Non-Linux UA cannot play H.264/AAC (proprietary codecs a real Windows/macOS has via OS)
br.codec_os_incoherent ·
What it catches
Camoufox source: audioCodecs/videoCodecs unspoofed — real container codec support leaks under a spoofed non-Linux UA. v0.74.3: category corrected coherence->ENVIRONMENT — the premise that a real Windows/macOS browser ALWAYS has H.264/AAC is BUILD-dependent, not universal. H.264/AAC are PROPRIETARY codecs; open-source Chromium (ungoogled-chromium, several Linux-distro Chromium packages, some flatpak/snap builds) is compiled WITHOUT them and can return canPlayType='' for H.264/AAC even on Windows/macOS. A real ungoogled-chromium user therefore trips this, so it must only CORROBORATE (cap at suspicious), never convict — proprietary-codec support is a build property, not an OS contradiction. The Linux-container OS-spoofs that trip it (os-spoof, ios-ua-spoof, iframe-spoof, stealth-patched) are all still convicted by the hard cross-layer tells (net.tcp_os_vs_ua, ua_platform_vs_ch_platform, ch_ua_version_vs_ua, cdp_runtime_enabled).
Signals it reads
browser.codec_os_incoherent
How it fires
present