Documentation update for -mp4 feature

README.html

@@ -16,6 +16,8 @@ which “-lang” overrides). Format is <code>-lang fr:es:en</code>, where
 French (“fr”) is the first choice, if available, then Spanish (“es”),
 etc. $LANGUAGE has the same format: <code>-lang</code> (by itself)
 suppresses playing of dubbed audio if $LANGUAGE is set.</p></li>
+<li><p>Support for recording Mirror-mode/Audio-mode (but not HLS) Audio
+and Video to mp4 file (new option -mp4 [fn]).</p></li>
 <li><p>Support for <strong>service discovery using a Bluetooth LE
 “beacon”</strong> for both Linux/*BSD and Windows (as an alternative to
 Bonjour/Rendezvous DNS-SD service discovery). <strong>This can be used
@@ -33,9 +35,11 @@ below</a>.</p></li>
 <li><p>option <code>-vrtp &lt;rest-of-pipeline&gt;</code> bypasses
 rendering by UxPlay, and instead transmits rtp packets of decrypted h264
 or h265 video to an external renderer (e.g. OBS Studio) at an address
-specified in <code>rest-of-pipeline</code>. (Note: this is video only,
-an option “-rtp” which muxes audio and video into a mpeg4 container
-still needs to be created: Pull Requests welcomed).</p></li>
+specified in <code>rest-of-pipeline</code>. Similarly,
+<code>-artp &lt;rest-of-pipeline&gt;</code> forwards decoded audio as
+L16 RTP packets. Both options can be used together to forward video and
+audio (as separate concurrent streams) to external
+applications.</p></li>
 <li><p>(for Linux/*BSD Desktop Environments using D-Bus). New option
 <code>-scrsv &lt;n&gt;</code> provides screensaver inhibition (e.g., to
 prevent screensaver function while watching mirrored videos without
@@ -1113,6 +1117,11 @@ and some iPhones) can send h265 video if a resolution “-s wxh” with h
 &gt; 1080 is requested. The “-h265” option changes the default
 resolution (“-s” option) from 1920x1080 to 3840x2160, and leaves default
 maximum framerate (“-fps” option) at 30fps.</p>
+<p><strong>-mp4 [fn]</strong> Record mirror-mode and audio-mode
+audio/video to a mp4 file, while watching/listening. File name is
+fn.n.(format).mp4, (default “fn” = “recording”). The number
+<code>n</code> = 1,2,… increments with each new connection. “format”
+(e.g. “H264.AAC”) indicates H264/H265 video, AAC/ALAC audio.</p>
 <p><strong>-hls [v]</strong> Activate HTTP Live Streaming support. With
 this option YouTube videos can be streamed directly from YouTube servers
 to UxPlay (without passing through the client) by clicking on the
@@ -1313,6 +1322,13 @@ rtph265pay as appropriate: <em>pipeline</em> should start with any
 rtph26xpay options (such as config_interval= or aggregate-mode =),
 followed by a sending method: <em>e.g.</em>,
 <code>"config-interval=1 ! udpsink host=127.0.0.1 port=5000</code>“.</p>
+<p><strong>-artp <em>pipeline</em></strong>: forward decoded audio as
+L16 RTP packets to somewhere else, without local playback. Uses
+rtpL16pay (16-bit signed big-endian PCM, 44100Hz stereo):
+<em>pipeline</em> should start with any rtpL16pay options (such as pt=),
+followed by a sending method: <em>e.g.</em>,
+<code>"pt=96 ! udpsink host=127.0.0.1 port=5002"</code>. iOS volume
+control still works over RTP.</p>
 <p><strong>-v4l2</strong> Video settings for hardware h264 video
 decoding in the GPU by Video4Linux2. Equivalent to
 <code>-vd v4l2h264dec -vc v4l2convert</code>.</p>
@@ -1928,10 +1944,11 @@ screensaver while UxPlay is running (Linux/*BSD only). Add password
 support (-pw) using a displayed pin code as a password that changes
 every time (and not as a one-time pin). Add support for Service
 Discovery using a Bluetooth LE beacon. Add -vrtp option for forwarding
-decrypted h264/5 video to an external renderer (e.g., OBS Studio). Check
-that option input strings have valid UTF-8 encoding. New option
-<code>-lang fr:es:en</code> to specify language preferences for YouTube
-HLS videos when they offer a choice.</p>
+decrypted h264/5 video to an external renderer (e.g., OBS Studio), and
+-artp for audio. Check that option input strings have valid UTF-8
+encoding. New option <code>-lang fr:es:en</code> to specify language
+preferences for YouTube HLS videos when they offer a choice. New option
+-mp4 for recording to a mp4 file (Mirror and Audio mode, not HLS)</p>
 <p>1.72.2 2025-07-07 Fix bug (typo) in DNS_SD advertisement introduced
 with -pw option. Update llhttp to v 9.3.0</p>
 <p>1.72.1 2025-06-06 minor update: fix regression in -reg option; add