Learn more about Optcore SDI video transceiver solution. Introduction to DWDM. Geo says: 8k 10bit HDR 60hz uncompressed require 60 Gbps bandwidth! Optcore says: Thank you for the correction, we will follow and revise it accordingly. Leave a Reply Cancel reply You must be logged in to post a comment. Orders placed during the holiday will be processed on October 8. Hence, the number of cameras needed to capture vivid details such as facial features or license plate is largely reduced.
These systems can be directly upgraded from analog to HD-SDI; therefore, installers can simply replace front-end products. This is because when integrating SDI and IP systems, the front-end HD-SDI real-time video streams are captured into a video encoder, then the converted digital signals are distributed to a video matrix switcher for real-time monitoring.
The signals are then further sent to an encoder for storing. This approach ensures HD rendition in monitoring and storing. While bad connections or false linkage of connectors in analog systems simply cause horizontal strips or jitters on the video, HD-SDI camera installations, on the other hand, cannot stand any false connections because the video will be lost.
Analog video signal frequency is in waveforms whereas HD-SDI signal frequency looks like serrated edges. Transmission Currently, HD-SDI supports a limited transmission distance of meters on regular video coaxial cables.
As with all things digital, there is much change and much to talk about. It's been around since about and is quite literally the savior of high definition interfacing and delivery at modest cost over medium-haul distances using RG-6 style video coax. The technical data is essentially the same, but the standard's relationship to other SMPTE standards is now clarified via a roadmap within the new release.
And so it goes, but the real reason to discuss HD-SDI today is to introduce you to some of its variations. The variations are taking on new meaning as the industry encounters the need for higher color depth and expanded transmission bandwidth.
The digital cinema industry is well aware of the new flavors of HD-SDI and, in some applications, uses its variants to feed the voracious data appetite of the digital cinema projector. This is digital component with the luminance channel having full bandwidth sampling at This format is sufficient for high definition television.
But, its robustness and simplicity is pressing it into the higher bandwidth demands of digital cinema and other uses like bit, level signal formats, refresh rates above 30 frames per second, and larger picture formats. This adaptation supports component and RGB sources of bits and bits as well as an "alpha" channel. The alpha channel provides support for chroma keying and background clipping mattes. When the alpha channel is present, the sampling structure is referred to as SMPTE M spreads out the image information between the two channels to distribute the data payload.
Odd-numbered lines map to link A and even-numbered lines map to link B. Table 1 indicates the organization of , , and data with respect to the available frame rates.
Applications like digital cinema demand the uncompressed, bit structure; meaning that each channel is full bandwidth RGB or component format with bit depth per color. According to Table 1, a wide variety of frame rates may be accommodated, but digital cinema typically utilizes the 24 frame progressive mode listed so as to preserve the film look. Since this standard is an extension of SMPTE M, the original HD-SDI format, its versatility is utilized for some digital cinema interfacing installations; although at this time, the digital cinema infrastructure is still under considerable development and change.
Dual-link HD-SDI is certainly a step forward, but it demands that the interfacing devices be capable of managing a certain amount of timing skew that can occur as the signal travels through two separate cable pathways. It is imperative that cable length be managed closely to guard against increased skew time. Signal timing difference at the source must not exceed 40 nanoseconds. Wouldn't it be nice if we could manage the two data streams on one cable? In order to transmit the same information as two separate HDSDI streams, the clocking rate is simply doubled.
This arrangement is called a "virtual interface" within M. The only difference is that our dB calculation for cable loss at one half the clock rate moves from MHz to 1. Essentially, the loss is about double for the same distance with the same cable; or, we can transmit the signal half as far.
Table 2 summarizes the scope of image formats handled in this dual-rate standard. The mapping structure supports various rates from bit component up to bit component and RGB. Increasing the bit depth improves the image's dynamic range.
In the new release of SMPTE M, the roadmap shows this transport interface tied in to the taxonomy through SMPTE M, also updated in , which describes how to format data for use within the ancillary data space supplied in all television serial digital standards.
The ancillary space is the time interval previously devoted to horizontal and vertical blanking in the analog television system. SMPTE M takes the transport concept back into the standard definition production environment for support of and line video. Further, this standard sets the structure for transport of a variety of video data including MPEG-2 encoded video. Of course, the DV format for consumer video cameras arrived earlier, but for most it just didn't seem like digital video.
I think we've only recognized what digital video can be since the moment we could really interact with it, or touch it so to speak And, that's the way it is with anything digital. When it's working, it's very, very good; when it stops working, we're lost.
There's only one way to describe the non-working situation: "It's broke. The road of progress is paved with resolve and vanquished challenges. Experience guides each of us along that road. Experience tells us to consider alternatives; to research other successful solutions to technical challenges. Such is the case here. The television industry has used the high definition serial digital interface, or HD-SDI, for about 10 years now to trundle full bandwidth, uncompressed HD video from point A to point B within the television production environment.
With the DVI having more press and wide use, it's important to establish a point of reference right here before moving on. RGB 8-bit image data via bit symbols is transferred over the DVI using three digital data lines and one clock line.
That's four parallel differential line pairs not including display communications and control. Each of the three video data pairs operates at a rate of 1. The clock rate is variable from 25 to MHz depending on the resolution desired. So, DVI has quite a lot of rate flexibility, but is challenging to distribute with its multiple data line pairs and interface control requirements.
High definition video is transferred at 10 bits per symbol in the Y, U, V domain. That's another designation for component video, which provides a quality level of lossless compression.
All digital television signals, including high definition rates up to x at 30 frames interlaced, are managed successfully over the HD-SDI.
The component format allows transmission of HD because the luminance Y channel is the only full bandwidth channel. The U and V channels representing chroma are transmitted at one-half bandwidth; an acceptable tradeoff based on our understanding of the human visual system.
What's an alpha channel? Read on. ATSC standard definition and high definition rates are ultimately compressed using MPEG-2 in order to fit them within the bandwidth limits of one television channel.
After compression, the high definition video rate plummets to The number of bit transitions creates the illusion that the signal appears to be crossing the zero axis at each bit position creating a display called an "eye pattern".
The "eye" refers to the opening between the maxima and minima between each bit cell transition. In this presentation, the eye pattern illustrates a clean, open, strong source signal. Normal signal level is 0. The rise and fall times are nominally picoseconds.
Eye pattern quality is one measure for successful data transmission. As the signal propagates through a coaxial cable, transition times lengthen just as they do with an analog signal. Slowing signal transitions and cable attenuation cause amplitude decrease, which results in the eye closing down.
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