Upload live android webcam video to RTP/RTSP Server

Question

I have already done proper research, but still lack information on the thing I would like to achieve.

So I would like to program an application where the user can record a video and instantly (live) upload the video to a RTP/RTSP Server. The server side will not be a problem. The thing I am unclear about is how to achieve this on the phone-side.

My research so far is that I have to write the video on recording to a local socket rather than to a file, because the 3gp files if written to a file cannot be accessed, until finalized (when the video is stopped and the header information have been written to the video about length and others).

When the socket receives the continuous data, I will need to wrap it into a RTP packet and send it to the remote server. I possibly will also have to do basic encoding first (which is not so important yet).

Does anybody have any idea, if this theory is correct so far. I would also like to know if someone could point me to a few code-snippets of similar approaches, especially for sending the video on the fly to the server. I am not sure yet how to do that.

Thank you very much and best regards

Answer 1

Your overall approach sounds correct, but there are a couple of things you need to consider.

So I would like to program an application where the user can record a video and instantly (live) upload the video to a RTP/RTSP Server.

• I'm assuming you want to upload to an RTSP server so that it can redistribute the content to multiple clients?
• How will you handle the signaling/setup of the RTP session to the RTSP server? You need to notify the RTSP server somehow that a user is going to upload live media so that it can open the appropriate RTP/RTCP sockets etc.
• How will you handle authentication? Multiple client devices?

My research so far is that I have to write the video on recording to a local socket rather than to a file, because the 3gp files if written to a file cannot be accessed, until finalized (when the video is stopped and the header information have been written to the video about length and others).

Sending frames in real-time over RTP/RTCP is the correct approach. As the capture device captures each frame, you need to encode/compress it and send it over the socket. 3gp, like mp4, is a container format used for file storage. For live capture there is no need to write to a file. The only time this makes sense is e.g. in HTTP Live Streaming or DASH approaches, where media is written to a transport stream or mp4 file, before being served over HTTP.

When the socket receives the continuous data, I will need to wrap it into a RTP packet and send it to the remote server. I possibly will also have to do basic encoding first (which is not so important yet).

I would disagree, encoding is very important, you'll likely never manage to send the video otherwise, and you'll have to deal with issues such as cost (over mobile networks) and just the sheer volume of media depending on resolution and framerate.

Does anybody have any idea, if this theory is correct so far. I would also like to know if someone could point me to a few code-snippets of similar approaches, especially for sending the video on the fly to the server. I am not sure yet how to do that.

Take a look at the spydroid open source project as a starting point. It contains many of the necessary steps including how to configure the encoder, packetise to RTP, send RTCP, as well as some RTSP server functionality. Spydroid sets up an RTSP server so media is encoded and sent once an RTSP client such as VLC is used to setup an RTSP session. Since your application is driven by the phone user wanting to send media to a server, you may need to consider another approach to start the sending, even if you send some kind of message to the server to for instance setup an RTSP session like in spydroid.

Answer 2

A year ago I created android app that could stream its camera/microphone using rtsp over tcp to wowza media server.

General approach is to create unix socket, get its file descriptor and feed it to android media recorder component. Then media recorder is then instructed to record camera video in mp4/h264 format to that file descriptor. Now, your app reads the client socket, parses mp4 to remove the header and get iframes from it and wraps it into rtsp stream on fly.

Something similar can also be done for sound (normally AAC). Of course you have to handle time stamping your self and the most tricky thing in entire approach is video/audio synchronisation.

So here is first part of it. Something that can be called rtspsocket. It negotiates with media server in connect method and after that you can write into it the stream itself. I will show it later.

