Support for Python 3

[siuyiuyeung]

I am interested in Blackmagic device frame capturing for OpenCV processing.

Will Python 3 be supported?
Or any tips for upgrading the current version that can be compatible with Python 3?

I am really appreciate any help from you.

[dzhoshkun]

Hi @justprotato Thanks for your interest in GIFT-Grab. I'm definitely keen on supporting Python 3. Only, I've never tested GIFT-Grab with Python 3 so far.

That said, I've managed to build GIFT-Grab against Python 3 on my Ubuntu 16.04 using the following:

1. when bootstrapping Boost.Python simply append the --with-python-version=3.5 (or your Python 3 version) option.
2. build GIFT-Grab from source by selecting the appropriate options

With this build, python3 -c 'import pygiftgrab' seems to run fine (as a quick test).

Can you see whether you can reproduce this on your system and then give GIFT-Grab a try with your Blackmagic card?

[dzhoshkun]

TODOs:

• provide a Boost built against Python 3 dev libs on:
  • Adelie
  • device-specific runners
• modify pypi CI script to support both Python versions (possibly a bash loop)
• modify linux CI script to support both Python versions (possibly a bash loop in conj. with virtualenv for running pytest)
• modify device-specific CI scripts in line with the above two points

[dzhoshkun]

• how about using tox for this?

[dzhoshkun]

• https://docs.python.org/3/howto/pyporting.html

[dzhoshkun]

• strings (in test utils) should be turned into bytes (for Python 3)

[dzhoshkun]

• remove all Python 2 specific code such as bash script headers

[aaronmswan]

Hi, I'm also interested in this. What is the status of python 3 support? Much appreciated.

[dzhoshkun]

@aaronmswan What operating system are you using?

[aaronmswan]

Thanks for getting back to me. We were looking at using this tool on Ubuntu 18.04 and CentOS 7/8.

However, I think at this point we might use a custom solution. From a cursory glance, it looks like the focus of GIFT-grab is more for reading than writing.

If you are interested in our use case, we are trying to write video frames and KLV metadata as VANC out to a DeckLink Blackmagic device using the 10 bit YUV pixel format (bmdFormat10BitYUV). Our video frames and KLV data are currently produced in python.

[dzhoshkun]

Thanks @aaronmswan

With GG we've focused on real-time video processing pipelines involving acquisition, scientific computing and encoding, but haven't done any work on writing to a physical output port. One way to write out to a Blackmagic device would be to implement a new VideoTarget (see this figure in our paper).

We've been using GG with Python 3.7 on a Windows machine for one of our internal projects, which is why I asked what OS you are on. The Windows support is experimental and on this branch. In the above commit, I've tried to isolate the Python3-related changes from that branch. Haven't tested it, but it should be all you need to compile GG against Python3, if you fancy giving it a go.