Allow reading RTSP message body by Content-Length.

Related to Issue: #8941.

RTSP message body's format is not regulated by the RTSP spec, meaning it can
use either CRLF or LF as its line terminator. The old code assumes every line
ends with CRLF (RTSP message and the message body); the new code will rely on
the Content-Length information to receive the bytes for the message body.

#minor-release

PiperOrigin-RevId: 377475565

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspMessageUtil.java

@@ -38,6 +38,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Ascii;
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
@@ -107,6 +108,8 @@ import java.util.regex.Pattern;
       Pattern.compile("Basic realm=\"([\\w\\s@.]+)\"");
 
   private static final String RTSP_VERSION = "RTSP/1.0";
+  private static final String LF = new String(new byte[] {Ascii.LF});
+  private static final String CRLF = new String(new byte[] {Ascii.CR, Ascii.LF});
 
   /**
    * Serializes an {@link RtspRequest} to an {@link ImmutableList} of strings.
@@ -167,7 +170,7 @@ import java.util.regex.Pattern;
    *     removed.
    */
   public static byte[] convertMessageToByteArray(List<String> message) {
-    return Joiner.on("\r\n").join(message).getBytes(RtspMessageChannel.CHARSET);
+    return Joiner.on(CRLF).join(message).getBytes(RtspMessageChannel.CHARSET);
   }
 
   /** Removes the user info from the supplied {@link Uri}. */
@@ -211,7 +214,7 @@ import java.util.regex.Pattern;
   /** Returns the corresponding String representation of the {@link RtspRequest.Method} argument. */
   public static String toMethodString(@RtspRequest.Method int method) {
     switch (method) {
-      case RtspRequest.METHOD_ANNOUNCE:
+      case METHOD_ANNOUNCE:
         return "ANNOUNCE";
       case METHOD_DESCRIBE:
         return "DESCRIBE";
@@ -291,7 +294,7 @@ import java.util.regex.Pattern;
     List<String> headerLines = lines.subList(1, messageBodyOffset);
     RtspHeaders headers = new RtspHeaders.Builder().addAll(headerLines).build();
 
-    String messageBody = Joiner.on("\r\n").join(lines.subList(messageBodyOffset + 1, lines.size()));
+    String messageBody = Joiner.on(CRLF).join(lines.subList(messageBodyOffset + 1, lines.size()));
     return new RtspResponse(statusCode, headers, messageBody);
   }
 
@@ -314,7 +317,7 @@ import java.util.regex.Pattern;
     List<String> headerLines = lines.subList(1, messageBodyOffset);
     RtspHeaders headers = new RtspHeaders.Builder().addAll(headerLines).build();
 
-    String messageBody = Joiner.on("\r\n").join(lines.subList(messageBodyOffset + 1, lines.size()));
+    String messageBody = Joiner.on(CRLF).join(lines.subList(messageBodyOffset + 1, lines.size()));
     return new RtspRequest(requestUri, method, headers, messageBody);
   }
 
@@ -324,6 +327,11 @@ import java.util.regex.Pattern;
         || STATUS_LINE_PATTERN.matcher(line).matches();
   }
 
+  /** Returns the lines in an RTSP message body split by the line terminator used in body. */
+  public static String[] splitRtspMessageBody(String body) {
+    return Util.split(body, body.contains(CRLF) ? CRLF : LF);
+  }
+
   /**
    * Returns the length in bytes if the line contains a Content-Length header, otherwise {@link
    * C#LENGTH_UNSET}.

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/SessionDescriptionParser.java

@@ -41,8 +41,6 @@ import java.util.regex.Pattern;
   private static final Pattern MEDIA_DESCRIPTION_PATTERN =
       Pattern.compile("(\\S+)\\s(\\S+)\\s(\\S+)\\s(\\S+)");
 
-  private static final String CRLF = "\r\n";
-
   private static final String VERSION_TYPE = "v";
   private static final String ORIGIN_TYPE = "o";
   private static final String SESSION_TYPE = "s";
@@ -71,7 +69,7 @@ import java.util.regex.Pattern;
     @Nullable MediaDescription.Builder mediaDescriptionBuilder = null;
 