package com.example.android.streaming.streaming.rtsp;  import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.UnsupportedEncodingException; import java.math.BigInteger; import java.net.InetSocketAddress; import java.net.Socket; import java.net.SocketException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.Locale; import java.util.concurrent.ConcurrentHashMap;  import android.util.Base64; import android.util.Log;  import com.example.android.streaming.StreamingApp; import com.example.android.streaming.streaming.Session; import com.example.android.streaming.BuildConfig;  public class RtspSocket extends Socket {     public static final int RTSP_HEADER_LENGTH = 4;     public static final int RTP_HEADER_LENGTH = 12;     public static final int MTU = 1400;      public static final int PAYLOAD_OFFSET = RTSP_HEADER_LENGTH + RTP_HEADER_LENGTH;     public static final int RTP_OFFSET = RTSP_HEADER_LENGTH;      private ConcurrentHashMap<String, String> headerMap = new ConcurrentHashMap<String, String>();      static private final String kCRLF = "\r\n";      // RTSP request format strings     static private final String kOptions = "OPTIONS %s RTSP/1.0\r\n";     static private final String kDescribe = "DESCRIBE %s RTSP/1.0\r\n";     static private final String kAnnounce = "ANNOUNCE %s RTSP/1.0\r\n";     static private final String kSetupPublish = "SETUP %s/trackid=%d RTSP/1.0\r\n";     @SuppressWarnings("unused")     static private final String kSetupPlay = "SETUP %s/trackid=%d RTSP/1.0\r\n";     static private final String kRecord = "RECORD %s RTSP/1.0\r\n";     static private final String kPlay = "PLAY %s RTSP/1.0\r\n";     static private final String kTeardown = "TEARDOWN %s RTSP/1.0\r\n";      // RTSP header format strings     static private final String kCseq = "Cseq: %d\r\n";     static private final String kContentLength = "Content-Length: %d\r\n";     static private final String kContentType = "Content-Type: %s\r\n";     static private final String kTransport = "Transport: RTP/AVP/%s;unicast;mode=%s;%s\r\n";     static private final String kSession = "Session: %s\r\n";     static private final String kRange = "range: %s\r\n";     static private final String kAccept = "Accept: %s\r\n";     static private final String kAuthBasic = "Authorization: Basic %s\r\n";     static private final String kAuthDigest = "Authorization: Digest username=\"%s\",realm=\"%s\",nonce=\"%s\",uri=\"%s\",response=\"%s\"\r\n";      // RTSP header keys     static private final String kSessionKey = "Session";     static private final String kWWWAuthKey = "WWW-Authenticate";      byte header[] = new byte[RTSP_MAX_HEADER + 1];     static private final int RTSP_MAX_HEADER = 4095;     static private final int RTSP_MAX_BODY = 4095;      static private final int RTSP_RESP_ERR = -6;     // static private final int RTSP_RESP_ERR_SESSION = -7;     static public final int RTSP_OK = 200;     static private final int RTSP_BAD_USER_PASS = 401;      static private final int SOCK_ERR_READ = -5;      /* Number of channels including control ones. */     private int channelCount = 0;      /* RTSP negotiation cmd seq counter */     private int seq = 0;      private String authentication = null;     private String session = null;      private String path = null;     private String url = null;     private String user = null;     private String pass = null;     private String sdp = null;      private byte[] buffer = new byte[MTU];      public RtspSocket() {         super();         try {             setTcpNoDelay(true);             setSoTimeout(60000);         } catch (SocketException e) {             Log.e(StreamingApp.TAG, "Failed to set socket params.");         }         buffer[RTSP_HEADER_LENGTH] = (byte) Integer.parseInt("10000000", 2);     }      public byte[] getBuffer() {         return buffer;     }      public static final void setLong(byte[] buffer, long n, int begin, int end) {         for (end--; end >= begin; end--) {             buffer[end] = (byte) (n % 256);             n >>= 8;         }     }      public void setSequence(int seq) {         setLong(buffer, seq, RTP_OFFSET + 2, RTP_OFFSET + 4);     }      public void setSSRC(int ssrc) {         setLong(buffer, ssrc, RTP_OFFSET + 8, RTP_OFFSET + 12);     }      public void setPayload(int payload) {         buffer[RTP_OFFSET + 1] = (byte) (payload & 0x7f);     }      public void setRtpTimestamp(long timestamp) {         setLong(buffer, timestamp, RTP_OFFSET + 4, RTP_OFFSET + 8);     }      /** Sends the RTP packet over the network */     private void send(int length, int stream) throws IOException {         buffer[0] = '$';         buffer[1] = (byte) stream;         setLong(buffer, length, 2, 4);         OutputStream s = getOutputStream();         s.write(buffer, 0, length + RTSP_HEADER_LENGTH);         s.flush();     }      public void sendReport(int length, int ssrc, int stream) throws IOException {         setPayload(200);         setLong(buffer, ssrc, RTP_OFFSET + 4, RTP_OFFSET + 8);         send(length + RTP_HEADER_LENGTH, stream);     }      public void sendData(int length, int ssrc, int seq, int payload, int stream, boolean last) throws IOException {         setSSRC(ssrc);         setSequence(seq);         setPayload(payload);         buffer[RTP_OFFSET + 1] |= (((last ? 