29 lines
1.1 KiB
Markdown
29 lines
1.1 KiB
Markdown
# Protobuf protocol
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This protocol was created by adsb-tools. This specification is official.
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## Format
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[Protocol buffer](https://developers.google.com/protocol-buffers/docs/overview) encoding.
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Proto definition is [here](https://github.com/flamingcowtv/adsb-tools/blob/master/proto/adsb.proto).
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Stream is a series of Adsb records with length encoded in a prefix (protobuf isn't self
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delimiting). The prefix is structured such that an entire stream is a valid AdsbStream
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record.
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First frame must always be an AdsbHeader; frames can otherwise appear in any order, including
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additional headers.
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## Prefix
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* `0x0a`: in protobuf encoding, field #1, type 2 (length-encoded bytes); (1 << 3) | 2
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* Length of packet not including prefix, encoded as a [base 128 varint](https://developers.google.com/protocol-buffers/docs/encoding#varints)
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## Packet
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See [definition file](https://github.com/flamingcowtv/adsb-tools/blob/master/proto/adsb.proto)
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for details.
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## Tips
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To decode a stream file:
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`$ protoc-c --proto_path=adsb-tools/proto --decode=AdsbStream adsb-tools/proto/adsb.proto < streamfile`
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