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Refactored AV1 packetize
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@mondain
mondain committed Jul 21, 2024
1 parent 5d344e9 commit 8d5c5e8
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Showing 3 changed files with 73 additions and 155 deletions.
59 changes: 0 additions & 59 deletions io/src/main/java/org/red5/io/obu/OBUParser.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2044,63 +2044,4 @@ public static boolean obuHasSize(byte obuHeader) {
return (obuHeader & OBU_SIZE_PRESENT_BIT) != 0;
}

public static int readUVarint(ByteBuffer buffer) {
int value = 0;
int shift = 0;
while (buffer.hasRemaining()) {
byte b = buffer.get();
value |= (b & 0x7F) << shift;
if ((b & LEB128.MSB_BITMASK) == 0) {
return value;
}
shift += 7;
if (shift >= 64) {
return -1; // overflow
}
}
return -1; // incomplete
}

public static int[] readUVarint(byte[] buffer) {
// index 0 is the value, index 1 is the number of bytes read
int[] result = new int[] { 0, -1 };
int shift = 0;
for (int i = 0; i < buffer.length; i++) {
byte b = buffer[i];
// value entry
result[0] |= (b & 0x7F) << shift;
if ((b & LEB128.MSB_BITMASK) == 0) {
result[1] = i + 1;
break;
}
shift += 7;
if (shift >= 64) {
result[1] = -1; // overflow
break;
}
}
return result; // if index 1 == -1 we're incomplete or overflowed
}

public static int[] readUVarint(byte[] buffer, int offset) {
// index 0 is the value, index 1 is the number of bytes read
int[] result = new int[] { 0, -1 };
int shift = 0;
for (int i = offset; i < buffer.length; i++) {
byte b = buffer[i];
// value entry
result[0] |= (b & 0x7F) << shift;
if ((b & LEB128.MSB_BITMASK) == 0) {
result[1] = i + 1;
break;
}
shift += 7;
if (shift >= 64) {
result[1] = -1; // overflow
break;
}
}
return result; // if index 1 == -1 we're incomplete or overflowed
}

}
124 changes: 40 additions & 84 deletions io/src/main/java/org/red5/io/rtp/AV1Packetizer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -191,60 +191,6 @@ public int depacketize(byte[] payload) throws Exception {
return OBUElements.size();
}

/**
* Packetizes a list of AV1 OBU elements.
*
* @param obuElements list of OBUInfo
* @param mtu maximum transmission unit
* @return list of packets
*/
public List<byte[]> packetize(List<OBUInfo> obuInfos, int mtu) {
List<byte[]> payloads = new LinkedList<>();
for (OBUInfo obuInfo : obuInfos) {
// obuInfo.data does not include the OBU header
byte[] payload = obuInfo.data.array();
byte frameType = (byte) ((obuInfo.obuType.getValue() & OBU_FRAME_TYPE_MASK) >> OBU_FRAME_TYPE_BITSHIFT);
if (frameType == OBU_FRAME_TYPE_SEQUENCE_HEADER) {
sequenceHeader = payload;
} else {
int payloadDataIndex = 0;
int payloadDataRemaining = payload.length;
byte obuCount = 0;
// no meta no need to add to metadata size
int metadataSize = 0;
if (sequenceHeader != null && sequenceHeader.length > 0) {
// metadata size is small so 1 byte to hold its leb128 encoded length
metadataSize += sequenceHeader.length + 1;
obuCount++;
}
do {
int outOffset = 1; // AV1_PAYLOADER_HEADER_SIZE
byte[] out = new byte[Math.min(mtu, payloadDataRemaining + metadataSize)];
out[0] = (byte) (obuCount << W_BITSHIFT);
if (obuCount == 2) {
out[0] ^= N_MASK;
out[1] = (byte) LEB128.encode(sequenceHeader.length);
System.arraycopy(sequenceHeader, 0, out, 2, sequenceHeader.length);
outOffset += sequenceHeader.length + 1; // 1 byte for LEB128
sequenceHeader = null;
}
int outBufferRemaining = out.length - outOffset;
System.arraycopy(payload, payloadDataIndex, out, outOffset, outBufferRemaining);
payloadDataRemaining -= outBufferRemaining;
payloadDataIndex += outBufferRemaining;
if (!payloads.isEmpty()) {
out[0] ^= Z_MASK;
}
if (payloadDataRemaining != 0) {
out[0] ^= Y_MASK;
}
payloads.add(out);
} while (payloadDataRemaining > 0);
}
}
return payloads;
}