     // Lines are separated by an CRLF.
-    for (String line : Util.split(sdpString, CRLF)) {
+    for (String line : RtspMessageUtil.splitRtspMessageBody(sdpString)) {
       if ("".equals(line)) {
         continue;
       }

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspMessageChannelTest.java

@@ -66,11 +66,21 @@ public final class RtspMessageChannelTest {
                 .build(),
             "v=安卓アンドロイド\r\n");
 
+    RtspResponse describeResponse2 =
+        new RtspResponse(
+            200,
+            new RtspHeaders.Builder()
+                .add(RtspHeaders.CSEQ, "4")
+                .add(RtspHeaders.CONTENT_TYPE, "application/sdp")
+                .add(RtspHeaders.CONTENT_LENGTH, "73")
+                .build(),
+            "v=安卓アンドロイド\n" + "o=test 2890844526 2890842807 IN IP4 127.0.0.1\n");
+
     RtspResponse setupResponse =
         new RtspResponse(
             200,
             new RtspHeaders.Builder()
-                .add(RtspHeaders.CSEQ, "3")
+                .add(RtspHeaders.CSEQ, "5")
                 .add(RtspHeaders.TRANSPORT, "RTP/AVP/TCP;unicast;interleaved=0-1")
                 .build(),
             "");
@@ -97,6 +107,8 @@ public final class RtspMessageChannelTest {
                     convertMessageToByteArray(serializeResponse(optionsResponse)));
                 serverOutputStream.write(
                     convertMessageToByteArray(serializeResponse(describeResponse)));
+                serverOutputStream.write(
+                    convertMessageToByteArray(serializeResponse(describeResponse2)));
                 serverOutputStream.write(Bytes.concat(new byte[] {'$'}, interleavedData1));
                 serverOutputStream.write(Bytes.concat(new byte[] {'$'}, interleavedData2));
                 serverOutputStream.write(
@@ -118,7 +130,7 @@ public final class RtspMessageChannelTest {
         new RtspMessageChannel(
             message -> {
               receivedRtspResponses.add(message);
-              if (receivedRtspResponses.size() == 3 && receivedInterleavedData.size() == 2) {
+              if (receivedRtspResponses.size() == 4 && receivedInterleavedData.size() == 2) {
                 receivingFinished.set(true);
               }
             });
@@ -148,9 +160,17 @@ public final class RtspMessageChannelTest {
                 "content-length: 28",
                 "",
                 "v=安卓アンドロイド"),
+            /* describeResponse2 */
+            ImmutableList.of(
+                "RTSP/1.0 200 OK",
+                "cseq: 4",
+                "content-type: application/sdp",
+                "content-length: 73",
+                "",
+                "v=安卓アンドロイド\n" + "o=test 2890844526 2890842807 IN IP4 127.0.0.1"),
             /* setupResponse */
             ImmutableList.of(
-                "RTSP/1.0 200 OK", "cseq: 3", "transport: RTP/AVP/TCP;unicast;interleaved=0-1", ""))
+                "RTSP/1.0 200 OK", "cseq: 5", "transport: RTP/AVP/TCP;unicast;interleaved=0-1", ""))
         .inOrder();
     assertThat(receivedInterleavedData)
         .containsExactly(

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspMessageUtilTest.java

@@ -480,4 +480,18 @@ public final class RtspMessageUtilTest {
     assertThat(authenticationInfo.realm).isEqualTo("LIVE555 Streaming Media");
     assertThat(authenticationInfo.opaque).isEmpty();
   }
+
+  @Test
+  public void splitRtspMessageBody_withCrLfLineTerminatorMessageBody_splitsMessageBody() {
+    String[] lines = RtspMessageUtil.splitRtspMessageBody("line1\r\nline2\r\nline3");
+
+    assertThat(lines).asList().containsExactly("line1", "line2", "line3").inOrder();
+  }
+
+  @Test
+  public void splitRtspMessageBody_withLfLineTerminatorMessageBody_splitsMessageBody() {
+    String[] lines = RtspMessageUtil.splitRtspMessageBody("line1\nline2\nline3");
+
+    assertThat(lines).asList().containsExactly("line1", "line2", "line3").inOrder();
+  }
 }