Required: 'use_mmap' resurrection for DLNA/UPnP play

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Required: 'use_mmap' resurrection for DLNA/UPnP play

Postby pinkgold » August 26th, 2017, 5:02 am

Some XMOS USB DACs, such as Chord QBD76 series, don't play DoP source with DLNA (UPNP with upmpdcli) if 'use_mmap' option disabled.

And in case of using DLNA Media Server such as JRiver and foobar2000 + upmpdcli + MPD, wrong information sent to DAC from MPD also without 'use_mmap' enabled, only noise played when playing 24bit music source.

So I suggest resurrection of 'use_mmap' option.

Here is some hw_params of each case:

* case #1: only noise played with all music source
RW_INTERLEAVED
format: S32_LE
subformat: STD
channels: 2
rate: 96000 (96000/1) # and all other rates
period_size: 2048
buffer_size: 8192

* case #2: no error with all music source
access: MMAP_INTERLEAVED
format: S32_LE
subformat: STD
channels: 2
rate: 44100 (44100/1) # and all other rates
period_size: 2048
buffer_size: 8192

On every cases, only difference between noise played and no error was 'RW_INTERLEAVED' and 'MMAP_INTERLEAVED'.

So I tried to downgrade my MPD from 0.20 to 0.19 and add 'use_mmap' enabled, then 'MMAP_INTERLEAVED' sent to DAC for all music sources and noise gone. no errors.

Please resurrect 'use_mmap' option.
pinkgold
 
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Joined: August 26th, 2017, 4:42 am

Re: Required: 'use_mmap' resurrection for DLNA/UPnP play

Postby max » August 28th, 2017, 7:08 am

No. What you see is probably a driver bug, and that bug must be fixed. MPD is the wrong place to do this.
max
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Re: Required: 'use_mmap' resurrection for DLNA/UPnP play

Postby pinkgold » August 28th, 2017, 10:22 am

max wrote:No. What you see is probably a driver bug, and that bug must be fixed. MPD is the wrong place to do this.


Thanks for fast reply :D

Then I should find the builder of /usr/lib/modules/4.4.84-1-ARCH/kernel/sound/usb/hiface/snd-usb-hiface.ko.gz

and ask him to correct the source.

Good to hear it's not MPD's fault.
pinkgold
 
Posts: 2
Joined: August 26th, 2017, 4:42 am

Re: Required: 'use_mmap' resurrection for DLNA/UPnP play

Postby max » August 28th, 2017, 11:35 am

If you use such an old kernel version, there's no point in asking anybody to do something. First you should upgrade to the latest kernel to check if it's already fixed.
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