pcm6cast - multicast raw PCM audio over IPv6 using RTP
pcm6cast [-t ttl] [-p payload] [-z payload size] [-f filename] [-l] [-d device] [-i] [-s ssrc] <multicast group>/<port>
pcm6cast(1) encapsulates audio into a stream of RTP packets and multicasts (or unicasts) them to an IPv6 address. It can take audio from sound card, audio file or STDIN. Audio must be in the same format as one of the supported static payload types.
The port number should be an even number (RTCP reports are sent one port higher).
Return usage and version information.
Sets TTL (Time To Live) for packets sent. Packets will ignored after they have passed this number of routers. Default is 5, maximum is 127.
Payload type of the encoded packets. pcm6cast currently only supports the following four static payload types. Default is 10.
Payload 0: PCMU, 8khz, Mono
Payload 8: PCMA, 8khz, Mono
Payload 10: L16, 44.1khz, Stereo
Payload 11: L16, 44.1khz, Mono
Payload size of the packets. Allows you to choose the length of the payload data (in bytes) for each packet transmitted. This is usually a number between 300 bytes and 1300 bytes. This isn't normally required - a payload size will be selected based on the chosen payload type. Note that the maximum packet size (MTU) is determined by your networking equipment. Also be careful of IP-in-IP tunnelling as packets will have two IP headers which makes it more likely that the packet will be too big and get fragmented.
Use audio file filename as the source of the audio to be multicast. Audio file format can be AIFF/WAVE/.snd/.au. The sample rate and number of channels should be the same as the chosen payload type. The encoding of the samples should be 16-bit twos complement.
Loop the audio file. Repeat playing the audio file. Only valid with -f.
Use sound card device as source of audio. Your operating system must support the OSS (basic) API.
Use STDIN as source of audio. Audio must be the same sample rate and number of channels as the chosen payload type. The sample format should be 16-bit two's complement and using the system endianess.
Usually a random SSRC is generated, however if you want to ensure that an SSRC remain constant between invocations of the program, then you may specify it here as a hexadecimal number.
pcm6cast -f audiofile.aiff FF03::123/5010
Broadcast a sound file out to multicast group FF02::123 on port 5010.
pcm6cast -d /dev/dsp -p 8 FF03::123/5010
Broadcast audio from sound card using payload type 8.
pcm6cast(1) does not currently use RTCP (it should)
Written by Nicholas J Humfrey, <njh@ecs.soton.ac.uk>
Main web site: http://www.ecs.soton.ac.uk/~njh/pcm6cast/
RTP Payload types: http://www.iana.org/assignments/rtp-parameters
pcm6client(1)
Copyright © 2003,2004 University of Southampton. Free use of this software is granted under the terms of the GNU Lesser General Public License (LGPL)
Version 0.1
Last updated 19-May-2004 10:57:47 BST