Sharing files from authenticated sites
Sharing files from authenticated sites
Should I be concerned before I share a video I downloaded from a site I needed to log in to with a username and password? Does the file I have include data that references my account? If so is there away to remove it before I share it?
Signed I am tired of feeling like I don't contribute to the community.
It's unlikely that there's some identifying information, but you can use ffmpeg (using the "copy" codec to avoid a re-encode) to strip metadata. It's also theoretically possible for the video to have used some stenography techniques, but that would be much harder and expensive for the video creator/publisher so I doubt that happened.
It's not unlikely. Watermarking is real. And they don't make it easy to strip off.
why is your username a password
Would this require specific stripping flags or is a simple
ffmpeg -i video.mkv -c:v copy -c:a copy out.mkvenough?
Use
-map_metadata -1to strip all metadata.The :v and :a is not needed.
ffmpeg -i video.mkv -c copy output.mkv
This will automatically copy the audio and the video without a reencode.
- Yes, because:
- It could
- And if it does, you probably can’t remove it
Streaming sites can embed an unhearable data stream into audio signal. It’s possible
That being said, it’s extremely improbable, given the costs to do it at scale.
If you’re part of a large company’s beta program and have access to some unreleased product, maybe worry.
If you grabbed a file from some mega host updown whatever site, don’t worry.
And if you’re still worried, take a sha256 hash and put it into google search. If you get any results that even mention your file’s title, then you’re good.
Can't you convert to to some lossy format?. Mp3 compresses files by erasing all audio channels outside (or on the edge of) human hearing range, maybe there's some format that does the same in video? (I was thinking of mp4, but mp4 is lossless)
Spread-spectrum audio watermarks will survive multiple re-encodings and are extremely difficult to detect.
Iirc google widevine will embed a device code, and if a pirated copy of some content is found, they will blacklist the gpu’s device code so it can’t receive 4k content anymore. That’s video, but it’s the same idea.
I think Amazon does this, right?
A stream copy with only a audio change is pretty cheap computation wise.