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Al Jazeera English TVC Technical Requirements

Producers should be free to make the programme in the manner of their choosing. This document merely sets out the technical requirements to ensure that material delivered is of a satisfactory standard. However, it also draws attention to areas that may impact upon technical parameters and the quality of programmes.
The content covers three areas -

Technical

Requirements

These sections describe the technical standards required to deliver material to Aljazeera International in such a way that the programme is fit to perform the purpose(s) for which it was commissioned and will pass flawlessly through the broadcasters systems. These are broadly pass / fail objective measurements.

Quality

Requirements

These deal with broadly subjective quality issues for the pictures and sound. Careless shooting, inappropriate production methods and faulty or substandard equipment can cause avoidable impairment to sound or vision. The ITU / CCIR 5 point grading scale will be used to assess programmes for quality and the commissioner should indicate what level of standards are required.

Operational

Requirements

All material delivered must be to the correct standard, be accompanied by the correct line-up sequences and accompanied with the correct information for the “Ingest” or delivery process.

Due to the rapid rate of technical development, use of specific equipment is constantly under review. This document will be subject to periodic updates to reflect this reality, but please consult your resource provider for advice on specific issues.

3 TECHNICAL RESPONSIBILITIES FOR PROGRAMMES

3.1 General Responsibilities

The Director of Technology of Aljazeera International is required to ensure that programme technical quality is maintained to a satisfactory standard for international distribution.

3.2 Technical Liaison & delivery

The subject of the email should be Technical Standards Questions

3.3 Relaxation of Standards

Any proposal to deliver programme material which does not conform to the technical standards in these guidelines must be agreed beforehand. All programmes are expected to meet the required technical standards, and the recognised exemption categories are tightly constrained and may not be invoked for the general convenience of programme makers.
The production company may apply for special exemption prior to the start of production. This will allow discussions to proceed at an early stage and, although in no way guaranteed, will reduce the likelihood of subsequent difficulties.
There are four recognised categories for technical exemption:

Artistic interest - innovative or experimental productions which are made, of necessity, by those who do not have access to equipment or facilities meeting broadcast quality standards.

Historic interest - news or programmes of a documentary nature which show historic events taking place or whose subject matter requires the use of archive material.

Actuality material - news, features or documentaries of an actuality nature where better quality has not been possible because of limitations placed on the format or physical size of equipment used. Such limitations are those incurred as a result of shooting in difficult areas such as war zones, isolated locations, confined spaces or other difficult environments.

Early television and cinema - excerpts from historical archives where low technical quality was due to the then current performance of equipment used in its creation or where quality is now lower than at the time of original showing because of film or video ageing.

4 GENERAL TECHNICAL REQUIREMENTS

4.1 General Signal Requirements

Although the majority of programming is now produced and delivered digitally, the signals must still be compliant with analogue standards. For example, excessive (illegal) levels are likely to cause severe picture disturbances when copied to analogue tape formats such as Betacam SP, or sound buzz on analogue transmission.

4.2 Video System Standards

All signals and recordings supplied shall be of the 1080i/50 (interlaced) high definition standard.

4.2.1 Programme signal parameters

Video signals must correspond to the reference line-up levels. These include peak sound, maximum luminance and colour difference (Y Cr Cb) component and black levels. Care must be taken to avoid illegal colours (Y Cr Cb component signals exceeding the gamut limit) which may be generated by caption and graphics systems.

4.2.2 Video Levels and Gamut (illegal signals):

Video levels including any line-up shall be received within the specified limits allowing the programme material to be used without adjustment. Video levels must be compatible with the PAL System EBU Recommendation R103-2000

Luminance limits -1% and 103%

Chrominance 105% max - RGB values to not exceed limits -5% to +105%

Overshoots can be ignored by the use of a low pass IRE filter. Single lines with larger errors caused by vertical processing such as aperture correction and aspect ratio conversion are permitted if they do not exceed the -1% Luminance limit.

4.2.3 Vertical blanking

Vertical blanking should fall within SMPTE 274M/295M specifications, as stated in section 14 “Analogue Synch” and section 15 “Analogue Interface” and in ITU-R specification BT.709-4. The vertical blanking interval should equal lines 1-20 and lines 561-563 of the first field and lines 564-583 and lines 1124-1125 in the
second field.

4.2.4 Horizontal blanking

Horizontal blanking should fall within SMPTE 274M/295M specifications, as stated in section 14 “Analogue Synch” and section 15 “Analogue Interface” and ITU-R specification BT.709-4. Horizontal blanking should be between 280 clock periods and a maximum of 292 clock periods, creating a blanking width of between 3.775 microseconds and 3.935 microseconds when a clock period is equal to 13.48 nanoseconds.

