stb-tester 0.20 release

[David Röthlisberger]

0.20: Stb-tester ported to GStreamer 1; OCR accuracy improvements

http://stb-tester.com/release-notes.html#0.20

Stb-tester has been ported to GStreamer 1, so it is incompatible with
your existing "source_pipeline" (and possibly "sink_pipeline")
configuration from stb-tester 0.18.

No changes are needed to your test scripts.

If you're upgrading from 0.18, see the release notes for the 0.19 beta
release.

Thanks to Lewis Haley and Máté Szendrő for extensive testing, bug reports, and
patches.

##### Breaking changes since 0.19 beta

* `stbt.ocr` returns a unicode object rather than a string.
* Note that 0.19 beta introduces significant breaking changes (to your stbt
configuration files, not to your test scripts) from 0.18; see the 0.19 beta
release notes for details.

##### User-visible changes since 0.19 beta

Changes to the Python API:

* Improvements to OCR (optical character recognition):
* Accuracy improvements (see
[this blog post](http://stb-tester.com/blog/2014/04/14/improving-ocr-accuracy.html)
for details).
* Callers of `stbt.ocr` can specify the expected language.
* Callers of `stbt.ocr` can pass custom dictionaries and custom patterns
to tesseract (the OCR engine that stb-tester uses).
* Callers of `stbt.ocr` can fine-tune any of tesseract's paramaters.
Note that the effect, and even existence, of these parameters can
vary from one version of tesseract to another.
* For details see the
[`stbt.ocr` API documentation](http://stb-tester.com/stbt.html#ocr)
and [OCR Tips](http://stb-tester.com/ocr.html).
* `stbt.ocr` debug (enabled with `stbt run -v`) reports the region
you specified.
* `stb-tester/tests/validate-ocr.py` is a script that you can use to
measure the effect of changing OCR parameters against your own private
corpus of test screenshots.
* `stbt.Region` has new convenience methods to create a Region from x & y
coordinates instead of width & height, and to check if a Region is contained
within another. For details see the
[`stbt.Region` API documentation](http://stb-tester.com/stbt.html#Region).
* `stbt.debug` output is now UTF-8.

Changes to the command-line tools:

* Improve `stbt run` latency on slow computers and after video-capture device
restarts ([issue #137](https://github.com/drothlis/stb-tester/issues/137),
introduced in 0.19).
* `stbt power` supports the ATEN brand of network-controlled power distribution
units (thanks to Aiman Baharna).
* `stbt tv` fixed on OS X (broken in 0.19 in the port to GStreamer 1).
* `stbt lint` gives a better error message when no arguments are given.
* `stbt control` no longer needs `nose` (a python testing tool) to run.
(Dependency introduced in 0.19.)
* `stbt screenshot` skips the first frame, because some V4L video-capture
hardware delivers a single black frame before the real video stream.
* `stbt batch run` classifies Blackmagic Intensity Pro problems correctly
(broken in 0.19).
* Fixed deprecation warning printed by `stbt templatematch` (introduced in
0.19).
* `stbt run` with `GST_DEBUG_DUMP_DOT_DIR` defined will now dump the debugging
information for the appropriate pipeline. Previously we dumped debugging
information for the source pipeline, even if the error came from the sink
pipeline.
* All `stbt run` debug output is UTF-8.
* `stbt run -vv` image-matching debug output shows more precise values for
the threshold of the first pass of the image processing algorithm.

Other changes:

* The report generated by `stbt batch` has improved the presentation of the
currently-selected row: Instead of highlighting it in blue, you can still see
the green/red/yellow colour so you can tell whether that test-run passed or
failed.
* The Virtual Machine creation script in `extra/vm/` is now based on Ubuntu
14.04 (instead of 12.04) and installs stb-tester 0.20 from the Ubuntu PPA
(instead of installing the version of stb-tester from your source checkout on
the host machine).
* Ubuntu packaging fixes: The stb-tester package now installs lsof (used by
`stbt batch run` if you're using the Blackmagic Intensity Pro video-capture
card), gstreamer1.0-libav (for H.264 decoder if you're using a video-capture
device that provides H.264-encoded video; on Fedora you have to install this
manually from rpmfusion), and the tesseract-ocr English language data.
* Fedora packaging fixes: The stb-tester package now installs lsof,
gstreamer1-plugins-bad-free-extras (for the GStreamer `decklinksrc` element
for the Blackmagic Intensity Pro).

##### Developer-visible changes since 0.19 beta

* `make check` now passes with pylint 1.x (and it continues to pass with pylint
0.x).
* The tarball generated by `make dist` is more deterministic (running `make
dist` twice should now result in tarballs with the same checksum --
at least when running `make dist` on the same machine).

[David Röthlisberger]

On 10 Jun 2014, at 10:02, David Röthlisberger <da...@stb-tester.com> wrote:
> 0.20: Stb-tester ported to GStreamer 1; OCR accuracy improvements

I should add that the "Getting Started" guide has been rewritten for
stb-tester 0.20 / GStreamer 1; I recommend that you re-read it:
http://stb-tester.com/getting-started.html

Also we have added two new articles to the technical documentation:

* Backwards compatibility notes:
http://stb-tester.com/backwards-compatibility.html

* OCR Tips: http://stb-tester.com/ocr.html