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> Temu-quality CCTV recorders Those DVR/NVR (including networked cameras) should be among the first things hackers should liberate from their proprietary firmw

> Temu-quality CCTV recorders Those DVR/NVR (including networked cameras) should be among the first things hackers should liberate from their proprietary firmware: they all use Linux but keep it tight closed and quite often phone home somewhere in China, officially to allow users connect via the phone app (another big security concern) to their cloud service, which also means the feed goes through there. One can buy the board alone by searching for "dvr board" on aliexpress and other shops; they're cheap and could be repurposed for other interesting uses because of their fast ADCs for example.

namibj 2y ago
You can't just mention those ADCs without giving at least some representative specs...
- squarefoot 2y ago
  How could I give specs about undocumented chips running a closed system? We know they can sample 1080p video, therefore they must have several MHz bandwidth. Should anyone manage to hack into the internal OS (which is Linux, albeit with closed drivers) and reverse engineer the basic drivers functions, we'd have a cheap platform to play with. As an example, I would explore the possibility to use their ADCs for multi band SDR applications, as the 8 input channel board costs only around $30. Unfortunately there are a lot of ifs, but if I had the skills I would at least attempt a reverse engineering on the cheaper model.
  - namibj 2y ago
    That's already plenty specs. Only thing missing is a bit more detail as to the claimed video standard over which they do 1080p.
    - squarefoot 2y ago
      I worked with some of them years ago and they had plain PAL/NTSC inputs which are low res, but more recent models should be all AHD compatible, which is hi res albeit still analog. The standard was created by Korean company NextChip. https://www.nextchip.com/en/ahd/ahd.php https://www.nextchip.com/en/ahd/ahd.php https://en.wikipedia.org/wiki/HDcctv https://en.wikipedia.org/wiki/HDcctv edit: just found some data about a manufacturer of high res video sampling chipsets, along with some open source software for them. https://www.unifore.net/product-highlights/nvr-dvr-hisilicon-solution-hi3536-hi3531-hi3521-hi3520d.html https://www.unifore.net/product-highlights/nvr-dvr-hisilicon... https://github.com/openhisilicon https://github.com/openhisilicon
      - namibj 2y ago
        Hmmm, thanks. It seems AHD 1 is 720p30 and AHD 2 is 1080p30, but basically just plain yellow RCA jack (just, well, overclocked accordingly). Usability as SDR depends on how well the genlock can be turned off, and how well the h/v blanking can be eliminated. One of them, the NVP6114, seems to have a COLOROFF_x register and a selectable color kill mode (no Y/C separation vs. after Y/C separation). The no-separation + color kill seems to be the closest to dumb ADC, if genlock can be eliminated. AGC seems to be somewhat optional.

namibj 2y ago

You can't just mention those ADCs without giving at least some representative specs...

squarefoot 2y ago
How could I give specs about undocumented chips running a closed system? We know they can sample 1080p video, therefore they must have several MHz bandwidth. Should anyone manage to hack into the internal OS (which is Linux, albeit with closed drivers) and reverse engineer the basic drivers functions, we'd have a cheap platform to play with. As an example, I would explore the possibility to use their ADCs for multi band SDR applications, as the 8 input channel board costs only around $30. Unfortunately there are a lot of ifs, but if I had the skills I would at least attempt a reverse engineering on the cheaper model.
- namibj 2y ago
  That's already plenty specs. Only thing missing is a bit more detail as to the claimed video standard over which they do 1080p.
  - squarefoot 2y ago
    I worked with some of them years ago and they had plain PAL/NTSC inputs which are low res, but more recent models should be all AHD compatible, which is hi res albeit still analog. The standard was created by Korean company NextChip. https://www.nextchip.com/en/ahd/ahd.php https://www.nextchip.com/en/ahd/ahd.php https://en.wikipedia.org/wiki/HDcctv https://en.wikipedia.org/wiki/HDcctv edit: just found some data about a manufacturer of high res video sampling chipsets, along with some open source software for them. https://www.unifore.net/product-highlights/nvr-dvr-hisilicon-solution-hi3536-hi3531-hi3521-hi3520d.html https://www.unifore.net/product-highlights/nvr-dvr-hisilicon... https://github.com/openhisilicon https://github.com/openhisilicon
    - namibj 2y ago
      Hmmm, thanks. It seems AHD 1 is 720p30 and AHD 2 is 1080p30, but basically just plain yellow RCA jack (just, well, overclocked accordingly). Usability as SDR depends on how well the genlock can be turned off, and how well the h/v blanking can be eliminated. One of them, the NVP6114, seems to have a COLOROFF_x register and a selectable color kill mode (no Y/C separation vs. after Y/C separation). The no-separation + color kill seems to be the closest to dumb ADC, if genlock can be eliminated. AGC seems to be somewhat optional.