finished implementing timestamp, along with refactoring services

* added VideoInfo(AbstractVideoInfo) constructor, to support later implementation for reusing info scraped into VideoPreviewInfo, into VideoInfo
* Made the Extractor class behave as a per-video object;
    - most method return values are video-specific, so it makes sense (to me) to have Extractor be stateful.
    - The only stateless methods are getVideoUrl(), getVideoId() and loadDecryptionCode(String)
* Implemented a constructor for YoutubeExtractor, which performs all initialisation work

app/src/main/java/org/schabi/newpipe/AbstractVideoInfo.java

@@ -7,9 +7,10 @@ public abstract class AbstractVideoInfo {
     public String id = "";
     public String title = "";
     public String uploader = "";
+    //public int duration = -1;
     public String thumbnail_url = "";
     public Bitmap thumbnail = null;
     public String webpage_url = "";
     public String upload_date = "";
-    public long view_count = 0;
+    public long view_count = -1;
 }

app/src/main/java/org/schabi/newpipe/VideoInfo.java

@@ -24,44 +24,76 @@ import android.graphics.Bitmap;
 
 /**Info object for opened videos, ie the video ready to play.*/
 public class VideoInfo extends AbstractVideoInfo {
+    private static final String TAG = VideoInfo.class.toString();
+
     public String uploader_thumbnail_url = "";
     public Bitmap uploader_thumbnail = null;
     public String description = "";
-    public int duration = -1;
-    public int age_limit = 0;
-    public int like_count = 0;
-    public int dislike_count = 0;
-    public String average_rating = "";
     public VideoStream[] videoStreams = null;
     public AudioStream[] audioStreams = null;
+    public int videoAvailableStatus = VIDEO_AVAILABLE;
+    public int duration = -1;
+
+    /*YouTube-specific fields
+    todo: move these to a subclass*/
+    public int age_limit = 0;
+    public int like_count = -1;
+    public int dislike_count = -1;
+    public String average_rating = "";
     public VideoPreviewInfo nextVideo = null;
     public VideoPreviewInfo[] relatedVideos = null;
-    public int videoAvailableStatus = VIDEO_AVAILABLE;
+    public int startPosition = -1;//in seconds. some metadata is not passed using a VideoInfo object!
-    //public int startPosition = 0;//in seconds. some metadata is not passed using a VideoInfo object!
-
-    private static final String TAG = VideoInfo.class.toString();
 
     public static final int VIDEO_AVAILABLE = 0x00;
     public static final int VIDEO_UNAVAILABLE = 0x01;
     public static final int VIDEO_UNAVAILABLE_GEMA = 0x02;//German DRM organisation
 
-    public static class VideoStream {
+
-        public VideoStream(String url, int format, String res) {
+    public VideoInfo() {}
-            this.url = url; this.format = format; resolution = res;
+
+
+    /**Creates a new VideoInfo object from an existing AbstractVideoInfo.
+     * All the shared properties are copied to the new VideoInfo.*/
+    public VideoInfo(AbstractVideoInfo avi) {
+        this.id = avi.id;
+        this.title = avi.title;
+        this.uploader = avi.uploader;
+        this.thumbnail_url = avi.thumbnail_url;
+        this.thumbnail = avi.thumbnail;
+        this.webpage_url = avi.webpage_url;
+        this.upload_date = avi.upload_date;
+        this.upload_date = avi.upload_date;
+        this.view_count = avi.view_count;
+
+        //todo: better than this
+        if(avi instanceof VideoPreviewInfo) {//shitty String to convert code
+            String dur = ((VideoPreviewInfo)avi).duration;
+            int minutes = Integer.parseInt(dur.substring(0, dur.indexOf(":")));
+            int seconds = Integer.parseInt(dur.substring(dur.indexOf(":")+1, dur.length()));
+            this.duration = (minutes*60)+seconds;
         }
+
+    }
+
+    public static class VideoStream {
         public String url = "";     //url of the stream
         public int format = -1;
         public String resolution = "";
+
+        public VideoStream(String url, int format, String res) {
+            this.url = url; this.format = format; resolution = res;
+        }
     }
 
     public static class AudioStream {
-        public AudioStream(String url, int format, int bandwidth, int samplingRate) {
-            this.url = url; this.format = format;
-            this.bandwidth = bandwidth; this.samplingRate = samplingRate;
-        }
         public String url = "";
         public int format = -1;
         public int bandwidth = -1;
         public int samplingRate = -1;
+
+        public AudioStream(String url, int format, int bandwidth, int samplingRate) {
+            this.url = url; this.format = format;
+            this.bandwidth = bandwidth; this.samplingRate = samplingRate;
+        }
     }
 }

app/src/main/java/org/schabi/newpipe/VideoInfoItemViewCreator.java

@@ -57,7 +57,7 @@ public class VideoInfoItemViewCreator {
         }
         holder.itemVideoTitleView.setText(info.title);
         holder.itemUploaderView.setText(info.uploader);
-        holder.itemDurationView.setText(info.duration);
+        holder.itemDurationView.setText(""+info.duration);
         if(!info.upload_date.isEmpty()) {
             holder.itemUploadDateView.setText(info.upload_date);
         } else {

