MPEG TS Support

Hi Andrew,

the current assumption in conquest is that all data can be 'transcoded' by conquest from one syntax to another. With mpeg that would not be a good idea. So it is a rather fundamental change.

Thus:
one would need to add mpeg as acceptd syntax during negotation (simple)
one would need to ignore incoming compression for mpeg images (simple)
when negation an outgoing transfer syntax and a mpeg image is part of the set to be sent, mpeg would need to be added as syntax (more complex).
one would need to ignore outgoing compression for mpeg images (simple)

These things require some fairly major code changes. However, when I looked at it before I tried to add the coder/decoder for mpeg.

If you are on linux, you could relatively easily try / help to add these. Compiling on windows is a bit more involved.

Marcel

Hm,

just looked a bit more: it is more complex because transfer syntax is not maintained in the database. I.e. to know if mpeg needs to be added in an outgoing data request, one would have to first read all the image headers. Alternatively one could always request mpeg outgoing, but that would mean that images must be skipped on the fly if mpeg was not accepted. Needs some more thought....

Marcel

Hi Andrew,

the latest source code is part of the release 1.4.19b zip. Yesterday I tested adding TransferSyntaxUID to the database at image level by modifying dicom.sql (which breaks database compatibility with existing databases), but the server than still seems to run correctly once the database is regenerated.

You would need to add:

if(!DDOPtr->GetVR(0x0002, 0x0010))
{
vr = new VR ( 0x0002, 0x0010, 0, FALSE );
DDOPtr->Push(vr);
}

to every

Retrieve :: SearchOn

routine in dgate.cpp to make that any move will get the transferSyntax infomation. This is the same mechanism to get the private filename and device field. The actual move is in StandardRetrieveNKI :: Read in nkiqrsop.cpp. Compression and decompressing of images is centralized in recompress() in the same file.

Please keep code changes to a minimum, localized and well documented and update the manual update history in the files. I will merge code changes through a file compare.

thanks!

Marcel