1 : 0) & 0x01) << 7);         send(length + RTP_HEADER_LENGTH, stream);     }      public int getChannelCount() {         return channelCount;     }      private void write(String request) throws IOException {         try {             String asci = new String(request.getBytes(), "US-ASCII");             OutputStream out = getOutputStream();             out.write(asci.getBytes());         } catch (IOException e) {             throw new IOException("Error writing to socket.");         }     }      private String read() throws IOException {         String response = null;         try {             InputStream in = getInputStream();             int i = 0, len = 0, crlf_count = 0;             boolean parsedHeader = false;              for (; i < RTSP_MAX_BODY && !parsedHeader && len > -1; i++) {                 len = in.read(header, i, 1);                 if (header[i] == '\r' || header[i] == '\n') {                     crlf_count++;                     if (crlf_count == 4)                         parsedHeader = true;                 } else {                     crlf_count = 0;                 }             }             if (len != -1) {                 len = i;                 header[len] = '\0';                 response = new String(header, 0, len, "US-ASCII");             }         } catch (IOException e) {             throw new IOException("Connection timed out. Check your network settings.");         }         return response;     }      private int parseResponse(String response) {         String[] lines = response.split(kCRLF);         String[] items = response.split(" ");         String tempString, key, value;          headerMap.clear();         if (items.length < 2)             return RTSP_RESP_ERR;         int responseCode = RTSP_RESP_ERR;         try {             responseCode = Integer.parseInt(items[1]);         } catch (Exception e) {             Log.w(StreamingApp.TAG, e.getMessage());             Log.w(StreamingApp.TAG, response);         }         if (responseCode == RTSP_RESP_ERR)             return responseCode;          // Parse response header into key value pairs.         for (int i = 1; i < lines.length; i++) {             tempString = lines[i];              if (tempString.length() == 0)                 break;              int idx = tempString.indexOf(":");              if (idx == -1)                 continue;              key = tempString.substring(0, idx);             value = tempString.substring(idx + 1);             headerMap.put(key, value);         }          tempString = headerMap.get(kSessionKey);         if (tempString != null) {             // Parse session             items = tempString.split(";");             tempString = items[0];             session = tempString.trim();         }          return responseCode;     }      private void generateBasicAuth() throws UnsupportedEncodingException {         String userpass = String.format("%s:%s", user, pass);         authentication = String.format(kAuthBasic, Base64.encodeToString(userpass.getBytes("US-ASCII"), Base64.DEFAULT));     }      public static String md5(String s) {         MessageDigest digest;         try {             digest = MessageDigest.getInstance("MD5");             digest.update(s.getBytes(), 0, s.length());             String hash = new BigInteger(1, digest.digest()).toString(16);             return hash;         } catch (NoSuchAlgorithmException e) {             e.printStackTrace();         }         return "";     }      static private final int CC_MD5_DIGEST_LENGTH = 16;      private String md5HexDigest(String input) {         byte digest[] = md5(input).getBytes();         String result = new String();         for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)             result = result.concat(String.format("%02x", digest[i]));         return result;     }      private void generateDigestAuth(String method) {         String nonce, realm;         String ha1, ha2, response;          // WWW-Authenticate: Digest realm="Streaming Server",         // nonce="206351b944cb28fe37a0794848c2e36f"         String wwwauth = headerMap.get(kWWWAuthKey);         int idx = wwwauth.indexOf("Digest");         String authReq = wwwauth.substring(idx + "Digest".length() + 1);          if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, String.format("Auth Req: %s", authReq));          String[] split = authReq.split(",");         realm = split[0];         nonce = split[1];          split = realm.split("=");         realm = split[1];         realm = realm.substring(1, 1 + realm.length() - 2);          split = nonce.split("=");         nonce = split[1];         nonce = nonce.substring(1, 1 + nonce.length() - 2);          if (BuildConfig.DEBUG) {             Log.d(StreamingApp.TAG, String.format("realm=%s", realm));             Log.d(StreamingApp.TAG, String.format("nonce=%s", nonce));         }          ha1 = md5HexDigest(String.format("%s:%s:%s", user, realm, pass));         ha2 = md5HexDigest(String.format("%s:%s", method, url));         response = md5HexDigest(String.format("%s:%s:%s", ha1, nonce, ha2));         authentication = md5HexDigest(String.format(kAuthDigest, user, realm, nonce, url, response));     }      private int options() throws IOException {         seq++;         StringBuilder request = new StringBuilder();         