/**
* Packetizes an AV1 payload.
*
Expand Down Expand Up @@ -295,39 +241,49 @@ public List<byte[]> packetize(byte[] payload, int mtu) {
return payloads;
}

// Payload fragments a AV1 packet across one or more byte arrays
// See AV1Packet for description of AV1 Payload Header
public static LinkedList<byte[]> marshal(int mtu, byte[] payload) {
/**
* Packetizes a list of AV1 OBU, consisting of a sequence header and one or more OBU elements.
*
* @param obuElements list of OBUInfo
* @param mtu maximum transmission unit
* @return list of packets
*/
public List<byte[]> packetize(List<OBUInfo> obuInfos, int mtu) {
LinkedList<byte[]> payloads = new LinkedList<>();
int aggregationHeaderLength = 1;
int maxFragmentSize = mtu - aggregationHeaderLength - 2;
int payloadDataRemaining = payload.length;
int payloadDataIndex = 0;
// Make sure the fragment/payload size is correct
if (Math.min(maxFragmentSize, payloadDataRemaining) > 0) {
while (payloadDataRemaining > 0) {
int currentFragmentSize = Math.min(maxFragmentSize, payloadDataRemaining);
int leb128Size = 1;
if (currentFragmentSize >= 127) {
leb128Size = 2;
}
byte[] out = new byte[aggregationHeaderLength + leb128Size + currentFragmentSize];
int leb128Value = LEB128.encode(currentFragmentSize);
if (leb128Size == 1) {
out[1] = (byte) leb128Value;
} else {
out[1] = (byte) (leb128Value >> 8);
out[2] = (byte) leb128Value;
}
System.arraycopy(payload, payloadDataIndex, out, aggregationHeaderLength + leb128Size, currentFragmentSize);
payloads.add(out);
payloadDataRemaining -= currentFragmentSize;
payloadDataIndex += currentFragmentSize;
if (payloads.size() > 1) {
out[0] ^= Z_MASK;
}
if (payloadDataRemaining != 0) {
out[0] ^= Y_MASK;
for (OBUInfo obuInfo : obuInfos) {
// obuInfo.data does not include the OBU header
byte frameType = (byte) ((obuInfo.obuType.getValue() & OBU_FRAME_TYPE_MASK) >> OBU_FRAME_TYPE_BITSHIFT);
byte[] payload = obuInfo.data.array();
int payloadDataRemaining = payload.length, payloadDataIndex = 0;
logger.debug("Frame type: {}", frameType);
// Make sure the fragment/payload size is correct
if (Math.min(maxFragmentSize, payloadDataRemaining) > 0) {
while (payloadDataRemaining > 0) {
int currentFragmentSize = Math.min(maxFragmentSize, payloadDataRemaining);
int leb128Value = LEB128.encode(currentFragmentSize);
byte[] out;
if (currentFragmentSize >= 127) { // leb takes at least 2 bytes
int outLen = aggregationHeaderLength + 2 + currentFragmentSize;
out = new byte[outLen];
out[1] = (byte) (leb128Value >> 8);
out[2] = (byte) leb128Value;
System.arraycopy(payload, payloadDataIndex, out, aggregationHeaderLength + 2, currentFragmentSize);
} else { // leb expected to be 1 byte
out = new byte[aggregationHeaderLength + 1 + currentFragmentSize];
out[1] = (byte) leb128Value;
System.arraycopy(payload, payloadDataIndex, out, aggregationHeaderLength + 1, currentFragmentSize);
}
payloads.add(out);
payloadDataRemaining -= currentFragmentSize;
payloadDataIndex += currentFragmentSize;
if (payloads.size() > 1) {
out[0] ^= Z_MASK;
}
if (payloadDataRemaining != 0) {
out[0] ^= Y_MASK;
}
}
}
}
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