How to play Youtube video in ExoPlayer in Android?

Question

I am trying to play youtube video in exoplayer but here is some confusion I don't know what is DASH url, I have only real youtube url like "https://www.youtube.com/watch?v=v1uyQZNg2vE" , I have no idea how to generate dash url form real url.

Dash Url:

new Sample("Google Glass",
        "http://www.youtube.com/api/manifest/dash/id/bf5bb2419360daf1/source/youtube?"
        + "as=fmp4_audio_clear,fmp4_sd_hd_clear&sparams=ip,ipbits,expire,as&ip=0.0.0.0&"
        + "ipbits=0&expire=19000000000&signature=255F6B3C07C753C88708C07EA31B7A1A10703C8D."
        + "2D6A28B21F921D0B245CDCF36F7EB54A2B5ABFC2&key=ik0", DemoUtil.TYPE_DASH),

Real Url :

 https://www.youtube.com/watch?v=v1uyQZNg2vE

Answer 1

I've written a class that retrieves actual YouTube video streaming URL for format like DASH and HLS using http://www.youtube.com/get_video_info?&video_id=[video_id]&el=info&ps=default&eurl=&gl=US&hl=en url with video ID as described by Karim Abdell Salam. I have also tested the URL in an app that uses ExoPlayer and it works:

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Map;
import java.util.TreeMap;

/**
 * Represents youtube video information retriever.
 */
public class YouTubeVideoInfoRetriever
{
    private static final String URL_YOUTUBE_GET_VIDEO_INFO = "http://www.youtube.com/get_video_info?&video_id=";

    public static final String KEY_DASH_VIDEO = "dashmpd";
    public static final String KEY_HLS_VIDEO = "hlsvp";

    private TreeMap<String, String> kvpList = new TreeMap<>();

    public void retrieve(String videoId) throws IOException
    {
        String targetUrl = URL_YOUTUBE_GET_VIDEO_INFO + videoId+"&el=info&ps=default&eurl=&gl=US&hl=en";
        SimpleHttpClient client = new SimpleHttpClient();
        String output = client.execute(targetUrl, SimpleHttpClient.HTTP_GET, SimpleHttpClient.DEFAULT_TIMEOUT);
        parse(output);
    }

    public String getInfo(String key)
    {
        return kvpList.get(key);
    }

    public void printAll()
    {
        System.out.println("TOTAL VARIABLES=" + kvpList.size());

        for(Map.Entry<String, String> entry : kvpList.entrySet())
        {
            System.out.print( "" + entry.getKey() + "=");
            System.out.println("" + entry.getValue() + "");
        }
    }

    private void parse(String data) throws UnsupportedEncodingException
    {
        String[] splits = data.split("&");
        String kvpStr = "";

        if(splits.length < 1)
        {
            return;
        }

        kvpList.clear();

        for(int i = 0; i < splits.length; ++i)
        {
            kvpStr = splits[i];

            try
            {
                // Data is encoded multiple times
                kvpStr = URLDecoder.decode(kvpStr, SimpleHttpClient.ENCODING_UTF_8);
                kvpStr = URLDecoder.decode(kvpStr, SimpleHttpClient.ENCODING_UTF_8);

                String[] kvpSplits = kvpStr.split("=", 2);

                if(kvpSplits.length == 2)
                {
                    kvpList.put(kvpSplits[0], kvpSplits[1]);
                }
                else if(kvpSplits.length == 1)
                {
                    kvpList.put(kvpSplits[0], "");
                }
            }
            catch (UnsupportedEncodingException ex)
            {
                throw ex;
            }
        }
    }

    public static class SimpleHttpClient
    {
        public static final String ENCODING_UTF_8 = "UTF-8";
        public static final int DEFAULT_TIMEOUT = 10000;

        public static final String HTTP_GET = "GET";

        public String execute(String urlStr, String httpMethod, int timeout) throws IOException
        {
            URL url = null;
            HttpURLConnection conn = null;
            InputStream inStream = null;
            OutputStream outStream = null;
            String response = null;

            try
            {
                url = new URL(urlStr);
                conn = (HttpURLConnection) url.openConnection();
                conn.setConnectTimeout(timeout);
                conn.setRequestMethod(httpMethod);

                inStream = new BufferedInputStream(conn.getInputStream());
                response = getInput(inStream);
            }
            finally
            {
                if(conn != null && conn.getErrorStream() != null)
                {
                    String errorResponse = " : ";
                    errorResponse = errorResponse + getInput(conn.getErrorStream());
                    response = response + errorResponse;
                }

                if (conn != null)
                {
                    conn.disconnect();
                }
            }

            return response;
        }

        private String getInput(InputStream in) throws IOException
        {
            StringBuilder sb = new StringBuilder(8192);
            byte[] b = new byte[1024];
            int bytesRead = 0;

            while (true)
            {
                bytesRead = in.read(b);
                if (bytesRead < 0)
                {
                    break;
                }
                String s = new String(b, 0, bytesRead, ENCODING_UTF_8);
                sb.append(s);
            }

            return sb.toString();
        }

    }
}

Here is the test code:

public static void main(String[] args)
{
    String youTubeVideoID = "v1uyQZNg2vE";

    YouTubeVideoInfoRetriever retriever = new YouTubeVideoInfoRetriever();

    try
    {
        retriever.retrieve(youTubeVideoID);
        System.out.println(retriever.getInfo(YouTubeVideoInfoRetriever.KEY_DASH_VIDEO));
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
}