From 6dc4bec201ee152559eb4f27ea5693205551748d Mon Sep 17 00:00:00 2001
From: Koushik Dutta <koushd@gmail.com>
Date: Tue, 11 Aug 2026 12:49:25 -0700
Subject: [PATCH] onvif: fix backchannel clock and aggregation. fixes
 https://github.com/koush/scrypted/issues/2118

---
 plugins/onvif/src/onvif-intercom.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/plugins/onvif/src/onvif-intercom.ts b/plugins/onvif/src/onvif-intercom.ts
index d9f7cbba4..ee9b770d8 100644
--- a/plugins/onvif/src/onvif-intercom.ts
+++ b/plugins/onvif/src/onvif-intercom.ts
@@ -150,8 +150,10 @@ export class OnvifIntercom implements Intercom {
                         return;
                     }
 
-                    const elapsedRtpTimeMs = Math.abs(pending.header.timestamp - p.header.timestamp) / 8000 * 1000;
-                    if (elapsedRtpTimeMs <= 160 && pending.payload.length + p.payload.length <= 1024) {
+                    const clock = defaultMatch.clock || 8000;
+                    const canAggregate = defaultMatch.ffmpegEncoder === 'pcm_mulaw' || defaultMatch.ffmpegEncoder === 'pcm_alaw';
+                    const elapsedRtpTimeMs = Math.abs(pending.header.timestamp - p.header.timestamp) / clock * 1000;
+                    if (canAggregate && elapsedRtpTimeMs <= 160 && pending.payload.length + p.payload.length <= 1024) {
                         pending.payload = Buffer.concat([pending.payload, p.payload]);
                         return;
                     }