app/src/main/java/org/schabi/newpipe/VideoItemDetailActivity.java

@@ -64,27 +64,25 @@ public class VideoItemDetailActivity extends AppCompatActivity {
             // this means the video was called though another app
             if (getIntent().getData() != null) {
                 videoUrl = getIntent().getData().toString();
-                Log.i(TAG, "video URL passed:\"" + videoUrl + "\"");
+                //Log.i(TAG, "video URL passed:\"" + videoUrl + "\"");
                 StreamingService[] serviceList = ServiceList.getServices();
                 Extractor extractor = null;
                 for (int i = 0; i < serviceList.length; i++) {
                     if (serviceList[i].acceptUrl(videoUrl)) {
                         arguments.putInt(VideoItemDetailFragment.STREAMING_SERVICE, i);
-                        try {
                         currentStreamingService = i;
-                            extractor = ServiceList.getService(i).getExtractorInstance();
+                        //extractor = ServiceList.getService(i).getExtractorInstance();
-                        } catch (Exception e) {
-                            e.printStackTrace();
-                        }
                         break;
                     }
                 }
-                if(extractor == null) {
+                if(currentStreamingService == -1) {
                     Toast.makeText(this, R.string.urlNotSupportedText, Toast.LENGTH_LONG)
                             .show();
                 }
-                arguments.putString(VideoItemDetailFragment.VIDEO_URL,
+                //arguments.putString(VideoItemDetailFragment.VIDEO_URL,
-                        extractor.getVideoUrl(extractor.getVideoId(videoUrl)));//cleans URL
+                //        extractor.getVideoUrl(extractor.getVideoId(videoUrl)));//cleans URL
+                arguments.putString(VideoItemDetailFragment.VIDEO_URL, videoUrl);
+
                 arguments.putBoolean(VideoItemDetailFragment.AUTO_PLAY,
                         PreferenceManager.getDefaultSharedPreferences(this)
                                 .getBoolean(getString(R.string.autoPlayThroughIntent), false));

app/src/main/java/org/schabi/newpipe/VideoItemDetailFragment.java

@@ -90,16 +90,18 @@ public class VideoItemDetailFragment extends Fragment {
     private class ExtractorRunnable implements Runnable {
         private Handler h = new Handler();
         private Extractor extractor;
+        private StreamingService service;
         private String videoUrl;
 
-        public ExtractorRunnable(String videoUrl, Extractor extractor, VideoItemDetailFragment f) {
+        public ExtractorRunnable(String videoUrl, StreamingService service, VideoItemDetailFragment f) {
-            this.extractor = extractor;
+            this.service = service;
             this.videoUrl = videoUrl;
         }
         @Override
         public void run() {
             try {
-                VideoInfo videoInfo = extractor.getVideoInfo(videoUrl);
+                this.extractor = service.getExtractorInstance(videoUrl);
+                VideoInfo videoInfo = extractor.getVideoInfo();
                 h.post(new VideoResultReturnedRunnable(videoInfo));
                 if (videoInfo.videoAvailableStatus == VideoInfo.VIDEO_AVAILABLE) {
                     h.post(new SetThumbnailRunnable(
@@ -239,7 +241,7 @@ public class VideoItemDetailFragment extends Fragment {
 
                     //this is horribly convoluted
                     //TODO: find a better way to convert YYYY-MM-DD to a locale-specific date
-                    //suggestions welcome
+                    //suggestions are welcome
                     int year  = Integer.parseInt(info.upload_date.substring(0, 4));
                     int month = Integer.parseInt(info.upload_date.substring(5, 7));
                     int date  = Integer.parseInt(info.upload_date.substring(8, 10));
@@ -255,6 +257,7 @@ public class VideoItemDetailFragment extends Fragment {
                     descriptionView.setMovementMethod(LinkMovementMethod.getInstance());
 
                     actionBarHandler.setVideoInfo(info.webpage_url, info.title);
+                    actionBarHandler.setStartPosition(info.startPosition);
 
                     // parse streams
                     Vector<VideoInfo.VideoStream> streamsToUse = new Vector<>();
@@ -357,7 +360,7 @@ public class VideoItemDetailFragment extends Fragment {
                 StreamingService streamingService = ServiceList.getService(
                         getArguments().getInt(STREAMING_SERVICE));
                 extractorThread = new Thread(new ExtractorRunnable(
-                        getArguments().getString(VIDEO_URL), streamingService.getExtractorInstance(), this));
+                        getArguments().getString(VIDEO_URL), streamingService, this));
 
                 autoPlayEnabled = getArguments().getBoolean(AUTO_PLAY);
                 extractorThread.start();

app/src/main/java/org/schabi/newpipe/VideoPreviewInfo.java

@@ -26,10 +26,7 @@ import android.os.Parcelable;
 
