Add MPS/MPEG-PS demuxer (H.264 video + ATRAC3+ audio packets)

- Parse PS packets, PES headers and PTS/DTS timestamps
- 'mps' CLI command samples packets from a stream
- Validated on Batman Begins 00001.MPS (Annex-B H.264 + 2-channel ATRAC3+)

cli/src/main/java/dev/quoije/umd/cli/Main.java

@@ -3,6 +3,7 @@ package dev.quoije.umd.cli;
 
 import dev.quoije.umd.iso.UmdIsoFile;
 import dev.quoije.umd.iso.UmdIsoReader;
+import dev.quoije.umd.mps.MpsDemuxer;
 import dev.quoije.umd.playlist.Playlist;
 import dev.quoije.umd.sfo.Sfo;
 
@@ -14,7 +15,7 @@ import java.util.Map;
 /** Command-line front-end for the UMD player library. */
 public final class Main {
 
-    private static final String USAGE = "usage: umdplayer dump <image.iso>";
+    private static final String USAGE = "usage: umdplayer dump <image.iso>\n       umdplayer mps <image.iso> <streamName>";
 
     private Main() {
     }
@@ -29,6 +30,7 @@ public final class Main {
         try {
             exitCode = switch (args[0]) {
                 case "dump" -> dump(requireArg(args, 1));
+                case "mps" -> mps(requireArg(args, 1), requireArg(args, 2));
                 case "help", "--help", "-h" -> {
                     System.out.println(USAGE);
                     yield 0;
@@ -151,6 +153,47 @@ public final class Main {
         return String.format("%02d:%02d:%02d.%02d", hours, minutes, secs, hundredth);
     }
 
+    private static int mps(String imagePath, String streamName) throws IOException {
+        try (UmdIsoReader iso = new UmdIsoReader(Path.of(imagePath))) {
+            try (MpsDemuxer demuxer = MpsDemuxer.open(iso, streamName)) {
+                int count = 0;
+                int videoPackets = 0;
+                int audioPackets = 0;
+                while (count < 40) {
+                    MpsDemuxer.Packet packet = demuxer.nextPacket();
+                    if (packet == null) {
+                        break;
+                    }
+                    count++;
+                    String type = packet.isVideo()
+                            ? "video"
+                            : packet.isAudio() ? "audio(ch=" + packet.channel() + ")" : "other";
+                    System.out.printf("%d: stream=0x%02X %s pts=%d len=%d%n",
+                            count, packet.streamId(), type, packet.pts(), packet.payload().length);
+                    if (packet.isVideo()) {
+                        videoPackets++;
+                        if (videoPackets == 1) {
+                            System.out.println("    first video payload: " + hexPrefix(packet.payload(), 16));
+                        }
+                    } else if (packet.isAudio()) {
+                        audioPackets++;
+                    }
+                }
+                System.out.printf("Sampled %d packets (%d video, %d audio)%n",
+                        count, videoPackets, audioPackets);
+            }
+        }
+        return 0;
+    }
+
+    private static String hexPrefix(byte[] data, int max) {
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < Math.min(data.length, max); i++) {
+            sb.append(String.format("%02X ", data[i] & 0xFF));
+        }
+        return sb.toString().trim();
+    }
+
     private static byte[] readFile(UmdIsoReader iso, String path) throws IOException {
         if (!iso.hasFile(path)) {
             return null;