[MacPorts] #56417: transcode @1.1.7_21 fails to build with ffmpeg 4

[MacPorts]

#56417: transcode @1.1.7_21 fails to build with ffmpeg 4
------------------------+-----------------------
  Reporter:  tehcog     |      Owner:  Liontooth
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.4.3
Resolution:             |   Keywords:
      Port:  transcode  |
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Comment (by ajdudman):

 Sorry for my slow response with the **Portfile.diff** attachment.  I do
 not have a GitHub account.

 Hello bunk3m, you have ffmpeg 4 installed and are using the current
 **Portfile** and its patches designed for ffmpeg 3.


 See attached **main.3.log** for a successful build log of transcode using
 my submitted attachments and ffmpeg 4.

 {{{
 port -svd build transcode build.jobs=1
 }}}
 Still remaining, code should be added to reject ffmpeg 3.

 It is a shame upstream has no checks nor tests to be run.

-- 
Ticket URL: <https://trac.macports.org/ticket/56417#comment:7>
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