Transcoding DSD256 on Melco

[PJ4301]

Hello everyone,

I have been using MinimServer on Melco N1ZH/2 for almost two years and it has been working fine with my PS Audio DirectStream DAC and Bridge II network streaming module. My normal scenarios of usage are:

1. Melco USB out - Matrix X-SPDIF 2 USB Interface - I2S LVDS via HDMI - PS Audio DirectStream DAC. Control point is Melco HD App on iPad. Supported bitrate thru this chain is limited by DAC's DSD128 or PCM 24/352 via I2S.

2. Melco Ethernet out - Bridge II network streaming module - DAC. Control point is MConnect HD on iPad. Supported bitrate thru this chain is limited by Bridge II's DSD64 and 24/192.

Recently I got some DSD256 files so I tried MinimServer for transcoding DSD256 to PCM 24/352 so that it can be played via above scenario 1.

My music files are stored in Melco N1ZH/2 and other 2 Windows 10 PCs, all 3 machines are on same LAN. I then have MinimStreamer installed on all 3 machines. I also installed ffmpeg on Melco (using the package provided by MinimServer) and the other two Windows 10 PCs (doanloaded from web). Setup of stream.transcode is "dsf(>128):wav24".

It works fine on the two Windows 10 PCs. I use Melco as streamer to play files stored on Windows PC, with Melco HD App as control point. DSD256 files can be played smoothly, Melco HD App as control point shows WAV 24/352, and DAC shows PCM 24/352.

However the same is not working on Melco. I use Melco as streamer to play files stored on Melco, with Melco HD App as control point. When clicking the DSD256 files Melco HD App shows it's being played, with progressing bar moving and bitrate shown as WAV 24/352 (seems alright), but no sound is ever produced by the DAC, and from DAC it is shown as PCM 16/352. I tried modifying the output file setting:

dsf(>128):wav24
dsf(>128):wav24;352
dsf(>128):wav24;176
dsf(>128):wav24;88
dsf(>128):L24;176

All are the same. Appreciate if anyone can help me out here. Thanks!

Attached please find the log file.

[simoncn]

The Melco has a Marvell Armada 370 1.2 GHz single-core processor and this is not powerful enough to transcode DSD256 to PCM 24/352 in real time. There is nothing that MinimServer or MinimStreamer can do to overcome this hardware limitation. Your Windows 10 PCs have more powerful Intel processors that are able to handle this workload.

[PJ4301]

(18-07-2020 19:50)simoncn Wrote:  The Melco has a Marvell Armada 370 1.2 GHz single-core processor and this is not powerful enough to transcode DSD256 to PCM 24/352 in real time. There is nothing that MinimServer or MinimStreamer can do to overcome this hardware limitation. Your Windows 10 PCs have more powerful Intel processors that are able to handle this workload.

Thanks Simon for the quick response. It's a pitty that it's Melco's hardware limitation then seems nothing can be done except that I have to keep all my music files with higher bitrate than DSD128 on PC.

Thanks for the advice.

[simoncn]

The other option is to do offline conversion using a conversion utility. This takes more disk space but will probably sound better.

[PJ4301]

(19-07-2020 16:44)simoncn Wrote:  The other option is to do offline conversion using a conversion utility. This takes more disk space but will probably sound better.

Thanks. Yeah that’s worth a try. Not sure whether can do it with foobar. Any other conversion tools that you may suggest?

[GreenMtnGringo]

I was going to suggest the free Sonore DSD2FLAC utility, but it appears that it tops out at DSD128 on the input side:

http://sonore.us/dsd2flac.html

The other thing I wanted to mention is that I seem to recall reading some time ago on the PS Audio forum that PS Audio DirectStream DAC designer Ted Smith may have a potential future firmware update in the works that would make the DAC capable of decoding DSD256. You might want to do a search for DSD256 on that forum and see if there are any updates on that front.

[simoncn]

There are a number of suggestions on this page.