ALSA: snd_pcm_hw_params() failure - Invalid argument I am working on a ALSA project, and I have a TV tunner card plugged intot the PCI interface. Allows downmixing sound from 4-6 channels to 2 channel stereo output. I try to capture the audio from the tunner card, and the followings are the code:. Alsa-lib API pretend to be an alsa device and provide a name for caller to open. 8Kz and 384KHz sample rate. I've tried to create links /dev/audio -> /dev/audio1 and even renamed it but it didn't help. PCM data flow through FIFO to ALSA In SHARED mode, a timing model is also used, but it lives in the AAudioService. 6 kernels, thereby replacing OSS ( Open Sound System ), which was used in the 2. alsaloop supports multiple soundcards, adaptive clock synchronization, adaptive rate resampling using the samplerate library (if available in the system). The Advanced Linux Sound Architecture (ALSA) is the standard audio API of Linux as of kernel version 2. SND_PCM_FORMAT_DSD_U16_LE, As the parameters stand, the query is performed only to the hw PCM devices, not the abstracted PCM object in alsa-lib. It does not provide the advanced features (such as timer-based scheduling and network audio) of PulseAudio. So here we are on the final chapter of the ALSA driver series. Building & installing the ALSA loopback device under Ubuntu The ALSA Loopback sound card is a virtual soundcard that is created once the ALSA kernel module snd-aloop is loaded. \par Latency measuring tool \par: alsa-lib/test/latency. Configuring ALSA Audio output on Analog and HDMI of Raspberry Pi Here I dump sequence of commands I used to get audio working in Raspberry Pi B Model with the help of guides referred at end of post. First we need to check if alsa had recognized and our sound. I'm trying to programm with alsa libraries and I got some code from an article that introduces to alsa programming. This page describes the few steps needed to install and use ALSA (the Advanced Linux Sound Architecture) with Red Hat Linux or Fedora. Add SNDRV_PCM_RATE_352800 and SNDRV_PCM_RATE_384000 defines to pcm. Configuring ALSA Audio output on Analog and HDMI of Raspberry Pi Here I dump sequence of commands I used to get audio working in Raspberry Pi B Model with the help of guides referred at end of post. c example shows the measuring of minimal latency between capture and playback devices. front" to "pcm. pcm "spdif" slave. Package alsa-base. c:7843:(snd_pcm_recover) underrun occurred If I set speakers to default output, then sound works properly and I can even switch the output over to headset after starting applications from PlayOnLinux. The ALSA library provides a level of abstraction, such as the PCM and control abstractions, over the audio devices provided by the kernel modules. What's more, it's thread-safe, works well with SMP machines, and is backward-compatible with OSS/Free (using OSS emulation module). The simpler approach has its drawbacks: if an application stops playing audio, it will disappear from the JACK world, which can be quite inconvenient. Settings for other chip sets will vary, see Alsa-Project for more examples. alsaloop supports multiple soundcards, adaptive clock synchronization, adaptive rate resampling using the samplerate library (if available in the system). Each PCM device in all cards in the system has a procfs directory like this, where X is the card index number (such as from /proc/asound/cards) and Y in the PCM device index (such as from /proc/asound/pcm). Writing an ALSA driver: PCM Hardware Description Welcome to the fourth installment in my "Writing an ALSA Driver" series. If recording with interleaved mode samples the file is automatically split before the 2GB filesize. As in the ALSA PCM case, a core set of routines is exposed; 93 each driver implementer will have to write support for a set of 94 mandatory routines and possibly make use of optional ones. Linux でサウンド関係のプログラムを開発する際に必須になる ALSA のバッファについて書きます。