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How do you know what bands they are watermarking? And isn't it likely they use some within the normal speech band?
by j4yav 6y ago
How do you know what bands they are watermarking? And isn't it likely they use some within the normal speech band?
- megous 6y agoWhy would re-encoding into mp3 help? The audio is probably already in some low bitrate similar codec.
- semi-extrinsic 6y agoIf you pick a bad enough codec, it should mask watermarks by distorting the sound, while still allowing speech to be audible. Maybe something like mu-law, which only has 3 kHz bandwidth centered on human speech (as opposed to mp3 with usually 44.1 kHz) would perform best.
- ddingus 6y agoAt those rates, the audio loses credence.
- quenix 6y agoI think the idea is that if they use audible frequencies, the user will, well, _hear_ them.
- eru 6y agoPeople are used to artifacts in zoom calls, the sound quality ain't always the best. I also noticed that zoom corrects for lag in my connection by speeding up and slowing down speech. (I noticed that when my counterpart was running a metronome.) Zoom could artificially introduce micro-lags to encode data. Eg as a human I can't really tell whether some sound starts on an even or an odd milli-second.
- ddingus 6y agohttps://blogalytics.typepad.com/files/a-technical-look-at-arbitrons-ppm-system.pdf https://blogalytics.typepad.com/files/a-technical-look-at-ar... Not really. And if a user does, they will hear rather mundane codec artifacts, and or noise that is basically like other noise. Given a redundant mark, and the system I linked has multiple, concurrent redundancy, the chance of the mark surviving grows with the amount of audio. They can literally drop marks during speech the entire time.
- j4yav 6y agoIt's not like it's a voiceover that explains who is watching the video. It can be a series of quiet pops.
- ddingus 6y agoExtremely likely. That is probably the best place to put it.