Can't output Prores files with burn in

[jrsndl]

Describe the bug
Global publish plugin configured to encode Prores files fails to produce Prores with burn in.

To Reproduce
Steps to reproduce the behavior:

1. Configure Prores encoding in presets/plugins/global/publish.json
   "codec": [ "-codec:v prores_ks", "-profile:v 3", "-pix_fmt yuv422p10le"]
2. Configure burn in (any text) for the Prores output.
3. Publish version from Nuke
4. Extract burnins fails:

"Executing arguments was not successful: "('"C:\Users\Public\pype_env2/Scripts/python.exe" "Q:\dev\pypesetup\repos\pype\pype\scripts\otio_burnin.py" "c:/users/jiri~1.sin/appdata/local/temp/tmpbw_iyz.json"',)""

RuntimeError: Failed to render '//dps150/zback/_GFX_storage/T009_pypetestAA/shots/trs001/work/compositing/renders/nuke/renderCompositingMain/renderCompositingMain.baked_reviewProresHqburnin.mov': "ffmpeg" -i "//dps150/zback/_GFX_storage/T009_pypetestAA/shots/trs001/work/compositing/renders/nuke/renderCompositingMain/renderCompositingMain.baked_reviewProresHq.mov" -vf "drawtext=fontfile='C:\\Windows\\Fonts\\arial.ttf':text='trs001 v005':x=5:y=h-text_h-5:[email protected]:fontsize=25:box=1:boxborderw=5:[email protected]" -codec:v prores -profile:v hq -b:v 143777771 -pix_fmt yuv422p10le -g 1 -y "//dps150/zback/GFX_storage/T009_pypetestAA/shots/trs001/work/compositing/renders/nuke/renderCompositingMain/renderCompositingMain.baked_reviewProresHqburnin.mov"'

Note that above ffmpeg command works if you replace -codec:v prores with -codec:v prores_ks

Expected behavior
Pype should be able to output Prores with burn in the same as with other codecs.

Desktop (please complete the following information):

• OS: Windows 10
• Host: Nuke 11.3

Possible Fix
It seems like most codecs in ffmpeg have working default encoders, and the only problem is the Prores encoder. Since otio_burnin script uses ffprobe to re-encode the output with burn in, quick but hacky solution might be to simply replace the prores encoder by custom dictionary.
https://github.com/pypeclub/pype/blob/1d940f8b8bacf1aa2a21f292ccb15275bf04b102/pype/scripts/otio_burnin.py#L547

if codec_name:
    encoders = {'prores': 'prores_ks', 'h264': 'libx264'}
    ffmpeg_args.append("-codec:v {}".format(encoders.get(codec_name, codec_name)))

[mkolar]

Resolved by #960

@jrsndl thanks for detailed report

[mkolar]

an important note is that if the original prores wasn't created with ffmpeg, it won't figure out the codec, so I'd call it partial fix