request.append(String.format(kOptions, url));         request.append(String.format(kCseq, seq));         request.append(kCRLF);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- OPTIONS Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- OPTIONS Response ---\n\n" + response);         return parseResponse(response);     }      @SuppressWarnings("unused")     private int describe() throws IOException {         seq++;         StringBuilder request = new StringBuilder();         request.append(String.format(kDescribe, url));         request.append(String.format(kAccept, "application/sdp"));         request.append(String.format(kCseq, seq));         request.append(kCRLF);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- DESCRIBE Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- DESCRIBE Response ---\n\n" + response);         return parseResponse(response);     }      private int recurseDepth = 0;      private int announce() throws IOException {         seq++;         recurseDepth = 0;         StringBuilder request = new StringBuilder();         request.append(String.format(kAnnounce, url));         request.append(String.format(kCseq, seq));         request.append(String.format(kContentLength, sdp.length()));         request.append(String.format(kContentType, "application/sdp"));         request.append(kCRLF);         if (sdp.length() > 0)             request.append(sdp);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- ANNOUNCE Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- ANNOUNCE Response ---\n\n" + response);          int ret = parseResponse(response);         if (ret == RTSP_BAD_USER_PASS && recurseDepth == 0) {             String wwwauth = headerMap.get(kWWWAuthKey);             if (wwwauth != null) {                 if (BuildConfig.DEBUG)                     Log.d(StreamingApp.TAG, String.format("WWW Auth Value: %s", wwwauth));                 int idx = wwwauth.indexOf("Basic");                 recurseDepth++;                  if (idx != -1) {                     generateBasicAuth();                 } else {                     // We are assuming Digest here.                     generateDigestAuth("ANNOUNCE");                 }                  ret = announce();                 recurseDepth--;             }         }         return ret;     }      private int setup(int trackId) throws IOException {         seq++;         recurseDepth = 0;         StringBuilder request = new StringBuilder();         request.append(String.format(kSetupPublish, url, trackId));         request.append(String.format(kCseq, seq));          /* One channel for rtp (data) and one for rtcp (control) */         String tempString = String.format(Locale.getDefault(), "interleaved=%d-%d", channelCount++, channelCount++);          request.append(String.format(kTransport, "TCP", "record", tempString));         request.append(kCRLF);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- SETUP Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- SETUP Response ---\n\n" + response);          int ret = parseResponse(response);         if (ret == RTSP_BAD_USER_PASS && recurseDepth == 0) {             String wwwauth = headerMap.get(kWWWAuthKey);             if (wwwauth != null) {                 if (BuildConfig.DEBUG)                     Log.d(StreamingApp.TAG, String.format("WWW Auth Value: %s", wwwauth));                 int idx = wwwauth.indexOf("Basic");                 recurseDepth++;                  if (idx != -1) {                     generateBasicAuth();                 } else {                     // We are assuming Digest here.                     generateDigestAuth("SETUP");                 }                  ret = setup(trackId);                 authentication = null;                 recurseDepth--;             }         }         return ret;     }      private int record() throws IOException {         seq++;         recurseDepth = 0;         StringBuilder request = new StringBuilder();         request.append(String.format(kRecord, url));         request.append(String.format(kCseq, seq));         request.append(String.format(kRange, "npt=0.000-"));         if (authentication != null)             request.append(authentication);         if (session != null)             request.append(String.format(kSession, session));         request.append(kCRLF);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- RECORD Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- RECORD Response ---\n\n" + response);         int ret = parseResponse(response);         if (ret == RTSP_BAD_USER_PASS && recurseDepth == 0) {             String wwwauth = headerMap.get(kWWWAuthKey);             if (wwwauth != null) {                 if (BuildConfig.DEBUG)                     Log.d(StreamingApp.TAG, String.format("WWW Auth Value: %s", wwwauth));                 int idx = wwwauth.indexOf("Basic");                 recurseDepth++;                  if (idx != -1) {                     generateBasicAuth();                 } else {                     // We are assuming Digest here.                     generateDigestAuth("RECORD");                 }                  ret = record();                 authentication = null;                 recurseDepth--;             }         }         return ret;     }      @SuppressWarnings("unused")     private int play() throws