 /**Info object for previews of unopened videos, eg search results, related videos*/
 public class VideoPreviewInfo extends AbstractVideoInfo implements Parcelable {
-
-
     public String duration = "";
-
     protected VideoPreviewInfo(Parcel in) {
         id = in.readString();
         title = in.readString();

app/src/main/java/org/schabi/newpipe/services/Extractor.java

@@ -22,9 +22,94 @@ package org.schabi.newpipe.services;
 
 import org.schabi.newpipe.VideoInfo;
 
-/**Scrapes information from a video streaming service (eg, YouTube). To implement*/
+/**Scrapes information from a video streaming service (eg, YouTube).*/
-public interface Extractor {
+public abstract class Extractor {
-    VideoInfo getVideoInfo(String siteUrl);
+    public String pageUrl;
-    String getVideoUrl(String videoId);
+    public VideoInfo videoInfo;
-    String getVideoId(String videoUrl);
+
+    public Extractor(String url) {
+        this.pageUrl = url;
+    }
+
+    /**Fills out the video info fields which are common to all services.
+     * Probably needs to be overridden by subclasses*/
+    public VideoInfo getVideoInfo()
+    {
+        if(videoInfo == null) {
+            videoInfo = new VideoInfo();
+        }
+
+        if(videoInfo.webpage_url.isEmpty()) {
+            videoInfo.webpage_url = pageUrl;
+        }
+
+        if(videoInfo.title.isEmpty()) {
+            videoInfo.title = getTitle();
+        }
+
+        if(videoInfo.duration  < 1) {
+            videoInfo.duration = getLength();
+        }
+
+
+        if(videoInfo.uploader.isEmpty()) {
+            videoInfo.uploader = getUploader();
+        }
+
+        if(videoInfo.description.isEmpty()) {
+            videoInfo.description = getDescription();
+        }
+
+        if(videoInfo.view_count == -1) {
+            videoInfo.view_count = getViews();
+        }
+
+        if(videoInfo.upload_date.isEmpty()) {
+            videoInfo.upload_date = getUploadDate();
+        }
+
+        if(videoInfo.thumbnail_url.isEmpty()) {
+            videoInfo.thumbnail_url = getThumbnailUrl();
+        }
+
+        if(videoInfo.id.isEmpty()) {
+            videoInfo.id = getVideoId(pageUrl);
+        }
+
+        /** Load and extract audio*/
+        if(videoInfo.audioStreams == null) {
+            videoInfo.audioStreams = getAudioStreams();
+        }
+        /** Extract video stream url*/
+        if(videoInfo.videoStreams == null) {
+            videoInfo.videoStreams = getVideoStreams();
+        }
+
+        if(videoInfo.uploader_thumbnail_url.isEmpty()) {
+            videoInfo.uploader_thumbnail_url = getUploaderThumbnailUrl();
+        }
+
+        if(videoInfo.startPosition < 0) {
+            videoInfo.startPosition = getTimeStamp();
+        }
+
+        //Bitmap thumbnail = null;
+        //Bitmap uploader_thumbnail = null;
+        //int videoAvailableStatus = VIDEO_AVAILABLE;
+        return videoInfo;
+    }
+
+    public abstract String getVideoUrl(String videoId);
+    public abstract String getVideoId(String siteUrl);
+    public abstract int getTimeStamp();
+    public abstract String getTitle();
+    public abstract String getDescription();
+    public abstract String getUploader();
+    public abstract int getLength();
+    public abstract int getViews();
+    public abstract String getUploadDate();
+    public abstract String getThumbnailUrl();
+    public abstract String getUploaderThumbnailUrl();
+    public abstract VideoInfo.AudioStream[] getAudioStreams();
+    public abstract VideoInfo.VideoStream[] getVideoStreams();
 }

app/src/main/java/org/schabi/newpipe/services/StreamingService.java

@@ -25,7 +25,7 @@ public interface StreamingService {
         public String name = "";
     }
     ServiceInfo getServiceInfo();
-    Extractor getExtractorInstance();
+    Extractor getExtractorInstance(String url);
     SearchEngine getSearchEngineInstance();
 
     /**When a VIEW_ACTION is caught this function will test if the url delivered within the calling

app/src/main/java/org/schabi/newpipe/services/youtube/YoutubeExtractor.java

@@ -3,6 +3,7 @@ package org.schabi.newpipe.services.youtube;
 import android.util.Log;
 import android.util.Xml;
 
+import org.json.JSONException;
 import org.json.JSONObject;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
@@ -46,14 +47,225 @@ import java.util.regex.Pattern;
  * along with NewPipe.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-public class YoutubeExtractor implements Extractor {
+public class YoutubeExtractor extends Extractor {
 
     private static final String TAG = YoutubeExtractor.class.toString();
+    private String pageContents;
+    private Document doc;
+    private JSONObject jsonObj;
+    private JSONObject playerArgs;
 
