To be specific, in MC 27 for sending to the DLNA bridge:
What are the upsampling options, if any, for 44.1/16 files?
What are the upsampling options, if any, for DSD 64 files?
Are there options for converting PCM files to DSD?
You can upsample 44.1/16 to 48, 88, 96, 176, 192, 352, 384, 705, 768 and to 1x, 2x, 4x, 8x DSD with the caveat that upsampling to DSD is dependent on the speed of our CPU. DSD can be DoP or native, except that 8x is, I believe, native only.
DSD 64 can be upsampled to 2x,4x, 8x DSD but that process goes through a PCM intermediate state and is cpu intensive.
PCM can be upsampled to DSD - see above.
DSD can be converted to PCM , with the caveat that the low pass filters are at 24 Khz and 48 dB/octave, and 30 or 50 Khz and 24 dB/octave, although other filters can be set using DSP options. You may have to set your own filters with DSPs for DLNA. I am not sure if the standard filters can be applied for DLNA. The original PCM sample rate on conversion is 1/8th the original DSD sample rate and can be be upsampled or downsampled from there.
Note than "on the fly" convertion to DSD is an all or nothing setting. Everything gets upsampled to the set DSD sample rate. You can upsample PCM files based on their initial sample rate.
You can also selectively convert any files to any supported format by creating a new file, that can then be output through DNLA.