Differences

This shows you the differences between two versions of the page.

--- guides:ssdv [2015/10/19 22:31] – [Packet Format] fsphil
+++ guides:ssdv [2016/06/30 09:35] (current) – [Packet Format] fsphil
@@ Line 16: / Line 16: @@
 |    9 | Width        |    1 | Width of the image in MCU blocks (pixels / 16) 0 = Invalid |
 |   10 | Height       |    1 | Height of the image in MCU blocks (pixels / 16) 0 = Invalid |
-|   11 | Flags        |    1 | 00000exx: 00000 = Reserved, e = EOI flag (1 = Last Packet), xx = Subsampling Mode (0 = 2x2, 1 = 1x2, 2 = 2x1, 3 = 1x1) |
+|   11 | Flags        |    1 | 00qqqexx: 00 = Reserved, qqq = JPEG quality level (0-7 XOR 4), e = EOI flag (1 = Last Packet), xx = Subsampling Mode (0 = 2x2, 1 = 1x2, 2 = 2x1, 3 = 1x1) |
 |   12 | MCU offset   |    1 | Offset in bytes to the beginning of the first MCU block in the payload, or 0xFF if none present |
 |   13 | MCU index    |    2 | The number of the MCU pointed to by the offset above (big endian), or 0xFFFF if none present |
@@ Line 90: / Line 90: @@
 ===== History =====
+  * 2015-10-19: An EOI flag was added to the header, using one of the previously reserved bits. This bit should be set to 0 except on the final packet for the current image.
   * Some final changes made to the format 2012-03-04. Images produced with this version of the encoder will be compatible with all future decoders.