Technical Delivery Requirements

In practice it is difficult to avoid generating signals slightly out of range and it is considered reasonable to allow a small

tolerance:

• The RGB components and the corresponding Luminance (Y) signal, should not normally exceed the “Preferred Minimum/Maximum” range of digital sample levels in the table below,
• Measuring equipment should indicate an “Out-of-Gamut” occurrence only after the error exceeds 1% of an integrated area of the active image.

For further details see the EBU Recommendation, EBU R 103.
Any signals outside the “Preferred Minimum/Maximum” range are described as having a gamut error (or as being out of gamut). Signals cannot exceed the “Total Video Signal Range” and will therefore be clipped.

Guidance for production of HDR programmes is available in ITU-R BT.2408 — Guidance for operational practices in HDR television production. The broadcaster should be consulted before an HDR production commences.

The Recommendation ITU-R BT.2100 specifies two High Dynamic Range (HDR) methodologies: Hybrid Log Gamma (HLG) and Perceptual Quantisation (PQ).

For NRK the preferred HDR delivery format is HLG HDR. If you can’t comply with this, NRK reserves the right to convert PQ to HLG using the approach described in ITU-R BT. 2408, Chapter 6.

HD and UHD images must fill the active picture area (HD 1920×1080 and UHD 3840×2160). No ‘blanking errors’ are permitted on new, up-converted, or archive material.

However, a two-pixel tolerance will be permitted during CG or complex overlay sequences where key signals, graphic overlays or other effects do not fully cover the background image. Where animated key signals or overlays cause moving highlights at the edge of the active image it is preferable to blank these pixels completely. A note of the timecodes and reasons for these errors should accompany the delivered programme. 

Cuts in material must happen on frame boundaries (i.e. between field 2 and field 1). Motion on psf material must always occur between field 2 and field 1 (i.e. field 1 dominance).

Note – It is possible to shoot material at 1080p/50. If this is done, the correct 2-frame marker phasing must be maintained when down-converting to 1080i/25 or 1080psf/25 (SMPTE ST 2051).

Some UHD programmes will contain some material from standard definition and high definition originals and sources that do not meet the UHD requirements. This material is all called ‘non-UHD’ in this document. Non-UHD material includes material acquired using the following methods or formats:

• All SD and HD formats;
• Cameras that do not meet the requirements of EBU R118 for UHD Tier 2;
• All codecs with bit rates below those specified in EBU R118 for UHD;
• Film that does not meet the required standard.

To maintain a high standard and meet audience expectations the amount of non-UHD material is limited to 25% of the programme’s total duration. Non-UHD material must not be used for large uninterrupted sections of the programme, unless agreed by the broadcaster. This includes archive material. 

Some high definition programmes will contain some material from standard definition originals, and sources which are not considered to meet HD broadcast standards, such as domestic camcorders. This material is all called ‘non-HD’ in this document. 

To maintain a high standard and meet audience expectations the amount of non-HD material is limited to 25% of the programme’s total duration. Non-HD material must not be used for large uninterrupted sections of the programme, unless agreed by the broadcaster. This includes archive material. 

Non-HD material 

Material acquired using the following methods or formats is considered to be below the high definition standard and will therefore be treated as non-HD: 

• HDV from all manufactures 
• Most cameras with image sensors under ½”  
• Frame based (intra-frame) recording formats below 100Mb/s  

• Inter-frame based recording formats below 50Mb/s 
• Material generated or processed on 720 line equipment  
• Film not meeting the requirement for HD in section Film for HD and UHD Aquisition 

For delivery to dedicated movie channels or at the discretion of the broadcaster, programmes may be delivered with an active picture in the cinema ratios of 2.35:1 (21:9) or 1.85:1, centred vertically between black bars in a 16:9 frame, filling the width of the frame, and with no geometric distortion. 

Short sequences of images surrounded by black borders, (floating images), may be used for artistic effect. Note however, that widescreen consumer TV sets operating in Auto Zoom / Auto mode often interpret large black borders at the top and bottom of the screen as letterbox, so are likely to enlarge the picture. The resulting unpredictable zooming can be annoying for the viewer and undermine the artistic intent. If used, the black space around floating images must be consistent across sequences of images. 