単にゲームを作る程度であれば互換性や利便性を考えて SDL 等の上位のライブラリを使うべきだと思いますが、特にライブ音源やボイスチャット等、タイミングが要求される物を開発する際に必要に. I am trying to combine multiple streams (8 streams ) of audio (PCM -48Kz,16bit,2ch), in IMX8. For Die hard Audiophiles, this resampling is a real source of irritation as CD audio is made using PCM at 44. pcm "hw:0,0" slave. In console: You will receive a lot of warnings saying ALSA lib pcm. c:7843:(snd_pcm_recover) underrun occurred If I set speakers to default output, then sound works properly and I can even switch the output over to headset after starting applications from PlayOnLinux. Alsa-lib API pretend to be an alsa device and provide a name for caller to open. PCM data flow through FIFO to ALSA In SHARED mode, a timing model is also used, but it lives in the AAudioService. How to select an ALSA sound card and have concurrent, simultaneus playback using dmix This blog post is tutorial which describes how to select a default sound card and run multiple playbacks simultaneously, using ALSA on Linux, without a sound server. The ALSA Library package contains the ALSA library used by programs (for instance alsa-utils programs) requiring an access to the ALSA sound interface. c example shows various transfer methods for the playback direction. It does not provide the advanced features (such as timer-based scheduling and network audio) of PulseAudio. 6 AlsaBuildConfig AlsaCVS AlsaFeatures AlsaFixing AlsaGlossary AlsaKar AlsaKernel AlsaMidi. The previous trial on skypekit audio ([SKYPEKIT][DM368][IPNC] Audio PCM Experiment on DM368-IPNC) was using OSS (/dev/dsp) for Audio PCM host input and output voice. 表示设备overrun(capture)或者underrun(playback). The actual state can be determined using snd_pcm_state() call. On chipsets without PD/ELD support, ALSA assumes that the monitor supports any and all audio features, not just basic audio. " Alsa asound. pcm format and i can't play it. This page describes the few steps needed to install and use ALSA (the Advanced Linux Sound Architecture) with Red Hat Linux or Fedora. ALSA stands for the Advanced Linux Sound Architecture. Well the first thing I would do would be to fix your buffer sizes. They can then use those ALSA drivers for high level. Essentially, hardware expects a certain datatype for the sound sample, and you're providing the wrong one. alsa-lib/test/latency. 6 kernels, thereby replacing OSS ( Open Sound System ), which was used in the 2. Enabling Equalizer on Raspberry Pi using ALSA equal Plugin Posted on May 4, 2018 by max This post shows how to setup a system wide equalizer on Raspberry Pi using ALSA equal plugin. ALSA - Advanced Linux Sound Architecture ALSA utils contains the command line utilities for the ALSA project. 2 The mixer. The simplest and easiest way to test microphone ( MIC ) on your linux system is to use default alsa tools which come with alsa sound system package. It does not provide the advanced features (such as timer-based scheduling and network audio) of PulseAudio. Below section Basics of Audio gives you more details about these terminologies. !default { type plug slave. alsa-lib/test/pcm. Update rates list in pcm_native. ALSA: snd_pcm_hw_params() failure - Invalid argument I am working on a ALSA project, and I have a TV tunner card plugged intot the PCI interface. ALSA lib pcm. Re: espeak TTS ALSA Unknown PCM cards Thu Mar 01, 2018 5:39 pm This is great, but I think we can add a step where you make a backup copy of the file before making these changes. 2 Version of this port present on the latest quarterly branch. c:7843:(sndpcmrecover) underrun occurred The sound gets distorted, filled with static and it plays really fast. a no removable of Pulseaudio packages and configuration which in turn not remove ubuntu-desktop package which is needed for future distribution upgrade). Edit: changing the prealloc setting resizes the buffer I'm talking about. The sound device to connect will be the onboard sound system of the Pi as the "sound card. ALSA, which stands for Advanced Linux Sound Architecture, provides audio and MIDI ( Musical Instrument Digital Interface) functionality to the Linux operating system. I am working on audio capturing using ALSA in linux platform. Using the ALSA JACK PCM plugin. It is installed by default in most desktop distributions. The slaved pcm output channel must itself be capable of mixing. asoundrc XML files. It doesn't really depend on the age of the application, as long as it supports your current ALSA and opens a PCM-device, instead of a hardware (HW) device. PCM0 can routedigital audio to I2S DAI0, I2S DAI1 or PDM DAI2. Posted: Sun Jul 27, 2014 2:10 pm Post subject: [SOLVED] Cannot get alsa sound to work I have tried to get alsa to work on my Thinkpad Caron X1 fore some time. Previously when using ALSA, I could have the PCM volume set to 25% then adjust the master volume from 0-100%. c: Wir wurden durch das POLLOUT-Set geweckt, allerdings lieferte ein anschliessender snd_pcm_avail() den Wert 0 oder einen anderen Wert < min_avail. Matt Garman wrote: > Is there a way to query alsa to see what sample rates and formats > the sound hardware natively supports? Try the