The Remap feature in Astra allows modify the Packet Identifier (PID) for MPEG-TS elementary streams.
Remapping Stream PIDs is beneficial in various scenarios:
To identify available elementary streams and their PIDs, it's necessary to analyze the channel. This can be achieved by launching the built-in MPEG-TS analyzer either from the channel menu or directly from the channel settings.
On the provided screenshot, we can see the following elementary streams:
Each elementary stream is represented by a unique Packet Identifier (PID), which can be used for Stream Remapping in Astra.
Please note that PID value could be in range from 32 to 8190.
In order to perform the stream remapping, we will change the PMT PID to 100, the video stream PID to 101, and audio stream PID to 102. This operation can be conducted by appending the
map.pmt=100&map.video=101&map.audio.eng=102 option to the input address
For stream remapping across all inputs, the
Remap tab in the channel settings can be used.
In the "Map PIDs" field,
pmt=100, video=101, audio.eng=102 has been set. This alters the PIDs of the video and English audio streams to 101 and 102, respectively, across all inputs.
To verify the results of the applied stream filter, click "Apply" to save the changes. Next, launch the built-in MPEG-TS analyzer again. This will allow you to check if the unnecessary streams have been successfully filtered out.
Selector determinates what PID should be changed to the new value
pmt - PID for Program Map Table (PMT)
video - video stream
audio - any audio stream. You may define this option twice if you have several audio streams, for example:
video=101, audio=102, audio=103
audio.eng - audio stream with defined language code
ac3 - AC3 audio stream. The
audio selector could be used for AC3 streams as well
aac - AAC audio stream. The
audio selector could be used for ACC streams as well
371 - original PID
pcr - PID for packets with PCR. Usually the PCR timestamp delivered with video stream packets
sub - subtitle stream
ttx - teletext stream
ait - PID for Application Information Table (AIT)