Hi, On 03/24/2017 07:33 PM, Ben Hilburn wrote: > - I wonder what would be the workflow when creating a SigMF recording. > An issue might be that you cannot immediately write the SigMF meta file > during recording. (For example, the hash has to be calculated after the > recording. Or the annotations have to be written after the capture > segments.). Did you plan to create the meta data in memory and write the > file when the flow graph shuts down (which might cause data loss when > you experience a segfault) or do you write meta data to disk in an > intermediate format that you have to post-process manually to create the > final SigMF files.
> > > So the SigMF spec is designed specifically to enable writing the > > metadata and dataset files in a streaming manner. > > Can annotations and capture segments be interleaved or how is it > possible to write the metadata in a streaming manner? > > > No, they cannot. If your capture details aren't changing (center > frequency, bandwidth, etc.,), then you can stream the annotations as > they are continuous, but you can't hop back and forth between them. But that means in all but the simples case the metadata cannot be written in a streaming manner. And worse, you cannot know in advance. If the SigMF sink wrote thousands of annotations and the SDR experiences an underrun, it creates a new segment and invalidates basically the whole file. So, AFAIS, we're back at the problem above, i.e., the sink needs a way to deal with that. Best, Bastian _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
