Linux-audio-user April 2003

linux-audio-user@lists.linuxaudio.org

129 participants
150 discussions

[linux-audio-user] Re: Latency with ALSA

by norbert_wolff＠t-online.de

On 01 Apr 2003 22:57:28 -0500 Nick <nicktsocanos(a)charter.net> wrote: > I am writing audio applications that are real-time. > I had been using Port Audio which is really very good, even without root > priviledges, it does a very good job. I want to support other sound > drivers, in case someone doesn't have Port Audio or can't get it to > work. > > I have just built my ALSA driver, it works ok, but I am getting terrible > latency problems and buffer underruns. The thing is it is a real-time > application, it must get audio to the card as soon as possible. Why is > it that OSS with Port Audio works so well, and my ALSA setup is > suffering? > > Is there something I need to do to ALSA to get near real-time > performance from it? I have heard people mention patching their kernel > for low latency. I have Jack but I have not started working with it yet. > Should I dump ALSA and just go for Jack? Is there something I need to do > to my kernel to get better performance? I would get Planet CCRMA if it > supported my OS, but it doesn't, so I have to tweak my box manually. High Nick ! At the moment there are two different approaches for low-latency in the linux-kernel. The first is from Ingo Molnar; it's quite simple but efficient (conditional scheduling at critical places). You can get it at http://people.redhat.com/mingo/lowlatency-patches/lowlatency-2.4.0-test7-A0 The second is made by Robert Love, it makes real heavy Changes in the Kernel which have a noticeable negative impact on overall System-througput, but the results are quite amazing ! The Patch is integrated int the 2.5-Kernel (CONFIG_PREEMPT), patches for 2.4 are available at ftp://ftp.kernel.org/pub/linux/kernel/people/rml/preempt-kernel/v2.4/ I use Robert's patch with the 2.5-Kernel since half a year without Problems; The interactive response of the Sytem under high loads is now MUCH better. Lacking real real-time Software i don't know if it helps there too. If the low-latency patches for the Kernel don't cure your Problem, consider testing a new 2.5.6x-Kernel; the scheduler was really improved in the last months ...

21 years, 8 months

[linux-audio-user] Re: Looking for a command-line/console mode program to.

by Roel de Wit

Hi, Thanks for quick the feedback.. Sox seems to come the closest to what I want such a program to do. --- Roel / Utopia Sound Division http://www.utopiasd.com

21 years, 8 months

[linux-audio-user] Latency with ALSA

by Nick

I am writing audio applications that are real-time. I had been using Port Audio which is really very good, even without root priviledges, it does a very good job. I want to support other sound drivers, in case someone doesn't have Port Audio or can't get it to work. I have just built my ALSA driver, it works ok, but I am getting terrible latency problems and buffer underruns. The thing is it is a real-time application, it must get audio to the card as soon as possible. Why is it that OSS with Port Audio works so well, and my ALSA setup is suffering? Even if I set the frame rate higher (the number of frames to the card) I still get buffer underruns. I am talking maybe 70 milliseconds now. This is sad, because I know with DirectX I can get about 35 ms timing with it on this machine.With ASIO I have done better than that. Even running as root and scheduling the app to real-time priority (50) I get buffer underruns. So, something must not be right with my setup. I have tried setting the frames written to all sorts of latencies, and it does reduce the drop outs, but I am still getting them. I tried buffering the sound and dropping it in blocks, but it wasn't working correctly. This is a bit disappointing so far. Is there something I need to do to ALSA to get near real-time performance from it? I have heard people mention patching their kernel for low latency. I have Jack but I have not started working with it yet. Should I dump ALSA and just go for Jack? Is there something I need to do to my kernel to get better performance? I would get Planet CCRMA if it supported my OS, but it doesn't, so I have to tweak my box manually. Thanks -- Nick <nicktsocanos(a)charter.net>

21 years, 8 months

[linux-audio-user] Looking for a command-line/console mode program to...

by Roel de Wit

Hi, I'm looking for a command-line/console mode program which is available for Linux and Windows which can resample samples (e.g. 48 Khz to 22 Khz) and to some 'equalizer' processing to those samples. The result should of course be written to the disc again. I'm looking for such a program for the use in the installer of a commercial set of piano instruments which we want to make available under windows and linux (currently only in the soundfont format, but the product isn't released yet). The program doesn't have to be free to use and I'm willing to pay for it's use as long as the price isn't above my budget (around 100 euros). --- Roel / Utopia Sound Division http://www.utopiasd.com