4.2.5 Video white levels

White level should not exceed 700mV for component signals, and program black levels should not extend below 0V (DC). Neither the program luminance whites
nor blacks should be clipped excessively. For colour difference signals R-Y and B- Y, levels shall not exceed 700 mV or fall below 0 mV when set at a 350 mV offset.

4.3 Audio Standards

Programmes shall be delivered in mono or stereo format as required. The use of pre- emphasis and/or noise-reduction schemes during acquisition and post production is acceptable. However, the programme for final delivery should have no pre-emphasis or noise reduction scheme applied unless specifically required.

Left audio shall be present on the A leg or Channel 1.

Right audio shall be present on the B leg or Channel 2.

Mono shall be in Dual Mono format with identical and coherent audio on both left and right channels.

Finished programme material intended for transmission with stereo sound, whether recorded on videotape or for live transmission, must carry sound in A/B (left/right) form.

4.3.1 Audio Levels

Reference Level shall represent a level which is 8dB less than the maximum allowed during the programme as measured with a PPM. Reference Level is often referred to as “Zero Level”, “Line-up Level”, “0dB”, “0dBu” or PPM4.

Digital Audio Reference level is defined as 18dB below the maximum coding value

(-18dBFS) to EBU recommendation R68-2000.

Mono derived from stereo shall be to the M6 practice where the mono signal is derived according to: “Mono = (L+R) - 6dB”

4.3.2 Audio Line-Up

Line-up tones serve to identify individual signal channels and provide reference levels. This will ensure the programme transmitted will be within the signal level limits specified above and will be broadcast as the producer intended.

All tones must have been sourced to a tolerance of +/- 0.1dB.

Mono line-up tone shall be at a frequency of 1 kHz +/- 100Hz and represent 8dB

less than the maximum allowable peak.

For stereo sources, stereo line-up tone shall be provided at a frequency of 1kHz

+/- 100Hz and shall indicate the left and right programme legs as described in

EBU recommendation R49-1999.

All tones must be sinusoidal, free of distortion and shall be phase coherent between channels. Optionally, step tone sequences may be provided, but all tones must have been sourced at the same level and be phase coherent on stereo feeds or tracks.

4.3.3 Stereo Balance and Phase

The two stereo legs, when sending identical programme (mono), shall match within 0.5dB and be phase coherent to less than 15 degrees at 10kHz.

5 GENERAL QUALITY REQUIREMENTS

5.1 Technical quality grading

The overall quality of sound and vision will be separately assessed in controlled monitoring conditions and any impairments noted. At the end of the technical review the programme will be judged against the ITU-R five-point grading scale -

Grade 5 Imperceptible impairment

Grade 4 Perceptible but not annoying impairment

Grade 3 Slightly annoying impairment

Grade 2 Annoying impairment

Grade 1 Very annoying impairment

New commissioned programmes should meet a minimum of grade 4 for sound and vision quality. The minimum acceptable quality for any programme is grade 3 unless there are valid reasons for technical exemption, in which case details should be clearly stated on the recording report.

5.2 General picture quality requirements

The pictures should be appropriately sharp, free of excessive overshoots and normally exhibit no perceptible levels of noise. Black or white crushing in the main areas of interest should be avoided and colours, especially skin tones, should be natural.

Aljazeera International wishes to encourage the use of innovative programme making techniques. Nothing in this document should prohibit the use of any production technique provided a suitable quality product results. An unavoidable consequence of today’s rapid technical developments makes it inherently difficult to define precisely a suitable quality product. Subjective descriptions leading to imprecise advice will inevitably follow. A competent resource provider should be able to give advice on achieving good quality results.

In certain circumstances, for example shooting actuality material or where a high level of mobility is required, the use of a HDV “palmcorder” type camera may be considered acceptable for acquisition, but specific agreement from Aljazeera International must be sought for this. If the use of this format is agreed, particular attention is required to sound and lighting considerations.

The use of material from all other non-broadcast and domestic videotape formats is not permissible except in exceptional circumstances. The use of up-converted standard definition may be allowed if it falls into the categories described in section 3.3. Any use of such material must always be fully discussed and agreed in advance with Aljazeera International.

5.3 General audio requirements

Audio signals must be suitable for reproduction in a domestic environment. Dynamic range should be restricted and changes in loudness controlled so that the viewer has no need to adjust volume during or between programmes. All stereo recordings must provide good mono compatibility.

