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Linux Streaming

This is a note-scrape-no-paper-book for a paper i should submit to get my credits for the class. Its mainly about streaming under linux. Here is one simillar, but older article on audio streaming.

What is Streaming

Streaming is a way how to produce and process media so that they can be seen during downloading.

Architecture

Source

  • Any sound input (through Alsa, Jack, OSS)
  • Any internal player (xmms, mp123)
  • Source “pushes up” the data to the repeater (darkice, oggfwd, plugins for players, etc)

Repeater

  • Provides content for the clients
  • Can serve more streams at once - mountpoints
  • Can be in relation to other repeaters
  • Can be the same machine then source

Client

  • Client receives stream, decompresses, then playback

Audio Streaming

In this section we cover two main forms of audio streaming under linux: mp3 and ogg. We will not pay attention to other formats, like realmedia or windows media. Quicktime is a possibility 1).

Source

Any sound-input routed into the soundcard. Controllable through ALSA or OSS. Possible to steer audio in Jack. Can be also a XMMS player. There two main alternatives:

  • External stream-forwarder
  • Plugin, built-in forwarding functionality

External stream-forwarder

In case of sound you use various softwares, icecast people have released a number of ices bindings to different programming languages, so the possibilities are broad. The most used are:

Built-in stream-forwarder

In case of various music products, the capability to send out the data to a streaming-server is allready built-in or in the possibillity of plugins. An example is the player Xmms, where you can install a plugin sending the played music irectly to the Streaming server. Another example is Muse software, or software for music production like pure-data..

Repeater

Darwin Streaming Server

Darwin Streaming Server is a free streaming server from Apple. It should run under under Linux - from the link you can download 2) the source code or packages for Fedora Core. Ill try to make it run here, then i report.

Shoutcast

Shoutcast is runnable under Linux, but has a weird licence, and you get a precompiled binary. Shoutcast is able to stream only data in .mp3 format, which in itself is problematic under linux. There is no licence needed for using mp3 format for uncommercial purposes:

Do I need a license to stream mp3, mp3PRO or mp3surround encoded content over the Internet?

Yes. A license is needed for commercial (i.e., revenue-generating) use 
of mp3/mp3PRO in broadcast systems (terrestrial, satellite, cable and/or 
other distribution channels), streaming applications (via Internet, 
intranets and/or other networks), other content distribution systems 
(pay-audio or audio-on-demand applications and the like) or for use 
of mp3/mp3PRO on physical media (compact discs, digital versatile 
discs, semiconductor chips, hard drives, memory cards and the like). 

However, no license is needed for private, non-commercial activities 
(e.g., home-entertainment, receiving broadcasts and creating a personal 
music library), not generating revenue or other consideration of any 
kind or for entities with associated annual gross revenue less than 
US$ 100 000.00. 

source

IceCast

IceCast is open-source and distributable under GNU\GPL licence.

Clients

How-To

Server

First of we should have a streaming server allready installed and at our disposal. If true, goto here. If not, we will install our streaming server now. I chose IceCast.

get the new libogg:

wget http://downloads.xiph.org/releases/ogg/libogg-1.1.3.tar.gz

decompress:

tar -xzvf icecast-2.3.1.tar.gz

configure && make. The path to libogg can be different on your system, and depends on YOUR settings.

./configure --with-ogg=/usr/local/lib
make 

Install:

make install

edit the configuration file 3) More to the config-file options soon, or just RTFM

vi /usr/local/etc/icecast.xml

Now just run icecast

icecast -c /usr/local/etc/icecast.xml

Depends on settings but the admin interface is on http://ip-of-server:8000/admin/

source “puts up” the data, with a password, then mounts it on some mountpoint. The mountpoint is accessible through: http://ip-of=server:8000/mountpoint_name

Icecast is able to stream .ogg streams and also mp3. Newest addistions include the Theora library which is used for streaming video in ogg/theora format.

