From 6346d5fbe1e4265cc84ba28874b147fdbee4629f Mon Sep 17 00:00:00 2001
From: cclohmar <claus.lohmar@lohmar.co.uk>
Date: Tue, 20 Oct 2026 08:10:09 +0100
Subject: [PATCH] fix: skip in-progress .part segments and enable MP4 faststart

- /api/recordings no longer lists rec_*.part.mp4 files: FFmpeg has not
  written the moov atom yet, so they can never play. The in-progress
  segment was always the newest entry at the top of the list.
- Record new segments with -movflags +faststart so the MP4 index is at
  the front. iOS/Safari otherwise tail-seeks the moov and stalls.
- Add playsinline to the playback video for inline iOS playback.
- Add scripts/remux-faststart.sh to convert the existing archive
  (dry-run by default, atomic, preserves mtime for retention).
---
 api.go                     |   8 ++-
 public/index.html          |   2 +-
 recorder.go                |   1 +
 scripts/remux-faststart.sh | 133 +++++++++++++++++++++++++++++++++++++
 4 files changed, 142 insertions(+), 2 deletions(-)
 create mode 100755 scripts/remux-faststart.sh

diff --git a/api.go b/api.go
index 11b28bc..ef1ffd8 100644
--- a/api.go
+++ b/api.go
@@ -479,11 +479,17 @@ func (s *Server) handleRecordings(w http.ResponseWriter, r *http.Request) {
 		}
 		name := entry.Name()
 
-		// Only process rec_*.mp4 files (not snap_*.jpg).
+		// Only process completed rec_*.mp4 files (not snap_*.jpg).
 		if !strings.HasPrefix(name, "rec_") || !strings.HasSuffix(strings.ToLower(name), ".mp4") {
 			continue
 		}
 
