Adaptive Streaming Improvements (#236)

* adaptive rewrite improvements:
- Add 'application/vnd.apple.mpegurl' as HLS type in rules.yaml and default_rewriter.py
- Support setting max resolution and max bandwidth to choose, defaults to 480x854 and 200000 respectively
- LiveWebLoader provides a get_custom_metadata for specifying WARC-JSON-Metadata header, per mime type (TODO: support customization via rules)
- When filtering, first limiting by resolution (if set), then by bandwidth (if set), otherwise default to max bandwidth
- Max resoluton/max bandwidth stored in WARC record under WARC-JSON-Metadata as 'adaptive_max_resolution' and 'adaptive_max_bandwidth' to ensure replayability. If absent, choose absolute max in manifest to be backwards compatible
- Add sample HLS and DASH manifests for testing, with and without max resolution/bandwidth settings.

pywb/rewrite/content_rewriter.py

@@ -8,6 +8,7 @@ from warcio.utils import to_native_str
 import re
 import webencodings
 import tempfile
+import json
 
 from pywb.utils.io import StreamIter, BUFF_SIZE
 
@@ -197,11 +198,27 @@ class BufferedRewriter(object):
                 stream_buffer.write(buff)
 
         stream_buffer.seek(0)
-        return StreamIter(self.rewrite_stream(stream_buffer))
+        return StreamIter(self.rewrite_stream(stream_buffer, rwinfo))
 
-    def rewrite_stream(self, stream):
+    def rewrite_stream(self, stream, rwinfo):
         raise NotImplemented('implement in subclass')
 
+    def _get_record_metadata(self, rwinfo):
+        client_metadata = rwinfo.record.rec_headers.get_header('WARC-JSON-Metadata')
+        if client_metadata:
+            try:
+                return json.loads(client_metadata)
+            except:
+                pass
+
+        return {}
+
+    def _get_adaptive_metadata(self, rwinfo):
+        metadata = self._get_record_metadata(rwinfo)
+        max_resolution = int(metadata.get('adaptive_max_resolution', 0))
+        max_bandwidth = int(metadata.get('adaptive_max_bandwidth', 1000000000))
+        return max_resolution, max_bandwidth
+
 
 # ============================================================================
 class StreamingRewriter(object):

pywb/rewrite/default_rewriter.py

@@ -63,6 +63,7 @@ class DefaultRewriter(BaseContentRewriter):
 
         # HLS
         'application/x-mpegURL': 'hls',
+        'application/vnd.apple.mpegurl': 'hls',
 
         # DASH
         'application/dash+xml': 'dash',

pywb/rewrite/rewrite_amf.py

@@ -7,7 +7,7 @@ from pywb.rewrite.content_rewriter import BufferedRewriter
 # ============================================================================
 # Experimental: not fully tested
 class RewriteAMF(BufferedRewriter):  #pragma: no cover
-    def rewrite_stream(self, stream):
+    def rewrite_stream(self, stream, rwinfo):
         try:
             from pyamf import remoting
 

pywb/rewrite/rewrite_dash.py

@@ -1,5 +1,5 @@
 from contextlib import closing
-from io import BytesIO, StringIO
+from io import BytesIO
 import json
 
 import xml.etree.ElementTree as ET
@@ -9,11 +9,12 @@ from pywb.rewrite.content_rewriter import BufferedRewriter
 
 # ============================================================================
 class RewriteDASH(BufferedRewriter):
-    def rewrite_stream(self, stream):
+    def rewrite_stream(self, stream, rwinfo):
-        res_buff, best_ids = self.rewrite_dash(stream)
+        res_buff, best_ids = self.rewrite_dash(stream, rwinfo)
         return res_buff
 
-    def rewrite_dash(self, stream):
+    def rewrite_dash(self, stream, rwinfo):
+        max_resolution, max_bandwidth = self._get_adaptive_metadata(rwinfo)
         ET.register_namespace('', 'urn:mpeg:dash:schema:mpd:2011')
         namespaces = {'mpd': 'urn:mpeg:dash:schema:mpd:2011'}
 