The audio shall be free of spurious signals such as noise, hum and cross-talk. Sibilance, distortion wow and flutter shall not be apparent.

The audio shall not show dynamic and frequency response artifacts as a result of the action of noise reduction or low bit rate coding systems. Audio compression should be used as little as possible as this tends to increase impairments.

5.4 Sound to vision synchronisation

The relative timing of sound to vision should not exhibit any perceptible error. Sound must not lead or lag vision in excess of 20ms (1 field at 25 frames per second). A sound delay of greater than 20ms can be acceptable where this occurs in context to give a perception of distance.

5.5 Electronic Video Processing

Due to international distribution of Aljazeera International and the requirement for standards conversion, any use of video processing must be agreed with Aljazeera International, this includes the use of film effect and noise reduction.

5.5.1 Standard Definition Standards Conversions

The use of Motion Compensating (sometimes know as Motion Predictive or
Motion Vector) standard converters is preferred.

5.5.2 High Definition Standards Conversions

As they become available the use of Motion Compensating HD standards converters is preferred. It is also acceptable to use speed change to transfer between high definition standards as long as the due attention is given to the audio. Currently speed change is the preferred method of changing between 25 and 24 frame HD standards.

5.5.3 Up Conversions

Where it is permissible to use standard definition material in a high definition programme, care must be taken to deliver the best possible quality. This is particularly important when material has to be standards converted as well as up converted. Use of standard definition material must be cleared with Aljazeera International.

5.5.4 Film Effect

Most high definition cameras can capture in both interlaced and progressive modes. It is not acceptable to add film effect to high definition. Where film motion is a requirement the use of progressive capture is the preferred method.

5.5.5 Flashing Images and Repetitive Patterns

Flickering or intermittent lights and certain types of repetitive visual patterns can cause problems for some viewers who have photosensitive epilepsy. Television is by nature a flickering medium and it is not possible to completely eliminate the risk of causing convulsions in viewers with photosensitive epilepsy. However steps
can be taken to reduce unnecessary risks.
The following guidance on the major factors involved is provided for reference, but the Ofcom guidelines should be consulted for complete information.

Rapidly flickering images should not change at a fast rate i.e. less than

360ms (9 frames at 25 frames per second) between each flash.

If brightness changes for a given area of a picture are less than 25% of screen maximum brightness then that area may be discounted.

In marginal cases such images should be avoided if they are positioned near the centre of the screen.

Changes in colour are not a problem unless they affect the red channel substantially.

Prominent and regular patterns which cover a large proportion of the picture area should be avoided, especially if they represent bars, spirals,

or ‘dartboard patterns. Moving or flickering regular patterns are particularly hazardous.

Care needs to be taken also with computer generated images, which, if highly detailed, can cause a high degree of 25Hz inter-line flicker in the displayed television picture.

Video luminance level as measured on a waveform monitor does not simply equate to screen luminance (brightness) and cannot be used to assess brightness without correcting for Gamma.

5.6 Delivery on Videotape

5.6.1 Technical Acceptance Procedures

All programmes delivered on videotape must have been quality assessed and be transmission legal. Any programmes failing to meet the required technical standards, or in breach of other acceptance requirements will be referred back to the supplying production company.

5.6.2 Videotape Format

Programmes should be delivered on the HDCAM component videotape format and shall comply with the SMPTE 274-1998 and SMPTE 295-1997 standards. In all cases the submitted videotape recording must be fully compliant with the manufacturer’s technical specification thereby ensuring format compatibility.

5.6.3 Recording Reports

Every tape submitted must be accompanied by a completed recording report. The report must include full details of the programme supplier and recording facility house and programme title/ subtitle. It must also include technical information including the origination format, timecode of first frame of picture (FFOP) and details of the aspect ratio and safe areas used. The recording report must provide clear references to any part of the programme content that may attract low grades (especially below grade 3).

5.6.4 Line-up Test Signals and Leader

The start of programme and any subsequent part should be preceded by a countdown clock indicating production number, programme title, subtitle, episode number (where appropriate), part number and part duration. The clock must provide a clear countdown of at least 20 seconds cutting to black at three seconds prior to the start of the programme. The clock must appear round when viewed on a screen of the same aspect ratio the programme is intended to be viewed on.

