marcoc1712 wrote: > LMS via C-3PO plugin is sending DSF or DFF to the player. > But how do you know which? I mean... if you resample to DSD you have to know the output format, don't you? Is that normally DSF then?
> > They are not LMS native" they are so called "native", probably starting > by steinberg people talking abiut ASIO formats. > Sorry, typo. Meant to say "native DSD". > > No, sorry, The only documentation I was able to find is the one i > pointed to you AND the code by daphile patches that you could find in my > repo in gitHub. > I'm lookig for some better spec for ASIO formats to be used with PA. > > > > > > > maybe you could try a search over the XMOS documentation: > > https://www.xmos.com/search/content?term=DSD. > > > > > I _think_ I have been through all of these but will look again. > > > > > > > header: I was talking about header, but is non a 'real' header, is the > > way the device is opened by ALSA, see output_alsa.c > > > > > But that's all PCM. > It assumes the DSD bitstream is already packaged as PCM and then > selects the applicable PCM format to open ALSA and send. It doesn't > know anything about DSD. > > If I know all this I can probably do the same, but what I'd like to do > is to understand the stream and then either send it directly to USB or > resample to PCM if I have to use the built-in DAC (e.g. if headphones > are connected). So I need to understand I'm getting DSD and what > format it is in and all of that. > > Here are my topics: > > > > - For the life of me I can't get my DSD DAC to recognize DSD input > when connected to any iThingy. Not with my App, not with Onkyo one > (which claims to be able to do this but is still an iOS 6 app). Not > with DoP, not with native. All of that works fine with the DAC > connected to a Raspberry Pi. - I'm especially concerned that not even DoP works. I mean... This > is being generated server-side and I don't touch it yet the DAC > interprets it as high-sample-rate PCM. No idea whether iOS touches > the data but I wouldn't know how and why. - What I want to do is be able to announce DSD as a player > capability and just send it to a USB device. - But if no USB device is connected (this can switch on the fly in > iOS, if you e.g. pull out the cable), I need to switch to PCM. I > could ever re-announce the player to the server without the DSD > capability but that would probably reset all the playback. If I > understand the whole thing I could just as well re-sample to PCM. > > > > > > > > > > See how Squeezelite pack the data into pcm formats. > > > > > I didn't find any code for this. Do you have a pointer? To me it looks > like it just sends the data it gets from the server to ALSA. > > > > > > > No, there is nothing 'ready made', we have sample implementation that > > works and we could adapt them to work in our application too. I was > > lucky that Daphile produced the patch to be applied to squeezelite in > > ALSA, then I've to find out the way with ASIO. > > > > > So if it's not ready-made then you have to have implemented it > yourself :) So you should know what format you implemented, shouldn't > you? > Or did Kimmo do all this? I'll ask him, too, I have already > implemented a ton of Daphile support, this feature is actually > supposed to go along with that. > > > > > > > Is not like that, it wrap and pack DSD data into pcm frames, using > > different formats (one of them is DOP) , depending on capabilities of > > the audio device. > > > > > Hm, so SqueezeLite gets the capabilities from the audio device? > Maybe I have to look closer at SqueezeLite but I didn't find any code > that re-packages DSD into PCM, I only found (3rd party) code that > re-samples DSD into PCM. > > > > > > > It's just an open source work that Triode included in squeezelite AND > > dsdPlay plugin long time ago. No needs to reinvent the wheel here, but I > > preffer NOT to send DSD to squeezelite and let it convert back to PCM. > > Since it knows what codecs the dac is capable and with slimpropo it > > retunrs this info to LMS, C-3PO disable dsd output for that player, so > > conversion - if needed -is applied server side. > > > > > Yes, I know, that's what I'd use, too, if I have to, it's an MIT > license so that works ("open source" might also mean GPL which would > prevent it from being usable on iOS, GPL forbids that). > > > > > > > It' easy, source code is there and completely open, too bad is not like > > that with ASIO or others. > > > > > Where? That's what I'm asking for all the time, for the life of me I > can't find it. > There doesn't seem to be any specification of what format these > "native" DSD streams are actually sent in to the DAC. Sorry, might > just be just me being dumb but I don't find it. > And I've asked on this forum half a dozen times in different places > and didn't get a pointer as well. > > > > > > > Can't help here, but have a look to the XMOS site, they claims support > > for iOs for their interfaces and have a development platform. > > > > > What they say is that they have MFI support. > I do have the MFI specs but what that means is only that a vendor > using their chipset can tell iOS what formats are supported and how > they can do this. It doesn't say anything about how the actual formats > work or how you select the correct mode on the DAC side. > Maybe I have to ask them. > > > > > > > BTW, Somehow the device should be opened, this is normally done by > > drivers call from applications via sound system (or operating system), > > don't know nothing about iOs, but how it open and talk with the sound > > device?> > > No idea, this is all hidden from the application layer. They will > surely have a driver (actually I could look that up in the MFI specs > but it doesn't really help because it doesn't tell me what happens on > the application side). > I can only see "output routes" with certain capabilities and one of > them indeed is raw USB audio output but if I use that I have to > understand what to send. iOS doesn't know DSD or DoP so you have to do > all that on top of the transparent raw data channel and you can't > directly select a USB mode or send USB commands or something. --- learn more about iPeng, the iPhone and iPad remote for the Squeezebox and Logitech UE Smart Radio as well as iPeng Party, the free Party-App, at penguinlovesmusic.com *New: iPeng 9, the Universal App for iPhone, iPad and Apple Watch* ------------------------------------------------------------------------ pippin's Profile: http://forums.slimdevices.com/member.php?userid=13777 View this thread: http://forums.slimdevices.com/showthread.php?t=106956 _______________________________________________ Squeezecenter mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/squeezecenter