attached program. card0 { type hw card 0} card0 is the fake alsa device name, with type hw, which represents for the first real alsa device. [Alsa-xmms-user] snd_pcm_writei sometimes returns -EPIPE, Daiki Ueno <=. c example shows various transfer methods for the playback direction. Port details: alsa-lib ALSA compatibility library 1. asoundrc to use my plugin and run aplay, ALSA complains?. front" to "pcm. And I have used alsaconf to configure my sound card. First we need to check if alsa had recognized and our sound. This driver option allows the list of available elements presented to clients to be filtered by name. ALSA Alsamixer. c example shows the measuring of minimal latency between capture and playback devices. ALSA 2015-11-01. arecord arecord application is used to record the audio coming from audio in line. It supports several file formats and multiple soundcards with multiple devices. This would be useful in the scenario where the application actually has lots of data to write but only attempts to write to the. * for alsa data endian definitions one can look at alsa project documentation and alsa mail lists. EDIT Added ls -l /dev/snd/ EDIT Added amixer -c 0 Im trying to get my ubuntu server 12. alsa-pcm: Binding to the ALSA Library API (PCM audio). FreshPorts - new ports, applications. created for that use case designed for codec drivers reuse. It allows to reuse codec drivers across multiple architectures and provides an API to integrate them with the SoC audio interface. the buffer is completely empty. bool alsa_test_output_configuration (struct alsa *alsa, snd_pcm_format_t dmt, int channels, int sampling_rate); Test the output configuration specified by channels and sampling_rate for the output devices. ALSA: snd_pcm_hw_params() failure - Invalid argument I am working on a ALSA project, and I have a TV tunner card plugged intot the PCI interface. libasound_module_pcm_a52. alsa-lib/test/latency. For audio capture, a similar model is used, but the PCM data flows in the opposite direction. The ALSA_OSS_DEBUG can be set to enable some debugging messages. I am working on audio capturing using ALSA in linux platform. This is useful for on SoC DSPdrivers that expose several ALSA PCMs and can route to multiple DAIs. plug { @args [ SLAVE ] @args. This is useful for on SoC DSP drivers that expose several ALSA PCMs and can route to multiple DAIs. Use of the alsa-oss library is recommended over the use of OSS-emulation drivers if you want to use ALSA's PCM plugin layer. This will make the default PCM (audio) output card #1 and the default control also card #1 Raspbian Wheezy - Updating alsa options If you're using Wheezy, we'll edit the audio system configuration file with. 6 AlsaBuildConfig AlsaCVS AlsaFeatures AlsaFixing AlsaGlossary AlsaKar AlsaKernel AlsaMidi. The stack trace looks like ALSA searches for device number 0. I have had a closer look at the volume controls available in amixer and alsamixer and I cannot find where there is a volume control for the HifiBerry DAC+ output, now that the PCM volume control is no longer present. It consists of a set of kernel drivers, an application programming interface (API) library and utility programs for supporting sound under Linux. For Die hard Audiophiles, this resampling is a real source of irritation as CD audio is made using PCM at 44. 95 96 The main additions are 97 98 - get_caps 99 This routine returns the list of audio formats supported. Configuration for ALSA Receiving and Playing Raw PCM on Raspberry Pi Analogue Output c++ , linux , audio , raspberry-pi , alsa No. ALSA provides a number of useful command line utilities that can be used to gather information about sound cards, playback and record audio, and configure sound cards. Contents: Introduction; What is ALSA. org by myself, but now the original question is solved and I can see where to start from to learn as much as I wish about alsa. Using the ALSA JACK PCM plugin. x86_64 alsa-plugins-pulseaudio-1. Allows native ALSA applications to access a PulseAudio sound daemon. The Pi shows none until you create one with PCM, which stands for Pulse Code Modulation. FreshPorts - new ports, applications. c: Wir wurden durch das POLLOUT-Set geweckt, allerdings lieferte ein anschliessender snd_pcm_avail() den Wert 0 oder einen anderen Wert < min_avail. Besides thesound device drivers, ALSA also bundles a user space library forapplication developers who want to use driver features with a higher level APIthan direct. ALSA lib pcm. We will use it to create modules to