diff --git a/README.md b/README.md
index 2f6de6f..bb4286f 100644
--- a/README.md
+++ b/README.md
@@ -252,6 +252,23 @@ Non-browser HW decode (GStreamer `v4l2codecs`, FFmpeg via
 ohm is a useful starting point for anyone who wants to pick up the
 multiplanar port.
 
+#### Why not "Brave via our system ffmpeg" or Chromium's own V4L2 decoder?
+
+- **System ffmpeg is not a decoder source for Chromium/Brave.** Chromium
+  links a vendored ffmpeg fork; even the Arch-style `use_system_ffmpeg`
+  builds use system `libavcodec` only as a pure software decoder
+  (`FfmpegVideoDecoder`), with no `hw_device_ctx` / hwaccel wiring.
+  Installing our `ffmpeg-v4l2-request-git` would not give Brave HW decode.
+- **Chromium's own `V4L2VideoDecoder` class is compiled into `brave-bin`**
+  (verified via `strings`) but gated behind ChromeOS-only runtime factory
+  checks. `UseChromeOSDirectVideoDecoder` / `V4L2FlatStatelessVideoDecoder`
+  feature flag names do **not** appear as strings in the brave-bin binary
+  — only `AcceleratedVideoDecodeLinuxGL` does, which is a VA-API gate, not
+  a V4L2 gate. Enabling those flags at the command line is a no-op on this
+  build. Unlocking V4L2 on Linux Brave would require either (a) a Chromium
+  rebuild with different buildflags, or (b) upstream patches to extend the
+  V4L2 decoder factory to Linux non-ChromeOS targets.
+
 ### Acceptance criterion
 
 **1080p @ 30 fps, no dropped frames.** Applies to every device and every