Apply changes in YoutubeStreamExtractor

Extract post live DVR streams as post live streams instead of live streams.

A new class has been in order to improve code: ItagInfo, which stores an itag, the content (URL) extracted and if its an URL or not.
A functional interface has been added in order to abstract the stream building: StreamBuilderHelper.
Also add the cver parameter added by the desktop web client on the corresponding streams (a new method has been added in YoutubeParsingHelper to check this and another for Android streams).

Some code in these classes has been also refactored/improved/optimized.

Author: AudricV

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/ItagInfo.java

@@ -0,0 +1,37 @@
+package org.schabi.newpipe.extractor.services.youtube;
+
+import javax.annotation.Nonnull;
+import java.io.Serializable;
+
+public final class ItagInfo implements Serializable {
+
+    @Nonnull
+    private final String content;
+    @Nonnull
+    private final ItagItem itagItem;
+    private boolean isUrl;
+
+    public ItagInfo(@Nonnull final String content,
+                    @Nonnull final ItagItem itagItem) {
+        this.content = content;
+        this.itagItem = itagItem;
+    }
+
+    public void setIsUrl(final boolean isUrl) {
+        this.isUrl = isUrl;
+    }
+
+    @Nonnull
+    public String getContent() {
+        return content;
+    }
+
+    @Nonnull
+    public ItagItem getItagItem() {
+        return itagItem;
+    }
+
+    public boolean getIsUrl() {
+        return isUrl;
+    }
+}

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeParsingHelper.java

@@ -71,6 +71,7 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Random;
+import java.util.regex.Pattern;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -246,6 +247,11 @@ private YoutubeParsingHelper() {
     private static final String FEED_BASE_CHANNEL_ID =
             "https://www.youtube.com/feeds/videos.xml?channel_id=";
     private static final String FEED_BASE_USER = "https://www.youtube.com/feeds/videos.xml?user=";
+    private static final Pattern C_WEB_PATTERN = Pattern.compile("&c=WEB");
+    private static final Pattern C_TVHTML5_SIMPLY_EMBEDDED_PLAYER_PATTERN =
+            Pattern.compile("&c=TVHTML5_SIMPLY_EMBEDDED_PLAYER");
+    private static final Pattern C_ANDROID_PATTERN = Pattern.compile("&c=ANDROID");
+    private static final Pattern C_IOS_PATTERN = Pattern.compile("&c=IOS");
 
     private static boolean isGoogleURL(final String url) {
         final String cachedUrl = extractCachedUrlIfNeeded(url);
@@ -1190,7 +1196,7 @@ public static JsonBuilder<JsonObject> prepareTvHtml5EmbedJsonBuilder(
             @Nonnull final Localization localization,
             @Nonnull final ContentCountry contentCountry,
             @Nonnull final String videoId) {
-                // @formatter:off
+        // @formatter:off
         return JsonObject.builder()
                 .object("context")
                     .object("client")
@@ -1588,4 +1594,46 @@ public static String generateTParameter() {
         return RandomStringFromAlphabetGenerator.generate(
                 CONTENT_PLAYBACK_NONCE_ALPHABET, 12, numberGenerator);
     }
+
+    /**
+     * Check if the streaming URL is a URL from the YouTube {@code WEB} client.
+     *
+     * @param url the streaming URL on which check if it's a {@code WEB} streaming URL.
+     * @return true if it's a {@code WEB} streaming URL, false otherwise
+     */
+    public static boolean isWebStreamingUrl(@Nonnull final String url) {
+        return Parser.isMatch(C_WEB_PATTERN, url);
+    }
+
+    /**
+     * Check if the streaming URL is a URL from the YouTube {@code TVHTML5_SIMPLY_EMBEDDED_PLAYER}
+     * client.
+     *
+     * @param url the streaming URL on which check if it's a {@code TVHTML5_SIMPLY_EMBEDDED_PLAYER}
+     *            streaming URL.
+     * @return true if it's a {@code TVHTML5_SIMPLY_EMBEDDED_PLAYER} streaming URL, false otherwise
+     */
+    public static boolean isTvHtml5SimplyEmbeddedPlayerStreamingUrl(@Nonnull final String url) {
+        return Parser.isMatch(C_TVHTML5_SIMPLY_EMBEDDED_PLAYER_PATTERN, url);
+    }
+
+    /**
+     * Check if the streaming URL is a URL from the YouTube {@code ANDROID} client.
+     *
+     * @param url the streaming URL on which check if it's a {@code ANDROID} streaming URL.
+     * @return true if it's a {@code ANDROID} streaming URL, false otherwise
+     */
+    public static boolean isAndroidStreamingUrl(@Nonnull final String url) {
+        return Parser.isMatch(C_ANDROID_PATTERN, url);
+    }
+
+    /**
+     * Check if the streaming URL is a URL from the YouTube {@code IOS} client.
+     *
+     * @param url the streaming URL on which check if it's a {@code IOS} streaming URL.
+     * @return true if it's a {@code IOS} streaming URL, false otherwise
+     */
+    public static boolean isIosStreamingUrl(@Nonnull final String url) {
+        return Parser.isMatch(C_IOS_PATTERN, url);
+    }
 }