-    // These lists only contain itag formats that are supported by the common Android Video player.
+    // static values
-    // How ever if you are heading for a list showing all itag formats look at
+    private static final String DECRYPTION_FUNC_NAME="decrypt";
-    // https://github.com/rg3/youtube-dl/issues/1687
 
+    // cached values
+    private static volatile String decryptionCode = "";
+
+
+    public YoutubeExtractor(String pageUrl) {
+        super(pageUrl);//most common videoInfo fields are now set in our superclass, for all services
+        pageContents = Downloader.download(cleanUrl(pageUrl));
+        doc = Jsoup.parse(pageContents, pageUrl);
+
+        //attempt to load the youtube js player JSON arguments
+        try {
+            String jsonString = matchGroup1("ytplayer.config\\s*=\\s*(\\{.*?\\});", pageContents);
+            jsonObj = new JSONObject(jsonString);
+            playerArgs = jsonObj.getJSONObject("args");
+
+        } catch (Exception e) {//if this fails, the video is most likely not available.
+            // Determining why is done later.
+            videoInfo.videoAvailableStatus = VideoInfo.VIDEO_UNAVAILABLE;
+            Log.d(TAG, "Could not load JSON data for Youtube video \""+pageUrl+"\". This most likely means the video is unavailable");
+        }
+
+        //----------------------------------
+        // load and parse description code, if it isn't already initialised
+        //----------------------------------
+        if (decryptionCode.isEmpty()) {
+            try {
+            // The Youtube service needs to be initialized by downloading the
+            // js-Youtube-player. This is done in order to get the algorithm
+            // for decrypting cryptic signatures inside certain stream urls.
+                JSONObject ytAssets = jsonObj.getJSONObject("assets");
+                String playerUrl = ytAssets.getString("js");
+
+                if (playerUrl.startsWith("//")) {
+                    playerUrl = "https:" + playerUrl;
+                }
+                decryptionCode = loadDecryptionCode(playerUrl);
+            } catch (Exception e){
+                Log.d(TAG, "Could not load decryption code for the Youtube service.");
+                e.printStackTrace();
+            }
+        }
+    }
+
+    @Override
+    public String getTitle() {
+        try {//json player args method
+            return playerArgs.getString("title");
+        } catch(JSONException je) {//html <meta> method
+            je.printStackTrace();
+            Log.w(TAG, "failed to load title from JSON args; trying to extract it from HTML");
+        } try { // fall through to fall-back
+            return doc.select("meta[name=title]").attr("content");
+        } catch (Exception e) {
+            Log.e(TAG, "failed permanently to load title.");
+            e.printStackTrace();
+            return "";
+        }
+    }
+
+    @Override
+    public String getDescription() {
+        try {
+            return doc.select("p[id=\"eow-description\"]").first().html();
+        } catch (Exception e) {//todo: add fallback method
+            Log.e(TAG, "failed to load description.");
+            e.printStackTrace();
+            return "";
+        }
+    }
+
+    @Override
+    public String getUploader() {
+        try {//json player args method
+            return playerArgs.getString("author");
+        } catch(JSONException je) {
+            je.printStackTrace();
+            Log.w(TAG, "failed to load uploader name from JSON args; trying to extract it from HTML");
+        } try {//fall through to fallback HTML method
+            return doc.select("div.yt-user-info").first().text();
+        } catch (Exception e) {
+            e.printStackTrace();
+            Log.e(TAG, "failed permanently to load uploader name.");
+            return "";
+        }
+    }
+
+    @Override
+    public int getLength() {
+        try {
+            return playerArgs.getInt("length_seconds");
+        } catch (JSONException je) {//todo: find fallback method
+            Log.e(TAG, "failed to load video duration from JSON args");
+            je.printStackTrace();
+            return -1;
+        }
+    }
+
+    @Override
+    public int getViews() {
+        try {
+            String viewCountString = doc.select("meta[itemprop=interactionCount]").attr("content");
+            return Integer.parseInt(viewCountString);
+        } catch (Exception e) {//todo: find fallback method
+            Log.e(TAG, "failed to number of views");
+            e.printStackTrace();
+            return -1;
+        }
+    }
+
+    @Override
+    public String getUploadDate() {
+        try {
+            return doc.select("meta[itemprop=datePublished]").attr("content");
+        } catch (Exception e) {//todo: add fallback method
+            Log.e(TAG, "failed to get upload date.");
+            e.printStackTrace();
+            return "";
+        }
+    }
+
+    @Override
+    public String getThumbnailUrl() {
+        //first attempt getting a small image version
+        //in the html extracting part we try to get a thumbnail with a higher resolution
+        // Try to get high resolution thumbnail if it fails use low res from the player instead
+        try {
+            return doc.select("link[itemprop=\"thumbnailUrl\"]").first().attr("abs:href");
+        } catch(Exception e) {
+            Log.w(TAG, "Could not find high res Thumbnail. Using low res instead");
+            //fall through to fallback
+        } try {
+            return playerArgs.getString("thumbnail_url");
+        } catch (JSONException je) {
+            je.printStackTrace();
+            Log.w(TAG, "failed to extract thumbnail URL from JSON args; trying to extract it from HTML");
+            return "";
+        }
+    }
+
+    @Override
+    public String getUploaderThumbnailUrl() {
+        try {
+            return doc.select("a[class*=\"yt-user-photo\"]").first()
+                    .select("img").first()
+                    .attr("abs:data-thumb");
+        } catch (Exception e) {//todo: add fallback method
+            Log.e(TAG, "failed to get uploader thumbnail URL.");
+            e.printStackTrace();
+            return "";
+        }
+    }
+
+    @Override
+    public VideoInfo.AudioStream[] getAudioStreams() {
+        try {
+            String dashManifest = playerArgs.getString("dashmpd");
+            return parseDashManifest(dashManifest, decryptionCode);
+
+        } catch (NullPointerException e) {
+            Log.e(TAG, "Could not find \"dashmpd\" upon the player args (maybe no dash manifest available).");
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return new VideoInfo.AudioStream[0];
+    }
+
+    @Override
+    public VideoInfo.VideoStream[] getVideoStreams() {
+        try{
+            //------------------------------------
+            // extract video stream url
+            //------------------------------------
+            String encoded_url_map = playerArgs.getString("url_encoded_fmt_stream_map");
+            Vector<VideoInfo.VideoStream> videoStreams = new Vector<>();
+            for(String url_data_str : encoded_url_map.split(",")) {
+                Map<String, String> tags = new HashMap<>();
+                for(String raw_tag : Parser.unescapeEntities(url_data_str, true).split("&")) {
+                    String[] split_tag = raw_tag.split("=");
+                    tags.put(split_tag[0], split_tag[1]);
+                }
+
+                int itag = Integer.parseInt(tags.get("itag"));
+                String streamUrl = URLDecoder.decode(tags.get("url"), "UTF-8");
+
+                // if video has a signature: decrypt it and add it to the url
+                if(tags.get("s") != null) {
+                    streamUrl = streamUrl + "&signature=" + decryptSignature(tags.get("s"), decryptionCode);
+                }
+
+                if(resolveFormat(itag) != -1) {
+                    videoStreams.add(new VideoInfo.VideoStream(
+                            streamUrl,
+                            resolveFormat(itag),
+                            resolveResolutionString(itag)));
+                }
+            }
+            return videoStreams.toArray(new VideoInfo.VideoStream[videoStreams.size()]);
+
+        } catch (Exception e) {
+            Log.e(TAG, "Failed to get video stream");
+            e.printStackTrace();
+            return new VideoInfo.VideoStream[0];
+        }
+    }
+
+    /**These lists only contain itag formats that are supported by the common Android Video player.
+    However if you are looking for a list showing all itag formats, look at
+    https://github.com/rg3/youtube-dl/issues/1687 */
     public static int resolveFormat(int itag) {
         switch(itag) {
             // video
@@ -91,187 +303,76 @@ public class YoutubeExtractor implements Extractor {
         }
     }
 