@@ -26,24 +27,32 @@ class RewriteDASH(BufferedRewriter):
 
         for period in root.findall('mpd:Period', namespaces):
             for adaptset in period.findall('mpd:AdaptationSet', namespaces):
-
                 best = None
+                best_resolution = 0
+                best_bandwidth = 0
+
                 for repres in adaptset.findall('mpd:Representation', namespaces):
-                    bandwidth = int(repres.get('bandwidth', '0'))
+                    curr_resolution = int(repres.get('width', '0')) * int(repres.get('height', '0'))
-                    if not best or bandwidth > int(best.get('bandwidth', '0')):
+                    curr_bandwidth = int(repres.get('bandwidth', 0))
+                    if curr_resolution and max_resolution:
+                        if curr_resolution <= max_resolution and curr_resolution > best_resolution:
+                            best_resolution = curr_resolution
+                            best_bandwidth = curr_bandwidth
+                            best = repres
+                    elif curr_bandwidth <= max_bandwidth and curr_bandwidth > best_bandwidth:
+                        best_resolution = curr_resolution
+                        best_bandwidth = curr_bandwidth
                         best = repres
 
-                if best:
+                if best is not None:
                     best_ids.append(best.get('id'))
 
                 for repres in adaptset.findall('mpd:Representation', namespaces):
                     if repres != best:
                         adaptset.remove(repres)
 
-        string_io = StringIO()
-        tree.write(string_io, encoding='unicode', xml_declaration=True)
         buff_io = BytesIO()
-        buff_io.write(string_io.getvalue().encode('utf-8'))
+        tree.write(buff_io, encoding='UTF-8', xml_declaration=True)
         buff_io.seek(0)
         return buff_io, best_ids
 

pywb/rewrite/rewrite_hls.py

@@ -7,23 +7,43 @@ from pywb.rewrite.content_rewriter import BufferedRewriter
 # ============================================================================
 class RewriteHLS(BufferedRewriter):
     EXT_INF = re.compile('#EXT-X-STREAM-INF:(?:.*[,])?BANDWIDTH=([\d]+)')
+    EXT_RESOLUTION = re.compile('RESOLUTION=([\d]+)x([\d]+)')
+
+    def rewrite_stream(self, stream, rwinfo):
+        max_resolution, max_bandwidth = self._get_adaptive_metadata(rwinfo)
 
-    def rewrite_stream(self, stream):
         buff = stream.read()
 
         lines = buff.decode('utf-8').split('\n')
-        best = None
         indexes = []
         count = 0
         best_index = None
 
+        best_bandwidth = 0
+        best_resolution = 0
+
         for line in lines:
             m = self.EXT_INF.match(line)
             if m:
                 indexes.append(count)
-                bandwidth = int(m.group(1))
+                curr_bandwidth = int(m.group(1))
-                if not best or bandwidth > best:
+
-                    best = bandwidth
+                # resolution
+                m2 = self.EXT_RESOLUTION.search(line)
+                if m2:
+                    curr_resolution = int(m2.group(1)) * int(m2.group(2))
+                else:
+                    curr_resolution = 0
+
+                if max_resolution and curr_resolution:
+                    if curr_resolution > best_resolution and curr_resolution <= max_resolution:
+                        best_resolution = curr_resolution
+                        best_bandwidth = curr_bandwidth
+                        best_index = count
+
+                elif curr_bandwidth > best_bandwidth and curr_bandwidth <= max_bandwidth:
+                    best_resolution = curr_resolution
+                    best_bandwidth = curr_bandwidth
                     best_index = count
 
             count = count + 1

pywb/rewrite/test/test_content_rewriter.py

@@ -10,8 +10,12 @@ from pywb.rewrite.wburl import WbUrl
 from pywb.rewrite.url_rewriter import UrlRewriter
 from pywb.rewrite.default_rewriter import DefaultRewriter
 
+from pywb import get_test_dir
+import os
+import json
 import pytest
 
+
 @pytest.fixture(params=[{'Content-Type': 'text/html'},
                         {'Content-Type': 'application/xhtml+xml'},
                         {'Content-Type': 'application/octet-stream'},
@@ -28,9 +32,11 @@ class TestContentRewriter(object):
     def setup_class(self):
         self.content_rewriter = DefaultRewriter()
 
-    def _create_response_record(self, url, headers, payload):
+    def _create_response_record(self, url, headers, payload, warc_headers):
         writer = BufferWARCWriter()
 
