JRiver decodes DSD to 352.8kHz PCM.
When converting DSD to PCM MC converts to 1/8th of the original sample rate. 1xDSD (2.8MHz) converts to 352 KHz, 2x goes to 705 KHz, etc.
DoP does not convert to PCM, it simply uses the PCM file format. It packs the 0s and 1s in 16 of the 24 bits of a sample and then those are unpacked back to DSD by the DAC. The DoP format is 1/16th of the original sample rate, corresponding to the 16 bits. So, 1xDSD goes to 176 KHz DoP, 2xDSD goes to 352 KHz and so on.
For a 2.8 MHz DSD, a DoP representation is 176 KHz and a conversion to PCM by MC is 352 KHz.
If the DoP is 352 KHz, then the original must be 2xDSD (5.6 MHz).
Audio path will display what MC is doing - either packing into DoP or converting to PCM - and display the final sample rate.
For reference, DoP uses the 8 most significant bits of a 24 bit sample as a special code to identify that the is a DoP format, and it uses the other 16 bits for the 0s and 1s of the DSD file. The DAC sees the 8 MSBs and knows it is DoP and unpacks the other 16 bits into a DSD stream. The 8 MSBs were chosen to produce a low level white noise, in case the DAC does not recognizes the DoP marker. This avoids overly loud sound if the DAC does not recognize the DoP signal.