-
-    // static values
-    private static final String DECRYPTION_FUNC_NAME="decrypt";
-
-    // cached values
-    private static volatile String decryptionCode = "";
-
-    public void initService(String site) {
-        // The Youtube service needs to be initialized by downloading the
-        // js-Youtube-player. This is done in order to get the algorithm
-        // for decrypting cryptic signatures inside certain stream urls.
-
-        // Star Wars Kid is used as a dummy video, in order to download the youtube player.
-        //String site = Downloader.download("https://www.youtube.com/watch?v=HPPj6viIBmU");
-        //-------------------------------------
-        // extracting form player args
-        //-------------------------------------
-        try {
-            String jsonString = matchGroup1("ytplayer.config\\s*=\\s*(\\{.*?\\});", site);
-            JSONObject jsonObj = new JSONObject(jsonString);
-
-            //----------------------------------
-            // load and parse description code
-            //----------------------------------
-            if (decryptionCode.isEmpty()) {
-                JSONObject ytAssets = jsonObj.getJSONObject("assets");
-                String playerUrl = ytAssets.getString("js");
-                if (playerUrl.startsWith("//")) {
-                    playerUrl = "https:" + playerUrl;
-                }
-                decryptionCode = loadDecryptionCode(playerUrl);
-            }
-
-        } catch (Exception e){
-            Log.d(TAG, "Could not initialize the extractor of the Youtube service.");
-            e.printStackTrace();
-        }
-    }
-
     @Override
-    public String getVideoId(String videoUrl) {
+    public String getVideoId(String url) {
-        String id = "";
+        String id;
-        Pattern pat;
+        String pat;
 
