VC-2 / Dirac Pro (ST 2042) Bitrate Calculator
SMPTE · Raw and stream bitrate for one VC-2 / Dirac Pro (ST 2042) signal.
- Raw bitrate
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- Stream bitrate (VC-2 / Dirac Pro (ST 2042))
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- Compression ratio
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- Streams on 1 GbE
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- Streams on 10 GbE
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- Recommended link
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- Endpoint power
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Supports up to 444 · 12-bit. Wavelet mezzanine codec behind Atlona OmniStream.
About VC-2 / Dirac Pro (ST 2042)
VC-2, also known as Dirac Pro and standardized as SMPTE ST 2042, is a lightweight wavelet mezzanine codec — best known as the engine inside Atlona OmniStream.
VC-2 is designed for professional mezzanine work: visually lossless, low latency and simple enough to encode/decode in hardware. It compresses each frame independently like JPEG 2000, but with a lighter transform that suits live switching.
The bitrate is the raw signal divided by the codec ratio (this tool models ≈10:1). It supports 4:4:4, so a 1080p30 4:4:4 source drops from about 1.49 Gbps raw to roughly 149 Mbps — comfortably one of several streams on 1 GbE.
Worked example
A 1080p30 4:2:0 signal is 746.5 Mbps raw; VC-2 compresses it about 10:1, so the stream is about 74.6 Mbps. That is the "mezzanine" profile behind 1 GbE AVoIP.
Frequently asked questions
Is VC-2 the same as Dirac?
Dirac Pro is the BBC-developed codec; VC-2 (SMPTE ST 2042) is its standardized form. They refer to the same technology.
Where is VC-2 used?
Mostly in pro AV — Atlona OmniStream is the flagship user — rather than broadcast, where JPEG 2000 and ST 2110 dominate.
VC-2 vs JPEG 2000?
Both are wavelet, frame-independent codecs; VC-2 trades a little bitrate efficiency for simpler, lower-cost hardware.
What is the difference between raw and stream bitrate?
Raw is the uncompressed signal (width × height × frame rate × bits per pixel); stream is what the codec actually puts on the wire after compression. The compression ratio is raw ÷ stream.
What do 4:4:4, 4:2:2 and 4:2:0 mean?
They describe chroma subsampling — how much colour detail is kept relative to brightness. 4:4:4 keeps full colour (3× bit depth per pixel), 4:2:2 keeps two-thirds, and 4:2:0 keeps half (1.5×).
Related calculators
- JPEG 2000 Bitrate Calculator
- Crestron NVX Bitrate Calculator
- Atlona OmniStream Bitrate Calculator
- IP Video Bitrate Calculator — compare every codec side by side.
- Switch Configurator — size the switch for these streams.
Disclaimer: bitrates are planning estimates. Confirm final figures with your codec and switch vendor.