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Sunday, February 12, 2012

Fedora 14 Audio Apps, PulseAudio, Real-time Sound and file volume normalizers, Codecs etc

Today I decided to delve into using, PulseAudio on my Fedora 14 Systems. I have known about PulseAudio, since I first started with Linux OS's back in 2005. But, I never took the time to find out just how to use it or even learn about it's many features. I tried playing with it here and there (without reading the instructions). And really didn't ever figure it out. I also tried using Jack, but it is even harder to me. Today, I was really wanting to find a way to Normalize all of the Audion being played on my System. What ever the source. I'm thinking of using the line in and line out. In order to use this Computer as a Mixer. Not only it's internal Sources. Audio and Video Players on this System. But also for other Sources. Like my TV Tuner - DVD Player, CD Player Etc... I spent all afternoon and evening Searching in Google and the Package Manager in Fedora 14 and decided that my best bet on achieving this, is by learning how to use PulseAudio. It has many features, besides Network Streaming. And the Add-on Apps that I have found. Add allot of things to what you can do with PulseAudio (beyond the standard ALSA Mixer). I found so much today. So many Audio Apps and Add-ons, that I can't began to name them all now. The ones that I ended up installing and playing with are, GMixer, PulseAudio Device Chooser, a Real Time EQ. Basically these are some Control and Mixer Apps for ALSA and PulseAudio, in order to be able to use them together. The Real Time EQ has a weird quirk. Every time you change the EQ, the Volume in Pulse Audio and or the Main ALSA Volume goes down, allot. I finally figured out that if you just move the Main Volume Slider in GMixer in ALSA Mode, just a little. The Volume will go back to normal. I kept on toggling back and forth, to change which ever Volume Setting that had ben Changed. It seemed to depend on which one you had open last in GMixer. It had no effect on the level in the Regular ALSA Volume Setting App. And you could only change - fix the Volume in GMixer. I kept on switching back and forth from ALSA to PulseAudio Mode for quite a while before I figured this out. So, be ware of this, if you install Real Time EQ. Also, I found a really good Sound Visualizer called ProjectM. After installation you can either open it up directly and it will Visualize, from what ever sound or music App that you have playing. Or you can select ProjectM in VLC, to make it the default Visualizer for Audio Played in VLC. I also found several Audio Volume Normalizers (for Audio Files not Realtime) that I haven't tried out yet. I will have to look again for a Real Time Volume Normalizer. But, I did find a Config file for ALSA that is suppose to achieve this in ALSA. But, I want a nice little App or Add-on for my GUI Apps. I've seen them before, back in Fedora 7 or 11 and never used them much at the time. I just need to find those Apps again or some new ones... Here's all of the Links to all of what I found today and the Wiki info on PulseAudio...

Fedora 14 Audio Apps, PulseAudio, Real-time Sound and file volume normalizers, Codecs etc
fedora volume normalize - Google Search
How to normalize volume level in avi files with mp3 audio streams -
RPM resource normalize
ATrpms - by Distribution > Fedora 14 > normalize
fedora volume normalize real time - Google Search
Realtime Volume Normalization : linux
miscfits: normalize all your movie audio on-the-fly with ALSA
Musicians' Guide
Musicians' Guide - Fedora 14
1.4.3. Level (Volume/Loudness)
GStreamer Good Plugins 0.10 Plugins Reference Manual
Applications/Multimedia RPM packages for Red Hat / Fedora / Aurora
rte RPM : Dries RPM Repository
alsa-utils RPM : Dries RPM Repository
PulseAudio - Wikipedia, the free encyclopedia
JACK Audio Connection Kit - Wikipedia, the free encyclopedia
Qjackctl - Wikipedia, the free encyclopedia
Raul |
Software |
The CELT ultra-low delay audio codec
Main Page - AlsaProject
GYachI Home Page
GYachI Home Page
PulseAudio Device Chooser 0.9.3
PulseAudio Preferences 0.9.10
pulseaudio-equalizer : Code : Conn O Griofa
xmms-pulse 0.9.4
PulseAudio Volume Control 1.0
PulseAudio Volume Meter 0.9.3
PulseAudio Volume Meter 0.9.3
projectM - Browse /presets-samples at
PulseAudio Device Chooser 0.9.3
Real Time Volume Leveler
Google Custom Search
DonsDeals: Fedora 14 Audio Apps, PulseAudio, Real-time Sound and file volume normalizers, Codecs etc
DonsDeals: Microcontroller based audio volume level compressor - The Great [Volume] Leveler (AVR Audio Compressor) | Non-Lexical Vocables
The Great [Volume] Leveler (AVR Audio Compressor) | Non-Lexical Vocables
real time volume leveler linux - Google Search
real time volume leveler - Google Search
real time volume leveler fedora linux - Google Search
Free Program Reduce Volume Level Downloads
Dynamic EQ from Audyssey - Rich Sound at Any Volume | Audyssey
dynamic eq fedora linux - Google Search
Audio Creation - FedoraProject
VLevel - About


