［三］三种 hls 解析源码 vlc ffmpeg exoplayer

来源：互联网发布：陕师大网络教育平台编辑：程序博客网时间：2024/06/11 19:04
第三种 exoplayer

/* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.google.android.exoplayer.hls;import com.google.android.exoplayer.C;import com.google.android.exoplayer.ParserException;import com.google.android.exoplayer.hls.HlsMediaPlaylist.Segment;import com.google.android.exoplayer.upstream.UriLoadable;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.Collections;import java.util.LinkedList;import java.util.List;import java.util.Queue;import java.util.regex.Pattern;/** * HLS playlists parsing logic. */public final class HlsPlaylistParser implements UriLoadable.Parser<HlsPlaylist> {  private static final String VERSION_TAG = "#EXT-X-VERSION";  private static final String STREAM_INF_TAG = "#EXT-X-STREAM-INF";  private static final String MEDIA_TAG = "#EXT-X-MEDIA";  private static final String DISCONTINUITY_TAG = "#EXT-X-DISCONTINUITY";  private static final String MEDIA_DURATION_TAG = "#EXTINF";  private static final String MEDIA_SEQUENCE_TAG = "#EXT-X-MEDIA-SEQUENCE";  private static final String TARGET_DURATION_TAG = "#EXT-X-TARGETDURATION";  private static final String ENDLIST_TAG = "#EXT-X-ENDLIST";  private static final String KEY_TAG = "#EXT-X-KEY";  private static final String BYTERANGE_TAG = "#EXT-X-BYTERANGE";  private static final String BANDWIDTH_ATTR = "BANDWIDTH";  private static final String CODECS_ATTR = "CODECS";  private static final String RESOLUTION_ATTR = "RESOLUTION";  private static final String LANGUAGE_ATTR = "LANGUAGE";  private static final String NAME_ATTR = "NAME";  private static final String AUTOSELECT_ATTR = "AUTOSELECT";  private static final String DEFAULT_ATTR = "DEFAULT";  private static final String TYPE_ATTR = "TYPE";  private static final String METHOD_ATTR = "METHOD";  private static final String URI_ATTR = "URI";  private static final String IV_ATTR = "IV";  private static final String AUDIO_TYPE = "AUDIO";  private static final String VIDEO_TYPE = "VIDEO";  private static final String SUBTITLES_TYPE = "SUBTITLES";  private static final String CLOSED_CAPTIONS_TYPE = "CLOSED-CAPTIONS";  private static final String METHOD_NONE = "NONE";  private static final String METHOD_AES128 = "AES-128";  private static final Pattern BANDWIDTH_ATTR_REGEX =      Pattern.compile(BANDWIDTH_ATTR + "=(\\d+)\\b");  private static final Pattern CODECS_ATTR_REGEX =      Pattern.compile(CODECS_ATTR + "=\"(.+?)\"");  private static final Pattern RESOLUTION_ATTR_REGEX =      Pattern.compile(RESOLUTION_ATTR + "=(\\d+x\\d+)");  private static final Pattern MEDIA_DURATION_REGEX =      Pattern.compile(MEDIA_DURATION_TAG + ":([\\d.]+),");  private static final Pattern MEDIA_SEQUENCE_REGEX =      Pattern.compile(MEDIA_SEQUENCE_TAG + ":(\\d+)\\b");  private static final Pattern TARGET_DURATION_REGEX =      Pattern.compile(TARGET_DURATION_TAG + ":(\\d+)\\b");  private static final Pattern VERSION_REGEX =      Pattern.compile(VERSION_TAG + ":(\\d+)\\b");  private static final Pattern BYTERANGE_REGEX =      Pattern.compile(BYTERANGE_TAG + ":(\\d+(?:@\\d+)?)\\b");  private static final Pattern METHOD_ATTR_REGEX =      Pattern.compile(METHOD_ATTR + "=(" + METHOD_NONE + "|" + METHOD_AES128 + ")");  private static final Pattern URI_ATTR_REGEX =      Pattern.compile(URI_ATTR + "=\"(.+)\"");  private static final Pattern IV_ATTR_REGEX =      Pattern.compile(IV_ATTR + "=([^,.*]+)");  private static final Pattern TYPE_ATTR_REGEX =      Pattern.compile(TYPE_ATTR + "=(" + AUDIO_TYPE + "|" + VIDEO_TYPE + "|" + SUBTITLES_TYPE + "|"          + CLOSED_CAPTIONS_TYPE + ")");  private static final Pattern LANGUAGE_ATTR_REGEX =      Pattern.compile(LANGUAGE_ATTR + "=\"(.+?)\"");  private static final Pattern NAME_ATTR_REGEX =      Pattern.compile(NAME_ATTR + "=\"(.+?)