Use Wowza nDVR playlist request with the Wowza Streaming Engine Java API

HLS

http://[wowza-ip-address]:1935/dvr/myStream/playlist.m3u8?DVR&wowzadvrplayliststart=20140211083000&wowzadvrplaylistduration=300000

MPEG-DASH

http://[wowza-ip-address]:1935/dvr/myStream/manifest.mpd?DVR&wowzadvrplayliststart=20140211083000&wowzadvrplaylistduration=300000

Creating custom playlist delegates 

If you want to provide your own playlist delegate, it would look very much like DvrStartDurationPlaylistRequestDelegate. You must provide two public methods and logic to determine your playlist request.

This method is called for a single bitrate playlist request:

public DvrPlaylistRequest getDvrPlaylistRequest(IHTTPStreamerApplicationContext appContext, IDvrStreamStore store, Map<String, String> queryMap)

This method is called to request an adaptive bitrate playlist:

public DvrPlaylistRequest getDvrPlaylistRequest(IHTTPStreamerApplicationContext appContext, List<IDvrStreamStore> stores, Map<String, String> queryMap)

See the Wowza Streaming Engine User's Guide for information on how to add your own code.

package com.example.dvr.impl;

import java.util.*;

import com.wowza.wms.application.WMSProperties;
import com.wowza.wms.dvr.*;
import com.wowza.wms.dvr.IDvrConstants.DvrTimeScale;
import com.wowza.wms.httpstreamer.model.IHTTPStreamerApplicationContext;
import com.wowza.wms.logging.WMSLoggerFactory;

public class DvrStartDurationPlaylistRequestDelegate extends DvrBasePlaylistRequestDelegate {
	private static final String CLASSNAME = "DvrStartDurationPlaylistRequestDelegate";
	private static final Class<DvrStartDurationPlaylistRequestDelegate> CLASS = DvrStartDurationPlaylistRequestDelegate.class;
    
    public static final String DVR_QUERYSTR_PLAYLIST_DURATION = "wowzadvrplaylistduration";
    public static final String DVR_QUERYSTR_PLAYLIST_START = "wowzadvrplayliststart";
    public static final String PROPKEY_DVR_PLAYLIST_DURATION_QUERY_PARAMETER = "dvrPlaylistDurationQueryParameter";
    public static final String PROPKEY_DVR_PLAYLIST_START_QUERY_PARAMETER = "dvrPlaylistStartQueryParameter";
    public static final String PROPKEY_DVR_PLAYLIST_LOG_REQUESTS = "dvrPlaylistDebugRequests";
    
    private boolean doDebug = false;

    
    public DvrPlaylistRequest getDvrPlaylistRequest(IHTTPStreamerApplicationContext appContext, IDvrStreamStore store, Map<String, String> queryMap) {       
        DvrPlaylistRequest availablePlaylist = getDefaultPlaylistRequest(DvrTimeScale.DVR_TIME, store);
        
        DvrPlaylistRequest newRequest = createRequestFromQueryParams(appContext, queryMap, availablePlaylist);
        
        return newRequest;
    }


    public DvrPlaylistRequest getDvrPlaylistRequest(IHTTPStreamerApplicationContext appContext, 
                                                                        List<IDvrStreamStore> stores, Map<String, String> queryMap) {
        DvrPlaylistRequest availablePlaylist = getDefaultPlaylistRequest(DvrTimeScale.DVR_TIME, stores);

        DvrPlaylistRequest newRequest = createRequestFromQueryParams(appContext, queryMap, availablePlaylist);

        return newRequest;
    }

    private DvrPlaylistRequest createRequestFromQueryParams(IHTTPStreamerApplicationContext appContext, 
                                                                                          Map<String, String> queryMap, DvrPlaylistRequest availablePlaylist) {
        DvrPlaylistRequest newRequest = new DvrPlaylistRequest();
        if (availablePlaylist != null) {
            newRequest.setPlaylistEnd(availablePlaylist.getPlaylistEnd());
            newRequest.setPlaylistStart(availablePlaylist.getPlaylistStart());
        }
        
        WMSProperties dvrProperties = getDvrProperties(appContext);
        String playStartQueryParameter = dvrProperties.getPropertyStr(PROPKEY_DVR_PLAYLIST_START_QUERY_PARAMETER, DVR_QUERYSTR_PLAYLIST_START);
        String playDurationQueryParameter = dvrProperties.getPropertyStr(PROPKEY_DVR_PLAYLIST_DURATION_QUERY_PARAMETER, DVR_QUERYSTR_PLAYLIST_DURATION);

	this.doDebug = dvrProperties.getPropertyBoolean(PROPKEY_DVR_PLAYLIST_LOG_REQUESTS, doDebug);


        String playStartStr = queryMap.get(playStartQueryParameter);
        String playDurationStr = queryMap.get(playDurationQueryParameter);

        if (doDebug) {
            WMSLoggerFactory.getLogger(CLASS).info(String.format("%s : Request: %s:%s %s:%s ", CLASSNAME, playStartQueryParameter, playStartStr, playDurationQueryParameter, playDurationStr)); 
            WMSLoggerFactory.getLogger(CLASS).info(String.format("%s : Available Playlist: %s ", CLASSNAME, availablePlaylist));   	
        }

        if (availablePlaylist == null) {
            if (doDebug) {
                WMSLoggerFactory.getLogger(CLASS).warn(String.format("%s : availablePlaylist is null.", CLASSNAME));    
            }
            return newRequest;
        }

        if (playStartStr != null)
        {
            try
            {
                long playStart = Long.parseLong(playStartStr);
                if (playStart < availablePlaylist.getPlaylistStart()) {
                	if (doDebug) {
                		WMSLoggerFactory.getLogger(CLASS).warn(String.format("%s : requestedStart:%d < availableStart:%d.  Using availableStart.", CLASSNAME, playStart, availablePlaylist.getPlaylistStart()));
                	}
                } 
                else if (availablePlaylist.hasSpecifiedEnd() && playStart > availablePlaylist.getPlaylistEnd()) {
                	if (doDebug) {
                		WMSLoggerFactory.getLogger(CLASS).warn(String.format("%s : requestedStart:%d > availableEnd:%d.", CLASSNAME, playStart, availablePlaylist.getPlaylistEnd()));   	
                	}
                } else {
                    newRequest.setPlaylistStart(playStart);
                } 
                