Timecode

Picture

Audio 1

Audio 2

Audio 3

Audio 4

09.58.00.00 (or Earlier)

EBU Bars

(100/0/75/0)

Coherent Step tone

(100Hz, 900Hz and above 10kHz)

Coherent Step tone

(100Hz, 900Hz and above 10kHz)

09.59.30.00

Ident and Clock

Stereo Ident or Line up

Tone at –18dBfs

(PPM4)

Stereo Ident or Line up

Tone at –18dBfs

(PPM4)

09.59.50.00

Ident and Clock

  

09.59.57.00

Black

Silence

Silence

10.00.00.00

Programme

Master

Left

(Lt)

Master

Right

(Rt)

M&E Left

(Lt)

M&E Right

(Rt)

      
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5.6.5 Recorded signal levels:

Programme sound and vision maximum levels must always correspond to the recorded reference tone and colour bar line-up signals according to the following tolerances-

Vision ±3%

Sound ±1dB.

Colour signals must be legal in PAL and YUV domains meeting the PAL specification. In line with PAL system I (1984) (section 4 para. 4) the video signal decoded to RGB shall not lie outside the levels corresponding to black level and white level apart from transient overshoots. This corresponds to luminance never lying outside its nominal black 0% and white 100% bounds. However, a more reasonable and acceptable working specification can be applied -

Black shall lie no more than 1% (or 2 bits) below nominal black level.

Peak White shall lie no higher than 3% (or 7 bits) above nominal white level.

When decoded to RGB each component signal must not lie above 105%

or below -5%.
All measurements can use an IRE filter to remove transient overshoots.

5.6.6 Audio Track Allocation

Audio track allocation must conform to EBU recommendation R48-2005 Table 1a unless otherwise stated in the programme contract.

5.6.7 Music and Effects tracks

Final mix minus commentary - this means no commentary, no extra readings or voiceovers should be on the music and effects track. The levels should not be dipped.
If a contributor appears in vision, their voice must continue through that piece on the music and effects tracks, even if they are not in vision throughout.

5.6.8 Timecode and control track

Both longitudinal timecode (LTC) and vertical interval timecode must be recorded throughout the line-up and programme and comply with EBU specification N12-
1994 (SMPTE 12M-1995).
Timecode must be contiguous, coherent and not pass through zero at any point from the start of the first countdown clock to beyond the end of the programme. LTC and VITC must have identical times.
DVITC or ancillary timecode are used then they must be identical to the LTC and VITC. Timecode and control track must have the correct phase relationship with the corresponding video signal.

6 WIDESCREEN PRODUCTION - SAFE AREAS

Programmes should always conform to the configuration - 16:9 widescreen shoot to protect
14:9.
These safe areas are defined as percentages of the full image in EBU recommendation R95-
2000 Appendix 3. In advance of any EBU recommendation for high definition, the pixel and line count should be as given in Appendix 1 of this document.
It is not acceptable for changes in aspect ratio display within a programme.

7 DELIVERY REQUIREMENTS

Please note these may differ between types of programmes.
All master videotapes supplied to Aljazeera International must be ready for exhibition and distribution having had, and passed, the Quality Assessment Review (QAR). Your commissioning executive can advise on suitable facility houses.

7.1 Programmes

7.1.1 Summary of materials required

Captioned version, HDCAM tape format
16:9 1080i/50, shot protected for 14:9, stereo final mix soundtrack to be recorded on audio channels A1 (left or left total) and A2 (right or right total). International sound to be recorded on audio channels A3 (left or left total) and A4 (right or right
total).
Textless version, HDCAM tape format
16:9 1080i/50, shot protected for 14:9, stereo final mix soundtrack to be recorded on audio channels A1 (left or left total) and A2 (right or right total). International sound to be recorded on audio channels A3 (left or left total) and A4 (right or right
total).
DVD or VHS captioned version
625 line PAL format non-regional with final audio mix and bitc. DVD type should be –R
DVD or VHS textless version
625 line PAL format non-regional with final audio mix and bitc. DVD type should be -R
All material to be fully labeled on the media box, with at least, programme number and title.
All material should have an accurate "cue sheet", as specified by the production guideline document, included in the packaging.

7.2 Photographic and Design Materials

7.2.1 Delivery of material

Mac zip or CD saved as an EPS or TIFF file. Floppy Mac Disc.
High resolution JPEG format with a resolution of at least 6 million pixels.
Images lifted off moving film or videotape are not acceptable.
All images and material submitted will remain the property of Al Jazeera.

8 APPENDIX 1

16:9 Shoot-to-protect 14:9-Action and Graphics Safe Areas

 

 

 
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