\"");  private static final Pattern AUTOSELECT_ATTR_REGEX =      HlsParserUtil.compileBooleanAttrPattern(AUTOSELECT_ATTR);  private static final Pattern DEFAULT_ATTR_REGEX =      HlsParserUtil.compileBooleanAttrPattern(DEFAULT_ATTR);  @Override  public HlsPlaylist parse(String connectionUrl, InputStream inputStream)      throws IOException, ParserException {    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));    Queue<String> extraLines = new LinkedList<String>();    String line;    try {      while ((line = reader.readLine()) != null) {        line = line.trim();        if (line.isEmpty()) {          // Do nothing.        } else if (line.startsWith(STREAM_INF_TAG)) {          extraLines.add(line);          return parseMasterPlaylist(new LineIterator(extraLines, reader), connectionUrl);        } else if (line.startsWith(TARGET_DURATION_TAG)            || line.startsWith(MEDIA_SEQUENCE_TAG)            || line.startsWith(MEDIA_DURATION_TAG)            || line.startsWith(KEY_TAG)            || line.startsWith(BYTERANGE_TAG)            || line.equals(DISCONTINUITY_TAG)            || line.equals(ENDLIST_TAG)) {          extraLines.add(line);          return parseMediaPlaylist(new LineIterator(extraLines, reader), connectionUrl);        } else {          extraLines.add(line);        }      }    } finally {      reader.close();    }    throw new ParserException("Failed to parse the playlist, could not identify any tags.");  }  private static HlsMasterPlaylist parseMasterPlaylist(LineIterator iterator, String baseUri)      throws IOException {    ArrayList<Variant> variants = new ArrayList<Variant>();    ArrayList<Subtitle> subtitles = new ArrayList<Subtitle>();    int bitrate = 0;    String codecs = null;    int width = -1;    int height = -1;    boolean expectingStreamInfUrl = false;    String line;    while (iterator.hasNext()) {      line = iterator.next();      if (line.startsWith(MEDIA_TAG)) {        String type = HlsParserUtil.parseStringAttr(line, TYPE_ATTR_REGEX, TYPE_ATTR);        if (SUBTITLES_TYPE.equals(type)) {          // We assume all subtitles belong to the same group.          String name = HlsParserUtil.parseStringAttr(line, NAME_ATTR_REGEX, NAME_ATTR);          String uri = HlsParserUtil.parseStringAttr(line, URI_ATTR_REGEX, URI_ATTR);          String language = HlsParserUtil.parseOptionalStringAttr(line, LANGUAGE_ATTR_REGEX);          boolean isDefault = HlsParserUtil.parseOptionalBooleanAttr(line, DEFAULT_ATTR_REGEX);          boolean autoSelect = HlsParserUtil.parseOptionalBooleanAttr(line, AUTOSELECT_ATTR_REGEX);          subtitles.add(new Subtitle(name, uri, language, isDefault, autoSelect));        } else {          // TODO: Support other types of media tag.        }      } else if (line.startsWith(STREAM_INF_TAG)) {        bitrate = HlsParserUtil.parseIntAttr(line, BANDWIDTH_ATTR_REGEX, BANDWIDTH_ATTR);        codecs = HlsParserUtil.parseOptionalStringAttr(line, CODECS_ATTR_REGEX);        String resolutionString = HlsParserUtil.parseOptionalStringAttr(line,            RESOLUTION_ATTR_REGEX);        if (resolutionString != null) {          String[] widthAndHeight = resolutionString.split("x");          width = Integer.parseInt(widthAndHeight[0]);          if (width <= 0) {            // Width was invalid.            width = -1;          }          height = Integer.parseInt(widthAndHeight[1]);          if (height <= 0) {            // Height was invalid.            height = -1;          }        } else {          width = -1;          height = -1;        }        expectingStreamInfUrl = true;      } else if (!line.startsWith("#") && expectingStreamInfUrl) {        variants.add(new Variant(variants.size(), line, bitrate, codecs, width, height));        bitrate = 0;        codecs = null;        width = -1;        height = -1;        expectingStreamInfUrl = false;      }    }    return new HlsMasterPlaylist(baseUri, Collections.unmodifiableList(variants),        Collections.unmodifiableList(subtitles));  }  private static HlsMediaPlaylist parseMediaPlaylist(LineIterator iterator, String baseUri)      throws IOException {    int mediaSequence = 0;    int targetDurationSecs = 0;    int version = 1; // Default version == 1.    