connect Alsa drivers to sound devices. pcms ([type=PCM_PLAYBACK]) ¶ List available PCM devices by name. We will finally fill in the meat of the driver with some simple handler callbacks for the PCM capture device we've been developing. ALSA can take a PCM signal and send it to your hardware by talking to the driver. It does not provide the advanced features (such as timer-based scheduling and network audio) of PulseAudio. * for alsa data endian definitions one can look at alsa project documentation and alsa mail lists. Here's dmesg info from the fb modprobe to just after the program freezes. In kernel 2. * right, data bytes and bits written in STX register use the same order as arranged in memory. Requires a DAC that supports DSD. # convert alsa API to jack API # use it with: # % aplay foo. This can be changed by setting the ALSA_OSS_PCM_DEVICE environment variable. You have searched for packages that names contain alsa in all suites, all sections, and all architectures. Created attachment 923637 dmesg output Description of problem: "ALSA lib pcm. The kernel then empties out the buffer into the soundcard (to be played) and then ALSA reports underrun - i. In fact I found a code does this,but the recorded sound file is in. snd_pcm_hw_params_set_rate_near() will change the rate to the nearest supported rate. The Pi shows none until you create one with PCM, which stands for Pulse Code Modulation. The test pattern in user space is similar to running 8 gst_launch/aplay instances simultaneously playing a wav file containing RAW PCM. c example shows various transfer methods for the playback direction. This works well in general on x86, but on some archs this may result in cache coherency issues when mmap is used. Then we have to specify the direction of the PCM stream, which can be either playback or capture. alsa-lib/test/pcm. As in the ALSA PCM case, a core set of routines is exposed; 93 each driver implementer will have to write support for a set of 94 mandatory routines and possibly make use of optional ones. Returns: count of filled descriptors This function fills the given poll descriptor structs for the specified PCM handle. card0 { type hw card 0} card0 is the fake alsa device name, with type hw, which represents for the first real alsa device. alsaaudio ¶. sound as well severity 527510 wishlist thanks Hi Robert, sorry for the delay. However I can't seem to find the information I need to get Alsa to run with anything higher than stereo. c:1399:(_snd_pcm_hw_open) Invalid value for card Interestingly, these errors show up in my root terminal, NOT my regular user terminal, where I ran firefox from. The following should serve as a guide for more advanced ALSA setups. Sitio oficial del Semillero "Advanced Digital Technologies" de la Universidad Pontificia Bolivariana Seccional Bucaramanga. c:7339:(snd_pcm_recover) overrun occurred Post by NithinChakravarthi » Mon Aug 25, 2014 10:40 am I am trying to record videos with vlc from USB webcam from A20 humming board. !default pulse ctl. The ALSA_OSS_DEBUG can be set to enable some debugging messages. You can test the sound output by running the command speaker-test -twav -c2. 8KHz and 384KHz sample rates. We will finally fill in the meat of the driver with some simple handler callbacks for the PCM capture device we've been developing. But could never connect, because the Pi missed the protocol A2DP - which was only available with PulseAudio as Bluetooth-Module. alsaaudio ¶. Alsamixer is a command line tool with "view" options to represent the sound device graphically. SND_PCM_FORMAT_DSD_U16_LE, As the parameters stand, the query is performed only to the hw PCM devices, not the abstracted PCM object in alsa-lib. ALSA is the default sound subsystem in the 3. That's awesome Thank you ! But how did you know that ? I'm reading debian wikis, I try to simplify and separate things in order to handle the complexity, forgetting others complicated advices to understand and play things myself, but for inventing such solutions using files I saw nowhere (well in fact the file was not even existing in the disk nor in the wiki !), I'm satisfied because it works. h, for 352k8 and 384k sample rates. c example shows the measuring of minimal latency between capture and playback devices. It allows to reuse codec drivers across multiple architectures and provides an API to integrate them with the SoC audio interface. This works well in general on x86, but on some archs this may result in cache coherency issues when mmap is used. API, which might lead to