Anybody in the Florida area want to get together for the OrbComm launch? I am working a temporary / long term assignment in Miami and considering driving to KSC for the OrbComm OG2 launch next Thursday (backup launch date is Friday).
Quote from: cscott on 06/05/2014 02:41 amBut I bet it *would* be helpful if someone would compile a list of the adjusted start/end positions of the FEC coding blocks referenced to the current .ts and including the discovered bit shifts, etc, like princess didI can calculate a mapping between file offsets in raw.ts and the current TS file if necessary, would this be useful?Also, if people want to calculate statistics on the bitflip errors then I have TS files that have more fixes than the current TS file - my current versions have correct contents for all PIDs except the data PID, i.e. all padding is correct, the Program Association Tables and Program Map Tables are all correct and the "padding" AFs in the data are correct too. One of my side projects is trying to make a TS file that's "what the rocket transmitted", so I can make that available to people who are doing statistical anaylsis on the error distribution. Let me know what you need and I'll make it available.
But I bet it *would* be helpful if someone would compile a list of the adjusted start/end positions of the FEC coding blocks referenced to the current .ts and including the discovered bit shifts, etc, like princess did
The postulated 56-byte FEC coding blocks turn out to be composed of alternate 25-byte and 31-byte "sub-blocks", starting at (zero-based) offsets of the form 56n + 29 and 56n + 54. Single bit-flips are found only in the first and last 15 bits of these blocks, with possible rare exceptions in high-error regions. All other bit-flip errors are combinations of "triple flips" (i.e., bit shifts of 0x8003) that do not cross the block boundaries.(That does not include frame-shift errors such as the one originally found by Shanuson, which are surprisingly common - I found at least 20 of them just in the "boilerplate" data, by amounts ranging from 1 bit to 12 bits and in both directions. But these seem to occur only after high-error regions, which may have damaged the framing information that was used in decoding the signal. They affect entire "sub-blocks" and garbage bits are shifted in at one end.)
I suspect the ship has already sailed and no-ones eager to go back to raw.ts. But I bet it *would* be helpful if someone would compile a list of the adjusted start/end positions of the FEC coding blocks referenced to the current .ts and including the discovered bit shifts, etc, like princess did:
Quote from: cscott on 06/05/2014 02:41 amI suspect the ship has already sailed and no-ones eager to go back to raw.ts. But I bet it *would* be helpful if someone would compile a list of the adjusted start/end positions of the FEC coding blocks referenced to the current .ts and including the discovered bit shifts, etc, like princess did:That's a good idea. It's actually a bit easier than that, because the frame-shift errors do not change the coding-block boundaries.
OK. I'm still coming to speed here, bear with me. Could you give me an example of a triple flip -- maybe the first one in the transport stream, just to pick one arbitrarily. It would help me a bunch if you could give me a short hex dump of a sequence in raw.ts, then the equivalent sequence in the fixed .ts showing the triple flip. If you gave me the offsets of the various features, as you label them, it would also sanity-check my understanding of how offsets are counted, etc.
Princess, could you get me a copy of your fixed .ts file?
Here is a very simple gif that shows the repairing of iframe 3 "in progress"...
Quote from: arnezami on 06/07/2014 07:35 amHere is a very simple gif that shows the repairing of iframe 3 "in progress"...The concept is very cool and educational, but this version looks like you've taken the final mmb and just apply commands as they come in the sequence. Not quite representative of the actual process. I have saved most of my intermediate mmbs for the frames I worked with. For example for iframe 121 it should show the initial good data search and later alignment. Then there was dc correction done by Quialiss and then final touches by SwissCheese.
Quote from: cscott on 06/07/2014 02:06 am Princess, could you get me a copy of your fixed .ts file?Sure, here's my best effort so far. This is a fixed version of faw_final_fixed.ts so it doesn't correspond bit-for-bit to raw.ts. The problem is that raw.ts loses its alignment from time to time and has to be realigned by removing 56 bytes each time (this may be significant).My best guess at the realignments are:Remove 56 bytes after packet 1224,and then remove 56 bytes after packet 4688,and then remove 56 bytes after packet 11637,and then remove 56 bytes after packet 18633,and then remove 56 bytes after packet 21551.Re-generate the file after each single removal for the next packet number to make sense. Each packet is 188 bytes long. Please note that these positions may not be exactly correct but it will give you the places to look for the right ones.Once you've done this you need to remove everything before the start of the first I-frame, because the raw_final_fixed files start there.I'm busy with other things today but I'll be back in about 12 hours to help out.
Edit: And I don't know why it's not animating. It works fine when I open it locally
Apparently the Wikispaces API doesn't allow file uploads. The auto-generated MMBs are uploaded here, in case you need to track down a bug:http://adama.nocdirect.com/~wronkiew/spx_crs3/mmbs/IainCole, can you change the youtube uploader to grab http://adama.nocdirect.com/~wronkiew/spx_crs3/landing_clockfix_3hr.mp4 ? I can then move the trigger to the 3hr script.
Maybe zip it and then upload. It seems the forum is doing something with the gif.
PS. Maybe its cooler/nicer to first show the positioning, and then show the luma/chroma fixes. Now I show them both at the same time. What do you think? And maybe showing the repairing of all iframes in sequence in a video. Maybe even include all P-frames... That could be cool too.
Quote from: arnezami on 06/07/2014 10:16 amMaybe zip it and then upload. It seems the forum is doing something with the gif.Here's the zip.
Pretty good list. I personally like to see Jakusb (the "dirt-master") on the list too. Because he gave us the list of dirt spots on the camera which allowed others to align blocks in the top part of the frames. But considering having only 15 spots its a good list.
Since 281 is the final iFrame and is currently washed out, it would be best to enhance the contrast so the video ends on a nicer image. I see the online editor now has a "suggest improvement to MMB" button. I like that a lot, submissions should be controlled and referreed by a benevolent dictator. This is a step in the right direction, but I know my limits ... perhaps someone more skilled at this can take it over the finish line. Frame 15(281) X:3545:01,X:2003:A0,0:0:559,40:1:-1,0:2:-2:25:25:25:25:0:0,0:10:-2:60:60:60:60:0:0:40,1:10:53276,32:10:-1::40,33:10:57352,0:13:69419:0:0:0:1:0:0:63,28:15:-2:-70:-70:-70:-70:0:0:63,29:15:83102,8:29:-1
Quote from: arnezami on 06/06/2014 07:29 pmWe need more T-shirts!! Clearly the solution is to cut the t-shirts in half.
We need more T-shirts!!