Some ‘pillar-boxed’ material is acceptable at the discretion of the broadcaster where it has been acquired on a medium that has the capability to be transferred to a legitimate HD resolution, for example, 35mm film shot using 4 perf at an aspect ratio narrower than 16:9. The pictures must be centrally framed in a 16:9 raster with no geometrical distortion.  

Archive material must be taken from the best available source, and any improvement or restoration work which could reasonably be expected must be done (for example grading, dropout repair or audio equalisation.)  

Particular care must be taken to deliver the best possible quality of up-converted material. In general standard definition pictures must look no worse than the original after being up converted, post processed and down converted. Only high quality up-conversion processes will achieve this. 

Standard definition video contains a half-line at top and bottom on alternate fields. This must be removed on up-conversion to HD, or it will be visible flickering at top and bottom of the HD frame. 

Any VITC or switching signals visible at the top of SD material must be removed. 

Any line blanking from SD signals must not appear in the HD conversion. 

For these reasons it is necessary that all SD material is zoomed in by a small amount on up-conversion.

Archive material should be zoomed to fill the 16:9 raster where possible without compromising the image quality or composition, otherwise it may be presented in a pillar-box format, which: 

• may be of an intermediate ratio between 4:3 and 16:9, but must be of consistent width across sequences,  
• must be centrally framed in the 16:9 raster,  
• must show no geometrical distortion, 
• must have clean and sharp pillar-box edges (i.e. any video or film edge artefacts may need to be blanked.) 
• must be black outside the active picture, unless otherwise specified by the broadcaster. 

Note: however, that consumer TV sets operating in Auto Zoom / Auto mode may enlarge the picture to fill the screen horizontally. The resulting unpredictable zooming can be annoying for the viewer and undermine the artistic intent

Any captions or text already in the archive material should be kept within the caption safe area if possible, but if not, should be noted in the accompanying documents. 

The minimum sensor resolution (pixel count) for single sensor cameras is 2880 x 1620 (Bayer patterned). EBU R 118 has details of the minimum criteria for single sensor cameras.  

DSLR cameras are acceptable for time-lapse sequences and stop-frame animation but are currently not suitable for use as video cameras. Exceptions can be made for covert shoots or dangerous locations at the discretion of the broadcaster. The broadcaster must agree to the use of DSLR cameras in advance of any shooting. 

The EBU Recommendation EBU R118 has details of UHD cameras and acceptable sensor resolutions. 

As general guidance UHD cameras should use the whole sensor (not just part of the sensor) to produce HD images.  

If the camera does have the option to use part of the sensor, the minimum pixel count should be 2880 x 1620 where Bayer filtering is used. 

HD images should preferably be produced electronically by either scaling from the full UHD image or resizing where part of the UHD image is being used in HD. 

Images from UHD cameras with 4K (4096 x 2160) sensors must be cropped to 3840 x 2160 (16:9) before scaling to HD. 

The EBU divides UHD cameras into two Tiers 

• UHD-1 Tier 1: have a sensor that can give full UHD resolution and have a pixel count of 3840 x 2160 in each of R and G and B or, a minimum pixel count of 5760 x 3240 where Bayer filtering is used. 

• UHD-1 Tier 2: have a sensor resolution that is below full UHD resolution (but greater than HD) and have a minimum sensor resolution of 3840 x 2160 where Bayer filtering is used. 

Both Tiers are acceptable for HD production but UHD-1 Tier 2 cameras should be checked with any co-producer requiring a higher resolution master. 

Cameras attached to these devices must meet the requirements in EBU R118 unless agreed with the broadcaster in advance.

Unless a drone or remote rig has adequate image stabilisers it is recommended that the camera attaché has a higher resolution than needed to allow electronic stabilisation to be carried out during post-production.

Programme producers are required to ensure drones and other remotely operated cameras are only controlled by trained and licenced operators when used in Norway. Producers should be aware of specific local and territorial restrictions and regulations especially when drones and remotely operated cameras are used outside of Norway.

Note: broadcasters may have additional requirements for the use of drones and remote cameras as part of their editorial or health and safety guidelines

Intermediate codecs used in post-production should be 10-bit 4:2:2 or better. It is acceptable to use the native camera codec provided the codec is constant throughout the production workflow.

HD and SD projects can be either interlaced or progressive. Electronically generated moving graphics and effects (such as rollers, DVE moves, wipes, fades and dissolves) must be generated to match the intended video scan to prevent unacceptable judder.

