singmai DB01 NTSC-PAL Video Decoder User Manual
- June 12, 2024
- singmai
Table of Contents
singmai DB01 NTSC-PAL Video Decoder
Product Information
Specifications
- Power: +9-14V (+12VDC nominal) @ ~340mA (all outputs driven)
- Dimensions: 120mm x 78mm x 27mm
- Video Input: NTSC-M or PAL. 75 input impedance (coaxial). 1V pk-pk nominal input. Maximum input before clipping 1.4V pk-pk
- Video Output: SDI (SMPTE-259M). 800mV pk-pk into 75Ω. >14dB return loss
- Luma Bandwidth:
- Chroma Bandwidth:
- Differential Gain/Phase:
Product Usage Instructions
Introduction
The DB01 is a broadcast-quality video decoder that accepts NTSC-M and PAL
video inputs. It is compatible with various video sources such as cameras, DVD
players, time-based corrected VCRs, and off-air broadcasts. However, it does
not support unstable sources like analog laserdiscs or non-TBC video tapes.
The output is converted to a serial digital interface (SDI) output.
Quick Start Guide
Connections:
- Connect the 12VDC jack from the adaptor to the +12VDC ‘Power in’ socket on the DB01. The ‘Power On’ LED should light up blue.
- Connect your video input to the video input (BNC). The DB01 accepts either NTSC-M or PAL video (auto selected based on the measured line standard).
- The decoded video is encoded to SDI format (SMPTE-259M). Connect the video output to a video recorder, monitor, or other SDI compatible device.
DB01 Technical Details
A simplified block diagram of the DB01 is shown in Figure 2.
Frequently Asked Questions (FAQ)
-
Q: What power source does the DB01 require?
A: The DB01 requires +9-14V (+12VDC nominal) power supply at approximately 340mA when all outputs are driven. -
Q: What type of video inputs does the DB01 support?
A: The DB01 supports NTSC-M or PAL video inputs with a 75Ω input impedance and a maximum input of 1.4V pk-pk before clipping.
Revisions
Introduction
DB01 is a broadcast quality video decoder accepting NTSC-M and PAL video inputs. DB01 accepts analogue CVBS inputs which it filters and clamps before converting to digital composite video using a 12-bit analogue to digital converter (ADC) running at 27MHz. Video decoding is performed using a modified version of SingMai’s PT6 video decoder IP core. A seven-tap comb filter adapts between 3D frame, 3D field, 3 line comb and a notch filter on a pixel by pixel basis based on a quality measurement of each comb mode. This provides the highest quality decoding with lowest artifacts. The DB01 accepts video sources such as cameras, DVD players, time based corrected VCRs and off-air broadcast, but it will not accept unstable video sources such as analogue laserdisc or non-TBC video tapes. The output from the video decoder is converted to a serial digital interface (SDI) output. DB01 requires 12VDC which is provided via the supplied AC-DC converter.
Quick start guide
Connect the DB01 to the supplied AC/DC adaptor. Fit the appropriate blades to
the adaptor for your country. Blades are supplied for North America, Europe,
UK, China and Australia. The adaptor accepts AC between 90 and 264VAC – the
full specification is provided in Appendix A.
The connections to the DB01 are shown in Figure 1. Connect the 12VDC jack from
the adaptor to the +12VDC ‘Power in’ socket on the DB01. The ‘Power On’ LED
should light up blue.
Connect your video input to the video input (BNC). The DB01 accepts either
NTSC-M or PAL video (auto selected depending on the measured line
standard).
The decoded video is encoded to serial digital interface (SDI) format (SMPTE- 259M). Connect the video output to a video recorder, monitor or other SDI compatible device. The DB01 uses a crystal-based voltage-controlled oscillator (VCO) to line-lock to the video input and this has a limited lock range. The DB01 will lock to almost all, cameras, DVDs, set-top boxes, off-air broadcasts and TBC VCRs, but it will not lock to non-TBC VCRs or analogue laserdiscs.
DB01 Technical Details
A simplified block diagram of the DB01 is shown in Figure 2.
- The +12VDC from the AC/DC power adaptor is filtered and protected from over-range or reverse polarity inputs. The 12VDC input is then regulated to provide clean power supplies for the module.
- The video input is pseudo-differentially received which reduces hum pickup over long cable runs. The video input is terminated by 75Ω and is protected from out-of-range inputs or glitches. The video is then filtered to remove out-of-band noise and sync-tip clamped before being converted to digital video using a 12-bit analogue-to-digital converter running at 27MHz.
- The video decoding uses a variant of the SingMai PT6 video decoder IP core. The video input is demodulated to a ‘simple’ notch filtered Y,U,V signal. This signal is then comb filtered. Two 3D combs and one 2D comb are used – a 3-tap frame comb, a 3-tap field comb and a 3-tap line comb. A narrow notch filter is also provided. The chosen comb mode is selected on a pixel-by-pixel basis, depending on a quality measurement of each mode. The 3D comb filter memory is provided by an SDRAM. The selected comb output is then added back to the demodulated output to provide a full bandwidth signal with very low artifacts. The video is then formatted to a BT656 compatible output before being sent to a SDI transmitter.
- The video decoder is a line-locked decoder. A crystal based 27MHz oscillator is frequency adjusted by the video decoder until horizontal (line) lock is achieved.
Specification
- Power: +9-14V (+12VDC nominal) @ ~340mA (all outputs driven).
- Dimensions: 120mm x 78mm x 27mm.
- Video input:
- NTSC-M or PAL.
- 75Ω input impedance (coaxial).
- 1V pk-pk nominal input. Maximum input before clipping 1.4V pk-pk.
- Video output:
- SDI (SMPTE-259M). 800mV pk-pk into 75 Ω.
-
14dB return loss.
- Luma bandwidth: 5.5MHz ± 0.2dB.
- Chroma bandwidth: 1.07MHz ± 0.2dB.
- Differential gain/phase: <1%, <1°.
- K- factor: <1%.
- Luma/chroma delay: <10ns.
- Latency: <34ms (NTSC). <41ms (PAL).
- Operating temperature: -10 – +40 degC.
Appendix
Appendix A: AC-DC adaptor
The specification for the supplied AC-DC adaptor is shown in Figures 3 and 4.