+		// Skip in-progress segments. FFmpeg only writes the MP4 index (moov)
+		// when it finalizes the file, so a .part.mp4 cannot be played yet.
+		if strings.HasSuffix(strings.ToLower(name), ".part.mp4") {
+			continue
+		}
+
 		info, statErr := entry.Info()
 		if statErr != nil {
 			continue
diff --git a/public/index.html b/public/index.html
index 73ed87d..8ce18b9 100644
--- a/public/index.html
+++ b/public/index.html
@@ -51,7 +51,7 @@
             </div>
             <div id="pb-clips" class="clip-grid"></div>
             <div id="pb-player" class="clip-player hidden">
-                <video id="pb-video" controls></video>
+                <video id="pb-video" controls playsinline></video>
                 <div style="display:flex;gap:8px;margin-top:12px">
                     <button id="pb-download" class="btn-primary">⬇ Download</button>
                     <button id="pb-close">✕ Close</button>
diff --git a/recorder.go b/recorder.go
index 8a6b4e4..2da89de 100644
--- a/recorder.go
+++ b/recorder.go
@@ -146,6 +146,7 @@ func (rm *RecorderManager) startRecorder(cam CameraConfig) {
 			"-an",              // drop audio (pcm_mulaw not supported in MP4)
 			"-c:v", "copy",     // stream-copy video: zero transcoding, near-zero CPU
 			"-t", "300",        // stop after 300 seconds (5 minutes) of input
+			"-movflags", "+faststart", // put the MP4 index first — Safari/iOS needs this
 			"-y",               // overwrite output without asking
 			partFile,
 		)
diff --git a/scripts/remux-faststart.sh b/scripts/remux-faststart.sh
new file mode 100755
index 0000000..3cc9f31
--- /dev/null
+++ b/scripts/remux-faststart.sh
@@ -0,0 +1,133 @@
+#!/usr/bin/env bash
+# NextNVR — remux-faststart.sh
+#
+# Moves the MP4 index atom (moov) to the front of existing recordings so they
+# start immediately in browsers, especially Safari/iOS. New recordings already
+# use -movflags +faststart; this script fixes the archive recorded before that
+# change.
+#
+# Usage:
+#   scripts/remux-faststart.sh [--apply] [recordings-path]
+#
+# Defaults to a dry run against /mnt/recordings. Writes are atomic (temp file
+# in the same directory + rename) and the original mtime is preserved so the
+# retention cleaner still sees the true recording age.
+#
+# Requirements: ffmpeg. python3 is optional — when present, files that already
+# have moov before mdat are skipped.
+
+set -euo pipefail
+
+APPLY=0
+ROOT="/mnt/recordings"
+
+usage() {
+    cat <<'EOF'
+Usage: remux-faststart.sh [--apply] [recordings-path]
+
+  --apply    Actually rewrite files (default: dry run, report only)
+  -h,--help  Show this help
+
+Rewrites completed rec_*.mp4 files so their MP4 index (moov) is at the front.
+In-progress *.part.mp4 files are never touched.
+EOF
+}
+
+for arg in "$@"; do
+    case "$arg" in
+        --apply) APPLY=1 ;;
+        -h|--help) usage; exit 0 ;;
+        --*) echo "error: unknown option: $arg" >&2; usage >&2; exit 2 ;;
+        *) ROOT="$arg" ;;
+    esac
+done
+
+command -v ffmpeg >/dev/null 2>&1 || { echo "error: ffmpeg not found" >&2; exit 1; }
+[ -d "$ROOT" ] || { echo "error: not a directory: $ROOT" >&2; exit 1; }
+
+# Returns 0 when moov already precedes mdat (faststart), 1 when it does not,
+# 2 when the file cannot be parsed.
+moov_is_first() {
+    python3 - "$1" <<'PY'
+import os
+import struct
+import sys
+
+path = sys.argv[1]
+size = os.path.getsize(path)
+off = 0
+order = []
+
+try:
+    with open(path, "rb") as f:
+        while off < size:
+            f.seek(off)
+            hdr = f.read(8)
+            if len(hdr) < 8:
+                break
+            atom_size = struct.unpack(">I", hdr[:4])[0]
+            atom_type = hdr[4:8].decode("latin1")
+            if atom_size == 1:
+                ext = f.read(8)
+                if len(ext) < 8:
+                    break
+                atom_size = struct.unpack(">Q", ext)[0]
+            order.append(atom_type)
+            if atom_size == 0:
+                break
+            off += atom_size
+except Exception:
+    sys.exit(2)
+
+if "moov" not in order or "mdat" not in order:
+    sys.exit(2)
+sys.exit(0 if order.index("moov") < order.index("mdat") else 1)
+PY
+}
+
+HAVE_PYTHON=0
+command -v python3 >/dev/null 2>&1 && HAVE_PYTHON=1
+
+total=0
+converted=0
+skipped=0
+failed=0
+
+echo "remux-faststart: root=$ROOT apply=$APPLY"
+
+while IFS= read -r -d '' file; do
+    total=$((total + 1))
+
+    if [ "$HAVE_PYTHON" -eq 1 ] && moov_is_first "$file"; then
+        skipped=$((skipped + 1))
+        continue
+    fi
+
+    if [ "$APPLY" -eq 0 ]; then
+        echo "would remux: $file"
+        converted=$((converted + 1))
+        continue
+    fi
+
+    tmp="${file%.mp4}.faststart.tmp.mp4"
+    if ffmpeg -nostdin -v error -y -i "$file" -c copy -movflags +faststart "$tmp" \
+        && touch -r "$file" "$tmp" \
+        && mv -f "$tmp" "$file"; then
+        converted=$((converted + 1))
+        echo "remuxed: $file"
+    else
+        failed=$((failed + 1))
+        rm -f "$tmp"
+        echo "FAILED: $file" >&2
+    fi
+
+    if [ $((converted % 100)) -eq 0 ] && [ "$converted" -gt 0 ]; then
+        echo "--- progress: $converted processed ---"
+    fi
+done < <(find "$ROOT" -type f -name 'rec_*.mp4' ! -name '*.part.mp4' -print0)
+
+echo
+echo "remux-faststart: scanned=$total remuxed=$converted skipped=$skipped failed=$failed"
+if [ "$APPLY" -eq 0 ] && [ "$converted" -gt 0 ]; then
+    echo "dry run — re-run with --apply to rewrite the files above"
+fi