21 years, 8 months

[linux-audio-user] Mixing pro and consumer gear

by Ross Vandegrift

Hello all, I'm preemptivly asking a question that'll hopefully be put to good use this week. I found a nice deal on a Delta44 off Ebay the other night, and jumped on it. Can't wait until it shows up! However, I'd like to *add* it to my machine, and keep me SB Live for some stuff like everyday listening and perhaps some cheap output monitoring. I've had friends tell me this doesn't work in Windows because Windows will only record at the lowest-common-denominator capabilities of all cards in the system (ie, 16/44 in a system with an Delta44 and an SBLive). Is this an issue with either ALSA or OSS in Linux 2.4? Also, I know there are emu10k1 audio routing utilities, and I know there are envy24 audio routing utilities. Is there a way I can route audio between the two cards at all? -- Ross Vandegrift ross(a)willow.seitz.com A Pope has a Water Cannon. It is a Water Cannon. He fires Holy-Water from it. It is a Holy-Water Cannon. He Blesses it. It is a Holy Holy-Water Cannon. He Blesses the Hell out of it. It is a Wholly Holy Holy-Water Cannon. He has it pierced. It is a Holey Wholly Holy Holy-Water Cannon. He makes it official. It is a Canon Holey Wholly Holy Holy-Water Cannon. Batman and Robin arrive. He shoots them.

21 years, 8 months

[linux-audio-user] Firewire

by Cornell III, Howard M

Are Firewire implementations hot-swappable? Is the four- or six-wire implementation more typical?

21 years, 8 months

[linux-audio-user] Re: Needing help in resolving the Pd-Gem package linker problem

by norbert_wolff＠t-online.de

On Mon, 31 Mar 2003 22:59:35 -0500 Ivica Bukvic <ico(a)fuse.net> wrote: > I am trying to compile Gem from source (for Pd), and while it does compile > without any problems at runtime (pd -lib Gem) I get the following issue: > > /usr/lib/pd/extra/Gem.pd_linux: /usr/lib/pd/extra/Gem.pd_linux: undefined > symbol: __ctype_toupper_loc > /usr/lib/pd/extra/Gem: can't load library It seems that you have used the headers of an old glibc when compiling and try to run with a newer glibc. __ctype_toupper_loc was introduced in September 2002 glibc (don't know the version-number). Execute the file /lib/libc.so.6, it will tell you its version. I don't know a way to look up the Version of your installed Header-Files from glibc, maybe you can ask your Package-Manager. Anyway, your Headers and Librarys MUST match ! > I tried building the static version, but then I get the following error: > g++ -o Gem.pd_linux -L/usr/X11R6/lib -L../../../GemLibs/liborb ../Manips/*.o > ../Particles/*.o ../Base/*.o ../MarkEx/*.o ../Pixes/*.o ../Controls/*.o > ../Nongeos/*.o ../Geos/*.o ../openGL/*.o -shared -lquicktime -lmpeg3 -lorb > -lglib -lgltt -lttf -ljpeg -ltiff -lpng -lglut -lGLU -lGL -Wl,-Bstatic -lz > -lm -Wl,-shared -Wl,-export-dynamic -lXxf86vm -lXext -lX11 > /usr/bin/ld: cannot find -lgcc_s > collect2: ld returned 1 exit status Your gcc was configured with "--enable-shared" to use a shared libgcc (called libgcc_s; only used for C++), but can't find it. See below Also you dont really try to build the static version, as -shared -Wl,-shared -Wl,-export-dynamic shows. > I then checked > ld -lgcc_s > > And the only thing I got was: > ld: warning: cannot find entry symbol _start; not setting start address > Now, could someone please tell me what the heck does this mean??? You have invoked the linker ld, ist is used to link a prog, not to query dependencies > ldd /usr/lib/libgcc_s.so gives: > libc.so.6 => /lib/i686/libc.so.6 (0x4001a000) > /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000) You have the needed lgcc_s in a place where the linker normaly looks for it. But > /usr/bin/ld: cannot find -lgcc_s says, that he can't find it ? Very strange ... Try to alter the specs-file from your gcc, it should be in the syme location as libgcc.a (try gcc --print-libgcc-file-name). The specs file contains a line like *libgcc: -lgcc replace -lgcc with the following line "%{!shared:-lgcc} %{shared:/usr/lib/libgcc_s.so}" (only valid for gcc3, i don't know if older gcc's use the same Syntax !!) In case of an accident (the file is very sensible with spaces) you can reconstruct the original specfile with gcc -dumpspecs > specs; or simply delete the file, gcc has a copy of it built in. You my also have a look in the linker-scripts from ld, there location depends on the configuration binutils, search for elf_i386*. Then look if the SEARCH_DIR-Entrys includes "/usr/lib". But the best thing you could do to solve your Problem is to reinstall your glibc, glibc-devel, gcc, g++ and binutils-packages, when this does not not help, consider switching to another distribution ... Regards Norbert

21 years, 8 months

[linux-audio-user] iCubeX experiences?

by j.c.w.

greetings all! i am a bit of a controller freak and have just started looking into the iCubeX system (http://www.infusionsystems.com/index.shtml). i used to roll all of my own control devices, but i am a bit short on time as of late (full time jobs tend to do that). i'd like to give this thing a chance. i see that paul davis (you rock, dude) wrote a gnu/linux editor for the device that controls a limited subset of its features, but it looks like the software hasn't been touched for some time. i am interested in using it with pd primarily and possibly jmax. my question is this: does anyone out there have any experience to share with me re: using this gadget with gnu/linux /only/. i don't do windows at home, so i'd like to know what i can expect. anywho, enough of that...so, anyone know anything about this doo-dad? thanks! j.c.w.

