Two Wrongs

(don't make a right)

Sensor and Controller Chip in "Roxcore 720p" Action Camera

by ~kqr

A friend of mine bought a cheap action camera (think GoPro except lower quality) that was on sale. I've been looking for an action camera that I can use on my cycling commutes to capture problems without having to stop and make notes, but anything capable of capturing a license number was way too expensive for me. When I heard about the sale, I got one too.

It's called a "Roxcore 720p Action Camera", and it's incredibly cheap at $200. There's virtually no information on that specific name though; it's pretty clear that we're talking about a Chinese product that is exported and sold with a hundred different names in various markets. I like to know what I buy, though, so thus began my quest to figure out what it is.

What I Found Out

The camera I bought

  • is a low-quality SJ4000 copy (and the SJ4000 in turn is a GoPro copy...).
  • often goes by names that have "A8" in them.
  • probably has an OmniVision OV9712 sensor.
  • probably has a sensor size of 1/4".
  • probably has an actual sensor resolution of 1280×800.

So it's not stellar, but it's not terrible either. Think of it as "a step below smartphones, but in a convenient case and nowhere near as valuable".

Note that while the camera is described as being capable of 5 megapixel stills, the sensor resolution is only 1 megapixel, so it may not be very useful to set the camera to capture stills at a higher resolution. But then again, it may not hurt either, since the controller chip is very clearly powerful enough to process those jpegs quick.

Finding This Out

If you're interested in how I arrived at this, these were the rough steps I took.

  1. Once I had figured out it was some sort of generic Chinese variant, I just looked at different Chinese action cameras to see if any of them struck me as visually similar. The SJCAM SJ4000 stood out as a candidate.
  2. Once I had a hunch there was some relation to the SJ4000, I added in some more clues. I know it has a maximum video resolution of 720p, it has around 100–105 degrees field of view, the battery is charged to 3.3 volts, and the screen on the back is 2 inches. I started searching Ebay, AliExpress and such for these terms in combination with SJ4000.
  3. Sure enough, some of the cameras listed had "SJ4000" in their title, but were clearly not real SJ4000s. Recurring terms in the titles were "Sunplus A8", "iCatch A8" and "A8 action camera".
  4. The EXIF data from the images talk about an SPCA1628, which I know from the previous step refers to a Sunplus manufactured camera controller chip! At least I assume so, since the SPCA1528 (one digit differs) is a general CMOS camera sensor controller card. There's surprisingly little concrete information on the SPCA1628.
  5. When combining searches for action camera, SPCA1628 and A8, some sales listings also mention the OmniVision OV9712 sensor. The OV9712 is a 1/4" sensor with an active grid of 1280×800 pixels, capable of producing 720p stills at 30 frames per second – perfectly matching the camera capability. I'm assuming this is what it is.

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