Baseband

================

Bug Fixes
---------

- Frame rates are now calculated correctly also for Mark 4 data in which the
first frame is the last within a second. [341]

- Fixed a bug where a VDIF header was not found correctly if the file pointer
was very close to the start of a header already. [346]

- In VDIF header verification, include that the implied payload must have
non-negative size. [348]

- Mark 4 now checks by default (``verify=True``) that frames are ordered
correctly. [349]

- ``find_header`` will now always check that the frame corresponding to
a header is complete (i.e., fits within the file). [354]

- The ``count`` argument to ``.read()`` no longer is changed in-place, making
it safe to pass in array scalars or dimensionless quantities. [373]

Other Changes and Additions
---------------------------

- The Mark 4, Mark 5B, and VDIF stream readers are now able to replace
missing pieces of files with zeros using ``verify='fix'``. This is
also the new default; use ``verify=True`` for the old behaviour of
raising an error on any inconsistency. [357]

- The ``VDIFFileReader`` gained a new ``get_thread_ids()`` method, which
will scan through frames to determine the threads present in the file.
This is now used inside ``VDIFStreamReader`` and, combined with the above,
allows reading of files that have missing threads in their first frame
set. [361]

- The stream reader info now also checks whether streams are continuous
by reading the first and last sample, allowing a simple way to check
whether the file will likely pose problems before possibly spending
a lot of time reading it. [364]

- Much faster localization of Mark 5B frames. [351]

- VLBI file readers have gained a new method ``locate_frames`` that finds
frame starts near the current location. [354]

- For VLBI file readers, ``find_header`` now raises an exception if no
frame is found (rather than return `None`).

- The Mark 4 file reader's ``locate_frame`` has been deprecated. Its
functionality is replaced by ``locate_frames`` and ``find_header``. [354]

- Custom stream readers can now override only part of reading a given frame
and testing that it is the right one. [355]

- The ``HeaderParser`` class was refactored and simplified, making setting
keys faster. [356]

- ``info`` now also provides the number of frames in a file. [364]

================

- This version only supports python3.

New Features
------------

- File information now includes whether a file can be read and decoded.
The ``readable()`` method on stream readers also includes whether the
data in a file can be decoded. [316]

Bug Fixes
---------

- Empty GUPPI headers can now be created without having to pass in
``verify=False``. This is needed for astropy 3.2, which initializes an empty
header in its revamped ``.fromstring`` method. [314]

- VDIF multichannel headers and payloads are now forced to have power-of-two
bits per sample. [315]

- Bits per complete sample for VDIF payloads are now calculated correctly also
for non power-of-two bits per sample. [315]

- Guppi raw file info now presents the correct sample rate, corrected for
overlap. [319]

- All headers now check that ``samples_per_frame`` are set to possible numbers.
[325]

- Getting ``.info`` on closed files no longer leads to an error (though
no information can be retrieved). [326]

Other Changes and Additions
---------------------------

- Increased speed of VDIF stream reading by removing redundant verification.
Reduces the overhead for verification for VDIF CHIME data from 50% (factor
1.5) to 13%. [321]

================

- VDIF and Mark 5B readers and writers now support 1 bit per sample.
[277, 278]

Bug Fixes
---------

- VDIF reader will now properly ignore corrupt last frames. [273]

- Mark5B reader more robust against headers not being parsed correctly
in ``Mark5BFileReader.find_header``. [275]

- All stream readers now have a proper ``dtype`` attribute, not a
corresponding ``np.float32`` or ``np.complex64``. [280]

- GUPPI stream readers no longer emit warnings on not quite FITS compliant
headers. [283]

Other Changes and Additions
---------------------------

- Added release procedure to the documentation. [268]

================

New Features
------------

- Expanded support for acccessing sequences of files to VLBI format
openers and `baseband.open`. Enabled `baseband.guppi.open` to open file
sequences using string templates like with `baseband.dada.open`. [254]

- Created `baseband.helpers.sequentialfile.FileNameSequencer`, a
general-purpose filename sequencer that can be passed to any format opener.
[253]

Other Changes and Additions
---------------------------

- Moved the Getting Started section to :ref:`"Using Baseband"
<using_baseband>`, and created a new quickstart tutorial under :ref:`Getting
Started <getting_started>` to better assist new users. [260]

==================

Bug Fixes
---------

- Ensure ``gsb`` times can be decoded with astropy-dev (which is to become
astropy 3.1). [249]

- Fixed rounding error when encoding 4-bit data using
``baseband.vlbi_base.encoding.encode_4bit_base``. [250]

- Added GUPPI/PUPPI to the list of file formats used by `baseband.open` and
`baseband.file_info`. [251]

================

New Features
------------

- Added a new `baseband.file_info` function, which can be used to inspect
data files. [200]

- Added a general file opener, `baseband.open` which for a set of formats
will check whether the file is of that format, and then load it using the
corresponding module. [198]

- Allow users to pass a ``verify`` keyword to file openers reading streams.
[233]

- Added support for the GUPPI format. [212]

- Enabled `baseband.dada.open` to read streams where the last frame has an
incomplete payload. [228]

API Changes
-----------

- In analogy with Mark 5B, VDIF header time getting and setting now requires
a frame rate rather than a sample rate. [217, 218]

- DADA and GUPPI now support passing either a ``start_time`` or ``offset``
(in addition to ``time``) to set the start time in the header. [240]

Bug Fixes
---------

Other Changes and Additions
---------------------------

- The `baseband.data` module with sample data files now has an explicit entry
in the documentation. [198]

- Increased speed of VLBI stream reading by changing the way header sync
patterns are stored, and removing redundant verification steps. VDIF
sequential decode is now 5 - 10% faster (depending on the number of
threads). [241]