delay. c:7843:(sndpcmrecover) underrun occurred The sound gets distorted, filled with static and it plays really fast. front cards. This is a rather complex option. !default { type hw card 1 device 0 } ctl. An ALSA stream is a data flow representing sound; the most common stream format is PCM that must be produced in such a way as to match the characteristics or parameters of the hardware, including: sampling rate : often 44. c example shows various transfer methods for the playback direction. UPDATE 2004-09-19 Ondrej Svetlik send me a note saying that in order to make XMMS work properly he had to disable mmap mode on XMMS configuration. The ALSA_OSS_DEBUG can be set to enable some debugging messages. 2005/04 Update : This page is completely obsolete by now, and only kept as a reference as to how to install ALSA on old 2. The slaved pcm output channel must itself be capable of mixing. The sound device to connect will be the onboard sound system of the Pi as the "sound card. As in the ALSA PCM case, a core set of routines is exposed; 93 each driver implementer will have to write support for a set of 94 mandatory routines and possibly make use of optional ones. I am able to capture audio using below code where I am passing "default" device into argument, and it will dump audio data into in. To make alsa applications work directly with pulseaudio we just need to set the default pcm and ctl to the pulse alsa plugin (configuration shown later). It allows to reuse codec drivers across multiple architectures and provides an API to integrate them with the SoC audio interface. This wraps DSD inside fake 24 bit PCM according to the DoP standard. Arguments are: type - can be either PCM_CAPTURE or PCM_PLAYBACK (default). The Pi shows none until you create one with PCM, which stands for Pulse Code Modulation. It looks that problem is with alsa, because alsa cant see any sound card. Found 64 matching packages. Intro-- Concepts-- Configuration-- Troubleshooting-- In practice. This works well in general on x86, but on some archs this may result in cache coherency issues when mmap is used. This driver option allows the list of available elements presented to clients to be filtered by name. The project was started because the OSS architecture is technically weak in some respects, and the free variant of OSS lacks some drivers available only in the commercial variant. so im wondering: in which place do you set the non-blocking mode ?; if this is only a audio channel, why it is "interleaved" ?. [Message part 1 (text/plain, inline)] clone 527510 -1 reassing -1 libasound2 retitle -1 ALSA lib pcm_dmix. In order to configure the ALSA sound subsystem to use the analog (jack) audio output, add the following file /etc/asound. Hello, yesterday i updated my osmc on Raspberry Pi 2 and after update mpd, which i use to play audio when tv is, off stop working. Although, please look into some of the suggestions I provided. This is available on almost all Linux distributions and is a simpler PCM audio mixing solution. Also, I'm sure that my sound card is OK. Consider using a hardware device instead rather than using the plug layer. Essentially, hardware expects a certain datatype for the sound sample, and you're providing the wrong one. aplay /usr/share/sounds/alsa/* should sound when everything is ok and the setup is done. Alsa-lib API pretend to be an alsa device and provide a name for caller to open. Advanced Linux Sound Architecture (ALSA) is the new Linux sound hardware abstraction layer that replaces OSS. c:7339:(snd_pcm_recover) overrun occurred Post by NithinChakravarthi » Mon Aug 25, 2014 10:40 am I am trying to record videos with vlc from USB webcam from A20 humming board. It looks that problem is with alsa, because alsa cant see any sound card. c example shows the minimal code to produce a sound. No support from ALSA and the sound chip required (except for bit-perfect 24 bit PCM support). The previous trial on skypekit audio ([SKYPEKIT][DM368][IPNC] Audio PCM Experiment on DM368-IPNC) was using OSS (/dev/dsp) for Audio PCM host input and output voice. This project aims to make bluetooth headsets of all types work well with Linux computers, from a standard desktop to a limited embedded device. This works well in general on x86, but on some archs this may result in cache coherency issues when mmap is used. Dynamic PCM allows an ALSA PCM device to digitally route its PCM audio tovarious digital endpoints during the PCM stream runtime. dmixer { type dmix ipc_key 1024 slave { pcm "hifiberry" channels 2 } } ctl. arecord is a command-line soundfile recorder for the ALSA soundcard driver. front cards. This page describes the few steps needed to install and use ALSA (the Advanced Linux Sound Architecture) with Red Hat Linux or Fedora. # convert alsa API to jack API # use it with: # % aplay foo. On chipsets without PD/ELD support, ALSA assumes that the monitor supports any and all audio features, not just basic audio. 