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Active Area and Reduced Blanking Proposal

WillemJan.Dirks@axon.tv

15-10-2013

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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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0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31CD SV mr r fv tv tu

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