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nstanger / process_podcast

Python script for processing and assembling a podcast from various input sources
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Add --preview option #17

Closed nstanger closed 7 years ago

nstanger commented 8 years ago

Issue by nstanger Wednesday Aug 17, 2016 at 02:47 GMT Originally opened as https://github.com/Otago-InfoSci-Database/Tools/issues/17

When rendering podcasts with separately recorded audio and video tracks, it’s a bit tedious to have to build the entire podcast in order to test whether the audio/video synchronisation is correct. A --preview option that renders, say, the first five minutes (or even a specified time range?) could be useful.

nstanger commented 7 years ago

Cunning plan: let --preview specify an output frame rate (-r option for ffmpeg, or could embed an fps=1 in the video concatenation part of the complex filter). A default of 1 is probably about right, and will be much faster than rendering the entire thing (about 1 minute to encode 36 minutes of video vs. 6 minutes at full rate). That should be enough to quickly spot major misalignments between video and audio.

Note that -r/fps supports fractions (e.g., 1/2 for one frame every two seconds).