OpenCaster

Original authors

• Lorenzo Pallara
• Andrea Venturi
  (domain avalpa.com is down, so e-mail addresses have been removed)

Introduction

This package is a collection of softwares for Linux system to play out and multiplex MPEG2 transport stream format.

About this fork

Fork done by Konrad Dąbek for internal purposes. This is still a work in progress! Goals:

• Merge own patches & cherry-picked patches created by the community
• Enable possibility to build partially under Windows (Cygwin), with some limitations (e.g. no network stack), I've made that successfully back in 2020, but never authored this in the form of commit. Some tools are working fine under Windows through Cygwin, e.g. sec2ts, ts2sec, building DSM-CC OC/DC, DVB-SSU
• Move to Python 3

Please be aware that as of 2025, OpenCaster hasn't received any updates for more than 12 years, with last changes originating from 2013.
In the meantime a lot of things have changed in the DVB world...

My (Konrad Dąbek) personal beliefs are that in 2025 OpenCaster should be used only if there's no other open source alternative present (e.g. DSMCC, DVB-SSU, TTX, Subtitling, MHP/HbbTV), at least until original authors or their successors will take over the development.
For most of other purposes you should seek for modern alternatives.

For tables management, monitoring, debugging, lab and demo purposes please consider to check TSDuck
For generation of MPEG TS with A/V please consider to check FFmpeg (FFmpeg is far from being perfect in DVB-SI tables generation, so teaming it up with TSDuck is a wise idea)

I'm (Konrad Dąbek) providing no support for this fork, I cannot give any guarantee that it will reflect robustness of Python 2 version.
There are no plans to introduce any fixes, updates or improvements except of continuation of attempts to make it work with Python 3 and Cygwin, at least partially.
Before reporting any issue please check behaviour on the original Python 2 release.

Use-cases

• MHP, MHEG5, HbbTv and others interactive tv standards object carousel broadcast
• Playout of locally stored, offline encoded audio and video for non-live tv and radio stations
• Multiplexing of input multicasted UDP transport stream to output multicasted UDP transport stream
• VOD system based on mpeg2 transport stream over IP or over DVB for walled garden network like hotels with coax or ethernet
• DVB-SSU update
• Data casting
• Teletext generator
• IP encapsualtor
• PSI/SI generator
• EPG generator

Integration

OpenCaster output has been successfully integrated with a long list of dvb products, among them there are products by Cisco/Scientific Atlanta, Ericsson/Tandberg, Dektec, Eurotek, Harmonic/Scopus, MainConcept, Mitan, Screen Service, Adtec, Wellav, Arris, Sr-Systems, Deltacast...

Manual

Avalpa Broadcast Server manual is available here: AvalpaBroadcastServerUserManual-v3.0.pdf

Test

OpenCaster has been tested with Rohde & Schwarz DVM100L, Rohde & Schwarz DVM 400, DekTec StreamXpert and a countless number of set top boxes, digital receivers and television sets.

Technical features

• PSI generation (PAT, PMT, NIT, SDT, TDT, AIT, TOT...)
• EPG/EIT generation
• Object and data carousel generation and receivement (MHP, MHEG5, HbbTv, DVB-SSU, DSMCC...)
• third party software AC-3, MPEG2 audio, MPEG2 video and H264 video encoders support
• Audio Description generation support
• IP encapsulation (MPE)
• Teletext generation
• CBR transport stream muxing
• PCR stamping
• Null packet replacement
• PID filtering
• PID remapping
• Null packet insertion
• Video buffer verifier
• PCR timing verifier
• PES headers analyzer
• MPEG2 video and MPEG2/AC-3 audio ES header analyzer
• M2TS file generation from TS file

Demo

A demonstration transport stream is available at this address: https://web.archive.org/web/20221006041331/http://www.avalpa.com/the-key-values/15-free-software/59-opencaster-demo-roll (OC3.demo.ts might be hard to be downloaded from WebArchive, original website is down, author of this fork has got the TS, but decided against uploading it to GitHub to avoid bloating the repo).

Handy tables

DVB-T Modulations:

Modulation	Coding rate	GI: 1/4	GI: 1/8	GI: 1/16	GI: 1/32
QPSK	1/2	4.976	5.529	5.855	6.032
QPSK	2/3	6.635	7.373	7.806	8.043
QPSK	3/4	7.465	8.294	8.782	9.048
QPSK	5/6	8.294	9.216	9.758	10.053
QPSK	7/8	8.709	9.676	10.246	10.556
16-QAM	1/2	9.953	11.059	11.709	12.064
16-QAM	2/3	13.271	14.745	15.612	16.086
16-QAM	3/4	14.929	16.588	17.564	18.096
16-QAM	5/6	16.588	18.431	19.516	20.107
16-QAM	7/8	17.418	19.353	20.491	21.112
64-QAM	1/2	14.929	16.588	17.564	18.096
64-QAM	2/3	19.906	22.118	23.419	24.128
64-QAM	3/4	22.394	24.882	26.346	27.144
64-QAM	5/6	24.882	27.647	29.273	30.160
64-QAM	7/8	26.126	29.029	30.737	31.668

Channel to frequency table:

Channel	Frequency [MHz]
21	474
22	482
23	490
24	498
25	506
26	514
27	522
28	530
29	538
30	546
31	554
32	562
33	570
34	578
35	586
36	594
37	602
38	610
39	618
40	626
41	634
42	642
43	650
44	658
45	666
46	674
47	682
48	690
49	698
50	706
51	714
52	722
53	730
54	738
55	746
56	754
57	762
58	770
59	778
60	786
61	794
62	802
63	810
64	818
65	826
66	834
67	842
68	850
69	858

MPEG Audio Layer 2 suggested bit rates:

• 56 kbps -> 1 pes packet -> 1 ts packet
• 112 kbps -> 1 pes packet -> 2 ts packets
• 160 kbps -> 1 pes packet -> 3 ts packets
• 224 kbps -> 1 pes packet -> 4 ts packets
  All the others fall in the middle and are not a wise choice.