+        warc_headers = warc_headers or {}
+
         payload = payload.encode('utf-8')
 
         http_headers = StatusAndHeaders('200 OK', headers, protocol='HTTP/1.0')
@@ -38,12 +44,13 @@ class TestContentRewriter(object):
         return writer.create_warc_record(url, 'response',
                                          payload=BytesIO(payload),
                                          length=len(payload),
-                                         http_headers=http_headers)
+                                         http_headers=http_headers,
+                                         warc_headers_dict=warc_headers)
 
     def rewrite_record(self, headers, content, ts, url='http://example.com/',
-                       prefix='http://localhost:8080/prefix/'):
+                       prefix='http://localhost:8080/prefix/', warc_headers=None):
 
-        record = self._create_response_record(url, headers, content)
+        record = self._create_response_record(url, headers, content, warc_headers)
 
         wburl = WbUrl(ts + '/' + url)
         url_rewriter = UrlRewriter(wburl, prefix)
@@ -217,5 +224,184 @@ class TestContentRewriter(object):
 
         assert b''.join(gen).decode('utf-8') == content
 
+    def test_hls_default_max(self):
+        headers = {'Content-Type': 'application/vnd.apple.mpegurl'}
+        with open(os.path.join(get_test_dir(), 'text_content', 'sample_hls.m3u8'), 'rt') as fh:
+            content = fh.read()
+
+        headers, gen, is_rw = self.rewrite_record(headers, content, ts='201701oe_',
+                                                  url='http://example.com/path/master.m3u8')
+
+        assert headers.headers == [('Content-Type', 'application/vnd.apple.mpegurl')]
+        filtered = """\
+#EXTM3U
+#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="WebVTT",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,URI="https://example.com/subtitles/"
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=4495000,RESOLUTION=1920x1080,CODECS="avc1.640028, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_6.m3u8
+"""
+
+        assert b''.join(gen).decode('utf-8') == filtered
+
+    def test_hls_custom_max_resolution(self):
+        headers = {'Content-Type': 'application/x-mpegURL'}
+        with open(os.path.join(get_test_dir(), 'text_content', 'sample_hls.m3u8'), 'rt') as fh:
+            content = fh.read()
+
+        metadata = {'adaptive_max_resolution': 921600,
+                    'adaptive_max_bandwidth': 2000000}
+
+        headers, gen, is_rw = self.rewrite_record(headers, content, ts='201701oe_',
+                                                  url='http://example.com/path/master.m3u8',
+                                                  warc_headers={'WARC-JSON-Metadata': json.dumps(metadata)})
+
+        assert headers.headers == [('Content-Type', 'application/x-mpegURL')]
+        filtered = """\
+#EXTM3U
+#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="WebVTT",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,URI="https://example.com/subtitles/"
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2505000,RESOLUTION=1280x720,CODECS="avc1.77.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_5.m3u8
+"""
+
+        assert b''.join(gen).decode('utf-8') == filtered
+
+    def test_hls_custom_max_bandwidth(self):
+        headers = {'Content-Type': 'application/x-mpegURL'}
+        with open(os.path.join(get_test_dir(), 'text_content', 'sample_hls.m3u8'), 'rt') as fh:
+            content = fh.read()
+
+        metadata = {'adaptive_max_bandwidth': 2000000}
+
+        headers, gen, is_rw = self.rewrite_record(headers, content, ts='201701oe_',
+                                                  url='http://example.com/path/master.m3u8',
+                                                  warc_headers={'WARC-JSON-Metadata': json.dumps(metadata)})
+
+        assert headers.headers == [('Content-Type', 'application/x-mpegURL')]
+        filtered = """\
+#EXTM3U
+#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="WebVTT",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,URI="https://example.com/subtitles/"
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1002000,RESOLUTION=640x360,CODECS="avc1.77.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_4.m3u8
+"""
+
+        assert b''.join(gen).decode('utf-8') == filtered
+
+    def test_dash_default_max(self):
+        headers = {'Content-Type': 'application/dash+xml'}
+        with open(os.path.join(get_test_dir(), 'text_content', 'sample_dash.mpd'), 'rt') as fh:
+            content = fh.read()
+
+        headers, gen, is_rw = self.rewrite_record(headers, content, ts='201701oe_',
+                                                  url='http://example.com/path/manifest.mpd')
+
+        assert headers.headers == [('Content-Type', 'application/dash+xml')]
+
+        filtered = """\
+<?xml version='1.0' encoding='UTF-8'?>