21 years, 8 months

[linux-audio-user] Needing help in resolving the Pd-Gem package linker problem (and hopefully learn something in the process :-)

by Ivica Bukvic

Hi all, This is the issue I've been dealing with for the past couple of hours. I am using mostly vanilla Mdk 9.0. I am trying to compile Gem from source (for Pd), and while it does compile without any problems at runtime (pd -lib Gem) I get the following issue: /usr/lib/pd/extra/Gem.pd_linux: /usr/lib/pd/extra/Gem.pd_linux: undefined symbol: __ctype_toupper_loc /usr/lib/pd/extra/Gem: can't load library I've tracked this one to the gcc library (please correct me if I am wrong). However, there are no errors at compile time: g++ -o Gem.pd_linux -L/usr/X11R6/lib -L../../../GemLibs/liborb ../Manips/*.o ../Particles/*.o ../Base/*.o ../MarkEx/*.o ../Pixes/*.o ../Controls/*.o ../Nongeos/*.o ../Geos/*.o ../openGL/*.o -shared -lquicktime -lmpeg3 -lorb -lglib -lgltt -lttf -ljpeg -ltiff -lpng -lglut -lGLU -lGL -lz -lm -Wl,-shared -Wl,-export-dynamic -lXxf86vm -lXext -lX11 I also tried adding all over the place -lgcc like this: g++ -o Gem.pd_linux -L/usr/X11R6/lib -L../../../GemLibs/liborb ../Manips/*.o ../Particles/*.o ../Base/*.o ../MarkEx/*.o ../Pixes/*.o ../Controls/*.o ../Nongeos/*.o ../Geos/*.o ../openGL/*.o -shared -lgcc -lquicktime -lmpeg3 -lorb -lglib -lgltt -lttf -ljpeg -ltiff -lpng -lglut -lGLU -lGL -lz -lm -Wl,-shared -lgcc -Wl,-export-dynamic -lgcc -lXxf86vm -lXext -lX11 and the compile is successful, but I still keep getting the same error. I tried building the static version, but then I get the following error: g++ -o Gem.pd_linux -L/usr/X11R6/lib -L../../../GemLibs/liborb ../Manips/*.o ../Particles/*.o ../Base/*.o ../MarkEx/*.o ../Pixes/*.o ../Controls/*.o ../Nongeos/*.o ../Geos/*.o ../openGL/*.o -shared -lquicktime -lmpeg3 -lorb -lglib -lgltt -lttf -ljpeg -ltiff -lpng -lglut -lGLU -lGL -Wl,-Bstatic -lz -lm -Wl,-shared -Wl,-export-dynamic -lXxf86vm -lXext -lX11 /usr/bin/ld: cannot find -lgcc_s collect2: ld returned 1 exit status make: *** [Gem.pd_linux] Error 1 I then checked ld -lgcc_s And the only thing I got was: ld: warning: cannot find entry symbol _start; not setting start address Now, could someone please tell me what the heck does this mean??? ldd /usr/lib/libgcc_s.so gives: libc.so.6 => /lib/i686/libc.so.6 (0x4001a000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000) At this point, I am confused and do not know what to do. I tried upgrading ldconfig, ld, and am currently recompiling gcc from a cooker source (which is taking a lot of time). So, I would greatly appreciate any help I can get on this issue, since the whole idea of linking is not so clear to me. Finally, I would appreciate the explanation of -Bstatic flag which seems to invoke -lgcc_s that is subsequently not found for whatever reason, despite the fact the ld otherwise finds it (with the aforementioned warning though). Any help on this issue is greatly appreciated! Sincerely, Ico

21 years, 8 months

[linux-audio-user] Help with mixer/preamp config (OT?)

by Bryan Koschmann - GKT

Hello, I'm am sure this is off topic but I am desparately seeking help. I am trying to figure out how the mixer/preamp/input card will coincide with each other. If I have a card with 4 inputs (either midiman digital or SB lives), I will be needing preamps. I looked at the M-Audio Audio Buddy, which seems like it simply has 2 XLR inputs and 2 1/4" outputs. That part is straightforward and I understand. However, I was looking at mixers and I got lost. I looked at a Eurorack (cant remember which model) for around $170. It had 4 XLR inputs, and the box said it had 4 mic preamp inputs. But, how do the outputs work? I was looking for 4 1/4" jacks marked "output 1" "output 2" and so forth. Where am I lost? Please forgive me for asking such newbie questions. I simply do not know where else to turn. I've searched the net high and low and didn't find the answers. Thank you very much in advance, Bryan

21 years, 8 months

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Linux-audio-user April 2003