UHD Projects are always progressive. Electronically generated moving graphics and effects (such as rollers, DVE moves, wipes, fades and dissolves) must be edited to prevent unacceptable judder. For 2160p/50 or 2160p/25 deliverables such effects must be edited at 50 or 25 frames per second respectively.

Archive or Lower Resolution (HD and SD) material will usually require de-interlacing and frame rate processing during up conversion to UHD.

It is usually best practice to convert SD or HD 60Hz standards to the equivalent SD/HD 50Hz standard before up conversion.

To prevent image degradation, Motion Compensation standards conversion sometimes known as Motion Predictive or Motion Vector Conversion should normally be used.

Speed change is the preferred method of converting from 24fps (including 23.976fps) to 25fps. Due attention must be given to the audio.

Software standards conversion packages should also use Motion Compensation processing. It is not permitted to use simple “timeline” conversion. Contact the broadcaster for more information.

Below are the recommended processes for frame rate conversion.

• 24p and 24/1.001p to 25p – speed change is the recommended conversion process.
• 24p and 24/1.001p to 50p – speed change plus frame doubling.
• 30p and 30/1.001p to 25p – Motion Compensated Conversion required.
• 30p and 30/1.001p to 50p – Motion Compensated Conversion required.
• 60p and 60/1.001p to 25p – not recommended, speak to broadcaster if required
• 60p and 60/1.001p to 50p – Motion Compensated Conversion required.
• HD 25PsF to UHD 25p – no frame rate conversion or de-interlacing required.
• HD 25PsF to UHD 50p – frame doubling, no de-interlacing required.
• SD/HD 25i to UHD 25p – use should be limited, de-interlacing.
• SD/HD 25i to UHD 50p – de-interlacing and frame doubling.
• De-interlacing processing should be carried out via a multi-field (five-field or greater) de-interlacer or a motion
  compensated de-interlacer.

Content acquired at 24 (24/1.001) fps which has been converted to 60 (60/1.001) interlace or progressive via the “2:3 pull down” process, should first have the repeated fields/frames removed to produce the original frame rate. The resulting video can then be replayed at 25 fps.

It is not acceptable to shoot 1080i/25 and add a film motion effect in post-production. High Definition cameras can capture in either 1080i/25 or 1080p/25. Where film motion is a requirement, progressive capture is the only acceptable method.

Conversion from 50 progressive frames per second material to 25 progressive frames per second is permitted, provided that the frame conversion process does not produce excessive motion judder or image softening or visible frame blending; and that an appropriate shutter speed has been used. The process must be agreed with the broadcaster in advance.

The minimum SD font height is 20 SD lines. Therefore, where burnt in UHD or HD text will be down converted, the minimum height of the text should be no less than:

• 40 HD lines/pixels (to be legible after down conversion);
• 80 UHD lines/pixels (to be legible after down conversion)

Scanning raster 576i/25: 16:9 safe areas for 16:9 presentation 

* Note: The total number of lines is 625 (active lines from 23 to 310 and 336 to 623 inclusive = 576 lines). 

** Note: The complete digital line comprises 864 samples. Of these, the “digital active line” comprises 720 samples or pixels (numbered from 0 – 719 inclusive) of which the image active line comprises pixels 9 to 710 inclusive (see EBU R92 concerning peculiarities of the 576i/25 (625/50) scanning raster). 

Scanning raster 1080i/25 and 1080psf/25: 16:9 safe areas for 16:9 presentation 

* Note: The total number of lines is 1125 (active lines from 21 to 560 and 584 to 1123 inclusive = 1080 lines). 

** Note: The complete digital line comprises 2200 pixels. Of these, the “digital active line” comprises 1920 pixels (numbered from 0 – 1919 inclusive). All active pixels are included in the image active line. 

Below is an illustration showing where NRK puts the logo (upper right corner), captions/subtitles and content rating (lower right corner) in the image with a scanning raster of 1080i/25 and 1080psf/25 with an aspect ratio of 16:9. In addition there’s a buffer area just above the captions/subtitles. Additional graphics must not be placed in any of these areas. 

To help working with graphics this document has attached a Photoshop template file called “Template for placement of graphics – 1920×1080.psd” which may be of help when placing graphics. It is shown below. The raster of this template file is 1920×1080 and it contains the NRK logo, captions/subtitles, buffer area above the captions/subtitles, content rating and a rectangle for the graphics safe area. All other areas of the image have full opacity.

