karsonkwan 發表於 2014-8-6 12:25 static/image/common/back.gif
睇黎MPD 對QNAP 網絡上既JITTER 都唔太高, buffer應可解決問題.
但係通常D人講緊CAS 最煩既JITTER 問題,...
of course.
karsonkwan 發表於 2014-8-6 12:25 static/image/common/back.gif
睇黎MPD 對QNAP 網絡上既JITTER 都唔太高, buffer應可解決問題.
但係通常D人講緊CAS 最煩既JITTER 問題,...
Yes，因為網絡頻寬 1Gb/s 比 USB 2.0 480Mb/s 頻寬大，所以降低 USB Host 的 jitter 比較重要。
較佳的接法有：
1) 一個host接一個device，因為其他devices會share頻寬。
2) USB線越短越好，少些干擾。
3) 可以的話使用獨立USB供電，小弟相信大家都明白電的重要性。
Software方面，小弟相信玩開Linux會明白：
1) 增加 player 和 IRQ 的 priorities。
2) 增加 network buffer。
3) 減少 alsa buffer。
4) 可以的話用 RT Kernel。
jackt 發表於 2014-8-6 14:24 static/image/common/back.gif
Yes，因為網絡頻寬 1Gb/s 比 USB 2.0 480Mb/s 頻寬大，所以降低 USB Host 的 jitter 比較重要。
較佳的 ...
獨立USB供電係咩意思？alsa buffer 係邊到set 呀師兄，減到幾多？
karsonkwan 發表於 2014-8-7 05:40 static/image/common/back.gif
獨立USB供電係咩意思？alsa buffer 係邊到set 呀師兄，減到幾多？
因為小弟用 squeezelite，舉例說明如下：
https://code.google.com/p/squeezelite/
Squeezelite v1.6.3, Copyright 2012-2014 Adrian Smith. See -t for license terms
Usage: ./squeezelite
-s <server>[:<port>]Connect to specified server, otherwise uses autodiscovery to find server
-o <output device> Specify output device, default "default", - = output to stdout
-l List output devices
-a <b>:<p>:<f>:<m> Specify ALSA params to open output device, b = buffer time in ms or size in bytes, p = period count or size in bytes, f sample format (16|24|24_3|32), m = use mmap (0|1)
-a <f> Specify sample format (16|24|32) of output file when using -o - to output samples to stdout (interleaved little endian only)
-b <stream>:<output>Specify internal Stream and Output buffer sizes in Kbytes
-c <codec1>,<codec2>Restrict codecs to those specified, otherwise load all available codecs; known codecs: flac,pcm,mp3,ogg,aac,wma,alac,dsd (mad,mpg for specific mp3 codec)
-d <log>=<level> Set logging level, logs: all|slimproto|stream|decode|output, level: info|debug|sdebug
-e <codec1>,<codec2>Explicitly exclude native support of one or more codecs; known codecs: flac,pcm,mp3,ogg,aac,wma,alac,dsd (mad,mpg for specific mp3 codec)
-f <logfile> Write debug to logfile
-m <mac addr> Set mac address, format: ab:cd:ef:12:34:56
-n <name> Set the player name
-N <filename> Store player name in filename to allow server defined name changes to be shared between servers (not supported with -n)
-p <priority> Set real time priority of output thread (1-99)
-r <rates>[:<delay>]Sample rates supported, allows output to be off when squeezelite is started; rates = <maxrate>|<minrate>-<maxrate>|<rate1>,<rate2>,<rate3>; delay = optional delay switching rates in ms
-R -u Resample, params = <recipe>:<flags>:<attenuation>:<precision>:<passband_end>:<stopband_start>:<phase_response>,
recipe = (v|h|m|l|q)(L|I|M)(s) , E = exception - resample only if native rate not supported, X = async - resample to max rate for device, otherwise to max sync rate
