Programming :: Alsa C API, Usage Of Function _snd_pcm_file_open()?
Feb 8, 2011
I had a look at the Spotify C API, and found that they were using the following code to output music from Spotify: snd_pcm_open(&h, dev, SND_PCM_STREAM_PLAYBACK, 0).
I want use this function instead: int _snd_pcm_file_open(snd_pcm_t **pcmp, const char *name, snd_config_t *root, snd_config_t *conf, snd_pcm_stream_t stream, int mode)The function is found here: http://www.alsa-project.org/alsa-doc...92e16f8abdc60a I'm not able to find anything in the documentation explaining what the two parameters snd_config_t *root and snd_config_t *conf is. What I'm trying to achieve is to write the stream to a file, and then read it from another application. But it would be even better if I could get the stream returned directly from the C application.
ive finaly set up upmixing on my X-Fi (fedora 12) but now i can hear 6 channel sound in XMMS player, Mplayer but not Rhythmbox. On some forum i found that rhythmbox is using Gstream config, where i can find it in Fedora 12 and how can i make rhythmbox use my alsa 20to51 mod ?
OSS, even though it's emulated *through* ALSA, consumes a microscopic fraction of straight ALSA's CPU usage. For example, when I'm playing something through ALSA with XMMS2, I'm getting about 25-30% CPU usage, but with OSS output, only 2%, tops. The same applies to any other application in which I can choose the output method. And, I'm on 10.04.
I am doing some Linux kernel programming for my research project. I need to record the timestamp (by using cpuid and rdtsc) when an interrupt handler (top half) is first invoked. Due to the time critical nature of the problem itself, I have to do the timestamping inside the interrupt handler itself (the first operation when the handler is called). However, I understand that tasks that are not so time critical should be deferred to a tasklet function (bottom half) for processing because other interrupts are disabled in a (top-half) interrupt handler. I am currently out of idea on how I can pass the timestamp information that I have obtained in the interrupt handler to the corresponding tasklet function.
I'm running 9.10. I was installing ALSA so that I could run my EMU 1616, and when I tried to go through the steps to install, I'm running into two errors that I've noticed so far. I think. Anyway, the first is that is states that the panelw library isn't there, and that alsamixer: function snd_ctl_open failed for default: No such device or address. The alsamixer one is really odd, since it's there, but I don't know why it won't run.
I initially had it running, and now it isn't. I've yet to get sound out of my EMU. the terminal window also tells me that it can't find the snd_emu file, even though it exists on the computer as well. I need an answer for a dummy.
I looked on the net for such function or example and didin't find anything, thus after having made one i guess it would be legitimate to drop it to see what others thinks of it.
#!/bin/bash addelementtoarray() { local arrayname=$1
fit a surface i.e. W(x,y) using svdfit() provided by "Numerical Recipes in C". svdfit() is written for curve fitting and not for surface fitting.But one can use svdfit(), as claimed by authors of NR book, to do surface fitting. On page 680 of NR book, authors have given a hint on how to use svdfit() for fitting a surface. But I have not understood it.This link may be helpful (Chapter 15 th is relevant here.):[URL]This is my problem:
Code: I have a set of 100 numbers. I want to fit a 2-Dimensional function W(x,y) to these numbers.
I've worked out how to get ALSA libasound code working for an application. However I can't workout how to get multiple sounds working at once. I can't seem to find any google examples of mutiple sounds. EG tune plays while pressing buttons makes clicks. I'm using an embedded board so need to use ALSA not an addon e.g. sdlmixer, jack, etc.
I have recently been forced to do a hardware upgrade (my previous mobo died). Now, sounds works ok with,amarok because kde has recognized the new hardware and switched to it.
..... does not work, likely because flash uses alsa-oss which is probably not configured automatically. I have tried uninstalling and reinstalling both alsa-oss and flash, but it didn't solve the problem.