Template-for-placement-of-graphics-1920×1080.zip

R128 introduces new terms for the measurements of audio. The terms used in this document, how they are measured and the delivery requirements are listed below.  

All programmes must be compliant with the Programme Loudness and Maximum True Peak requirements below. Other parameters are currently given for guidance only. 

Although the target loudness is -23 LUFS, in exceptional circumstances other target levels may be permitted by agreement with the broadcaster. Other target levels must be agreed with the broadcaster before the final mix. 

Note: Short-Form Content is defined as a programme of short duration, typically shorter than 30s (but up to approximately 2 minutes duration). In addition to advertisements (commercials) and promotional items, interstitials, stingers, bumpers and similar very short items belong to this category.

The following table is only for guidance on the true peak levels of different types of audio. At all times dialogue should be distinct and clear. 

Each stereo audio pair must have either EBU stereo or GLITS line-up tone (not a mix of both). Tone must be 1kHz, sinusoidal, free of distortion and phase coherent between channels). Audio files of GLITS and EBU stereo tones may be downloaded. See Line-up tones for more information. 

Digital Audio Reference level is defined as 18dB below the maximum coding value (-18dBFS). 

Stereo programme audio must be capable of mixing down to mono without causing any noticeable phase cancellation. 

Each group of surround tracks must carry BLITS tone. Tones must be sinusoidal, free of distortion and phase coherent between channels. Stereo tracks derived by down-mixing from the 5.1 audio should carry a down-mix of the BLITS tones, using the same down-mix parameters as those specified in the accompanying metadata. Any other stereo tracks delivered with the programme must carry stereo tone. is acceptable to use the EBU BLITS tone on HD programmes.

This section refers to timing requirements for AES audio pairs embedded in HD SDI signals. Very small timing differences between audio tracks in a surround programme will not be heard unless the stereo down-mix is monitored acoustically. An error of as little as one or two samples between the Left, Right and Centre channels can cause phasing and comb filtering for those listening in stereo.  

Timing differences between audio tracks in each AES pair in an SDI group and between each group containing a single audio programme must be no more than 0.2 samples (i.e. the timing between each track of the six audio tracks of a surround signal.)  

Note: This error has not been noticed on devices that treat audio as multi mono channel audio (e.g. NLEs). 

There are three modes for the placing of dialogue in a surround mix.

Mode 1 All dialogue should be present in each of the three front channels – but this does not mean that the dialogue must be at equal level in each of the front channels. Mode 1 is generally more suited to the home listening environment.
Mode 2 In-vision dialogue across the three front channels and out-of-vision dialogue in the centre channel only.
Mode 3 All dialogue in the centre channel only. Mode 3 is similar to cinema mixing and as such may be the least suited to the home listening environment.

For details of the mode required for each programme type see the broadcaster section at the beginning of this document.

The audio parameters controlled by the metadata include: centre and rear down-mix levels, LFE level, and the extent of any dynamic range control applied. Therefore:

• It is essential to check the automated down-mix using a monitoring system that applies or simulates the metadata settings. Any external processor (e.g. a Dolby DP570) must be set to apply the programme’s metadata;
• The Lt/Rt and Lo/Ro fold-down parameters used for down mixing must match the settings in the Dolby metadata – especially the down-mix levels of the CENTRE and SURROUND legs;
• pre-mixed stereo content should be up-mixed, where appropriate, to match the surround sound to maintain the
  audio image throughout a surround broadcast. A method of up mixing approved by the broadcaster must be
  adopted, which anchors dialogue to the front and disperses effects around the image;
• up-mixed material must also down-mix to stereo and mono with no audible artefacts. The injudicious use of phase shifting and delay within some up-mixing algorithms may become more noticeable in the subsequent receiver downmix process, and result in unacceptable down-mixed audio;
• where up mixing is not available, stereo sections or inserts containing speech should be “converged” (spread) across LEFT, RIGHT and CENTRE channels adding an element into the Centre channel of the surround mix. The front L/R channel levels should generally be 6dB lower than the Centre-channel level.

For general surround sound (e.g. audience reaction) phase-coherence invariably benefits both the wrap-around effect in 5.1 and the stereo down-mix. Coincident microphone techniques (e.g. crossed-pairs) tend to outperform spaced mono microphones in this context.

