diff --git a/index.js b/index.js
index f2c59ef..82495d5 100644
--- a/index.js
+++ b/index.js
@@ -325,7 +325,8 @@ const filterMasterPlaylist = async (m3u8Data, m3u8Url) => {
 };
 
 // Helper: processes an M3U8 playlist by converting any relative URLs to absolute,
-// proxying sub-playlists (.m3u8), and proxying decryption keys.
+// proxying sub-playlists (.m3u8), proxying decryption keys, and proxying segment files (.m4s, .m4v)
+// to bypass FFmpeg's strict extension security checks.
 const processM3U8 = (m3u8Data, m3u8Url, baseUrl) => {
     const lines = m3u8Data.split('\n');
     const processedLines = lines.map(line => {
@@ -352,13 +353,17 @@ const processM3U8 = (m3u8Data, m3u8Url, baseUrl) => {
                 }
                 if (uri.includes('.m3u8') && !uri.includes('key?url=')) {
                     uri = `${baseUrl}/m3u8?url=${encodeURIComponent(uri)}`;
+                } else if (uri.includes('.m4s') || uri.includes('.m4v')) {
+                    // Proxy fragmented MP4 files to bypass FFmpeg's strict extension checks
+                    const filename = uri.split('/').pop().split('?')[0].replace(/\.(m4s|m4v)$/, '.mp4');
+                    uri = `${baseUrl}/segment/${filename}?url=${encodeURIComponent(uri)}`;
                 }
                 return `URI="${uri}"`;
             });
             return processed;
         }
 
-        // 3. Rewrite main segment/variant playlist URLs to be absolute (and proxy variant playlists)
+        // 3. Rewrite main segment/variant playlist URLs to be absolute (and proxy variant playlists/segments)
         if (!processed.startsWith('#')) {
             let uri = processed;
             if (!uri.startsWith('http')) {
@@ -366,6 +371,10 @@ const processM3U8 = (m3u8Data, m3u8Url, baseUrl) => {
             }
             if (uri.includes('.m3u8')) {
                 uri = `${baseUrl}/m3u8?url=${encodeURIComponent(uri)}`;
+            } else if (uri.includes('.m4s') || uri.includes('.m4v')) {
+                // Proxy fragmented MP4 files to bypass FFmpeg's strict extension checks
+                const filename = uri.split('/').pop().split('?')[0].replace(/\.(m4s|m4v)$/, '.mp4');
+                uri = `${baseUrl}/segment/${filename}?url=${encodeURIComponent(uri)}`;
             }
             return uri;
         }
@@ -433,6 +442,41 @@ app.get('/m3u8', async (req, res) => {
     }
 });
 
+app.get('/segment/:filename', async (req, res) => {
+    const segmentUrl = req.query.url;
+    if (!segmentUrl) return res.status(400).send('Missing url parameter');
+
+    try {
+        const response = await axios.get(segmentUrl, {
+            headers: buildHeaders(),
+            responseType: 'stream',
+            timeout: 10000
+        });
+
+        if (response.headers['content-type']) {
+            res.header('Content-Type', response.headers['content-type']);
+        } else {
+            res.header('Content-Type', 'video/mp4');
+        }
+        if (response.headers['content-length']) {
+            res.header('Content-Length', response.headers['content-length']);
+        }
+
+        response.data.pipe(res);
+
+        req.on('close', () => {
+            if (response.data && typeof response.data.destroy === 'function') {
+                response.data.destroy();
+            }
+        });
+    } catch (error) {
+        console.error(`Error proxying segment: ${error.message}`);
+        if (!res.headersSent) {
+            res.status(500).send('Error proxying segment');
+        }
+    }
+});
+
 app.get('/key', async (req, res) => {
     const keyUrl = req.query.url;
     if (!keyUrl) return res.status(400).send('Missing url parameter');