-        if(videoUrl.contains("youtube")) {
+        if(url.contains("youtube")) {
-            pat = Pattern.compile("youtube\\.com/watch\\?v=([\\-a-zA-Z0-9_]{11})");
+            pat = "youtube\\.com/watch\\?v=([\\-a-zA-Z0-9_]{11})";
         }
-        else if(videoUrl.contains("youtu.be")) {
+        else if(url.contains("youtu.be")) {
-            pat = Pattern.compile("youtu\\.be/([a-zA-Z0-9_-]{11})");
+            pat = "youtu\\.be/([a-zA-Z0-9_-]{11})";
         }
         else {
-            Log.e(TAG, "Error could not parse url: " + videoUrl);
+            Log.e(TAG, "Error could not parse url: " + url);
             return "";
         }
-        Matcher mat = pat.matcher(videoUrl);
+        id = matchGroup1(pat, url);
-        boolean foundMatch = mat.find();
+        if(!id.isEmpty()){
-        if(foundMatch){
+            Log.i(TAG, "string \""+url+"\" matches!");
-            id = mat.group(1);
-            Log.i(TAG, "string \""+videoUrl+"\" matches!");
-        }
-        Log.i(TAG, "string \""+videoUrl+"\" does not match.");
             return id;
         }
+        Log.i(TAG, "string \""+url+"\" does not match.");
+        return "";
+    }
 
     @Override
     public String getVideoUrl(String videoId) {
         return "https://www.youtube.com/watch?v=" + videoId;
     }
 
-    public int getStartPosition(String siteUrl){
+    /**Attempts to parse (and return) the offset to start playing the video from.
-        String timeStamp = matchGroup1("((#|&)t=\\d{0,3}h?\\d{0,3}m?\\d{1,3}s?)", siteUrl);
+     * @return the offset (in seconds), or 0 if no timestamp is found.*/
-        Log.i(TAG, "time stamp:"+timeStamp);
+    @Override
-        //videoInfo.startPosition
+    public int getTimeStamp(){
+        String timeStamp = matchGroup1("((#|&)t=\\d{0,3}h?\\d{0,3}m?\\d{1,3}s?)", pageUrl);
 
-        //TODO: test this!
+        //TODO: test this
-        if(timeStamp.length() > 0) {
+        if(!timeStamp.isEmpty()) {
             String secondsString = matchGroup1("(\\d{1,3})s", timeStamp);
-            if(secondsString.length() == 0)//try again with unspecified units as seconds
-                secondsString = matchGroup1("t=(\\d{1,3})", timeStamp);
             String minutesString = matchGroup1("(\\d{1,3})m", timeStamp);
             String hoursString = matchGroup1("(\\d{1,3})h", timeStamp);
 
-            int seconds = (secondsString.length() > 0 ? Integer.parseInt(secondsString) : 0);
+            if(secondsString.isEmpty()//if nothing was got,
-            int minutes = (minutesString.length() > 0 ? Integer.parseInt(minutesString) : 0);
+            && minutesString.isEmpty()//treat as unlabelled seconds
-            int hours =   (hoursString.length()   > 0 ? Integer.parseInt(hoursString)   : 0);
+            && hoursString.isEmpty())
+                secondsString = matchGroup1("t=(\\d{1,3})", timeStamp);
 
-            return seconds + (60*minutes) + (3600*hours);//don't trust BODMAS!
+            int seconds = (secondsString.isEmpty() ? 0 : Integer.parseInt(secondsString));
+            int minutes = (minutesString.isEmpty() ? 0 : Integer.parseInt(minutesString));
+            int hours =   (hoursString.isEmpty()   ? 0 : Integer.parseInt(hoursString));
+
+            int ret = seconds + (60*minutes) + (3600*hours);//don't trust BODMAS!
+            Log.d(TAG, "derived timestamp value:"+ret);
+            return ret;
             //the ordering varies internationally
         }//else, return default 0
         return 0;
     }
 
     @Override
-    public VideoInfo getVideoInfo(String siteUrl) {
+    public VideoInfo getVideoInfo() {
-        String site = Downloader.download(siteUrl);
+        videoInfo = super.getVideoInfo();
-        VideoInfo videoInfo = new VideoInfo();
+        //todo: replace this with a call to getVideoId, if possible
-
+        videoInfo.id = matchGroup1("v=([0-9a-zA-Z_-]{11})", pageUrl);
-        Document doc = Jsoup.parse(site, siteUrl);
-
-        videoInfo.id = matchGroup1("v=([0-9a-zA-Z_-]{11})", siteUrl);
 
         videoInfo.age_limit = 0;
-        videoInfo.webpage_url = siteUrl;
 