It is essential that the mono and stereo down-mixes of a surround programme are monitored in at least equal measure to the surround mix. A large majority of viewers will be listening in stereo rather than 5.1 for some time to come.

It is also important to be aware that the centre channel could allow viewers listening in surround to overhear off-microphone
conversation not intended for broadcast, but which may be masked when monitoring in stereo or mono.

When a surround programme contains mono content interleaved with stereo pre-recorded items it is important to maintain the consistency of the sound image and prevent the effect of dialogue appearing to jump between Centre Only and Phantom Centre (Left/Right) only

Acquired programmes and movies can be received with or without metadata. Unless the audio is re-mixed during a compliance edit, any supplied metadata should be passed though. If no metadata exists the followin parameters should be used.

To assist in maintaining A/V sync through the post-production process, a ‘sync plop’ may be used. If the delivered programme leader contains one it must meet the following conditions: 

• The sync plop must be between timecode 09:59:57:06 and 09:59:57:08  
• The audio plop must be 1kHz tone on all tracks at -24dBFS (-18dBFS is acceptable for stereo programmes) 
• The duration of the vision flash must be 2 frames to allow it to pass through standards conversion successfully 
• The audio plop must be synchronous across all audio PCM audio tracks and with the video flash (within +/- 5 ms)  

If an end sync plop is used it must be no closer than 10 seconds to the end of the programme and comply with the relevant points above. 

Image parameters

Make sure the file is tagged with the correct technical metadata for Colour Primaries, Transfer Characteristics and Matrix Coefficients.

See example from MediaInfo — https://mediaarea.net/en/MediaInfo

Delivery codecs

When HDR is delivered an SDR version is also required.

Image parameters

Make sure the file is tagged with the correct technical metadata for Colour Primaries, Transfer Characteristics and Matrix Coefficients.

See example from MediaInfo — https://mediaarea.net/en/MediaInfo

Delivery codecs

In practice it is difficult to avoid generating signals slightly out of range and it is considered reasonable to allow a small tolerance:

• The RGB components and the corresponding Luminance (Y) signal, should not normally exceed the “Preferred Minimum/Maximum” range of digital sample levels.
• Measuring equipment should indicate an “Out-of-Gamut” occurrence only after the error exceeds 1% of an integrated area of the active image.

For further details see the EBU Recommendation, EBU R 103.

Any signals outside the “Preferred Minimum/Maximum” range are described as having a gamut error (or as being out of gamut). Signals cannot exceed the “Total Video Signal Range” and will therefore be clipped.

Guidance for production of HDR programmes is available in ITU-R BT.2408 — Guidance for operational practices in HDR television production. The broadcaster should be consulted before an HDR production commences.

The Recommendation ITU-R BT.2100 specifies two High Dynamic Range (HDR) methodologies: Hybrid Log Gamma (HLG) and Perceptual Quantisation (PQ).

For NRK the preferred HDR delivery format is HLG HDR. If you can’t comply with this, NRK reserves the right to convert PQ to HLG using the approach described in ITU-R BT. 2408, Chapter 6.

HD and UHD images must fill the active picture area (HD 1920×1080 and UHD 3840×2160). No ‘blanking errors’ are permitted on new, up-converted, or archive material.

However, a two-pixel tolerance will be permitted during CG or complex overlay sequences where key signals, graphic overlays or other effects do not fully cover the background image. Where animated key signals or overlays cause moving highlights at the edge of the active image it is preferable to blank these pixels completely. A note of the timecodes and reasons for these errors should accompany the delivered programme. 

Cuts in material must happen on frame boundaries (i.e. between field 2 and field 1). Motion on psf material must always occur between field 2 and field 1 (i.e. field 1 dominance).

Note – It is possible to shoot material at 1080p/50. If this is done, the correct 2-frame marker phasing must be maintained when down-converting to 1080i/25 or 1080psf/25 (SMPTE ST 2051).

This section gives details of the line-up tones that may be used for File, Tape and Live programmes. 

Line-up tone downloads 

EBU Line-up can be downloaded here: 

GLITS Line-up can be downloaded here: 

BLITS Line-up can be downloaded here: 

EBU – Stereo Line-up 

The EBU stereo tone sequence is a 1KHz tone at -18dBFS on Left and Right channels.  