            }
            catch(Exception e)
            {
            }
        }
        


        if (playDurationStr != null)
        {
            try
            {
                long playDuration = Long.parseLong(playDurationStr);
                long playEnd = newRequest.getPlaylistStart() + playDuration;
                if (playEnd < availablePlaylist.getPlaylistStart()) {
                	if (doDebug) {
                		WMSLoggerFactory.getLogger(CLASS).warn(String.format("%s : requestedEnd:%d < availableStart:%d.  Using availableStart.", CLASSNAME, playEnd, availablePlaylist.getPlaylistStart()));   	
                	}
                } else if (availablePlaylist.hasSpecifiedEnd() && playEnd > availablePlaylist.getPlaylistEnd()) {
                	if (doDebug) {
                		WMSLoggerFactory.getLogger(CLASS).warn(String.format("%s : requestedEnd:%d > availableEnd:%d.  Using availableEnd.", CLASSNAME, playEnd, availablePlaylist.getPlaylistEnd()));   	
                	}
                } else {
                    newRequest.setPlaylistEnd(playEnd);
                } 
            }
            catch(Exception e)
            {
            }
        }
        if (doDebug) {
            WMSLoggerFactory.getLogger(CLASS).info(String.format("%s : Resolved Playlist: %s ", CLASSNAME, newRequest));   	
        }

        return newRequest;
    }
}

Example: Query DVR store times

The following example code queries the DVR store in the playlist delegate to determine available times. Similar code may be useful when creating your own playlist request delegate.

The IDvrTimeMap maps between DRV manifest time, packet time, and UTC time when the time is reset:

private static final DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH:mm:ss");

public DvrPlaylistRequest getDvrPlaylistRequest(IHTTPStreamerApplicationContext appContext, IDvrStreamStore store, Map<String, String> queryMap) {
    // . . .
        
    // Look at store and determine type (audio or video)
    int type = this.chooseManifestType(store);
        
    IDvrManifest manifest = store.getManifest();

    DvrManifestEntry firstEntry = manifest.getFirstEntry(type);
    System.out.printf("first   : %s
", formatTime(firstEntry));

    // The last live DVR chunk is earlier than the last recorded for "live" stores
    if (store.isLive()) {
        DvrManifestEntry lastLiveEntry = manifest.getLastLiveEntry(type);
        System.out.printf("lastLive: %s
", formatTime(lastLiveEntry));
    }
        
    DvrManifestEntry lastRecordedEntry = manifest.getLastRecordedEntry(type);
    System.out.printf("lastRec : %s
", formatTime(lastRecordedEntry));
        
    IDvrTimeMap timeMap = manifest.getTimeMap();
    Collection<DvrManifestEntry> times = timeMap.getIndexMap().values();
    for (DvrManifestEntry e : times) {
        DvrManifestTimeMapEntry te = (DvrManifestTimeMapEntry)e;
        System.out.printf("timeSpan: %s
", formatTime(te));
    }
        
    // . . .
}

private String formatTime(DvrManifestEntry entry) {
    if (formatter == null || entry == null) {
        return "format error";
    }
    return String.format("dvrTime:%12d pt:%12d utcTime:%s", 
                                  entry.getStartTimecode(), entry.getPacketStartTime(), formatter.format(new Date(entry.getUtcStartTime())));
}

Example: Create a playlist request based on UTC time

The following example code creates a playlist request based on UTC time.

String UTC_FORMAT = "yyyy-MM-dd-HH:mm:ss";
DateFormat formatter = new SimpleDateFormat(UTC_FORMAT);

public DvrPlaylistRequest getDvrPlaylistRequest(IHTTPStreamerApplicationContext appContext, IDvrStreamStore store, Map<String, String> queryMap) {
    // . . . This could come from URL param or some other manner
    String startStr= "2012-02-14-11:30:00";

     // This is entire playlist request in UTC
     DvrPlaylistRequest fullPlaylistRequest = getDefaultLivePlaylistRequest(DvrTimeScale.UTC_TIME, store);

    // Convert start String to UTC
    Date date = null;
    if (!StringUtils.isEmpty(startStr)) {
         try {
            date = (Date)formatter.parse(startStr);  
         } catch (ParseException e) {
            date = null;
            //e.printStackTrace();
        }
    }
    // System.out.printf("'%s' --> date:%s", startStr, date);

     // If the date specified is less than the initial date we have to play, its not valid
     if (date != null && date.before(new Date(fullPlaylistRequest.getPlaylistStart())))
     {
          System.out.println("Requested start time before actual recording.");
          date = new Date(fullPlaylistRequest.getPlaylistStart());
     }

    DvrPlaylistRequest req;
    if (date != null) {
        req = new DvrPlaylistRequest(DvrTimeScale.UTC_TIME);
        req.setPlaylistStart(date.getTime());
    } else {
        // Use default
        req = super.getDvrPlaylistRequest(appContext, store, queryMap);
    }
    return req;
}