Add support for RTSP Mp4a-Latm

libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/RtpPayloadFormat.java

@@ -55,6 +55,7 @@ public final class RtpPayloadFormat {
   private static final String RTP_MEDIA_PCMU = "PCMU";
   private static final String RTP_MEDIA_VP8 = "VP8";
   private static final String RTP_MEDIA_VP9 = "VP9";
+  public static final String RTP_MEDIA_MPEG4_AUDIO = "MP4A-LATM";
 
   /** Returns whether the format of a {@link MediaDescription} is supported. */
   public static boolean isFormatSupported(MediaDescription mediaDescription) {
@@ -66,6 +67,7 @@ public static boolean isFormatSupported(MediaDescription mediaDescription) {
       case RTP_MEDIA_H263_2000:
       case RTP_MEDIA_H264:
       case RTP_MEDIA_H265:
+      case RTP_MEDIA_MPEG4_AUDIO:
       case RTP_MEDIA_MPEG4_VIDEO:
       case RTP_MEDIA_MPEG4_GENERIC:
       case RTP_MEDIA_OPUS:
@@ -97,6 +99,7 @@ public static String getMimeTypeFromRtpMediaType(String mediaType) {
       case RTP_MEDIA_AMR_WB:
         return MimeTypes.AUDIO_AMR_WB;
       case RTP_MEDIA_MPEG4_GENERIC:
+      case RTP_MEDIA_MPEG4_AUDIO:
         return MimeTypes.AUDIO_AAC;
       case RTP_MEDIA_OPUS:
         return MimeTypes.AUDIO_OPUS;
@@ -142,6 +145,7 @@ public static String getMimeTypeFromRtpMediaType(String mediaType) {
   public final Format format;
   /** The format parameters, mapped from the SDP FMTP attribute (RFC2327 Page 22). */
   public final ImmutableMap<String, String> fmtpParameters;
+  public final String mediaEncoding;
 
   /**
    * Creates a new instance.
@@ -154,12 +158,13 @@ public static String getMimeTypeFromRtpMediaType(String mediaType) {
    *     empty if unset. The keys and values are specified in the RFCs for specific formats. For
    *     instance, RFC3640 Section 4.1 defines keys like profile-level-id and config.
    */
-  public RtpPayloadFormat(
-      Format format, int rtpPayloadType, int clockRate, Map<String, String> fmtpParameters) {
+  public RtpPayloadFormat(Format format, int rtpPayloadType, int clockRate, Map<String,
+      String> fmtpParameters, String mediaEncoding) {
     this.rtpPayloadType = rtpPayloadType;
     this.clockRate = clockRate;
     this.format = format;
     this.fmtpParameters = ImmutableMap.copyOf(fmtpParameters);
+    this.mediaEncoding = mediaEncoding;
   }
 
   @Override

libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/RtspMediaTrack.java

@@ -31,7 +31,9 @@
 import androidx.media3.common.C;
 import androidx.media3.common.Format;
 import androidx.media3.common.MimeTypes;
+import androidx.media3.common.ParserException;
 import androidx.media3.common.util.CodecSpecificDataUtil;
+import androidx.media3.common.util.ParsableBitArray;
 import androidx.media3.common.util.UnstableApi;
 import androidx.media3.common.util.Util;
 import androidx.media3.extractor.AacUtil;
@@ -53,6 +55,7 @@
   private static final String PARAMETER_H265_SPROP_VPS = "sprop-vps";
   private static final String PARAMETER_H265_SPROP_MAX_DON_DIFF = "sprop-max-don-diff";
   private static final String PARAMETER_MP4V_CONFIG = "config";
+  private static final String PARAMETER_MP4A_C_PRESENT = "cpresent";
 