1 kHz on home stereos, or 48 kHz on home theaters, yet up to 88. The simplest and easiest way to test microphone ( MIC ) on your linux system is to use default alsa tools which come with alsa sound system package. net or at there website than you'll find on this forum. The ALSA_OSS_DEBUG can be set to enable some debugging messages. ~前回のあらすじ~ JuliusをセットアップしたらOSSとしてセットアップされたためにいろいろ頑張ったけどダメだったよ。 1. Basic PCM audio To write a simple PCM application for ALSA we first need a handle for the PCM device. The up-to-date reference generated from sources can be accessed here:. This is a rather complex option. * for alsa data endian definitions one can look at alsa project documentation and alsa mail lists. Alsa-lib API pretend to be an alsa device and provide a name for caller to open. This will lead to some problems for some applications like quake or wine, especially if they use the card only in the MMAP mode. An ALSA stream is a data flow representing sound; the most common stream format is PCM that must be produced in such a way as to match the characteristics or parameters of the hardware, including: sampling rate : often 44. ALSA is the Advanced Linux Sound Architecture:. In kernel 2. It is heavily multi-threaded and tries to excercise the ALSA library and driver quite a bit. In this mode Kodi must decode all audio formats to PCM for passing onto the PulseAudio, this can have the advantage of improve audio/video sync. # convert alsa API to jack API # use it with: # % aplay foo. asoundrc to use my plugin and run aplay, ALSA complains?. 2005/04 Update : This page is completely obsolete by now, and only kept as a reference as to how to install ALSA on old 2. ALSA プログラミングを始めてみました。注意すべき点は以下の通り。 Fedora Core の場合ドキュメントは /usr/share/doc/alsa-lib-devel. Some programs (naively) assume that for PCM data, the preamble in the file header is exactly 44 bytes long (as in the table above) and that the rest of the file contains sound data. Ok, I think I have figure out how to reproduce. What version of the pi are you using? and can you post your ~/. Allows native ALSA applications to work with jackd. ALSA lib pcm_hw. pcm "dmixer" } pcm. Below section Basics of Audio gives you more details about these terminologies. To make initial testing as simple as possible, I deleted the user ALSA configuration file, /home/pi/. install packages # apt-get install bluez-utils bluez-gnome bluez-alsa. alsa-lib/test/pcm. aplay /usr/share/sounds/alsa/* should sound when everything is ok and the setup is done. For audio capture, a similar model is used, but the PCM data flows in the opposite direction. Then we have to specify the direction of the PCM stream, which can be either playback or capture. "Alsa lib pcm. The following should serve as a guide for more advanced ALSA setups. Hi! Regarding the possibility of opening a device more than once: Yes it's possible, with the correct plugin type (dmix). org by myself, but now the original question is solved and I can see where to start from to learn as much as I wish about alsa. The disadvantage of this is that many of them will be irrelevant to your needs. \par Minimalistic PCM playback code \par: alsa-lib/test/pcm_min. A typical ALSA mixer contains a large number of elements, providing detailed control over all aspects of the sound system. Re: [SOLVED] '(snd_pcm_recover) underrun occurred' Pulseaudio has settings similar to alsas buffer_size , increase those. BlueZ 5 dropped support for alsa here. This tutorial assumes that you are familiar with the C++ programming language and the Linux operating system. Package alsa-base. ALSA stands for the Advanced Linux Sound Architecture. c: Wir wurden durch das POLLOUT-Set geweckt, allerdings lieferte ein anschliessender snd_pcm_avail() den Wert 0 oder einen anderen Wert < min_avail. libasound_module_pcm_jack. Besides thesound device drivers, ALSA also bundles a user space library forapplication developers who want to use driver features with a higher level APIthan direct. In order to configure the ALSA sound subsystem to use the analog (jack) audio output, add the following file /etc/asound. Added notes regarding incorrect textual reporting of the monitor's list of supported sample rates. Using an ALSA Loopback device and JACK alsa_in/alsa_out clients. Linux でサウンド関係のプログラムを開発する際に必須になる ALSA のバッファについて書きます。