>> > So how come that you don't get 'em with mpd?! >> >> In mpd I specify oss instead of alsa. If I specify alsa and involve >> dmix, I get static in mpd too. > > you say OSS... but was that the "real" oss (does it still exist for > modern kernels/hardware?!) or was it just the ALSA oss emulation? > > If it's the latter (as usually is on modern systems), then its just > the input interface that changes, you're goin' trough ALSA anyway. > > On the other end, if it really was the former (real OSS stack), then > likely you have a problem with mixed+conflicting drivers... ALSA and > "real" OSS can NOT coexist on a system. I don't have real OSS compiled into the kernel but I do have ALSA and the ALSA OSS emulation. When I switch mplayer to OSS, the static disappears. When I go back to ALSA with mplayer, the static returns. I have the exact same experience with mpd. So I think that's a big clue. What it means, I'm not sure. >> > again, I believe that your problem is completely unrelated to the >> > resampling algorithm used. > [...] >> Well, there is a blog post under "A little hint for hda ALSA users" which says: >> >> "if you own an hda-based soundcard and you head crackling sound while >> playing mp3s or similar, the problem is probably due to the bad >> samplerate conversion from 44100 to 48000." > > Sorry, I won't believe that. AFAIK ALSA is a "layered" stack where > higher level "functions" such as dmix and resampling are implemented > in their own layer which is "sitting on top" of the lover level ones > (such as hardware drivers). > Obviously the higher level functions are not implemented within the > hardware-specific low level drivers and -AFAIK- they remain the same > whatever low level driver is in use. So how/why something like any > given ALSA resampling algorithm could work differently when paired > with different hardware? > > BTW, on my HTPC (which by chance is the machine I'm on now) I have > an Intel DP35DP. That have an ICH9 HD Audio Controller. Which I use > when playing to the HDTV own speakers (rather than the HiFi system, > for which as said I use a Juli@). > > Needless to say, it works perfectly with any resampling algorithm, > using either analog or digital outputs at whatever sampling rate. > > I also have an old laptop with ICH4, my office desktop which have > ICH5, another laptop with ICH7, ... not counting the large number > of other Linux machines I manage at work. I believe I can say to > have seen quite some different hardware/software combinations. In > some 10+ years of Linux system management I have had troubles with > unsupported hardware, incomplete and/or broken drivers, etc, but > have never experienced "static" noise or otherwise broken audio > due to poor resampling using the default ALSA config. > > On the other end, your referenced blog says explicitely: > >> http://blog.flameeyes.eu/tag/alsa/page/2 >> >> "although I admit I haven’t tried it first hand, as I don’t have any hda-based soundcard beside the laptop" > > who should I believe? my own experience or his 2nd hand > rumors? ;-) > >> > Only once you've got the default config to work properly you may start >> > experimenting with more sophisticated options. >> >> That sounds good, but what else can I try? > > what I'd do as a first step is trying to get your own > distribution / installation / customizations out of the > mix. > > So get some proven Live CD/DVD (NOT Gentoo-based!) and > try with those. I'd try with Ubuntu 9.04, then perhaps > Mandriva 2009, good old Knoppix, etc. > > Try to get systems with several different kernel/alsa > version combinations, and report what happen... maybe > it'll turn out that you'll have to file a bug report. OK, I'll try a Live CD. - Grant ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
