In the history of the specification, we have three version of the documents such as ANSI/SMPTE 268M-1994, SMPTE 268M-2003 Revision of ANSI/SMPTE 268M-1994 and SMPTE ST 268:2014 Revision of SMPTE 268M-2003. We should to know the difference between these versions for the implementation of a software.
| Area | ANSI/SMPTE 268M-1994 | SMPTE 268M-2003 Revision of ANSI/SMPTE 268M-1994 | SMPTE ST 268:2014 Revision of SMPTE 268M-2003 |
|---|---|---|---|
| File information header | 16 fields | 16 fields | 16 fields |
| Image information header | 4 + (15 x 8) + 1 fields | 4 + (15 x 8) + 1 fields | 4 + (15 x 8) + 1 fields |
| Image source information header | 13 fields | 13 fields (Added data structure for additional source image information) | 13 fields (same as 2003) |
| Motion-picture film information header | 15 fields | 15 fields | 15 fields |
| Television information header | 17 fields | 17 fields | 17 fields |
| Values | Description |
|---|---|
| 0 | User defined (or unspecified single component) |
| 1 | Red (R) |
| 2 | Green (G) |
| 3 | Blue (B) |
| 4 | Alpha (matte) |
| 6 | Luma (Y) |
| 7 | Color Difference (Cb, Cr, subsampled by two) |
| 8 | Depth (Z) |
| 9 | Composite video |
| 10 | Reserved for future single components |
| 50 | R, G, B |
| 51 | R, G, B, Alpha |
| 52 | A, B, G, R |
| 53 | Reserved for future RGB ++ formats |
| 100 | Cb, Y, Cr, Y (4:2:2) |
| 101 | Cb, Y, A, Cr, Y, A (4:2:2:4) |
| 102 | Cb, Y, Cr (4:4:4) |
| 103 | Cb, Y, Cr, A (4:4:4:4) |
| 104 - 149 | Reserved for future CbYCr ++ formats |
| 150 | User-defined 2-component element |
| 151 | User-defined 3-component element |
| 152 | User-defined 4-component element |
| 153 | User-defined 5-component element |
| 154 | User-defined 6-component element |
| 155 | User-defined 7-component element |
| 156 | User-defined 8-component element |
| 157 - 254 | Reserved for future formats |
| Values | V1.0 | V2.0 | Changes |
|---|---|---|---|
| 0 | User defined | User defined | - |
| 1 | Printing density | Printing density | - |
| 2 | Linear | Linear | - |
| 3 | Logarithmic | Logarithmic | - |
| 4 | Unspecified video | Unspecified video | - |
| 5 | SMPTE 240M | SMPTE 274M | The target specification was changed to SMPTE 274M from V2.0. |
| 6 | CCIR 709-1 | ITU-R 709-4 | The target specification was changed to ITU-R 709-4 from V2.0. |
| 7 | CCIR 601-2 system B or G (625) | ITU-R 601-5 system B or G (625) | The target specification was changed to ITU-R 601-5 from V2.0. |
| 8 | CCIR 601-2 system M (525) | ITU-R 601-5 system M (525) | The target specification was changed to ITU-R 601-5 from V2.0. |
| 9 | Composite video (NTSC) | Composite video (NTSC) | - |
| 10 | Composite video (PAL) | Composite video (PAL) | - |
| 11 | Z (depth) - linear | Z (depth) - linear | - |
| 12 | Z (depth) - homogeneous | Z (depth) - homogeneous | - |
| 13 - 254 | Reserved for future use | Reserved for future use | - |
| Values | V1.0 | V2.0 | Changes |
|---|---|---|---|
| 0 | User defined | User defined | - |
| 1 | Printing density | Printing density | - |
| 2 | Not applicable | Not applicable | - |
| 3 | Not applicable | Not applicable | - |
| 4 | Unspecified video | Unspecified video | - |
| 5 | SMPTE 240M | SMPTE 274M | The target specification was changed to SMPTE 274M from V2.0. |
| 6 | ITU-R 709-1 | ITU-R 709-4 | The target specification was changed to ITU-R 709-4 from V2.0. |
| 7 | ITU-R 601-2 system B or G (625) | ITU-R 601-5 system B or G (625) | The target specification was changed to ITU-R 601-5 from V2.0. |
| 8 | ITU-R 601-2 system M (525) | ITU-R 601-5 system M (525) | The target specification was changed to ITU-R 601-2 from V2.0. |
| 9 | Composite video (NTSC) | Composite video (NTSC) | - |
| 10 | Composite video (PAL) | Composite video (PAL) | - |
| 11 | Not applicable | Not applicable | - |
| 12 | Not applicable | Not applicable | - |
| 13 - 254 | Reserved for future use | Reserved for future use | - |
| Values | V1.0 | V2.0 | Changes |
|---|---|---|---|
| 0 | Packed into 32-bit words | Packed into 32-bit words | - |
| 1 | Filled to 32-bit words | Filled to 32-bit words, method A | The name was changed from V2.0. |
| 2 | Reserved for future use | Filled to 32-bit words, method B | The new fill method was added from V2.0. |
| 3 - 7 | Reserved for future use | Reserved for future use | - |