   /** Prefix for the RFC6381 codecs string for AAC formats. */
   private static final String AAC_CODECS_PREFIX = "mp4a.40.";
@@ -208,6 +211,21 @@ public int hashCode() {
       case MimeTypes.AUDIO_AAC:
         checkArgument(channelCount != C.INDEX_UNSET);
         checkArgument(!fmtpParameters.isEmpty());
+        if(mediaEncoding.equals(RtpPayloadFormat.RTP_MEDIA_MPEG4_AUDIO)) {
+          boolean isConfigPresent  = true;
+          if (fmtpParameters.get(PARAMETER_MP4A_C_PRESENT) != null && fmtpParameters.get(
+              PARAMETER_MP4A_C_PRESENT).equals("0")) {
+            isConfigPresent  = false;
+          }
+          checkArgument(!isConfigPresent, "cpresent == 0 means we need to parse config");
+          @Nullable String configInput = fmtpParameters.get(PARAMETER_MP4V_CONFIG);
+          if (configInput != null && configInput.length() % 2 == 0) {
+            Pair<Integer, Integer> configParameters = getSampleRateAndChannelCount(configInput);
+            channelCount = configParameters.first;
+            clockRate = configParameters.second;
+            formatBuilder.setSampleRate(clockRate).setChannelCount(channelCount);
+          }
+        }
         processAacFmtpAttribute(formatBuilder, fmtpParameters, channelCount, clockRate);
         break;
       case MimeTypes.AUDIO_AMR_NB:
@@ -267,7 +285,8 @@ public int hashCode() {
     }
 
     checkArgument(clockRate > 0);
-    return new RtpPayloadFormat(formatBuilder.build(), rtpPayloadType, clockRate, fmtpParameters);
+    return new RtpPayloadFormat(
+        formatBuilder.build(), rtpPayloadType, clockRate, fmtpParameters, mediaEncoding);
   }
 
   private static int inferChannelCount(int encodingParameter, String mimeType) {
@@ -300,6 +319,32 @@ private static void processAacFmtpAttribute(
             AacUtil.buildAacLcAudioSpecificConfig(sampleRate, channelCount)));
   }
 
+  /**
+   * Returns a {@link Pair} of sample rate and channel count, by parsing the
+   *  MPEG4 Audio Stream Mux configuration.
+   *
+   * <p>fmtp attribute {@code config} includes the MPEG4 Audio Stream Mux
+   * configuration (ISO/IEC14496-3, Chapter 1.7.3).
+   */
+  private static Pair<Integer, Integer> getSampleRateAndChannelCount(String configInput) {
+    ParsableBitArray config  = new ParsableBitArray(Util.getBytesFromHexString(configInput));
+    int audioMuxVersion = config .readBits(1);
+    if (audioMuxVersion == 0) {
+      checkArgument(config .readBits(1) == 1, "Only supports one allStreamsSameTimeFraming.");
+      config .readBits(6);
+      checkArgument(config .readBits(4) == 0, "Only supports one program.");
+      checkArgument(config .readBits(3) == 0, "Only supports one numLayer.");
+      @Nullable AacUtil.Config aacConfig = null;
+      try {
+        aacConfig = AacUtil.parseAudioSpecificConfig(config , false);
+      } catch (ParserException e) {
+        throw new IllegalArgumentException(e);
+      }
+      return Pair.create(aacConfig.channelCount, aacConfig.sampleRateHz);
+    }
+    throw new IllegalArgumentException ("Only support audio mux version 0");
+  }
+
   private static void processMPEG4FmtpAttribute(
       Format.Builder formatBuilder, ImmutableMap<String, String> fmtpAttributes) {
     @Nullable String configInput = fmtpAttributes.get(PARAMETER_MP4V_CONFIG);

libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/reader/DefaultRtpPayloadReaderFactory.java

