active area and reduced blanking proposalgrouper.ieee.org/groups/1722/contributions/2013...video...
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H and V Blanking
§ Size depends on standard § 20-30% of frame for most common
standards § V-blanking Used for:
§ Closed captioning § Teletext § Timecode (VITC-ATC) § Vendor specific data
§ H-blanking: § Audio § EDH (SD) § Stream Type info (SMPTE352)
V1-blanking
H-blanking Field 1
Field 2
V2-blanking
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Bandwidth
§ Example for 1080P50-APVF 50Hz x 20bit x 1125 ln x 2640 pix
=2,96 Gb/s
§ Example for 1080P60-APVF 60Hz x 20bit x 1125 ln x 2200 pix
=2,97 Gb/s
§ Example for 1080P50-Active-Area 50Hz x 20bit x 1080 ln x 1920 pix
=2,07 Gb/s 30% reduction § Example for 1080P60-Active-Area 60Hz x 20bit x 1080 ln x 1920 pix
=2,48 Gb/s 16% reduction
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Active-Area
§ Only transmit active area (1920x1080)
§ Clear definition § Max reduction of BW § For all data in V-Blanking a separate
timed control stream must be added § Increase of latency due to active-
picture stretching over full frame § Easy integration of computer
graphics § No relation to blanking in
conventional signals (SDI, DVI, VGA)
Reduced blanking § Remove H blanking only (1920x1125) § No clear understanding § ~3 % less reduction § Data encapsulated in V-Blanking is
preserved, no need for additional transport mechanism.
§ Small increase of latency due to active-picture stretching over full line only
§ Constant timestamp interval 1st pixel of the line
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Parameters for defining raster § format: The format field identifies the video format of the PDU § avtp_timestamp field: the presentation time corresponds to the leading
edge of the start of the video line. § stream_data_length: contains the total number of octets in the AVTPDU
after the protocol specific header, which includes the APVF Header and the video data payload. The stream data length for a given APVF stream shall maintain a constant size in octets over the duration of the stream's lifetime (Formula for PDU packet size)
§ M0,M1,M2,M3, EVT: equal to APVF § H-Active-Pix: Number of pixels on horizontal line § V-Active-Ln: Number of vertical active lines in a field § V-total-ln: Total number of lines in a frame § sample field: The sample field indicates the component pixel sampling
structure and bit depth of the payload, and shall be set to one of the values given in Table X
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Parameters for defining raster (cont)
§ Interlaced: Add a bit in the header that indicates the source is interlaced § Map/Sample:Color standard values:
§ BT Rec.601/709 Full Range (0-255 in case of 8-bit) § BT Rec.601/709 Reduced Range (16-235 in case of 8-bit) § YCbCr, sRGB, YCgCo, Grayscale, xyz, YCM (Yellow,Cyan,Magenta)
§ Pixel Formats values: § Monochrome § 4:2:2 § 4:4:4 § 4:4:4:4 § 4:2:2:4 § Bayer grbg § Bayer rggb
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Parameters for defining raster (cont)
§ Pixel Depth values: 8, 10, 12, 16bit § Frate: basic frequencies (24, 25, 30, …) § Fmult: multiplier for Frate (2,3,4) § 1000/1001: bit to indicate divider § i_seq_num: see APVF § line_number: Free running counter starts at 0 on a frame boundary.
(M0 = end of video frame indicator) § Fcount: see APVF (Why?)
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Example of Active-Area 1080i50
§ stream_data_length = 1200 § V-total-ln = 1080 § V-Active-Ln = 1080 § H-Active-Pix = 1920 § M0 = Last PDU § M1 = Field 1 or 2 § Sample_Field = YCbCr § Interlaced = 1 § Pixel Formats values = 4:2:2 § Pixel Depth values = 10 § Frate = 25 § Fmult = 1 § Pd (1000/1001)= 0
V1-blanking
H-blanking
Field 1
Field 2
V2-blanking
M0 = 1
M1 = 0 M2 = 0 M3 = 0
M1 = 1 M2 = 0 M3 = 0
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Example of Reduced Blanking 1080i50
§ stream_data_length = 1200 § V-total-ln = 1125 § V-Active-Ln = 1080 § H-Active-Pix = 1920 § M0 = Last PDU § M1 = Field 1 or 2 § Sample_Field = YCbCr § Interlaced = 1 § Pixel Formats values = 4:2:2 § Pixel Depth values = 10 § Frate = 25 § Fmult = 1 § Pd (1000/1001)= 0
V1-blanking
H-blanking
Field 1
Field 2
V2-blanking
M0 = 1
M1 = 0
M1 = 1
M3 = 1
M3 = 0
M3 = 1
M3 = 1
M3 = 0
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Example of Reduced Blanking 1080P60
§ stream_data_length = 1200 § V-total-ln = 1125 § V-Active-Ln = 1080 § H-Active-Pix = 1920 § M0 = Last PDU § M1 = Always 0 § Sample_Field = YCbCr § Interlaced = 0 § Pixel Formats values = 4:2:2 § Pixel Depth values = 10 § Frate = 30 § Fmult = 2 § Pd (1000/1001)= 1
V-blanking
H-blanking
Frame 1
M0 = 1
M1 = 0
M1 = 0
M3 = 1
M3 = 0
M3 = 1
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Transmit interval
§ Outside scope of 1722 (?) § Implementer trade-off between latency and Bandwidth § No need for defining in stream since Presentation time will guarantee
correct Video timing
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121620 pd i M3M2M1 M024283236
avtp_timestamp
reserved
subtype version sequence_num reserved
stream_id
video_data_payload
h_active_pix
v_total_lnreserved
fratepixel_dept pixel_format Color_space
i_seq_numreserved
formatevt
line_number
stream_data_length
fmultv_active_ln
Header