Version 1.8.1

• Fix a bug where an unparseable ACARS message could cause the program to crash.
• Add a little bit of optimization when compiling with debugging enabled. Debug
  builds are now compiled with -Og flag rather than -O0. This makes debugging on
  a Raspberry Pi feasible - when -O0 was used, CPU usage was often too high and
  caused loss of samples and reduced decoding success rate.

Version 1.8.0

• Support for ATN-B2 Automatic Dependent Surveillance-Contract (ADS-C)
  version 2.
• Support for automatic reassembly of multiblock ACARS messages, MIAM file
  transfers and fragmented X.25 packets. Contents of reassembled messages is now
  logged in one piece and passed upwards to decoders of higher layer protocols /
  applications. Thanks to this, many large messages which so far were decoded
  partially and logged with "Unparseable ... PDU" errors due to fragmentation,
  are now decoded correctly. StatsD metrics for monitoring reassembly engine
  performance have been added.
• Logged messages may be enriched with ground stations details read from a text
  file in MultiPSK GS format. Look up --gs-file and --addrinfo options in
  README.md and dumpvdl2 usage text for more details.
• Logged messages may be enriched with aircraft details read from a Basestation
  SQLite database. SQLite3 library must be installed prior to compiling dumpvdl2
  in order for this feature to be enabled. Look up --bs-db and --addrinfo
  options in README.md and dumpvdl2 usage text for more details. Database
  entries are cached in memory. There are new StatsD metrics for monitoring
  performance and utilization of the cache.
• New --prettify-xml option enables pretty-printing of XML documents carried
  in ACARS and MIAM CORE messages. The purpose is to improve readability. If
  enabled, XML content will be printed as multiline text with proper indentation.
  This requires libacars built with libxml2 support.
• ACARS sublabel and MFI fields are now stripped from message text and logged as
  separate fields (if present).
• When compiled with debugging support, dumpvdl2 now has a new --debug command
  line option allowing configurable verbosity of debug messages. No debug output
  is produced by default. Refer to README.md for more details.
• Added extras subdirectory to the source tree. Additional content related to
  dumpvdl2 will be stored here. Currently bundled extras are: multitail color
  scheme for dumpvdl2 log files and vdl2grep script for grepping dumpvdl2 log
  files.
• Bug fixes, code cleanups.
• libacars version 2.0.0 or later is now required to compile and run dumpvdl2.

Version 1.7.1

• Fixed an issue where a truncated or corrupted ICAO APDU could cause a crash in ASN.1 decoder.
• Fixed an issue where NULL characters in XID attribute values could cause them do be printed partially. Any non-printable characters in octet strings printed as text are now replaced with periods.

Version 1.7.0

• Complete overhaul of output generation code. Messages are no longer printed directly into the output file, but rather stored in memory in a structured manner and serialized into an output string (still in memory), which is then printed into an output file. This change does not bring significant benefits or features yet, but is a major step towards multi-output, multi-format architecture in the next release. A side effect of this is more concise
  output formatting (indentation). The purpose of this is to better visualise message hierarchy (layered structure). Note: libacars version 1.3.0 or later is now required to compile and run dumpvdl2.
• Significant enhancements to CLNP, COTP and IDRP decoders. Most if not all protocol headers are now decoded and included in the output.
• Added a decoder for X.225 Session Protocol SPDUs.
• Added a decoder for VDL SNDCF error reports.
• XID: improved decoding of XID sequencing, Frequency support and System mask attributes.
• X.25: improved decoding of facility fields, call clearing causes and diagnostic codes.
• Minor bug fixes.

Version 1.6.0

• New build system based on cmake. Refer to README.md for new installation instructions.
• FANS/1-A CPDLC, ADS-C and ACARS decoders have been removed. These features have been moved to libacars library, which is now a mandatory dependency (compilation will fail if libacars is not installed). Refer to README.md for details.
• Added support for SoapySDR library (contributed by Fabrice Crohas). However there are still some limitations with respect to SDR types which dumpvdl2 can work with. As of now, the device must support a sampling rate of 2100000 samples per second. This will be addressed in a future release.
• The program should now compile and run on MacOS, however this hasn't been tested well. Feedback and bug reports are welcome.
• Minor bugfixes

Version 1.5.0

• Sync with the latest SDRPlay API v. 2.13 which is now required to compile the program
• Added support for SDRPlay RSPduo (with tuner selection, bias-T and notch filters)
• Added support for RSP1A features: Bias-T and broadcast notch filter
• Minor bugfixes

Version 1.4.0

• Major improvements to the DSP and decoding engine - gives much better decoding success rate, especially for weak transmissions from distant aircraft.
• Each VDL2 channel is now processed in a separate thread, which allows balancing the load onto multiple CPU cores.
• Fixed a nasty decoder bug which caused good frames to be corrupted during decoding stage and therefore missed.
• Added CRC checking for ACARS messages. If there is a CRC mismatch, the message will still be logged, but with an appropriate warning.
• New StatsD metric avlc.msg.air2air - counts messages from aircraft to aircraft (however strange it seems, such things happen in real life).
• New StatsD metric decoder.errors.too_long - counts VDL2 bursts dropped due to unreasonably large value in the length field.
• Due to changes in the decoding engine, the following StatsD metric are now obsolete and have been removed: avlc.errors.no_flag_start, avlc.errors.no_flag_end, decoder.errors.no_preamble.
• Added --extended-header command line option which causes a few decoder diagnostic parameters to be logged for each message. Refer to the FAQ in README.md for description of the fields.
• Other minor bugfixes and improvements.
• C11-capable compiler is now required to build the program.

Version 1.3.1

• Added decpdlc utility which decodes FANS-1/A CPDLC messages supplied from command line or from a file. Can be used to decode CPDLC traffic received via other media than VDL-2 (eg. ACARS, HFDL, SATCOM). Refer to "decpdlc" section in README.md for details.

Version 1.3.0

• Added decoder for FANS-1/A ADS-C messages
• Added decoder for FANS-1/A CPDLC messages
• Human-readable formatting of CPDLC and Context Management messages (if you still want the old format, add --dump-asn1 command line option)
• Added install rule to Makefile
• Added a sample systemd service file
• Bug fixes

Version 1.2.0

• Better input signal filtering - reduced bit error rate, 10-50% more
  messages successfully decoded.
• SDRPlay: major bugfixes in sample buffer handling code - shall now
  perform equally well as RTLSDR (or even better).
• SDRPlay: --gain knob replaced with --gr (gain reduction). This makes
  gain configuration in dumpvdl2 compatible with other SDRPlay apps.
  See README.md for details.
• SDRPlay: support for selecting device by serial number.
• Added optional build-time PLATFORM knob which sets CPU-specific
  compiler flags to optimize the code for various flavours of
  Raspberry Pi. Supported values: rpiv1, rpiv2, rpiv3.
• Other minor bug fixes