Source Setup

As an stream forwarder we will use darkice.. Its robust, command-line orientated, and fast. We compile darkice from the sources. The we just modify an .conf file, for example /etc/darkice.conf:

# this section describes general aspects of the live streaming session
[general]
duration        = 0        # duration of encoding, in seconds. 0 means forever
bufferSecs      = 5         # size of internal slip buffer, in seconds

# this section describes the audio input that will be streamed
[input]
device          = /dev/dsp  # OSS DSP soundcard device for the audio input
sampleRate      = 44100    # sample rate in Hz. try 11025, 22050 or 44100
bitsPerSample   = 16        # bits per sample. try 16
channel         = 1         # channels. 1 = mono, 2 = stereo

# this section describes a streaming connection to an IceCast2 server
# there may be up to 8 of these sections, named [icecast2-0] ... [icecast2-7]
# these can be mixed with [icecast-x] and [shoutcast-x] sections
[icecast2-0]
bitrateMode     = abr       # average bit rate
format          = vorbis    # format of the stream: ogg vorbis
bitrate         = 48       # bitrate of the stream sent to the server
quality         = 0.9
#sampleRate     = 16000
server          = tlis.sk
port            = 8000      # port of the IceCast2 server, usually 8000
username        = source
password        = ******    # source password to the IceCast2 server
mountPoint      = live.ogg  # mount point of this stream on the IceCast2 server
name            = IRS TLIS LIVE
description     = College Radio Bratislava, Slovakia >> www.tlis.sk
url             = http://www.tlis.sk/
genre           = Mixed    # genre of the stream
public          = yes       # advertise this stream?

[icecast2-1]
bitrateMode     = abr       # average bit rate
format          = vorbis    # format of the stream: ogg vorbis
bitrate         = 128        # bitrate of the stream sent to the server
quality         = 0.9
#sampleRate     = 16000
server          = tlis.sk
port            = 8000      # port of the IceCast2 server, usually 8000
username        = source
password        = *******    # source password to the IceCast2 server
mountPoint      = live_128.ogg  # mount point of this stream on the IceCast2 server
name            = IRS TLIS LIVE
description     = College Radio Bratislava, Slovakia >> www.tlis.sk
url             = http://www.tlis.sk/
genre           = Mixed    # genre of the stream
public          = yes       # advertise this stream?

After modification we just run darkice -c /etc.darkice.cfg, and everything we receive in the input device (/dev/dsp) is being forwarded to our streaming server. So lets put something into the input device :) The best and easiest way is to run an XMMS and just play some music. If you want to mix it, it is better to try some

Video Streaming

Video sreaming under Linux was, for licencing issues a bit weak, until the fabulous libtheora came and with it the OGG/Theora format. This is now something like the flagship of linux video streaming, so we will cover only this option.

Structure

Source

various…

Repeater

we will use libtheora and libvorbis enabled IceCast streaming server

Client

various, see above which can playback video..

How-to

Source

You need to have either the video on your harddisk, or for live streaming, a FireWire compatible Camera, and firewire enabled in linux. I will not go into this, but it is the main source of problems, when the ieee1394 is not working.

When you have the firewire up & ready, get and install the utikity called ffmpeg2theora. Examples how to use it are here

We pretend we have ieee1394 running. We should have also installed dvgrab:

This grabs the input from firewire, converts it to .ogg and sends output standard out:

dvgrab --format raw - | ffmpeg2theora -a 0 -v 5 -f dv -x 320 -y 240 -o /dev/stdout

We install another utility called oggfwd and send the stdout to theora-enabled icecast server:

dvgrab --format raw - | ffmpeg2theora -a 0 -v 5 -f dv -x 320 -y 240 -o /dev/stdout - | oggfwd  icecastserver  8000 pwd /theora.ogg

where icecastserver - is the url of our streaming server

8000 - can be any number for port number of icecast listener

pwd - password

/theora.ogg - mountpoint where we wish to have the video stream accesible

Server

To use the Ogg/Theora options, we will need an libvorbis and libtheora enabled installation of IceCast Streaming Server. We download the additional libraries (we expect that we have allready installed libogg):

Get libvorbis:

wget http://downloads.xiph.org/releases/vorbis/libvorbis-1.1.2.tar.gz

Get libtheora:

wget http://downloads.xiph.org/releases/theora/libtheora-1.0alpha7.tar.gz

then recompile icecast with these options (the exact location of the libs depends on YOUR settings)

./configure --with-ogg=/usr/local/lib --with-vorbis=/usr/local/lib --with-theora=/usr/local/lib

Client

1)
have to check how is it with its freeness and openness
2)
to skip signing in just use bugmenot
3)
the path to the config file can be also different
linux_streaming.1165446140.txt.gz · Last modified: 2007/04/17 12:58 (external edit)