単にゲームを作る程度であれば互換性や利便性を考えて SDL 等の上位のライブラリを使うべきだと思いますが、特にライブ音源やボイスチャット等、タイミングが要求される物を開発する際に必要に. Currently HW params fails to set 352. The up-to-date reference generated from sources can be accessed here:. arecord arecord application is used to record the audio coming from audio in line. I had a look at it and I think I'm on the right path. If the blocking behaviour is selected and it is running, then routine waits until all requested frames are played or put to the playback ring buffer. conf file as suggested in the Gentoo document , but it seemed to make no difference if it was there or not. Alsamixer is a command line tool with "view" options to represent the sound device graphically. Sitio oficial del Semillero "Advanced Digital Technologies" de la Universidad Pontificia Bolivariana Seccional Bucaramanga. Re: PCM driver / ALSA! Thu Dec 20, 2012 10:33 pm hi lucy i'm writing the same things as you, but i've started by few day to write code, and i think you have alredy done more work than me, are you interessed to share youre code and work togheder? contact me in private if you are interessed. libasound_module_pcm_vdownmix. Then we have to specify the direction of the PCM stream, which can be either playback or capture. Alsa: multiple output, multiple sound cards, multiple users I had some difficulties setting up alsa as I wanted, because I encountered some troubles: when more than one application was playing sound, the first one played nicely but the others wasn't playing at all, complaining about a "busy resource". What version of the pi are you using? and can you post your ~/. Everyone who has more to do with music on their Linux box than listening to stereo sound on a single sound card will sooner or later come into contact with ALSA. card 0 defaults. a no removable of Pulseaudio packages and configuration which in turn not remove ubuntu-desktop package which is needed for future distribution upgrade). This more complex but probably more robust approach is well-documented in this document. * for alsa data endian definitions one can look at alsa project documentation and alsa mail lists. ALSA Alsamixer. ALSA - Advanced Linux Sound Architecture ALSA utils contains the command line utilities for the ALSA project. It took me the better part of a day to get it working aswell. sound as well severity 527510 wishlist thanks Hi Robert, sorry for the delay. They are extracted from open source Python projects. But I seem to be stuck. 4 kernel-based distributions. 6 AlsaBuildConfig AlsaCVS AlsaFeatures AlsaFixing AlsaGlossary AlsaKar AlsaKernel AlsaMidi. What's more, it's thread-safe, works well with SMP machines, and is backward-compatible with OSS/Free (using OSS emulation module). This wraps DSD inside fake 24 bit PCM according to the DoP standard. You can test the sound output by running the command speaker-test -twav -c2. It allows to reuse codec drivers across multiple architectures and provides an API to integrate them with the SoC audio interface. I have included the lost attachment here were the underruns messages are shown ( lower part of message ). Have a fresh Arch Linux system setup. conf scroll down until you find the lines. ALSA can take a PCM signal and send it to your hardware by talking to the driver. arecord is a command-line soundfile recorder for the ALSA soundcard driver. front" to "pcm. net or at there website than you'll find on this forum. plug { @args [ SLAVE ] @args. I read the doc: about "snd_pcm_readi", it say it reads interleaved frames when non-blocking mode is set. sound as well severity 527510 wishlist thanks Hi Robert, sorry for the delay. ID 2 (radio) is Audio in and ID 3 (radioconv) is audio out If you choose to use the Terratec sound card you'll need to switch to line in mode and set the volume with the following commands (not necessary for the SignaLink USB). However, it is usually difficult to figure out exactly what needs to be done to output to multiple audio devices. * right, data bytes and bits written in STX register use the same order as arranged in memory. This document attempts to provide an introduction to the ALSA Audio API. If the PCM type hw is selected, ALSA tries to open the PCM devices directly with the parameters required by the application. c example shows the measuring of minimal latency between capture and playback devices.