flags = num in hex,
attenuation = attenuation in dB to apply (default is -1db if not explicitly set),
precision = number of bits precision (NB. HQ = 20. VHQ = 28),
passband_end = number in percent (0dB pt. bandwidth to preserve. nyquist = 100%),
stopband_start = number in percent (Aliasing/imaging control. > passband_end),
phase_response = 0-100 (0 = minimum / 50 = linear / 100 = maximum)
-D Output device supports DSD over PCM (DoP), delay = optional delay switching between PCM and DoP in ms
-v Visualiser support
-z Daemonize
-t License terms
Build options: LINUX ALSA EVENTFD RESAMPLE FFMPEG VISEXPORT DSD
-a 可以設定ALSA使用的buffer，
-b 可以設定 network buffer。
小弟的設定如下：/bin/nice --20 /root/squeezelite-mips-ar71xx -o hw:0,0 -a 4096:1024:32:1 -m `ifconfig eth1 | grep HWaddr | awk '{print $5}'` -n `cat /proc/sys/kernel/hostname` -D -d all=info -z獨立USB供電，可用內置或外置形式，例如 http://sotm-audio.com/english/products/tx-usbexp.php
http://ifi-audio.com/portfolio-view/micro-iusbpower/
本帖最後由 karsonkwan 於 2014-8-7 11:07 編輯
jackt 發表於 2014-8-7 10:19 static/image/common/back.gif
因為小弟用 squeezelite，舉例說明如下：
https://code.google.com/p/squeezelite/
Thanks 師兄，參考下你setting 先。
iUSB Power 買左冇幾耐啦。。。岩岩先係另一個post 討論緊，多隻香爐多隻鬼，唔多唔小都會唔見左D野。。。
但係又有人覺得有用。。。相信係比較低階DAC 效果會好D, 但都會Cut 頻。高階DAC 相信係可以做既野佢都做晒，Sotm 先前都有留意。。。
http://post76.hk/forum.php?mod=viewthread&tid=183564&extra=&page=1
本帖最後由 karsonkwan 於 2014-8-7 23:47 編輯
jackt 發表於 2014-8-7 10:19 static/image/common/back.gif
因為小弟用 squeezelite，舉例說明如下：
https://code.google.com/p/squeezelite/
audio_output {
type "alsa"
name "dCS Paganini PCP Audio 2"
device "hw:0,0"
auto_resample "no"
mixer_type "software"
# format "44100:16:2" optional
# mixer_device "default" optional
# mixer_control "PCM" optional
# mixer_index "0" optional
dsd_usb "yes"
呢個係我ALSA Config, 師兄有咩建議? 係咪好似冇左buffer_time "XXXXXX"
PhantomGTR 發表於 2014-8-5 16:12 static/image/common/back.gif
Replacing mpd:呢段 for voyage mpd kit 2.0 only.
Replacing with Japanese RT kernel in Kit 2.0:Then...
root@voyage:~# uname -a
Linux voyage 3.14.12-rt9-40719d #4 SMP PREEMPT RT Sun Jul 20 01:31:21 JST 2014 i686 GNU/Linux
Update 完Kernel mount 唔到個NAS {:6_123:}
root@voyage:~# mount -a
mount error: cifs filesystem not supported by the system
mount error(19): No such device
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)
本帖最後由 karsonkwan 於 2014-8-8 05:48 編輯
算啦...用NFS...
冇啦啦比GTR兄點我攪獲金{:6_136:} ...
karsonkwan 發表於 2014-8-8 04:51 static/image/common/back.gif
root@voyage:~# uname -a
Linux voyage 3.14.12-rt9-40719d #4 SMP PREEMPT RT Sun Jul 20 01:31:21 JST...
You need lot of drivers to support CIFS.
karsonkwan 發表於 2014-8-8 05:41 static/image/common/back.gif
算啦...用NFS...
冇啦啦比GTR兄點我攪獲金 ...
{:6_136:}{:6_136:}
(Post76 Android 手機版送出)
