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--- a/content/log/2025/construction-site-surveillance.md
+++ b/content/log/2025/construction-site-surveillance.md
@@ -58,9 +58,10 @@ There are two codec choices, mostly:
found in Wikipedia][14], it was used by 91% of video industry developers as
of September 2019. Every screen-equipped device that I tried can play it.
- *H.265* (a.k.a. _HEVC_) is a royalty- and patent-ridden codec which offers
- 25-50% [better compression ratios][15]. In my experience, the compression
- ratio was over 50%. It is amazing for transfer, un-playable on everything
- I've tried except Google Chrome browser on Android[^1].
+ 25-50% [better compression ratios][15] than H.264. In my experience, the
+ compression ratio was over 50% better than H.264. It is amazing for transfer,
+ un-playable on everything I've tried except Google Chrome browser on
+ Android[^1].
- *AV1* seems to be anecdotally on-par with H.265 and is not patent-ridden.
Camera cannot stream it, but lack of patent problems implies, it should be
good for recordings. However:
@@ -82,6 +83,11 @@ There are a few variables you may want to check:
remotely. I picked one with PTZ, but more out of curiosity than necessity.
Turns out, ONVIF (the "open" protocol to control PTZ cameras) is very poorly
supported, or not at all, with the NVRs I've tried.
+ - Later edit: PTZ is great during construction. I can zoom into a road if I
+ am expecting transport (and want to check, say, if it is not destroying
+ everything around), I can zoom into a particular area of the house if I
+ want to. Great choice for the first camera. Probably not for the second one
+ — it will get boring with time.
- Resolution versus visibility in low light. [ipcamtalk.com][2] has decent
recommendations, start there.
- Do your research in the [website][2], there are some great tips. I wish I had
@@ -100,7 +106,7 @@ two options for an NVR:
experience is "it is what it is". I.e. camera manufacturers may or may not be
the best NVR UX designers, especially when it comes to viewing the recordings
or live stream remotely. However, they will for sure create the best Camera ⇔
- NVR integration.
+ NVR integration. Most hassle-free, least control.
- Open source NVRs, which you can install to your existing home server. I
considered [frigate][3], [Moonfire NVR][4] and [ZoneMinder][5]. Since I use a
[home server]({{< ref "log/2023/nixos-subjective" >}}), I am self-hosting my
@@ -114,11 +120,11 @@ detection, not even "in theory". I have relatively powerful hardware in the
closet and want object detection for it.
Moonfire NVR's interface is ncurses-based, similar to how Linux kernel is
-configured. In opinion, for end-user product, one either offers file-based
+configured. In my opinion, for end-user product, one either offers file-based
configuration, or web-based configuration directly in the browser. Many
-projects do both (e.g. home-assistant, frigate). This is the first ncurses-based
-configuration for a consumer product. Which makes me wonder what their audience
-is.
+projects do both (e.g. home-assistant, frigate). This is the first
+ncurses-based configuration for a consumer product. Which makes me wonder what
+their audience is.
{{
}}
-Once configured, the recordings are printed as a timestamped list. Which is
+Once configured, the recordings are listed as a timestamped list. Which is
good if you know the time upfront, but is not great for discovery.
{{
}}
+I didn't go with Moonfire, because it is does not offer a good UX for
+discovering videos, and I much prefer file-based configuration.
+
## Setting up Frigate
*Frigate* seems to be what the kids use these days. Documentation is extensive,
@@ -142,10 +151,10 @@ It took a few evenings to get it to work, and it works.
A few tips before you get started:
-- for object detection you will need hardware support. Look at [recommended
+- For object detection you will need hardware support. Look at [recommended
hardware][6]. I went with Google Coral, but I've heard good things about
OpenVINO too.
-- start with go2rtc from the get-go. I had to re-configure all the Frigate
+- Start with go2rtc from the get-go. I had to re-configure all the Frigate
streams, which was way more annoying than it's worth if you start with
go2rtc. Saved a lot of bandwidth, too. More on that later.
@@ -173,13 +182,18 @@ cameras take ~21-24GiB/day.
Every 5 minutes a separate process captures a full-resolution picture of both
cameras: `5376x1520` and `2560x1440`. I have a bunch of timelapses already! If
-we meet in person, I will happily show.
+we meet in person, I will happily show them.
{{
}}
+{{
}}
+
Using exactly the same parameters (resolution, fps), but with h.264, the
bandwidth grows to 11 Mb/s. Which may not sound like a lot with today's fiber
everywhere, but is considerable on a 4G connection.
@@ -219,4 +233,4 @@ corners, but, in my opinion, in the end it's worth it.
[14]: https://go.bitmovin.com/hubfs/Bitmovin-Video-Developer-Report-2018.pdf
[15]: https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding
-[^1]: or vlc. Thanks to the French who make a point about not caring about royalties
+[^1]: Or vlc. Thanks to the French who make a point about not caring about royalties.