Commit Graph

3 Commits

Author SHA1 Message Date
Denny
341e740e77 [WIP] updated the 2 channel synthesizer to use a more SIMD friendly
filter structure.  Updated the channel results array buffer to produce
reusable buffers.

This has dropped the overall memory usage considerably when profiling.

Resolved issue in the processing chain where polyphase channel sources
were not being stopped and were stacking up in memory.
2018-05-10 08:08:20 -04:00
Denny
e395d737f8 [WIP]-39 updates to resolve issue with stopping channel streams. 2018-04-22 04:44:35 -04:00
Denny
e971ad4582 39 [WIP] - restructured the polyphase filter process. Previous version
was not computationally feasible with my 3rd Gen i7 processor running
and airspy at 10 MHz.  Restructured the polyphase channelizer to use
vector iteration structures that the JDK 9 JIT compiler can translate
into SIMD instructions.  Separated the IFFT processing from the filter
process so that they can be executed on separate threads and this allows
the processing to occur real time.

P25 C4FM decoding at 25 kHz channel sample rate using an airspy
10MHz sample stream seems to be working nicely with ~25% CPU usage and
~300 to 500 MB memory usage.  Incremental (parallel) channel decoding
should have a minimal increase in CPU loading since all of the 12.5 kHz
channels are available in the polyphase channelizer and the only
additional workload is the decoding of the 25 kHz sample stream.

There is still an issue with stopping channels and the channelizer keeps
 processing, and occasionally when starting traffic channels something
 deadlocks and causes out of memory.
2018-04-15 09:05:06 -04:00