Analog Devices ADV7850 Hardware Manual page 88

Function
sdp_3d_comb_en
1 
0
sdp_allow_3d_comb indicates if the ADV7850 has detected a non standard input for which 3D processing is not possible. For high quality
PAL and NTSC input signals with nominal timebase, 3D processing is possible. For unstable, noisy, or otherwise non standard video
signals, 3D processing is impossible. The user can disable 3D processing manually via sdp_3d_comb_en.
The ADV7850 applies a deglitching filter to the result of this decision, with the programmable time constant controlled by
sdp_allow_3d_filt_sel[2:0].
sdp_allow_3d_filt_sel[2:0], Addr 90 (SDP), Address 0x9A[2:0]
This control is used to set the time constant applied to the deglitching filter for the 3D comb decision.
Function
sdp_allow_3d_filt_sel[2
:0]
000
001 
010
011
100
101
110
111
The ADV7850 monitors the input signal for noise and characteristics that are undesirable for 3D processing (information about noisy or
very noisy input signal is accessible via
The ADV7850 characterizes the signal as a clean, noisy, or very noisy input signal, and assesses whether or not the input signal has the
following characteristics:
•
Incorrect number of lines
• Non standard block length
• Non standard frame length
• Non standard field length
• VCR head switches (unstable time base)
• No color burst (color kill is active)
For each input signal characterization (clean, noisy, or very noisy), it is possible to select whether or not the 3D comb is disabled on
detection of the above characteristics. Note that 3D processing, if enabled with non standard inputs, can cause undesirable artifacts.
The following controls allow the user to select the non standard characteristics that contribute to the
sdp_ckill_dis_3d, Addr 90 (SDP), Address 0xA3[7]
This control is used to enable 3D combing if color kill mode is active.
Function
sdp_ckill_dis_3d
1 
0
Rev. A May 2012
Description
Enable 3D comb filter
Disable 3D comb filter, enable 2D comb mode only
Description
No filtering
0.25 sec
0.55 sec
0.81 sec
1.10 sec
1.36 sec
1.63 sec
2.00 sec
sdp_very_noisy_ip and sdp_noisy_ip).
Description
Disable 3D comb if color kill active
Allow 3D comb even if color kill active
88
ADV7850
sdp_allow_3d_comb decision.