The Left channel is interrupted for 250ms every 3 seconds 

It is acceptable to use 440Hz EBU tone to identify international audio channels in a multi-channel bundle.

GLITS – Stereo Line-up 

The GLITS stereo tone sequence is a 1KHz tone at -18dBFS on Left and Right channels. The Left channel is interrupted for 250ms every 4 seconds and the Right channel interrupted twice 250ms after the Left channel. Each Right channel interruption lasts 250ms and the separation is also 250ms. 

It is acceptable to use 2KHz GLITS tone to identify international audio channels in a multi-channel bundle.

BLITS – Surround Line-up 

BLITS tone is defined in EBU Tech 3304 (http://tech.ebu.ch/docs/tech/tech3304.pdf) 

The BLITS tone sequence has three sections; 

The first is made up of short tones at -18dBFS, to identify each channel individually: 

• L/R: Front LEFT and Front RIGHT – 880 Hz 
• C: CENTRE – 1320 Hz 
• LFE: (Low Frequency Effects) – 82.5 Hz 
• Ls/Rs: Surround LEFT and Surround RIGHT – 660Hz. 

The second section identifies front left and right channels (L/R) only. 1kHz tone at -18dBfs is interrupted four times on the left channel and is continuous on the right.  

The last section consists of 2kHz tone at -24dBFS on all six channels. This can be used to check phase-reversal between any of the 5.1 legs. When the tone is summed to stereo using default – down-mix values this section should produce tones of approximately -18dBfs on the L & R channels. 

The BLITS sequence repeats approximately every 14 seconds. 

1.485 Gb/s HD-SDI connection, SMPTE 292M, [often known as 1.5Gbs HD-SDI]. This remains uncompressed along its route to the point of delivery.

Wherever possible, practical, or cost-effective, programmes should use an uncompressed 1.485Gbs HD-SDI connection.

In all instances where the signal can be carried uncompressed, audio for the programme should be carried as discrete linear PCM (unless Dolby E is requested by the broadcaster).

Links that provide a 1.5Gbs HD-SDI connection at the point of delivery, but which use compression/decompression along their route:

Locations with access to single hop fibre connections should use compression codecs that use nominal video bitrates of:

• JPEG2000 – 140 Mbps.
• MPEG4, H.264, Long GOP 4:2:2 – 45 Mbps.
• MPEG2, Long GOP, 4:2:2 – 60 Mbps.

NOTE: Today MPEG2 encoding for HD is not desirable. It is recommended to use JPEG2000 or H.264/AVC/MPEG4 part 10.

Where fibre is not available, links via satellite may be used. The following are permissible and achievable largely by using DVB-S2 modulation schemes. Modulation schemes should be carefully chosen so that the increase in transponder capacity (in MHz) required to deliver the optimal video bitrate (in Mbps) does not come at the cost of a decreased robustness of signal.

Single-hop satellite links should have a nominal video bitrate of:

• 27.5 Mbps MPEG4 H.264, Long GOP 4:2:2 or
• 45 Mbps MPEG2, Long GOP 4:2:2

NOTE: Today MPEG2 encoding for HD is not desirable. It is recommended to use H.264/AVC/MPEG4 part 10.

Codec requirements are listed in Appendix 1

Where the link directly feeds a second compressed link, the signal should not be decoded back to baseband but passed to the second link as a transport stream.

Stereo audio should be carried as MPEG1 Layer II (stereo) at 384kbs. Multi-channel audio may need to be carried as Dolby E. (see Audio Track Layout 6.7.3 Audio Track Allocation)

In some locations a point-to-point microwave link may be used as an alternative to satellite links. Microwave links can be used for short hops from the location to a fixed fibre link point or where a satellite up-link has to be remote from the production location. Where microwave links are used to feed a second compressed link, the signal should not be decoded back to baseband but passed to the second link as a transport stream.

The payload on the link should have a nominal video bitrate of:

• 45 Mbps MPEG4, H.264, Long GOP 4:2:2, or
• 60 Mbps MPEG2, Long GOP 4:2:2

NOTE: Today MPEG2 encoding for HD is not desirable. It is recommended to use H.264/AVC/MPEG4 part 10.

