[Ssc-dev] 3 working audio redaction methods for ffmpeg

[Hans-Christoph Steiner]

Hey all,

There was a big development in ffmpeg in the past month, they've redid how the audio filters work, so now you can actually do stuff with audio filters.  The downside is that its not in any released version yet.  Hopefully it'll be in 0.8.8.  I also had to tweak Andrew's vf_redact.c to work with the HEAD of ffmpeg's master.

That said, I know have an af_aredact.c audio redaction plugin working with 3 methods of redaction: 

- mute: zeros out the audio in that region
- buzzer: adds a loud buzzer sound in that region
- resample: resamples to 1.5kHz leaving voices understandable and giving a sense of the audio atmosphere

It uses a similar file format: comma separated values with start,end,redaction_method, i.e.:

1.129,2.391,mute
3.129,4.391,buzzer
5.129,6.391,resample
7.129,8.391,none

So the idea now is that there is a separate file for the audio redaction and the video redaction.  It would be possible to use the same file if that makes sense.  I just need start/end/method.  Now I'm off to get a fully working build for Android of all this.

.hc

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