How to check if a ,MDF file is unsorted?

Hi all,

I am trying to read on matlab several .MDF files. All of them are exported with the some tool and for some reasons, some of them are unsorted. I need to know which files are unsorted. Is there any way to do that?

Here is my code. If a file is unsorted I get an error when I read the file, so I added the two lines which sort the files (the two under comment), but in that case, if the file is sorted, I get an error at the mdfSort function. By knowing which files are unsorted, I can solve the problem with a If-statement.

for iFile=1:length(MDFFile)
    Duration=-1;    
%     sortedPath = mdfSort([MDFFolder MDFFile(iFile).name],'SortedMDFFile.mdf');
%     mdfObj = mdf('SortedMDFFile.mf4');
        mdfObj = mdf([MDFFolder MDFFile(iFile).name]);

    if isempty(mdfObj.ChannelNames)==0
        chlist = channelList(mdfObj);
        chlistS=table2struct(chlist);
        chlistName=convertStringsToChars([chlistS.ChannelName]);
        for iSig=1:length(Signals2Load)
            iCh=find(strcmp(chlistName,Signals2Load{iSig}));
            if isempty(iCh)==0
                data = read(mdfObj,chlistS(min(iCh)).ChannelGroupNumber,Signals2Load{iSig});
                if Duration<0
                    Duration=seconds(floor(max(data.Time)));
                    CanData(iFile).Time=[0:TS:Duration];
                end    
                CanData(iFile).(Signals2Load{iSig})=pchip(seconds(data.Time),data.(Signals2Load{iSig}),CanData(iFile).Time);
            end
        end
    else
        warning(['Problems in loading ' MDFFile(iFile).name])
    end
end

[Walter Roberson]

Perhaps you should use a try/catch ?

[Serbring]

Probably I have to. I do not like that much try/catch. In my opinion, it is not a synonim of good practice. Thanks.

Answer 1

[Elliott Blocha]

The MDF file format specifies that "finalized" MDF files must start with "MDF " in the first 8 bytes (including the 5 spaces). In hex this is:

4D 44 46 20 20 20 20 20

Unfinalized (including unsorted) MDF files have "UnFinMF " in the first 8 bytes (including the 1 space). In hex this is:

55 6E 46 69 6E 4D 46 20

Look into the "fopen" and "fread" functions to check for the "finalized" flag.

mdfSort might already do this check, so it may be faster to use a try/catch statement.

[Serbring]

Hi!

Thanks for your answer!!!