tsdemux

MPEG-TS (ISO/IEC 13818-1) demultiplexer.

Overview

This library is intended for content analysis and content demultiplexing in applications such as adaptive video streaming where tools such as ffmpeg may not be possible or suitable.

This software is licensed under an MIT license. See the LICENSE file for licensing information.

Multi-Threading

This library is single threaded and not thread-safe when attempting to manipulate a single Demux Context across multiple threads.

It is thread-safe if content is demultiplexed using a separate Demux Context per thread.

The tsinfo example, examples/tsinfo.c, creates a single Demux Context on a single (main) thread.

Documentation

The src/tsdemux.h header file contains the public API documentation. This header is distributed with the Library files.

The best place to get started would be the examples which are in the examples directory. The examples are documented tutorials with instructions on how to work with the library.

Installation

Dependencies

There are currently no external dependencies required to build this library.

It should be noted that development and testing by the author takes place on Linux (Debian), and to date, no compilation and testing has been on attempted on Little Endian Architectures.

Makefile Targets

The Makefile contains the following targets:

make static builds only the static library.
make tests builds the static library and all unit tests.
make examples builds the static library and all examples.
make all or make builds all of the above.
make check builds static library and unit tests, then executes the tests.
make style runs an astyle style=linux pass on the source code.

Debugging

To enable debugging add a DEBUG=1 argument to the make target. This will cause the library, unit tests and examples to be built with debugging enabled.

 make all DEBUG=1

Code Coverage

To output HTML code coverage statistics, use the COVERAGE=1 argument when using the check Make target.

Code Coverage uses gcov, lcov and gentml to gather and render statistics. If you're using Debian, gcov is more than likely already installed, but you'll need lcov which may also install genhtml.

 sudo apt-get install lcov

Run the tests with code coverage enabled:

 make clean
 make check COVERAGE=1

The coverage documentation is output into a coverage/html directory. Failing to clean the project with make clean prior to running make check COVERAGE=1 can cause an error to occur when generating the coverage documentation.

The debug option DEBUG=1 is automatically enabled when COVERAGE=1 is set.

Profiling

To build the library with gprof profiling set the variable PROFILING=1 when building the target.

make tests PROFILING=1 This will build the executables with profiling information.

To get a gprof report you will need to execute the executable which will generate a gmon.out file. From there you can export the profiling report using gprof.

Example

This will build the examples with Profiling enabled, run the tsinfoexample, output the profiling report to profile_report.txt and display the text of profile_report.txt to the screen.

 make clean
 make examples PROFILING=1
 ./examples/tsinfo.o myfile.ts
 gprof examples/tsinfo.o > profile_report.txt
 less profile_report.txt

Linux

From a terminal:

  make

Creates a bin directory containing static library and header files. This is no install step within the Makefile. If you are wanting to build files for debugging pass in a DEBUG=1 argument.

 make DEBUG=1`

To clean the repository and start a build from scratch:

 make clean
 make

To build and run all unit tests validating the library:

 make check

The unit tests will run individually regardless if any fail.

Examples

Examples showing how to use the library are in the examples directory. To build the examples:

 make examples

The examples are also built when using the all target.

The executables are built directly in the examples directory alongside the example source code. The examples are expecting to be run from the root project directory.

 ./examples/tsinfo.o myfile.ts

Contributing

Before making Pull Requests into this repository for review, please complete the following steps.

Code Style

Run a pass on the source code to ensure basic 'linux' styling using astyle:

 sudo apt-get install astyle
 make style

Unit Tests

Make sure all unit tests are passing. Ensure you provide new, or modify existing, unit tests covering any code changes.

Build unit tests:

 make tests

Build and execute unit tests:

 make check

See an existing unit test for guidance on writing unit tests. The framework is a very basic header file, test/test.h.

Valgrind - Memory Leaks

It's generally a good idea to check for memory leaks by running the examples through Valgrind.

 valgrind --leak-check=yes --track-origins=yes --log-file=valgrind_report.txt examples/tsinfo.o myfile.ts`

Not all warnings in Valgrind are valid errors, compare the results with the master branch.

godghdai/tsdemux