-        initService(site);
+        //average rating
-
-        //-------------------------------------
-        // extracting form player args
-        //-------------------------------------
-        JSONObject playerArgs = null;
-        {
         try {
-                String jsonString = matchGroup1("ytplayer.config\\s*=\\s*(\\{.*?\\});", site);
-                JSONObject jsonObj = new JSONObject(jsonString);
-                playerArgs = jsonObj.getJSONObject("args");
-            }
-            catch (Exception e) {
-                e.printStackTrace();
-                // If we fail in this part the video is most likely not available.
-                // Determining why is done later.
-                videoInfo.videoAvailableStatus = VideoInfo.VIDEO_UNAVAILABLE;
-            }
-        }
-
-        //-----------------------
-        // load and extract audio
-        //-----------------------
-        try {
-            String dashManifest = playerArgs.getString("dashmpd");
-            videoInfo.audioStreams = parseDashManifest(dashManifest, decryptionCode);
-
-        } catch (NullPointerException e) {
-            Log.e(TAG, "Could not find \"dashmpd\" upon the player args (maybe no dash manifest available).");
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-
-        try {
-            //--------------------------------------------
-            // extract general information about the video
-            //--------------------------------------------
-
-            videoInfo.uploader = playerArgs.getString("author");
-            videoInfo.title = playerArgs.getString("title");
-            //first attempt getting a small image version
-            //in the html extracting part we try to get a thumbnail with a higher resolution
-            videoInfo.thumbnail_url = playerArgs.getString("thumbnail_url");
-            videoInfo.duration = playerArgs.getInt("length_seconds");
             videoInfo.average_rating = playerArgs.getString("avg_rating");
-
+        } catch (JSONException e) {
-            //------------------------------------
-            // extract video stream url
-            //------------------------------------
-            String encoded_url_map = playerArgs.getString("url_encoded_fmt_stream_map");
-            Vector<VideoInfo.VideoStream> videoStreams = new Vector<>();
-            for(String url_data_str : encoded_url_map.split(",")) {
-                Map<String, String> tags = new HashMap<>();
-                for(String raw_tag : Parser.unescapeEntities(url_data_str, true).split("&")) {
-                    String[] split_tag = raw_tag.split("=");
-                    tags.put(split_tag[0], split_tag[1]);
-                }
-
-                int itag = Integer.parseInt(tags.get("itag"));
-                String streamUrl = URLDecoder.decode(tags.get("url"), "UTF-8");
-
-                // if video has a signature: decrypt it and add it to the url
-                if(tags.get("s") != null) {
-                    streamUrl = streamUrl + "&signature=" + decryptSignature(tags.get("s"), decryptionCode);
-                }
-
-                if(resolveFormat(itag) != -1) {
-                    videoStreams.add(new VideoInfo.VideoStream(
-                            streamUrl,
-                            resolveFormat(itag),
-                            resolveResolutionString(itag)));
-                }
-            }
-            videoInfo.videoStreams =
-                    videoStreams.toArray(new VideoInfo.VideoStream[videoStreams.size()]);
-
-        } catch (Exception e) {
             e.printStackTrace();
         }
 
@@ -279,7 +380,6 @@ public class YoutubeExtractor implements Extractor {
         // extracting information from html page
         //---------------------------------------
 
-
         // Determine what went wrong when the Video is not available
         if(videoInfo.videoAvailableStatus == VideoInfo.VIDEO_UNAVAILABLE) {
             if(doc.select("h1[id=\"unavailable-message\"]").first().text().contains("GEMA")) {
@@ -287,22 +387,6 @@ public class YoutubeExtractor implements Extractor {
             }
         }
 
-        // Try to get high resolution thumbnail if it fails use low res from the player instead
-        try {
-            videoInfo.thumbnail_url = doc.select("link[itemprop=\"thumbnailUrl\"]").first()
-                    .attr("abs:href");
-        } catch(Exception e) {
-            Log.i(TAG, "Could not find high res Thumbnail. Using low res instead");
-        }
-
-        // upload date
-        videoInfo.upload_date = doc.select("meta[itemprop=datePublished]").attr("content");
-
-        //TODO: Format date locale-specifically
-
-
-        // description
-        videoInfo.description = doc.select("p[id=\"eow-description\"]").first().html();
         String likesString = "";
         String dislikesString = "";
         try {
@@ -325,17 +409,8 @@ public class YoutubeExtractor implements Extractor {
             videoInfo.dislike_count = 0;
         }
 
-        // uploader thumbnail
-        videoInfo.uploader_thumbnail_url = doc.select("a[class*=\"yt-user-photo\"]").first()
-                .select("img").first()
-                .attr("abs:data-thumb");
-
-        // view count TODO:  locale-specific formatting
-        String viewCountString = doc.select("meta[itemprop=interactionCount]").attr("content");
-        videoInfo.view_count = Integer.parseInt(viewCountString);
-
         // next video
-        videoInfo.nextVideo = extractVideoInfoItem(doc.select("div[class=\"watch-sidebar-section\"]").first()
+        videoInfo.nextVideo = extractVideoPreviewInfo(doc.select("div[class=\"watch-sidebar-section\"]").first()
                 .select("li").first());
 
         // related videos
@@ -343,13 +418,14 @@ public class YoutubeExtractor implements Extractor {
         for(Element li : doc.select("ul[id=\"watch-related\"]").first().children()) {
             // first check if we have a playlist. If so leave them out
             if(li.select("a[class*=\"content-link\"]").first() != null) {
-                relatedVideos.add(extractVideoInfoItem(li));
+                relatedVideos.add(extractVideoPreviewInfo(li));
             }
         }
         videoInfo.relatedVideos = relatedVideos.toArray(new VideoPreviewInfo[relatedVideos.size()]);
         return videoInfo;
     }
 
