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Duplication
HD Technical Information Guide
The drive towards a High Definition standard is quickly emerging. There are multiple formats and standards that all fall under the "HD" heading. We have highlighted some major points to keep in mind when designing your delivery process whether through up conversions, down conversions, or international delivery formats.
Most HD formats are either 720 or 1080 line resolution. Newer HDV formats also work with 480 as a standard. 1080 offers either progressive or interlaced frame types. All 720 formats are progressive (720p).
1080i or 1080p formats are a larger frame size (1920 x 1080) than 720p (1280 x 720). Approximately 2.25 times more pixels are used in the larger frame size.
HD frame rates are generally 24, 25, 30 or 60 frames per second. Varicam 720p source material uses even a greater variance of shooting speeds for source footage acquisition.
It is desirable to label your frame rates on your masters to ensure proper servicing of your material. If possible, Varicam source frame rates should be clearly marked if changing speeds scene to scene.
Video formats are either 8 bit or 10 bit per color channel. 8 bit formats have 256 steps from black to white, while 10 bit have 1024 steps. The four basic sampling rates for HD are 4:4:4; 4:2:2; 4:1:1; and 4:2:0.
Audio formats range from more current standards of 96 kHz 24 bit to older digital standards of 16 bit- 48kHz. HD tape formats support at least 4 channels of audio and many support 8 to 12 channels of audio. These channels can be used for select elements like audio program master to M and E tracks. It is common for an HD master to have a multi-channel audio format like 5.1 or 7.1 as its final delivery format. Various broadcast and cable networks have their own technical standards for delivering final elements.
As with frame rates, clear labeling of your audio elements ensures a smooth delivery.
When working with New Media processes, files are either compressed or uncompressed data. An uncompressed 10 bit format holds significantly more data than compressed files. Though this higher quality signal flow can be desired, keep in mind additional processing time and hard drive storage requirements when designing your deliverables and schedule.
Our staff is here to assist you in answering these questions. The more information you have clarified on your elements or masters, the more streamlined the process becomes for you to attain your final delivery goals.
