![]() ![]() For this the elementary streams have to undergo two layers of packetization (Fig. In order to transmit a multimedia content (audio and video) across a channel, the two streams have to be converted in to a single stream of fixed sized packets. Since each frame is coded differently the size of each access unit also varies. An access unit is a coded representation of a frame. The encoded bit streams or elementary streams of H.264 and HEAACv2 are arranged as a sequence of access units. HEAACv2 is the adopted standard for ATSC-M/H and many other systems around the world. It comes with a fully featured toolset which enables coding in mono, stereo and multichannel modes (up to 48 channels). HE AAC v2 has been proven to be the most efficient audio compression tool available today. It is specifically designed for low bit rate applications such as streaming, mobile broadcasting etc. HEAACv2 or High efficiency advanced audio codec version 2 also known as enhanced aacplus is a low bit rate audio codec defined in MPEG4 audio profile belonging to the AAC family. Hence it is relevant and practical to encode/decode and multiplex/demultiplex both video and audio for replay at the receiver. ![]() H.264 covers only video coding and is not of much use unless the video is accompanied by audio. The H.264 has been adopted as the video standard for many applications around the world including ATSC. But the higher codingefficiency comes at the cost of increased complexity. This standard achieves much greater compression than its predecessors like MPEG-2 video, MPEG4 part2 visual etc. It was jointly developed by the VCEG (video coding experts group) of ITU-T (international telecommunication union) and the MPEG (moving pictures experts group) of ISO/IEC (international standards organization). Introduction H.264 is the latest and the most advanced video codec available today. It is shown that during decoding the audio-video synchronization is achieved with a maximum skew of 13ms.ġ. The proposed multiplexing and de-multiplexing algorithms followed to achieve synchronization are explained. It also introduces the concept of timestamps. This paper briefly introduces the MPEG2 systems, two layers of packetization namely program elementary stream (PES) and transport stream (TS). This paper presents a scheme to multiplex the elementary streams of H.264 video and HE AAC v2 audio using the MPEG2 systems specifications, then de-multiplex the transport stream and playback the decoded elementary streams with lip synchronization or audio-video synchronization. In a broadcasting system, multiplexing is a process in which two or more elementary streams are converted into a single transport stream ensuring synchronous playback of the elementary streams and proper buffer behavior at the decoder. MPEG2 part1 specifies two layers of packetization to achieve a transport stream suitable for digital transmission. You can implement N+1 redundancy by allocation of a hot swappable spare TSPlayer and the appropriate configuration under System Mgt->Peer Management.Television broadcasting applications such as ATSC-M/H, DVB require that the encoded audio and video streams to be transmitted across a network in a single transport stream containing fixed sized data packets that can be easily recognized and decoded at the receiver. For the standard platform, we would suggest an upper limit of eight simultaneous stream builds.įailure recovery of TSPlayer systems can be administered by use of the Peer Group capabilities of TSBroadcaster. The total number of transport streams built by TSBroadcaster is of course dependent on the performance of the host hardware. If more outputs are required, additional TSPlayer server platforms is recommend. Usually we recommend no more than four operational TSPlayers per TSBroadcaster or TSPlayer unit. The number of TSPlayers per TSBroadcaster is controlled by the license file. TSBroadcaster systems can build multiple transport streams but require one TSPlayer software server to be running to stream each output. TSBroadcaster Systems With Mutliple Outputs In the case of ASI output, the TSMux, subsystem.A suitable Linux-based server, typically an HP Proliant DL 360 G8 or similar running CentOS 6.3 or later.TSBroadcaster advanced software multiplexer (accessible through the "Outputs" tab).TSBroadcaster core software providing the Outputs, Operations, System Mgt and Task Mgt subsystems.TSPlayer can also operate as a generic MPEG stream player, including a multiplex capability, ideal for spooling a number of streams generated by third party tools. TSPlayer is an MPEG multi-program transport stream player which is particularly suitable for streaming EBIF and OCAP content, encoded and created by the TSBroadcaster and SoftOC products. ![]()
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