We all know SDI transceiver module and SDI gears are commonly used in broadcast TV transmission. It play an important role in video transmission.
At present, there are many SDI optical transceiver products on the market, but most of the SDI modules can not pass the SDI pathological checkfield and CRC test. We know SDI includes 12G-SDI, 6G-SDI, 3G-SDI, HD-SDI, SD-SDI now, but 3G-SDI and HD-SDI optical fiber gear are commonly used in TV video transmission. When the SDI fiber gear and SDI module without supporting pathological signal could also work on regular SDI signal, but there are many problems when transmitting SDI pathological signals with irregular rates. The probability of the problem may be a splash screen, a black screen, a blue screen during the HD video transmission process, or the continuous smooth playback of the picture cannot be guaranteed.
There are also other reasons causing above problems. Now most SDI modules adapt SFP types. Some suppliers use 1.25G rate for 1.485G HD-SDI, 2.5G rate for 2.97G 3G-SDI to save the production cost. These SFP modules is not special for SDI video. They are commonly used other aspects like Ethernet Switch transmission, DVI/HDMI fiber transmission. That is why the price is so different when you ask the same 3G bandwidth SFP module for the common and special SDI.
Of course, the optical transceiver module is the only one reason for a good SDI fiber gear like SDI fiber optic extender. The mainboard board also matters. Some supplier reduce the SDI recovery clock chip or use the second hand chip to save the production cost. The are also compression solution to make several SDI channels to a low rate. These products comes up with SDI solution of CCTV surveillance in the past 10 years. But now it is replaced mostly by AHD TVI CVI solution in security camera transmission.
The following is SDI SMPTE standard for reference.
SMPTE 259M: SD-SDI, bandwidth is 270Mbit/s, 360Mbit/s, 143Mbit/s, 177Mbit/s. Resolution is 480I, 576I.
SMPTE 344M: ED-SDI, bandwidth is 540Mbit/s. Resolution is 480P, 576P.
SMPTE 292M: HD-SDI, bandwidth is 1.485Gbit/s. Resolution is 720P, 1080I.
SMPTE 372M: Dual Link HD-SDI, bandwidth is 2.97Gbit/s. Resolution is 1080P60.
SMPTE 424M: 3G-SDI, bandwidth is 2.97Gbit/s. Resolution is 1080P60.
SMPTE ST2081: 6G-SDI, bandwidth is 6Gbit/s. Resolution is 2160P30.
SMPTE ST2082: 12G-SDI, bandwidth is 12Gbit/s. Resolution is 2160P60.