[SoundCloud] Fix getAudioStreams 401 response

Fix TeamNewPipe/NewPipe#2823

Author: TobiGr

extractor/src/main/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudStreamExtractor.java

@@ -1,5 +1,6 @@
 package org.schabi.newpipe.extractor.services.soundcloud;
 
+import com.grack.nanojson.JsonArray;
 import com.grack.nanojson.JsonObject;
 import com.grack.nanojson.JsonParser;
 import com.grack.nanojson.JsonParserException;
@@ -143,7 +144,7 @@ public List<AudioStream> getAudioStreams() throws IOException, ExtractionExcepti
         List<AudioStream> audioStreams = new ArrayList<>();
         Downloader dl = NewPipe.getDownloader();
 
-        String apiUrl = "https://api.soundcloud.com/i1/tracks/" + urlEncode(getId()) + "/streams"
+        String apiUrl = "https://api-v2.soundcloud.com/tracks/" + urlEncode(getId())
                 + "?client_id=" + urlEncode(SoundcloudParsingHelper.clientId());
 
         String response = dl.get(apiUrl, getExtractorLocalization()).responseBody();
@@ -154,11 +155,45 @@ public List<AudioStream> getAudioStreams() throws IOException, ExtractionExcepti
             throw new ParsingException("Could not parse json response", e);
         }
 
-        String mp3Url = responseObject.getString("http_mp3_128_url");
-        if (mp3Url != null && !mp3Url.isEmpty()) {
-            audioStreams.add(new AudioStream(mp3Url, MediaFormat.MP3, 128));
-        } else {
-            throw new ExtractionException("Could not get SoundCloud's track audio url");
+        // Streams can be streamable and downloadable - or explicitly not.
+        // For playing the track, it is only necessary to have a streamable track.
+        // If this is not the case, this track might not be published yet.
+        if (!responseObject.getBoolean("streamable")) return audioStreams;
+
+        try {
+            JsonArray transcodings = responseObject.getObject("media").getArray("transcodings");
+
+            // get information about what stream formats are available
+            for (Object transcoding : transcodings) {
+
+                JsonObject t = (JsonObject) transcoding;
+                String url = t.getString("url");
+
+                if (url != null && !url.isEmpty()) {
+
+                    // We can only play the mp3 format, but not handle m3u playlists / streams.
+                    // what about Opus?
+                    if (t.getString("preset").contains("mp3")
+                            && t.getObject("format").getString("protocol").equals("progressive")) {
+                        // This url points to the endpoint which generates a unique and short living url to the stream.
+                        // TODO: move this to a separate method to generate valid urls when needed (e.g. resuming a paused stream)
+                        url += "?client_id=" + SoundcloudParsingHelper.clientId();
+                        String res = dl.get(url).responseBody();
+
+                        try {
+                            JsonObject mp3UrlObject = JsonParser.object().from(res);
+                            // Links in this file are also only valid for a short period.
+                            audioStreams.add(new AudioStream(mp3UrlObject.getString("url"), 
+                                    MediaFormat.MP3, 128));
+                        } catch (JsonParserException e) {
+                            throw new ParsingException("Could not parse streamable url", e);
+                        }
+                    }
+                }
+            }
+
+        } catch (NullPointerException e) {
+            throw new ExtractionException("Could not get SoundCloud's track audio url", e);
         }
 
         return audioStreams;