IOException {         seq++;         recurseDepth = 0;         StringBuilder request = new StringBuilder();         request.append(String.format(kPlay, url));         request.append(String.format(kCseq, seq));         request.append(String.format(kRange, "npt=0.000-"));         if (authentication != null)             request.append(authentication);         if (session != null)             request.append(String.format(kSession, session));         request.append(kCRLF);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- PLAY Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- PLAY Response ---\n\n" + response);         int ret = parseResponse(response);         if (ret == RTSP_BAD_USER_PASS && recurseDepth == 0) {             String wwwauth = headerMap.get(kWWWAuthKey);             if (wwwauth != null) {                 if (BuildConfig.DEBUG)                     Log.d(StreamingApp.TAG, String.format("WWW Auth Value: %s", wwwauth));                 int idx = wwwauth.indexOf("Basic");                 recurseDepth++;                  if (idx != -1) {                     generateBasicAuth();                 } else {                     // We are assuming Digest here.                     generateDigestAuth("PLAY");                 }                  ret = record();                 authentication = null;                 recurseDepth--;             }         }         return ret;     }      private int teardown() throws IOException {         seq++;         recurseDepth = 0;         StringBuilder request = new StringBuilder();         request.append(String.format(kTeardown, url));         request.append(String.format(kCseq, seq));         if (authentication != null)             request.append(authentication);         if (session != null)             request.append(String.format(kSession, session));         request.append(kCRLF);         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- TEARDOWN Request ---\n\n" + request);         write(request.toString());         String response = read();         if (response == null)             return SOCK_ERR_READ;         if (BuildConfig.DEBUG)             Log.d(StreamingApp.TAG, "--- TEARDOWN Response ---\n\n" + response);         int ret = parseResponse(response);         if (ret == RTSP_BAD_USER_PASS && recurseDepth == 0) {             String wwwauth = headerMap.get(kWWWAuthKey);             if (wwwauth != null) {                 if (BuildConfig.DEBUG)                     Log.d(StreamingApp.TAG, String.format("WWW Auth Value: %s", wwwauth));                 int idx = wwwauth.indexOf("Basic");                 recurseDepth++;                  if (idx != -1) {                     generateBasicAuth();                 } else {                     // We are assuming Digest here.                     generateDigestAuth("TEARDOWN");                 }                  ret = record();                 authentication = null;                 recurseDepth--;             }         }         return ret;     }      public void connect(String dest, int port, Session session) throws IOException {         int trackId = 1;         int responseCode;          if (isConnected())             return;          if (!session.hasAudioTrack() && !session.hasVideoTrack())             throw new IOException("No tracks found in session.");          InetSocketAddress addr = null;         try {             addr = new InetSocketAddress(dest, port);         } catch (Exception e) {             throw new IOException("Failed to resolve rtsp server address.");         }          this.sdp = session.getSDP();         this.user = session.getUser();         this.pass = session.getPass();         this.path = session.getPath();         this.url = String.format("rtsp://%s:%d%s", dest, addr.getPort(), this.path);          try {             super.connect(addr);         } catch (IOException e) {             throw new IOException("Failed to connect rtsp server.");         }          responseCode = announce();         if (responseCode != RTSP_OK) {             close();             throw new IOException("RTSP announce failed: " + responseCode);         }          responseCode = options();         if (responseCode != RTSP_OK) {             close();             throw new IOException("RTSP options failed: " + responseCode);         }          /* Setup audio */         if (session.hasAudioTrack()) {             session.getAudioTrack().setStreamId(channelCount);             responseCode = setup(trackId++);             if (responseCode != RTSP_OK) {                 close();                 throw new IOException("RTSP video failed: " + responseCode);             }         }          /* Setup video */         if (session.hasVideoTrack()) {             session.getVideoTrack().setStreamId(channelCount);             responseCode = setup(trackId++);             if (responseCode != RTSP_OK) {                 close();                 throw new IOException("RTSP audio setup failed: " + responseCode);             }         }          responseCode = record();         if (responseCode != RTSP_OK) {             close();             throw new IOException("RTSP record failed: " + responseCode);         }     }      public void close() throws IOException {         if (!isConnected())             return;         teardown();         super.close();     } }