libvideo-streaming - Video streaming library

libvideo-streaming is a C library that handles the payloading and de-payloading of H.264 encoded video frames in an RTP stream.

Features

Sender

• H.264 encoded video payloading following RFC 6184, supporting:
  • single NAL unit packets
  • fragmentation packets (FU-A)
  • aggregation packets (STAP-A)
• serializing of Parrot video frame metadata as RTP header extensions
• serializing of Parrot video session metadata as RTCP SDES packets
• congestion control: packet drop on timeout with priority class
• statistics output:
  • RTCP receiver reports
  • Parrot receiver video stats
• no network implementation: the application must handle network sending/receiving

Receiver

• H.264 encoded video de-payloading following RFC 6184, supporting:
  • single NAL unit packets
  • fragmentation packets (FU-A)
  • aggregation packets (STAP-A)
• de-serializing of Parrot video frame metadata from RTP header extensions
• de-serializing of Parrot video session metadata from RTCP SDES packets
• pre-decoder error concealment: reconstructing missing slices as skipped slices to ensure a syntactically complete H.264 bitstream for decoders
• statistics computing:
  • RTCP receiver reports
  • Parrot receiver video stats
• no network implementation: the application must handle network sending/receiving

Dependencies

The library depends on the following Alchemy modules:

• libfutils
• libh264
• libpomp
• librtp
• libulog
• libvideo-metadata

Building

Building is activated by enabling libvideo-streaming in the Alchemy build configuration.

Operation

Threading model

The library is designed to run on a libpomp event loop (pomp_loop, see libpomp documentation). All API functions must be called from the pomp_loop thread. All callback functions are called from the pomp_loop thread.

Sender

The sender takes as input H.264 frames as a structure containing the NAL units information. The RTP payloading is performed and the packets to send are output through the send_data callback function. The control packets (RTCP) to send are output through the send_ctrl callback function. Packets are handled as pomp_buffer objects.

Receiver

The receiver takes as input data (RTP) and control (RTCP) packets. The RTP de-payloading is performed and the reconstructed frames are output through the recv_frame callback function. The control packets (RTCP) to send are output through the send_ctrl callback function. Packets are handled as pomp_buffer objects.

Testing

The library can be tested using the provided vstrm-test command-line program which sends an H.264 (annex B byte stream) file as an RTP/AVP stream and/or receives an RTP/AVP stream.

To build the test program, enable vstrm-test in the Alchemy build configuration.

For a list of available options, run

$ vstrm-test -h