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" mediaPresentationDuration="PT0H3M1.63S" minBufferTime="PT1.5S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" type="static">
+  <Period duration="PT0H3M1.63S" start="PT0S">
+    <AdaptationSet>
+      <ContentComponent contentType="video" id="1" />
+      <Representation bandwidth="4190760" codecs="avc1.640028" height="1080" id="1" mimeType="video/mp4" width="1920">
+        <BaseURL>http://example.com/video-10.mp4</BaseURL>
+        <SegmentBase indexRange="674-1149">
+          <Initialization range="0-673" />
+        </SegmentBase>
+      </Representation>
+      </AdaptationSet>
+    <AdaptationSet>
+      <ContentComponent contentType="audio" id="2" />
+      <Representation bandwidth="255236" codecs="mp4a.40.2" id="7" mimeType="audio/mp4" numChannels="2" sampleRate="44100">
+        <BaseURL>http://example.com/audio-2.mp4</BaseURL>
+        <SegmentBase indexRange="592-851">
+          <Initialization range="0-591" />
+        </SegmentBase>
+      </Representation>
+      </AdaptationSet>
+  </Period>
+</MPD>"""
+        assert b''.join(gen).decode('utf-8') == filtered
+
+    def test_dash_custom_max_resolution(self):
+        headers = {'Content-Type': 'application/dash+xml'}
+        with open(os.path.join(get_test_dir(), 'text_content', 'sample_dash.mpd'), 'rt') as fh:
+            content = fh.read()
+
+        metadata = {'adaptive_max_resolution': 921600,
+                    'adaptive_max_bandwidth': 2000000}
+
+        headers, gen, is_rw = self.rewrite_record(headers, content, ts='201701oe_',
+                                                  url='http://example.com/path/manifest.mpd',
+                                                  warc_headers={'WARC-JSON-Metadata': json.dumps(metadata)})
+
+        assert headers.headers == [('Content-Type', 'application/dash+xml')]
+
+        filtered = """\
+<?xml version='1.0' encoding='UTF-8'?>
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" mediaPresentationDuration="PT0H3M1.63S" minBufferTime="PT1.5S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" type="static">
+  <Period duration="PT0H3M1.63S" start="PT0S">
+    <AdaptationSet>
+      <ContentComponent contentType="video" id="1" />
+      <Representation bandwidth="2073921" codecs="avc1.4d401f" height="720" id="2" mimeType="video/mp4" width="1280">
+        <BaseURL>http://example.com/video-9.mp4</BaseURL>
+        <SegmentBase indexRange="708-1183">
+          <Initialization range="0-707" />
+        </SegmentBase>
+      </Representation>
+      </AdaptationSet>
+    <AdaptationSet>
+      <ContentComponent contentType="audio" id="2" />
+      <Representation bandwidth="255236" codecs="mp4a.40.2" id="7" mimeType="audio/mp4" numChannels="2" sampleRate="44100">
+        <BaseURL>http://example.com/audio-2.mp4</BaseURL>
+        <SegmentBase indexRange="592-851">
+          <Initialization range="0-591" />
+        </SegmentBase>
+      </Representation>
+      </AdaptationSet>
+  </Period>
+</MPD>"""
+
+        assert b''.join(gen).decode('utf-8') == filtered
+
+
+    def test_dash_custom_max_bandwidth(self):
+        headers = {'Content-Type': 'application/dash+xml'}
+        with open(os.path.join(get_test_dir(), 'text_content', 'sample_dash.mpd'), 'rt') as fh:
+            content = fh.read()
+
+        metadata = {'adaptive_max_bandwidth': 2000000}
+
+        headers, gen, is_rw = self.rewrite_record(headers, content, ts='201701oe_',
+                                                  url='http://example.com/path/manifest.mpd',
+                                                  warc_headers={'WARC-JSON-Metadata': json.dumps(metadata)})
+
+        assert headers.headers == [('Content-Type', 'application/dash+xml')]
+
+        filtered = """\
+<?xml version='1.0' encoding='UTF-8'?>
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" mediaPresentationDuration="PT0H3M1.63S" minBufferTime="PT1.5S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" type="static">
+  <Period duration="PT0H3M1.63S" start="PT0S">
+    <AdaptationSet>
+      <ContentComponent contentType="video" id="1" />
+      <Representation bandwidth="869460" codecs="avc1.4d401e" height="480" id="3" mimeType="video/mp4" width="854">
+        <BaseURL>http://example.com/video-8.mp4</BaseURL>
+        <SegmentBase indexRange="708-1183">
+          <Initialization range="0-707" />
+        </SegmentBase>
+      </Representation>
+      </AdaptationSet>
+    <AdaptationSet>
+      <ContentComponent contentType="audio" id="2" />
+      <Representation bandwidth="255236" codecs="mp4a.40.2" id="7" mimeType="audio/mp4" numChannels="2" sampleRate="44100">
+        <BaseURL>http://example.com/audio-2.mp4</BaseURL>
+        <SegmentBase indexRange="592-851">
+          <Initialization range="0-591" />
+        </SegmentBase>
+      </Representation>
+      </AdaptationSet>
+  </Period>
+</MPD>"""
+
+        assert b''.join(gen).decode('utf-8') == filtered
+
 
