update convert_mp4.sh script

[tbrannam]

-p makes command not fail if folder exists && seems to be required (ubuntu) additional protocols were required when processing 'Space 1999'

[warren-bank]

Hi. Thanks for the constructive feedback.

These are my immediate thoughts on what you've suggested:

• this ffmpegcmd string is descriptive, and purely for logging purposes

  • sometimes things break, and need to be rerun..
  • I find it's helpful to have a command-line dump that's (mostly) ready to use
  • for example, if all the files downloaded OK but ffmpeg fails..
    • I wouldn't want to accidentally delete all the files and start over
    • I'd want to cherry pick the one command that failed and massage its parameters a little until it succeeds
    • admittedly, this methodology isn't super polished..
      but the automatic operation succeeds without manual intervention almost all of the time
  • in terms of updating this log message:
  • mkdir -p isn't cross-platform
    • it wouldn't work on Windows.. so I wouldn't want to include it
  • you're right about replacing & with &&
    • I don't remember my reasoning, but it looks like a typo
  • the -protocol_whitelist ALL ffmpeg option shouldn't be necessary
    • only file is needed, and that's enabled by default

• regarding where these operations actually occur..

  • mkdir is done here
    • using node's fs module
  • this is the code in an external library dependency where ffmpeg is executed
  • called here
  • if I were to add any additional ffmpeg command-line options, this is where I would do so
    • adding -protocol_whitelist ALL (or, -protocol_whitelist file) here wouldn't hurt anything
    • however, I'm probably not going to..
      1. I'm lazy
      2. if it ain't broke..

[warren-bank]

after-thought..

regarding your comment that "additional protocols were required":

• the external library (mentioned) that performs all of the downloading needs to parse HLS manifests
• when it was written, its HLS manifest parser borrowed its methodology (and a lot of its code) from my HLS Proxy app
  • this was a long time ago, and it was based on the 1.x major version
  • since that time, the parser has been greatly improved and migrated from using regular expressions to a better strategy
• it's very possible that the manifests served by Tubi TV include some URLs that this old parser misses..
  • which could explain why ffmpeg fails unless an additional protocol (ex: https) is enabled

At the moment, I'm extremely "in the weeds" on a different project.. and can't switch my focus to digging into this right now. But I'll re-open this PR as a reminder to myself that I should circle back (at some later time) and perform some testing.