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Bug 1266 - GDF files are written in blocks of 1 gig (biosemi2ft buffer), but not concatinated when read
| Status | CLOSED FIXED |
| Reported | 2012-01-18 10:50:00 +0100 |
| Modified | 2012-04-11 16:48:31 +0200 |
| Product: | FieldTrip |
| Component: | fileio |
| Version: | unspecified |
| Hardware: | PC |
| Operating System: | Windows |
| Importance: | P3 major |
| Assigned to: | Robert Oostenveld |
| URL: | |
| Tags: | |
| Depends on: | 1366 |
| Blocks: | |
| See also: |
Stephen Whitmarsh - 2012-01-18 10:50:14 +0100
Similarly as our CTF data, GDF data is stored in blocks (of 1 gig). To read the data, apparantly the FT implementation does not contain the intelligence yet to concatinate the data chunks. Concatinating after ft_preprocessing would miss intermediate trials as it is unknown how the samples continue between files. Anyone have any idea?
Stephen Whitmarsh - 2012-03-06 16:42:55 +0100
BUMB!
Robert Oostenveld - 2012-03-10 09:01:53 +0100
there are two pieces in the buffer/cpp ODM code where new files are created with a number "GDF_BackgroundWriter.h" line 119 of 221 char suffix[12]; snprintf(suffix,12,"_%i.gdf", fileCounter); filename.append(suffix); and in "OnlineDataManager.h" line 459 of 764 if (fileCounter == 0) { curWriter->start(curFilename.c_str()); } else { char *compName = new char[curFilename.size() + 20]; sprintf(compName, "%s_S%i", curFilename.c_str(), fileCounter); The first seems to be related to the file size, i.e. the automatic splitting of a continuous recording over 1GB files. The second relates to the user stopping and starting saving multiple times, i.e. resulting in files that do not represent a continuous recording. So there are test.gdf test_1.gdf test_2.gdf ... and test.gdf test_S1.gdf test_S2.gdf where only the first should be auto-appended in ft_read_xxx
Robert Oostenveld - 2012-03-10 16:13:11 +0100
I made the required changes to the code, which was more work than expected :-( While making the changes, I also came across the solution for bug #1281. mbp> svn commit `cat out` Sending fileio/ft_read_data.m Sending fileio/ft_read_event.m Sending fileio/ft_read_header.m Sending fileio/private/read_biosig_data.m Sending fileio/private/read_biosig_header.m Sending fileio/private/read_combined_ds.m Adding test/test_bug1266.m Transmitting file data ....... Committed revision 5429.