Archive for the ‘BBC’ Category

BBC TV Technical Production Guidelines

Tuesday, July 16th, 2013

Some BBC documents I came across:

  • http://www.bbc.co.uk/guidelines/dq/contents/television.shtml
    • ID
      • DQ – Defining Quality
      • This section brings together all policies and standards that apply to the delivery of television programmes.
      • For other information, please see the TV Commissioning Site: http://www.bbc.co.uk/commissioning/.
    • Signal Levels
      • In a picture signal, each component is allowed to range between 0 and 100% (or 0mV and 700mV). This equates to digital sample levels 16 and 235 (8-bit systems) or 64 and 940 (10 bit systems).
    • Blanking
      • Digitally delivered pictures are considered to have a nominal active width of 702 pixels (52us) starting on the 10th pixel and ending on the 711th pixel in a standard REC 601 (720 sample) width.
      • A minimum width of 699 pixels (51.75us) within these limits must be achieved.
      • Additional active pixels outside the above limits must be an extension of the main picture.
      • Vertical Blanking must not exceed 26 lines per field.
      • Line 23 may contain a whole line of picture, be totally blank ed, or the last half may contain picture relevant to programme. Line 23 must not contain any form of signalling as it is likely to appear in picture during letterbox style presentation.
      • Likewise picture content in line 623 is also optional, but if present it must be related to the programme
    • Aspect Ratio
      • Active Picture Width
        • Active picture width is 52us / 702 pixels. All aspect ratio calculations are based on this. Any processes based on 720 pixel width may introduce unwanted geometry or safe area error.
    • Use of HD Material (for SD programmes)
      • Some standard definition programmes will contain material from high definition sources.
      • Particular care must be taken to deliver the best possible quality of down-converted material.
      • It is acceptable to use a broadcast VTR’s “on board” down converter to produce standard definition copies of high definition programmes.
      • Most non linear editing packages do not produce acceptable down conversion and should not be used without the broadcaster’s permission
    • Safe Areas for Captions
    • Audio
      • Stereo audio levels and measurement (loudness or volume)
        • Stereo programme audio levels are currently measured by Peak Programme Meters (PPM). The Maximum or Peak Programme Level must never exceed 8dBs above the programme’s reference level. The following levels, as measured on a PPM meter to BS6840: Part 10 with reference level set at PPM 4, are indicative of typical levels suitable for television, and are given as guidance only.
      • Stereo phase
        • Stereo programme audio must be capable of mixing down to mono without causing any noticeable phase cancellation.
      • Material (levels in PPM):
        • Dialog: Normal: 3-5, Peak 6
        • Uncompressed Music: Normal: 5, Peak 6
        • Compressed Music: Normal: 4, Peak:4
        • Heavy M&E (gunshots, loud traffic etc): Normal: 5-6
        • Background M&E (ambient office or street noise etc or light mood music): 1-3
  • http://www.bbc.co.uk/guidelines/dq/pdf/tv/tv_delivery_to_network_programmes_SD_v1.0-2011.pdf
    • Technical Standards for Delivery of Television Programmes to BBC
    • This document is only to be used for the delivery of programmes commissioned in Standard Definition (SD).