otherwise illegible will not be accepted.

It is Channel Four policy that, whilst wishing to allow sensible freedom in the dynamic range of its transmissions, audio signal levels should have a consistency of loudness such that the viewer does not have to adjust audio volume between transmission segments.

The use of audio compression to achieve a more “prominent” sound must therefore be accompanied by a corresponding eduction in the peak signal level. Channel Four reserves the right to make adjustments to the absolute signal level of supplied commercials.

Audio to register between L+4 and L+8 on the loudness scale, centred on L+6.

Channel Four accept delivery of commercials via these methods:

Electronic File Delivery
From IMD imdonline.co.uk 020 7468 6850 (London Office)
From Adstream adstream.tv 020 7691 6300 (London Office)

On Digi-Beta, send to: Channel Four Server Operations, 124 Horseferry Road, London SWIP 2TX

Playout via LNN, this will need to be co-ordinated by Clearcast. Tel No 020 7339 4700.

All facility companies will be aware of these methods.

All commercials sent to Channel Four must be supported by copy rotation instructions. These instructions should include product name, clock numbers, channel and areas of transmission, campaign dates and if more than one commercial of the same length, how you wish them to be used. Send these instructions to: