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Multicat

Simple and efficient multicast and transport stream manipulation

The multicat package contains a set of tools designed to easily and efficiently manipulate multicast streams in general, and MPEG-2 Transport Streams (ISO/IEC 13818-1) in particular.

The multicat suite of applications is very lightweight and designed to operate in tight environments. Memory and CPU usages are kept to a minimum, and they feature only one thread of execution.

The multicat program

multicat itself is a 1 input/1 output application. Inputs and outputs can be network streams (unicast and multicast), files, directories, character devices or FIFOs. It is thought to be a multicast equivalent of the popular netcat tool. Typical applications are recording live transport streams, or playing out TS files without modification. Also it is able to record a continuous stream into a directory, rotate the files periodically, and make seamless extracts from it.

Multicat tries to rebuild the internal clock of the input stream; but it wants to remain agnostic of what is transported, so in case of files the said clock is stored to an auxiliary file (example.aux accompanies example.ts) while recording. Other inputs are considered "live", and the input clock is simply derived from the reception time of the packets.

The ingests program

ingests is a companion application designed to manipulate TS files. It reads the PCR values of the file, and builds the auxiliary file that is necessary for multicat.

The combination of ingests and multicat makes a simple and efficient TS file streamer.

The aggregartp and reordertp programs

aggregartp splits a single RTP stream (for instance a high-bitrate signal) to several contribution links with load balancing.

reordertp takes one or multiple inputs (from aggregartp or another source known to reorder and/or add jitter to packets) and smoothes them out to output the original stream in correct order.

Get Multicat

The latest official version of Multicat is numbered 2.0, and is available via HTTP or FTP.

biTStream needs to be installed at build-time.

Hackers can participate to the development using Subversion. The code can be found at svn://svn.videolan.org/multicat and you can browse the source online.

User support is handled in the streaming mailing-list. There is also a developer-oriented mailing-list.