@@ -35,7 +35,11 @@ public RtpPayloadReader createPayloadReader(RtpPayloadFormat payloadFormat) {
       case MimeTypes.AUDIO_AC3:
         return new RtpAc3Reader(payloadFormat);
       case MimeTypes.AUDIO_AAC:
-        return new RtpAacReader(payloadFormat);
+        if(payloadFormat.mediaEncoding.equals(RtpPayloadFormat.RTP_MEDIA_MPEG4_AUDIO)){
+          return new RtpMp4aReader(payloadFormat);
+        } else {
+          return new RtpAacReader(payloadFormat);
+        }
       case MimeTypes.AUDIO_AMR_NB:
       case MimeTypes.AUDIO_AMR_WB:
         return new RtpAmrReader(payloadFormat);

libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/reader/RtpMp4aReader.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package androidx.media3.exoplayer.rtsp.reader;
+
+import static androidx.media3.common.util.Assertions.checkState;
+import static androidx.media3.common.util.Assertions.checkStateNotNull;
+import static androidx.media3.common.util.Assertions.checkArgument;
+import static androidx.media3.common.util.Util.castNonNull;
+import static androidx.media3.exoplayer.rtsp.reader.RtpReaderUtils.toSampleTimeUs;
+
+import androidx.annotation.Nullable;
+import androidx.media3.common.C;
+import androidx.media3.common.ParserException;
+import androidx.media3.common.util.ParsableBitArray;
+import androidx.media3.common.util.ParsableByteArray;
+import androidx.media3.common.util.UnstableApi;
+import androidx.media3.common.util.Util;
+import androidx.media3.exoplayer.rtsp.RtpPacket;
+import androidx.media3.exoplayer.rtsp.RtpPayloadFormat;
+import androidx.media3.extractor.ExtractorOutput;
+import androidx.media3.extractor.TrackOutput;
+
+import com.google.common.collect.ImmutableMap;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/**
+ * Parses an MP4A-LATM byte stream carried on RTP packets, and extracts MP4A-LATM Access Units.
+ * Refer to RFC3016 for more details.
+ */
+@UnstableApi
+/* package */ final class RtpMp4aReader implements RtpPayloadReader {
+  private static final String TAG = "RtpMp4aLatmReader";
+
+  private static final String PARAMETER_MP4A_CONFIG = "config";
+
+  private final RtpPayloadFormat payloadFormat;
+  private @MonotonicNonNull TrackOutput trackOutput;
+  private long firstReceivedTimestamp;
+  private int previousSequenceNumber;
+  /** The combined size of a sample that is fragmented into multiple subFrames. */
+  private int fragmentedSampleSizeBytes;
+  private long startTimeOffsetUs;
+  private long sampleTimeUsOfFragmentedSample;
+  private final int numberOfSubframes;
+
+  /** Creates an instance. */
+  public RtpMp4aReader(RtpPayloadFormat payloadFormat) {
+    this.payloadFormat = payloadFormat;
+    firstReceivedTimestamp = C.TIME_UNSET;
+    previousSequenceNumber = C.INDEX_UNSET;
+    fragmentedSampleSizeBytes = 0;
+    // The start time offset must be 0 until the first seek.
+    startTimeOffsetUs = 0;
+    sampleTimeUsOfFragmentedSample = C.TIME_UNSET;
+    try {
+      numberOfSubframes = getNumOfSubframesFromMpeg4AudioConfig(payloadFormat.fmtpParameters);
+    } catch (ParserException e) {
+      throw new IllegalArgumentException(e);
+    }
+  }
+
+  @Override
+  public void createTracks(ExtractorOutput extractorOutput, int trackId) {
+    trackOutput = extractorOutput.track(trackId, C.TRACK_TYPE_VIDEO);
+    castNonNull(trackOutput).format(payloadFormat.format);
+  }
+
+  @Override
+  public void onReceivingFirstPacket(long timestamp, int sequenceNumber) {
+    checkState(firstReceivedTimestamp == C.TIME_UNSET);
+    firstReceivedTimestamp = timestamp;
+}
+
+  @Override
+  public void consume(