I have a question about calling an asm function from C....It doesn't work unless I create an asm variable to hold the value of the function in....Why?Here's the code that doesn't work...
asmfile.s - version one Code: .section .data mydata: .ascii "this is the message! .equ mylen, . - mydata
I want to use backtrace() function to debug a crash issue. I tried this sample code to see how backtrace works. backtrace() function always returns 0 with the below code. Is there any kernel configuration that needs to be set for proper working of backtrace?
#include <execinfo.h> #include <stdio.h> #include <stdlib.h> /* Obtain a backtrace and print it to stdout. */ void print_trace (void)
Can you offer me the code about fmod() in C. I want to know how this function work, i am very interested in it because i have no idea to implement it, i want to know... how to write the function... not 'how to use the function' can anyone post the source codes of this function here?
i have an open source application that was developed in C++ (it uses objects and namespaces all over the place). I also have another application that was developed in C. Now i am trying to insert the code made in C into C++ application, but when i do that , i get this error on compilation of the source code:
Code: error: 'mpi_init_vars' was not declared in this scope the function mpi_init_vars() is not part of object oriented programming and it doesn't belong to any scope, it was compiled into an object file and i am linking it with all objects of C++ application.
How can invoke the C function from C++ object oriented code?
Code: #!/bin/sh #System commands and other configurable. IPT=/sbin/iptables IP6T=/sbin/ip6tables IPST=/usr/sbin/ipset MODP=/sbin/modprobe GET=/usr/bin/wget INT_NET=192.168.1.0/24 .....
I can find lots of tutorials in how to use if, then, else. However, how do I define a variable inside the function? SEE>> Code: for c in $ISO Also, am I using the 'test' command correctly( -/+ week as valid test)?
I am doing a web site program and what I need is to call a C program in the PHP cloud.Do u think it would be possible? The web site would get the user input from PHP UI and pass to the C program , the C program would process the function with the user input and output the a PHP page.
Code: return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG); What is the above function returning.I am not clear with definition of what is being returned in the above code.
i want to compile function c in java and compile library is success.. when i call the library in java and error is :
Exception in thread "main" java.lang.UnsatisfiedLinkError: no libfunc.so in java.library.path at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1689) at java.lang.Runtime.loadLibrary0(Runtime.java:823) at java.lang.System.loadLibrary(System.java:1028)
I'm having trouble getting ALSA to play multiple sound streams (multiple sounds at once). My code is running on an embedded ARM board using a AC97 sound. It will only play one without any mixing, I have to use pure ALSA as higher sound mixers are a nightmare to cross compile for ARM. I've tested my system with aplay for example
aplay -D plughw:0,1 bang.wav
works fine. So I tried dmix with
aplay -D plug:dmix Win.wav
That gave the following error
ALSA lib pcm_direct.c:1587snd_pcm_direct_parse_open_conf) The field ipc_gid must be a valid group (create group audio) aplay: main:550: audio open error: Invalid argument
I checked asound with
/etc # cat asound.conf pcm.EP93XX { type hw
[code]....
Does this mean dmix will not work? Is there someway with the above setup I can play multiple sounds? I have to use the vendor ALSA build (so can't update ALSA), I can change the .confs however. Also because I'm cross compiling things like pulseaudio SDL are very difficult to get working, so I basically need to use the above ALSA. Is there anyway I can find if dmix exists on the system?
Should add aplay -L does show dmix ? iec958 'cards.pcm.iec958' spdif 'cards.pcm.iec958'
i am programming to get a real number to show real-time system bandwidth used ? that mean the bandwidth used at the time my fuction running? am using C language to do that. so help me please!
I tried to make a (very simple) function to put in my .bashrc file to make a local backup of a file, but when I call the function and try to use tab completion I get the following error: Code: cp: cannot stat `help': No such file or directory The function I added is as follows:
Code: function bk { cp -f --backup=numbered ${1} ${1}.bak