Please speak to the broadcaster about multi-hop microwave links or combination microwave/satellite links

Stereo audio should be carried as MPEG1 Layer II (stereo) at 384kbs. Multi-channel audio should be carried as phase aligned stereo channels, alternatively as Dolby-E (not preferred) (see Audio Track Layout 6.7.3 Audio Track Allocation)

Image parameters

Image parameters

In all instances where the signal can be carried uncompressed, stereo audio for the programme should be carried as discrete linear PCM. If the signal must be carried in a compressed format, Stereo audio should be carried as MPEG1 Layer II (stereo) at 384kbs.

Multichannel (surround sound) should normally be discrete PCM where there is sufficient bandwidth available in the link to the point of delivery.

Phase-aligned stereo or Dolby E should be used for multi-channel audio when bandwidth is limited or at the request of the broadcaster. Settings for Dolby E encoding are in Appendix 2

Use of the Low Frequency Effect Channel (LFE) channel is optional. Use of the LFE channel should comply with Recommendation ITU-R BS.775.

There should be no sample timing differences between the individual channels of a surround signal.

Each stereo pair or multi-channel group (the 6 audio tracks of a surround sound signal) must be transported in a single SMPTE ST.302 PES in order to maintain the phase relationship between channels.

It is difficult to prescribe the exact audio track layout for all live programmes. International, host broadcaster, local requirements and link bandwidth may vary the audio layout requirements.

Some possible audio track allocations are listed here:

Two track delivery:

Four track delivery (dual stereo):

Four track delivery (stereo + coded 5.1):

Eight track delivery:

This section gives details of the line-up tones that may be used for File, Tape and Live programmes. 

Line-up tone downloads 

EBU Line-up can be downloaded here: 

GLITS Line-up can be downloaded here: 

BLITS Line-up can be downloaded here: 

EBU – Stereo Line-up 

The EBU stereo tone sequence is a 1KHz tone at -18dBFS on Left and Right channels.  

The Left channel is interrupted for 250ms every 3 seconds 

It is acceptable to use 440Hz EBU tone to identify international audio channels in a multi-channel bundle.

GLITS – Stereo Line-up 

The GLITS stereo tone sequence is a 1KHz tone at -18dBFS on Left and Right channels. The Left channel is interrupted for 250ms every 4 seconds and the Right channel interrupted twice 250ms after the Left channel. Each Right channel interruption lasts 250ms and the separation is also 250ms. 

It is acceptable to use 2KHz GLITS tone to identify international audio channels in a multi-channel bundle.

BLITS – Surround Line-up 

BLITS tone is defined in EBU Tech 3304 (http://tech.ebu.ch/docs/tech/tech3304.pdf) 

The BLITS tone sequence has three sections; 

The first is made up of short tones at -18dBFS, to identify each channel individually: 

• L/R: Front LEFT and Front RIGHT – 880 Hz 
• C: CENTRE – 1320 Hz 
• LFE: (Low Frequency Effects) – 82.5 Hz 
• Ls/Rs: Surround LEFT and Surround RIGHT – 660Hz. 

The second section identifies front left and right channels (L/R) only. 1kHz tone at -18dBfs is interrupted four times on the left channel and is continuous on the right.  

The last section consists of 2kHz tone at -24dBFS on all six channels. This can be used to check phase-reversal between any of the 5.1 legs. When the tone is summed to stereo using default – down-mix values this section should produce tones of approximately -18dBfs on the L & R channels. 

The BLITS sequence repeats approximately every 14 seconds. 

AV sync should be checked via the audio desk (not just the links truck in the case of OBs) at least once a day.

Any professional AV sync equipment is acceptable but systems that can be used across all audio tracks (up to 16) simultaneously are preferred.

AV sync timing through the audio desk to the point of delivery should be ±5ms.

AV sync timing should also be within ±5ms from any remote sources into a studio or an OB including non-live inserts from tape or file.

Any external reference source at a remote site should be locked to GPS.

Radio link cameras are always a compromise between delay and image quality. Image quality should always be the overriding consideration. Where radio and cabled cameras are mixed covering a location with lip-sync, and it is not possible to delay the audio, the radio camera should not have a delay greater than 40ms compared to the cable cameras. The director is responsible for making sure any visible lip-sync issues are kept to a minimum.

Where all cameras use radio links, the audio must be delayed to match the video. To minimise the issues caused by open talkback and presenter switched talkback the AV sync can be ±20ms