PulseAudio - Wikipedia, the free encyclopedia

From Wikipedia, the free encyclopedia

Developer(s) Lennart Poettering, Pierre Ossman, Shahms E. King, Tanu Kaskinen, Colin Guthrie
Stable release 1.1 / October 20, 2011; 3 months ago
Written in C[1]
Operating system FreeBSD, NetBSD, OpenBSD, Linux, Solaris, Mac OS X, and Windows
Platform ARM, PPC (PowerPC), x86 / IA-32, x86-64, and MIPS architecture
Type Sound server
License GNU Lesser General Public License 2.1[2]
PulseAudio (formerly Polypaudio) is a cross-platform, networked sound server commonly used on the Linux-based and FreeBSD operating systems.
PulseAudio runs under Microsoft Windows, Mac OS X, and POSIX-compliant platforms, such as Linux and FreeBSD. PulseAudio is free software released under the terms of the GNU Lesser General Public License 2.1.[2]



[edit] Design

PulseAudio operational flow chart
PulseAudio is a sound server, a background process accepting sound input from one or more sources (processes or capture devices) and redirecting it to one or more sinks (sound cards, remote network PulseAudio servers, or other processes).
One of the goals of PulseAudio is to reroute all sound streams through it, including those from processes that attempt to directly access the hardware (like legacy OSS applications). PulseAudio achieves this by providing adapters to applications using other audio systems, like aRts and ESD.
In a typical installation scenario under Linux, the user configures ALSA to use a virtual device provided by PulseAudio. Thus, applications using ALSA will output sound to PulseAudio, which then uses ALSA itself to access the real sound card. PulseAudio also provides its own native interface to applications that want to support PulseAudio directly, as well as a legacy interface for ESD applications, making it suitable as a drop-in replacement for ESD.
For OSS applications, PulseAudio provides the padsp utility, which replaces device files such as /dev/dsp, tricking the applications into believing that they have exclusive control over the sound card. In reality, their output is rerouted through PulseAudio.

[edit] Features

The main PulseAudio features include:
  • Per-application volume controls[3]
  • An extensible plugin architecture with support for loadable modules
  • Compatibility with many popular audio applications[4]
  • Support for multiple audio sources and sinks
  • Low-latency operation[citation needed] and support for latency measurement
  • A zero-copy memory architecture for processor resource efficiency
  • Ability to discover other computers using PulseAudio on the local network and play sound through their speakers directly
  • Ability to change which output device an application plays sound through while the application is playing sound (without the application needing to support this, and indeed without even being aware that this happened)
  • A command-line interface with scripting capabilities
  • A sound daemon with command line reconfiguration capabilities
  • Built-in sample conversion and resampling capabilities
  • The ability to combine multiple sound cards into one
  • The ability to synchronize multiple playback streams
  • Bluetooth audio devices with dynamic detection
  • The ability to enable system wide equalization

[edit] Adoption

PulseAudio is used in recent versions of several major linux distributions such as Fedora, Ubuntu, Mandriva, Linux Mint, openSUSE, and OpenWrt.[5] There is also growing support for PulseAudio in the GNOME project. Starting with version 4.5 (and further enhanced in 4.6) PulseAudio is also integrated into Plasma Workspaces primarily by PulseAudio contributor Colin Guthrie, adding support to Phonon (the KDE multimedia framework) and KMix (the integrated mixer application) as well as writing a new "Speaker Setup" GUI to aid the configuration of multi-channel speakers.
PulseAudio is being used as audio system on various Linux based mobile devices, including Nokia N900, Nokia N9 and the Palm Pre.[6]

