Preparing TV commercials for broadcast production can be a daunting task. There are so many variables and requirements, each station has its own specifications and guidelines, in addition to the various national advertising standards codes and practices. So What are the most common issues that tend to arise during TVC delivery?
We have talked to broadcast delivery engineers and compiled a checklist of common issues to look out for. These issues cover three general areas: the clapper board, also known as a slate, potential quality issues with the visuals, and audio.
The Clapper Board/Slate
Color bars, tones and countdown clocks are no longer required at the beginning of most TV commercials.
What is needed for every commercial, however, is the clapper board (sometimes called the ID board or slate), which should be positioned at the start of every ad being delivered.
The delivery service you are using may require the clapper or slate to be part of the video already, or supplied as a separate image file.
1. Clapper/Slate Information
The clapper/slate should contain four key pieces of information:
Key number which matches with the number the ad is booked under. This number is alphanumeric, but should be no longer than 13 characters, and should not contain any spaces or special characters.
Duration of the ad
Aspect ratio of the ad
Declaration that the audio levels have been set to comply with OP48 (Australia) or ATSC standards (US)
Of course, the clapper or slate can also display other things, such as the client name, the product/service being advertised in the commercial, the title of the commercial, and the agency.
Different countries have different standards, but here are some examples of the most common areas for audio mistakes.
2. Frames of Silence
Many stations require TV commercials to have 12 frames of silence at the beginning and end of the piece, which helps to create a smooth transition between each commercial, instead of each audio track starting and stopping suddenly.
3. Sound Levels
To ensure that commercials aren’t too loud or too soft, sound designers and editors are expected to control the sound levels of their pieces to ensure they comply with your local standards. For example, Australian OP48 specifies peaking level of -9dB, with averaging around -20dB. Overly high or low levels will be rejected by the broadcaster
Another standard which is used to ensure the audio in an ad is normalised against other ads is Loudness, K-weighted, relative to Full Scale (LKFS).
In the US, the relevant standard is the Commercial Advertisement Loudness Mitigation (CALM) Act as set forth by the Advanced Television Systems Committee (ATSC).
4. Sound Quality
You should also check for quality issues, such as pops, hissing and distortion in the audio track. These artifacts can be introduced during the recording or the editing phase, but tend to be pretty rare as they are usually picked up during the production process.
Another issue to look out for is the balance between left and right channels, to ensure both are of equal levels. Having one higher or lower than the other can result in disconcerting effect for the listener.
Finally, be on the lookout for desync issues, where the audio fails to match up to the visual footage. This can be especially critical when talking is involved: failure to properly synchronise speech with lip movements on screen can be particularly frustrating for viewers.
5. Aspect Ratio
Since moving from tapes to digital delivery, one of the most common problems plaguing broadcast commercials has been aspect ratio. It is easy to be confused, especially with the onset of high definition digital TV.
Most broadcasters will broadcast footage in 16:9 aspect ratio. But if you are using a delivery system, it’s usually easiest to provide your 16:9 commercials as 4:3 anamorphic files (just make sure to uncheck the box that defines the asset as 16:9 when exporting). The delivery systems will convert the file into 16:9 automatically for you.
As always, these requirements can differ depending on your broadcaster and delivery solution provider, so make sure to check with them and the technical specifications they provide for submitting your files.
6. Title and Safe Areas
Related to aspect ratio are the title and action safe areas. To ensure any critical textual or visual information is seen by viewers using older TV sets, broadcasters have typically specified title safe areas in the middle of the screen.
With current television sets, the larger action safe area can also be used. While title and action safe areas have traditionally been in the 4:3 aspect ratio, many broadcasters in Australia have standardised to the 16:9 safe area.
In the US, where the market is mixed, both 4:3 and 16:9 title safe are used.
7. Video Levels
Another common visual quality problem relates to white and black levels. Broadcasters have chrominance (color levels) and luminance (white/black levels) limits in place and will reject footage that breach these limits.
If white levels are too high, that results in the picture blowing out and a loss of details and quality. Making black levels too black results in details being “crushed” and lost. Both instances can result in the stations rejecting the ad.
8. Double/Duplicate Frames
With digital distribution and multi-national clients and agencies becoming the norm today, many ads are produced in either NTSC or PAL, then converted to the other standard. The different frame rates between the two can lead to double frames or missing frames.
Double frames are duplicated frames of footage which can lead to a jerking or skipping effect during playback. It’s important to watch the commercial closely, and if need be, go through the material frame by frame to spot duplicated or missing frames.
9. Video Artifacts
Finally, it’s a good idea to look for artifacts, which can be a problem especially when older or lower resolution material is re-purposed for commercials. This results in problems like aliasing (jagged edges), jerky animation, pixilation, and blurriness.