+
     private VideoInfo.AudioStream[] parseDashManifest(String dashManifest, String decryptoinCode) {
         if(!dashManifest.contains("/signature/")) {
             String encryptedSig = matchGroup1("/s/([a-fA-F0-9\\.]+)", dashManifest);
@@ -413,8 +489,10 @@ public class YoutubeExtractor implements Extractor {
         }
         return audioStreams.toArray(new VideoInfo.AudioStream[audioStreams.size()]);
     }
-
+    /**Provides information about links to other videos on the video page, such as related videos.
-    private VideoPreviewInfo extractVideoInfoItem(Element li) {
+     * This is encapsulated in a VideoPreviewInfo object,
+     * which is a subset of the fields in a full VideoInfo.*/
+    private VideoPreviewInfo extractVideoPreviewInfo(Element li) {
         VideoPreviewInfo info = new VideoPreviewInfo();
         info.webpage_url = li.select("a[class*=\"content-link\"]").first()
                 .attr("abs:href");
@@ -426,8 +504,10 @@ public class YoutubeExtractor implements Extractor {
 
         //todo: check NullPointerException causing
         info.title = li.select("span[class=\"title\"]").first().text();
-        info.view_count = Long.parseLong(li.select("span[class*=\"view-count\"]").first().text());
+        info.view_count = Long.parseLong(li.select("span[class*=\"view-count\"]")
+                .first().text().replaceAll("[^\\d]", ""));
         info.uploader = li.select("span[class=\"g-hovercard\"]").first().text();
+
         info.duration = li.select("span[class=\"video-time\"]").first().text();
 
         Element img = li.select("img").first();
@@ -491,6 +571,10 @@ public class YoutubeExtractor implements Extractor {
         return result.toString();
     }
 
+    private String cleanUrl(String complexUrl) {
+        return getVideoUrl(getVideoId(complexUrl));
+    }
+
     private String matchGroup1(String pattern, String input) {
         Pattern pat = Pattern.compile(pattern);
         Matcher mat = pat.matcher(input);
@@ -499,7 +583,7 @@ public class YoutubeExtractor implements Extractor {
             return mat.group(1);
         }
         else {
-            Log.e(TAG, "failed to find pattern \""+pattern+"\" inside of \""+input+"\"");
+            Log.w(TAG, "failed to find pattern \""+pattern+"\" inside of \""+input+"\"");
             new Exception("failed to find pattern \""+pattern+"\"").printStackTrace();
             return "";
         }

app/src/main/java/org/schabi/newpipe/services/youtube/YoutubeSearchEngine.java

@@ -62,7 +62,7 @@ public class YoutubeSearchEngine implements SearchEngine {
         String site;
         String url = builder.build().toString();
         //if we've been passed a valid language code, append it to the URL
-        if(languageCode.length() > 0) {
+        if(!languageCode.isEmpty()) {
           //assert Pattern.matches("[a-z]{2}(-([A-Z]{2}|[0-9]{1,3}))?", languageCode);
                 site  = Downloader.download(url, languageCode);
         }
@@ -101,6 +101,7 @@ public class YoutubeSearchEngine implements SearchEngine {
 
                 // video item type
             } else if(!((el = item.select("div[class*=\"yt-lockup-video\"").first()) == null)) {
+                //todo: de-duplicate this with YoutubeExtractor.getVideoPreviewInfo()
                 VideoPreviewInfo resultItem = new VideoPreviewInfo();
                 Element dl = el.select("h3").first().select("a").first();
                 resultItem.webpage_url = dl.attr("abs:href");
@@ -113,8 +114,9 @@ public class YoutubeSearchEngine implements SearchEngine {
                     e.printStackTrace();
                 }
                 resultItem.title = dl.text();
-                resultItem.duration = item.select("span[class=\"video-time\"]").first()
+
-                        .text();
+                resultItem.duration = item.select("span[class=\"video-time\"]").first().text();
+
                 resultItem.uploader = item.select("div[class=\"yt-lockup-byline\"]").first()
                         .select("a").first()
                         .text();
@@ -132,7 +134,7 @@ public class YoutubeSearchEngine implements SearchEngine {
                 }
                 result.resultList.add(resultItem);
             } else {
-                Log.e(TAG, "GREAT FUCKING ERROR");
+                Log.e(TAG, "unexpected element found:\""+el+"\"");
             }
         }
         return result;

app/src/main/java/org/schabi/newpipe/services/youtube/YoutubeService.java

@@ -33,8 +33,13 @@ public class YoutubeService implements StreamingService {
         return serviceInfo;
     }
     @Override
-    public Extractor getExtractorInstance() {
+    public Extractor getExtractorInstance(String url) {
-        return new YoutubeExtractor();
+        if(acceptUrl(url)) {
+            return new YoutubeExtractor(url);
+        }
+        else {
+            throw new IllegalArgumentException("supplied String is not a valid Youtube URL");
+        }
     }
     @Override
     public SearchEngine getSearchEngineInstance() {