[edit] Early adoption

When first adopted by the distributions, PulseAudio developer Lennart Poettering described it as "the software that currently breaks your audio".[7] Poettering later claimed that "Ubuntu didn't exactly do a stellar job. They didn't do their homework" in adopting PulseAudio[8] for Ubuntu "Hardy Heron" (8.04), a problem which was then improved with subsequent Ubuntu releases.[9] However, on October 2009, Poettering reported that he was still not happy with Ubuntu's integration of PulseAudio.[10]
Certain programs, such as Adobe Flash for Linux, caused instability in PulseAudio.[11][12] Newer implementations of Flash plugins do not require the conflicting elements, and as a result Flash and PulseAudio are now compatible.

[edit] Alternatives

  • ALSA provides a software mixer called dmix, which was developed prior to PulseAudio. This is available on almost all Linux distributions and is a simpler PCM audio mixing solution. It does not provide the advanced features (such as device aggregation, timer-based scheduling, and network audio) of PulseAudio. On the other hand, ALSA offers, when combined with corresponding sound cards, extremely low latencies.
  • JACK is a professional sound server, which provides real-time, low latency (i.e. 5 milliseconds or less) audio performance and, since JACK2, supports efficient load balancing by utilizing symmetric multiprocessing, that is the load of all audio clients can be distributed among several processors. Audio clients can be arbitrarily connected with each other. The graph, that is all connections among JACK clients, can be visualized and edited at runtime with various applications (e.g. Qjackctl), providing a means to overview the overall audio control flow and to modify the routing of all audio applications and hardware at any time. JACK is the preferred sound server for professional audio applications such as Ardour, Rezound, and LinuxSampler.
  • OSS. This was the original sound system used in Linux, but was deprecated after the 2.5 kernel.[13] Proprietary development was continued by 4Front Technologies - who in July 2007 released sources for OSS under CDDL for OpenSolaris and GPL for Linux.[14] The modern implementations Open Sound System v4, provide software mixing, resampling, and changing of the volume on a per-application basis; in contrast to PulseAudio, these features are implemented within the kernel.
PulseAudio can also inter-operate with existing sound systems, including those that were designed to exclusively lock the sound card (e.g. OSS v3).

[edit] See also

[edit] References

  1. ^ "PulseAudio", Analysis Summary (Ohloh), archived from the original on 2009-10-18, retrieved 2011-06-16
  2. ^ a b "License", PulseAudio git (, retrieved 2011-06-16
  3. ^ Interviews/LennartPoettering, FedoraProject, retrieved 2009-07-03
  4. ^ Pulse Audio wiki, PulseAudio, archived from the original on 2009-10-18, retrieved 2009-07-19
  5. ^ PulseAudio,, retrieved 2012-01-08
  6. ^ "Open source identity: PulseAudio creator Lennart Poettering", TechWorld, 8 October 2009
  7. ^ LPC: Linux audio: it's a mess,, archived from the original on 2009-10-18, retrieved 2009-07-03
  8. ^ Lennart Poettering (18 July 2008), PulseAudio FUD,, archived from the original on 2009-10-18, retrieved 2009-12-30
  9. ^ HOWTO: PulseAudio Fixes & System-Wide Equalizer Support, Ubuntu Forums, 2008-05-10, archived from the original on 2009-10-18, retrieved 2009-10-18
  10. ^ I'll Break Your Audio, Lennart Poettering Blog, 19 October 2009, retrieved 26 December 2009
  11. ^ No sound after running Flash, YouTube, etc. (pulseaudio solution), Ubuntu Forums, archived from the original on 2009-10-18, retrieved 2009-10-18
  12. ^ PulseAudio, Ubuntu Wiki, archived from the original on 2009-10-18, retrieved 2009-10-18
  13. ^ ,, 2004,[dead link]
  14. ^ 4Front technologies releases the source code for open sound system, Linux PR, 2007-06-14, retrieved 2012-01-08

[edit] External links

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