public class RtmpEncoder extends SimpleChannelDownstreamHandler {
private static final Logger logger = LoggerFactory.getLogger(RtmpEncoder.class);
private int chunkSize = 128;
private RtmpHeader[] channelPrevHeaders = new RtmpHeader[RtmpHeader.MAX_CHANNEL_ID];
private void clearPrevHeaders() {
logger.debug("clearing prev stream headers");
channelPrevHeaders = new RtmpHeader[RtmpHeader.MAX_CHANNEL_ID];
}
@Override
public void writeRequested(final ChannelHandlerContext ctx, final MessageEvent e) {
Channels.write(ctx, e.getFuture(), encode((RtmpMessage) e.getMessage()));
}
public ChannelBuffer encode(final RtmpMessage message) {
final ChannelBuffer in = message.encode();
final RtmpHeader header = message.getHeader();
if (header.isChunkSize()) {
final ChunkSize csMessage = (ChunkSize) message;
logger.debug("encoder new chunk size: {}", csMessage);
chunkSize = csMessage.getChunkSize();
} else if (header.isControl()) {
final Control control = (Control) message;
if (control.getType() == Control.Type.STREAM_BEGIN) {
clearPrevHeaders();
}
}
final int channelId = header.getChannelId();
header.setSize(in.readableBytes());
final RtmpHeader prevHeader = channelPrevHeaders[channelId];
if (prevHeader != null // first stream message is always large
&& header.getStreamId() > 0 // all control messages always large
&& header.getTime() > 0) { // if time is zero, always large
if (header.getSize() == prevHeader.getSize()) {
header.setHeaderType(RtmpHeader.Type.SMALL);
} else {
header.setHeaderType(RtmpHeader.Type.MEDIUM);
}
final int deltaTime = header.getTime() - prevHeader.getTime();
if (deltaTime < 0) {
logger.warn("negative time: {}", header);
header.setDeltaTime(0);
} else {
header.setDeltaTime(deltaTime);
}
} else {
// otherwise force to LARGE
header.setHeaderType(RtmpHeader.Type.LARGE);
}
channelPrevHeaders[channelId] = header;
if (logger.isDebugEnabled()) {
// logger.debug(">> {}", message);
}
final ChannelBuffer out =
ChannelBuffers.buffer(
RtmpHeader.MAX_ENCODED_SIZE + header.getSize() + header.getSize() / chunkSize);
boolean first = true;
while (in.readable()) {
final int size = Math.min(chunkSize, in.readableBytes());
if (first) {
header.encode(out);
first = false;
} else {
out.writeBytes(header.getTinyHeader());
}
in.readBytes(out, size);
}
return out;
}
}
