audio track is nowhere to find

[blanc]

Hi,

with Firefox addon „Video DownloadHelper“ 8 mp4 files are detected at https://www.bigmarker.com/access-intelligence-llc1/Navigating-the-Defense-Satcom-Netwo...=db1417a1c045:
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/768.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/audio.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/640.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/1280.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/320.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/1024.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/480.mp4
https://d38fobjf20dmzq.cloudfront.net/8917957c-e552-4ca5-b703-6f3333aef249/dash/1920.mp4
I’ve downloaded all of them but none seems to include the audio track, even audio.mp4. Question: where is the audio track hided? Youtube-dl and yt-dlp don’t work at all.

[ElCap]

as you would expect audio.mp4 is the audio track.....
the files are encrypted, thats why you cant just download them and play them

the key to decrypt it is in the html response - search for "dash_encryption_key"

[blanc]

with ffplay audio-audio.mp4 -decryption_key e808f874bcf1d2995df7837ae12f1873, I can only hear for ca. 10s and then: failed to read iv from the auxiliary info

[ElCap]

it decrypts with mp4decrypt and you can hear the whole file

[[ss]vegeta]

mp4decrypt.exe --key fd73303f6fc2ca78a5a9afb9a0a54db5:e808f874bcf1d2995df7837ae12f1873 "dash [dash].m4a" aud.mp4

https://we.tl/t-lNTRcr8312
ytdlp very much works for downloading
Here's your full video anyway
https://we.tl/t-gXVAOwZT4w

[anayaAO]

mp4decrypt.exe --key fd73303f6fc2ca78a5a9afb9a0a54db5:e808f874bcf1d2995df7837ae12f1873 "dash [dash].m4a" aud.mp4

https://we.tl/t-lNTRcr8312
ytdlp very much works for downloading
Here's your full video anyway
https://we.tl/t-gXVAOwZT4w

a really noob question but where to find the license url in this site

[[ss]vegeta]

a really noob question but where to find the license url in this site

There's no license url, just view page source, keys are there. @ElCap already mentioned but might have confused you with "html response".

[anayaAO]

a really noob question but where to find the license url in this site

There's no license url, just view page source, keys are there. @ElCap already mentioned but might have confused you with "html response".

ah i see

[jack_666]

Must have missed something here.

I looked at the source code and found this reference ....

mp4Url: "https://s3.amazonaws.com/bigmarker-extension/1538c575277b-c7f6fd92bd058790163d19ddf9ba4793/1538c575277b-c7f6fd92bd058790163d19ddf9ba4793.mp4",

Downloaded it, and it played with audio. No decryption needed.

I then downloaded vegeta's upload and found that they were both the same content.

Anyway, who would have thought to search the source for keys. Out of the box, lateral thinking. Edward de Bono would have been proud of you. Brilliant.

[[ss]vegeta]

Must have missed something here.

It's a somewhat bad implementation of Widevine, I guess. Or they have that link as a back-up.
When there's no license url I guess the next logical thing to do is to view the page source. But indeed, don't know if I would have thought of that if it wasn't for @ElCap.