
CTA-861 version:
CTA-861-G Standard from November 28, 2017

   +---------------+
   | KNOWN ISSUES: |
   +---------------+

1. CEA/CTA-861: Data Block Collection (DBC):
   The data structures in DBC are variable, and their layout depends on complex
   combinations of various fields values. Changing a single value (even a single bit)
   can change the whole layout of the block.
   In many cases, more than one value has to be changed to obtain a valid structure of
   different type, f.e.:
   changing ADB.SAD.AFC value to 15 (ACE: Audio Coding Extension Type Code) will cause
   error, because AFC=15 in byte 1 requires also a valid ACE value in byte 3.
   In such cases the editor will switch to a fallback mode, and the data structures
   will be displayed as "unknown/damaged".
   wxEDID Solution: (not yet implemented):
   A set of constructors which will immediately initialize the required block data fields,
   depending on selected type.
   The constructors could be invoked from contextual menus, by right-clicking on particular
   block in the block tree structure.

2. SVD: Short Video Descriptor:
   The data layout for this block depends on:
   a) CEA-861 header revision
   b) Video ID Code (VIC)
   wxEDID will always show the "native_mode" bit7 and the VIC as 8-bit value at the same time.
   This means, that changing "native_mode" bit can also change the VIC value.

3. VDDDB: VESA Display Device Data Block:
   VESA DDDB Standard, Version 1; September 25, 2006, section 2.7: Device Native Pixel Format
   A bug in the specification: The STD defines stored 16-bit H/V pixel count as (pix_count-1),
   (what gives the effective range of 1-65536 for 0x0-0xFFFF), but the Std says that thanks to (pix_count-1)
   formula the maximum is 65535x65535, which is not true.
   wxEDID will use range of 1-65536.

4. CEA-DBC: Extended Tag Code=3: VESA Video Timing Block Extension (VTB-EXT):
   CTA-861-F/G references VTB-EXT Standard, Release A, November 24, 2003.
   The VTB-EXT extension block is defined as a 128 byte structure, what exceeds the range allowed
   by the DBC Extended Tag header (30 bytes).
   None of the documents is addressing this issue.
   wxEDID will report error for Extended Tag Code=3.

5. Discrepancy in block length handling:
   a) CEA-DBC: Extended Tag Code=32: section 7.5.9 IFDB: InfoFrame Data Block:
      InfoFrame Type Code != 0x01 || 0x00: Short InfoFrame Descriptor Header:
      The payload length is counted from the first byte after the header
   b) CEA-DBC: Extended Tag Code=32: 7.5.9 IFDB: InfoFrame Data Block:
      InfoFrame Type Code = 0x01: Short Vendor-Specific InfoFrame Descriptor Header:
      The payload length excludes the first 3 bytes of IEEE OUI.
   This means that the length of header depends on InfoFrame Type Code.

6. For any block type, the payload data which is not strictly defined by the CTA-861-G
   is displayed as "unknown".

7. SLDB: Some speaker names used in CTA-861-F are changed in CTA-861-G. See Annex Q for details.
   wxEDID uses speaker names from the "G" revision - differences are mostly harmless.

NOTE:
In wxEDID v0.0.21 the data structures defined for CTA-861-G are *NOT* fully tested - simply,
I don't have a hardware which fully utilizes the "G" specification, so I can't make tests with
100% coverage.

If You'll find any bugs, please don't hesitate to contact me:
tomasz.pawlak@wp.eu