+      ParsableByteArray data, long timestamp, int sequenceNumber, boolean rtpMarker)
+      throws ParserException {
+    checkStateNotNull(trackOutput);
+
+    int expectedSequenceNumber = RtpPacket.getNextSequenceNumber(previousSequenceNumber);
+    if(fragmentedSampleSizeBytes > 0 && expectedSequenceNumber < sequenceNumber) {
+      outputSampleMetadataForFragmentedPackets();
+    }
+    for (int subFrame = 0; subFrame < numberOfSubframes; subFrame++) {
+      int sampleLength = 0;
+
+      /**
+       * This implements PayloadLengthInfo() in Chapter 1.7.3.1, it's only support one program and
+       * one layer.
+       * Each subframe starts with a variable length encoding.
+       */
+      while(data.getPosition() < data.limit()) {
+        int payloadMuxLength = data.readUnsignedByte();
+        sampleLength += payloadMuxLength;
+        if (payloadMuxLength != 0xff) {
+          break;
+        }
+      }
+
+      // Write the audio sample
+      trackOutput.sampleData(data, sampleLength);
+      fragmentedSampleSizeBytes += sampleLength;
+    }
+    sampleTimeUsOfFragmentedSample = toSampleTimeUs(startTimeOffsetUs, timestamp,
+        firstReceivedTimestamp, payloadFormat.clockRate);
+    if (rtpMarker) {
+      outputSampleMetadataForFragmentedPackets();
+    }
+    previousSequenceNumber = sequenceNumber;
+  }
+
+  @Override
+  public void seek(long nextRtpTimestamp, long timeUs) {
+    firstReceivedTimestamp = nextRtpTimestamp;
+    fragmentedSampleSizeBytes = 0;
+    startTimeOffsetUs = timeUs;
+  }
+
+  // Internal methods.
+
+  /**
+   * Parses an MPEG-4 Audio Stream Mux configuration, as defined in ISO/IEC14496-3. FMTP attribute
+   * contains config which is a byte array containing the MPEG-4 Audio Stream Mux configuration to
+   * parse.
+   *
+   * @param fmtpAttributes The format parameters, mapped from the SDP FMTP attribute.
+   * @return The number of subframes.
+   * @throws ParserException If the MPEG-4 Audio Stream Mux configuration cannot be parsed due to
+   *     unsupported audioMuxVersion.
+   */
+  private static int getNumOfSubframesFromMpeg4AudioConfig(
+      ImmutableMap<String, String> fmtpAttributes) throws ParserException {
+    @Nullable String configInput = fmtpAttributes.get(PARAMETER_MP4A_CONFIG);
+    int numberOfSubframes = 0;
+    if (configInput != null && configInput.length() % 2 == 0) {
+      byte[] configBuffer = Util.getBytesFromHexString(configInput);
+      ParsableBitArray scratchBits = new ParsableBitArray(configBuffer);
+      int audioMuxVersion = scratchBits.readBits(1);
+      if (audioMuxVersion == 0) {
+        checkArgument(scratchBits.readBits(1) == 1, "Invalid allStreamsSameTimeFraming.");
+        numberOfSubframes = scratchBits.readBits(6);
+        checkArgument(scratchBits.readBits(4) == 0, "Invalid numProgram.");
+        checkArgument(scratchBits.readBits(3) == 0, "Invalid numLayer.");
+      } else {
+        throw ParserException.createForMalformedDataOfUnknownType(
+            "unsupported audio mux version: " + audioMuxVersion, null);
+      }
+    }
+    return numberOfSubframes + 1;
+  }
+
+  /**
+   * Outputs sample metadata.
+   *
+   * <p>Call this method only when receiving a end of Mpeg4 partition
+   */
+  private void outputSampleMetadataForFragmentedPackets() {
+    trackOutput.sampleMetadata(
+        sampleTimeUsOfFragmentedSample,
+        C.BUFFER_FLAG_KEY_FRAME,
+        fragmentedSampleSizeBytes,
+        /* offset= */ 0,
+        /* cryptoData= */ null);
+    fragmentedSampleSizeBytes = 0;
+    sampleTimeUsOfFragmentedSample = C.TIME_UNSET;
+  }
+}