PID - TS Packet identifier
Elementary streams (video, audio) and information tables are packed to the TS-packets. Each packet has unique identifier - PID.
The PID value must be between 0 and 8191. The range 0 to 31 and 8191 is reserved and should not be used. You can use any PID in the range from 32 to 8190.
How to find PID values in the stream?
- With VLC player
Play the stream, then open Tools - Media Information - Codec. The "Original ID" field contains PID value.
- With Astra analyzer
Launch in console:
astra --analyze "stream address"
CBR/VBR - Bitrate
Stream bitrate has two types:
- VBR - variable bitrate, depends of the stream compression ratio
- CBR - constant bitrate, this is VBR stream stuffed with NULL-TS packets
NULL-TS packets have constant PID - 8191 and don't have payload, only zeros.
To generate CBR streams in Astra append the cbr option into the output address. Value should be in Kbit/s. For example:
Note: the "no_sync" option disables CBR
For versions below 5.63 - the CBR option must be used in conjunction with the "sync" option"
If stream bitrate higher than "cbr" value, then stream passed as is. Option works only for UDP-output. For any other formats no reason to use CBR.