tssi2 (Transport Stream Service Information v2)

tssi2 is a header-only library for parsing MPEG-2 and DVB Transport Streams in the domain of multimedia processing applications.

The entire implementation is provided inline in the headers under the include directory. A reference documentation is stored under docs. A modern C++ compiler (C++ 14 / C++ 17) is necessary.

While the main header include/tsparser.hpp provides access to the whole library, it is also possible to break out required parts. This comes in handy if you already have a PSI or PES assembler and need some additional tables or descriptors - in this case just include include/specifications.hpp.

Dependencies:

• C++ Guideline Support Library (header-only, included; mostly needed for gsl::span<const T>, a type just waiting for replacement by std::array_view<T> or std::basic_string_view<T>)

License

The GNU General Public License v3 applies to this project.

If you need another (e.g. commercial) license, contact me.

Features

<dl> <dt>📌 Fast</dt> <dd>See <a href="#benchmark">Benchmark</a></dd> <dt>📌 Modern and leak-free <a href="https://www.youtube.com/watch?v=JfmTagWcqoE">by default</a></dt> <dd>C++ 14 / C++ 17 / GSL</dd> <dt>📌 Under active development</dt> <dd>If there has not been an push for a while the next one will happen nevertheless.</dd> <dt>📌 Lightweight</dt> <dd>The library is a few kb in size and header-only.</dd> <dt>📌 Cross-platform</dt> <dd>Windows, Linux, Mac,... should be supported</dd> <dt>📌 No-throw</dt> <dd>Transport Streams are prone to data corruptions. tssi2 is designed to handle data errors and not to throw. This is not a no-throw guarantee! Some functions might throw (see the docs).</dd> <dt>📌 Multi-threading support</dt> <dd>Reentrant with shared mutual exclusion</dd> <dt>📌 (To some extent) class-less</dt> <dd>Processing of MPEG and DVB objects by stateless functions. No class overhead.</dd> <dt>📌 Modular</dt> <dd>Custom data processors can replaced provided processors on any level. Custom allocators are supported as well.</dd> </dl>

tssi1 offers some nice features like ISO 13818-6 handling and will remain available on GitHub.

Benchmark

tssi2 is compared against the simple memory read operation read.

void read(span<const char> data) {
    for (auto v : data) {}
}

Only the time spent in tssi2 or readis measured. Disc to memory transfers are omitted. Data is processed in 1MB chunks.

All tests were conducted on a HP Spectre x360 with Intel Core i7-7500U. The source code is available under examples/benchmark.

Quick start

We want to detect the transmission time of a Transport Stream. Let us suppose you already have included the stream and vector files from C++ and introduced the namespace std (a source file is available, see examples).

First of all, we load a Transport Stream into a buffer variable.

auto f = ifstream{ "examples/data/ard.ts", ifstream::binary };
auto b = vector<char>( 4000000 );
f.read(b.data(), b.size());

Keep in mind to check for errors in real programs. We skip this part to illustrate the API itself.

We now create a TSParser providing 188-byte TS packets for a PSIHeap that will process and store program-specific information for common usage (for this reason a shared pointer is used to share its ownership).

auto ts = tssi::TSParser<>();
auto heap = make_shared<PSIHeap<>>();

The time and date information is stored on packets with PID 0x14. We tell the parser what packets we are interested in and where to send them.

ts.pid_parser({ 0x14 }, heap);

This could also be a lambda

auto pid_parser = make_shared < LambdaNode >([&](auto data) { });
ts.pid_parser({ 0x100, 0x200, 0x300 }, pid_parser);

or a PESAssembler if you are interested in packetized elementary streams.

With the buffer and parser set up, we can process the data.

ts(b);

The PSI table_ids we are looking for are 0x70 and 0x73, but first we retrieve a data reference from the heap.

auto& psi_data = heap->psi_heap();
for (auto& v : psi_data)
    // v.first: section_identifier tuple 
    //   (table_id, table_id_ext, section_number)
    // v.second: PSISection
    if ((get<0>(v.first) == 0x70) || (get<0>(v.first) == 0x73)) {

Direct access to the section's data is available via v.second.psi_data().

        auto data = v.second.psi_data();

The functions to analyze sections and descriptors are organized in namespaces. Utilize the using statement if appropriate.

        using namespace tssi::etsi300468::time_date_section;
        auto time = UTC_time(data);
        cout << ctime(&time) << endl;
        break;
    }	

The program might now result in an output like:

  Fri Oct 28 23:06:06 2005

Documentation

Download or clone the repository to access the HTML documentation located under docs. For a full definition of all values have a look at the mentioned specifications.

Examples

Advertise by utilize:

• Data: 272MB Transport Stream sample (approx. 1min DVB satellite capture), test file for the following examples.
• Minimal: The quick start guide's source code.
• Benchmark: Basic chronometry.
• PSI Data: Parsing of Program-specific information to HTML.
• Audio/Video Parser: Extraction of elementary stream (audio and video in this case) to disc.
• Multi-threading: A demo on reading from PSIHeap while TSParser tries to fill it with new information.
• Video player: A video player using ffmpeg and SDL2.

Building the docs

Should you want to build the docs for yourself, make robodoc available and use doc.shor doc.bat. Modify the style either in the respective file or in robodoc.rc.