boolean live = true;    List<Segment> segments = new ArrayList<Segment>();    double segmentDurationSecs = 0.0;    boolean segmentDiscontinuity = false;    long segmentStartTimeUs = 0;    int segmentByterangeOffset = 0;    int segmentByterangeLength = C.LENGTH_UNBOUNDED;    int segmentMediaSequence = 0;    boolean isEncrypted = false;    String encryptionKeyUri = null;    String encryptionIV = null;    String line;    while (iterator.hasNext()) {      line = iterator.next();      if (line.startsWith(TARGET_DURATION_TAG)) {        targetDurationSecs = HlsParserUtil.parseIntAttr(line, TARGET_DURATION_REGEX,            TARGET_DURATION_TAG);      } else if (line.startsWith(MEDIA_SEQUENCE_TAG)) {        mediaSequence = HlsParserUtil.parseIntAttr(line, MEDIA_SEQUENCE_REGEX, MEDIA_SEQUENCE_TAG);        segmentMediaSequence = mediaSequence;      } else if (line.startsWith(VERSION_TAG)) {        version = HlsParserUtil.parseIntAttr(line, VERSION_REGEX, VERSION_TAG);      } else if (line.startsWith(MEDIA_DURATION_TAG)) {        segmentDurationSecs = HlsParserUtil.parseDoubleAttr(line, MEDIA_DURATION_REGEX,            MEDIA_DURATION_TAG);      } else if (line.startsWith(KEY_TAG)) {        String method = HlsParserUtil.parseStringAttr(line, METHOD_ATTR_REGEX, METHOD_ATTR);        isEncrypted = METHOD_AES128.equals(method);        if (isEncrypted) {          encryptionKeyUri = HlsParserUtil.parseStringAttr(line, URI_ATTR_REGEX, URI_ATTR);          encryptionIV = HlsParserUtil.parseOptionalStringAttr(line, IV_ATTR_REGEX);        } else {          encryptionKeyUri = null;          encryptionIV = null;        }      } else if (line.startsWith(BYTERANGE_TAG)) {        String byteRange = HlsParserUtil.parseStringAttr(line, BYTERANGE_REGEX, BYTERANGE_TAG);        String[] splitByteRange = byteRange.split("@");        segmentByterangeLength = Integer.parseInt(splitByteRange[0]);        if (splitByteRange.length > 1) {          segmentByterangeOffset = Integer.parseInt(splitByteRange[1]);        }      } else if (line.equals(DISCONTINUITY_TAG)) {        segmentDiscontinuity = true;      } else if (!line.startsWith("#")) {        String segmentEncryptionIV;        if (!isEncrypted) {          segmentEncryptionIV = null;        } else if (encryptionIV != null) {          segmentEncryptionIV = encryptionIV;        } else {          segmentEncryptionIV = Integer.toHexString(segmentMediaSequence);        }        segmentMediaSequence++;        if (segmentByterangeLength == C.LENGTH_UNBOUNDED) {          segmentByterangeOffset = 0;        }        segments.add(new Segment(line, segmentDurationSecs, segmentDiscontinuity,            segmentStartTimeUs, isEncrypted, encryptionKeyUri, segmentEncryptionIV,            segmentByterangeOffset, segmentByterangeLength));        segmentStartTimeUs += (long) (segmentDurationSecs * C.MICROS_PER_SECOND);        segmentDiscontinuity = false;        segmentDurationSecs = 0.0;        if (segmentByterangeLength != C.LENGTH_UNBOUNDED) {          segmentByterangeOffset += segmentByterangeLength;        }        segmentByterangeLength = C.LENGTH_UNBOUNDED;      } else if (line.equals(ENDLIST_TAG)) {        live = false;        break;      }    }    return new HlsMediaPlaylist(baseUri, mediaSequence, targetDurationSecs, version, live,        Collections.unmodifiableList(segments));  }  private static class LineIterator {    private final BufferedReader reader;    private final Queue<String> extraLines;    private String next;    public LineIterator(Queue<String> extraLines, BufferedReader reader) {      this.extraLines = extraLines;      this.reader = reader;    }    public boolean hasNext() throws IOException {      if (next != null) {        return true;      }      if (!extraLines.isEmpty()) {        next = extraLines.poll();        return true;      }      while ((next = reader.readLine()) != null) {        next = next.trim();        if (!next.isEmpty()) {          return true;        }      }      return false;    }    public String next() throws IOException {      String result = null;      if (hasNext()) {        result = next;        next = null;      }      return result;    }  }}
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