 

pywb/rules.yaml

@@ -12,9 +12,16 @@ default_filters:
 
     # ignore query args for the following mime types
     mimes:
-        - 'application/dash+xml'
+        # flash
         - 'application/x-shockwave-flash'
 
+        # dash
+        - 'application/dash+xml'
+
+        # hls
+        - 'application/x-mpegURL'
+        - 'application/vnd.apple.mpegurl'
+
     # apply following url normalization rules
     # on both match url and request url
     # to find a match (not limited to query argument removal)

pywb/warcserver/resource/responseloader.py

@@ -237,6 +237,10 @@ class LiveWebLoader(BaseLoader):
 
     UNREWRITE_HEADERS = ('location', 'content-location')
 
+    VIDEO_MIMES = ('application/x-mpegURL',
+                   'application/vnd.apple.mpegurl',
+                   'application/dash+xml')
+
     def __init__(self, forward_proxy_prefix=None, adapter=None):
         self.forward_proxy_prefix = forward_proxy_prefix
 
@@ -378,8 +382,15 @@ class LiveWebLoader(BaseLoader):
         if remote_ip:
             warc_headers['WARC-IP-Address'] = remote_ip
 
+        ct = upstream_res.headers.get('Content-Type')
+        if ct:
+            metadata = self.get_custom_metadata(ct, dt)
+            if metadata:
+                warc_headers['WARC-JSON-Metadata'] = json.dumps(metadata)
+
         warc_headers['Content-Type'] = 'application/http; msgtype=response'
 
+
         self._set_content_len(upstream_res.headers.get('Content-Length', -1),
                               warc_headers,
                               len(http_headers_buff))
@@ -455,6 +466,11 @@ class LiveWebLoader(BaseLoader):
             logger.debug('FAILED: ' + method + ' ' + load_url + ': ' + str(e))
             raise LiveResourceException(load_url)
 
+    def get_custom_metadata(self, content_type, dt):
+        if content_type in self.VIDEO_MIMES:
+            return {'adaptive_max_resolution': 1280 * 720,
+                    'adaptive_max_bandwidth': 2000000}
+
     def __str__(self):
         return  'LiveWebLoader'
 

sample_archive/text_content/sample_dash.mpd

@@ -0,0 +1,65 @@
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" mediaPresentationDuration="PT0H3M1.63S" minBufferTime="PT1.5S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011"
+type="static">
+  <Period duration="PT0H3M1.63S" start="PT0S">
+    <AdaptationSet>
+      <ContentComponent contentType="video" id="1" />
+      <Representation bandwidth="4190760" codecs="avc1.640028" height="1080" id="1" mimeType="video/mp4" width="1920">
+        <BaseURL>http://example.com/video-10.mp4</BaseURL>
+        <SegmentBase indexRange="674-1149">
+          <Initialization range="0-673" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="2073921" codecs="avc1.4d401f" height="720" id="2" mimeType="video/mp4" width="1280">
+        <BaseURL>http://example.com/video-9.mp4</BaseURL>
+        <SegmentBase indexRange="708-1183">
+          <Initialization range="0-707" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="869460" codecs="avc1.4d401e" height="480" id="3" mimeType="video/mp4" width="854">
+        <BaseURL>http://example.com/video-8.mp4</BaseURL>
+        <SegmentBase indexRange="708-1183">
+          <Initialization range="0-707" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="686521" codecs="avc1.4d401e" height="360" id="4" mimeType="video/mp4" width="640">
+        <BaseURL>http://example.com/video-7.mp4</BaseURL>
+        <SegmentBase indexRange="708-1183">
+          <Initialization range="0-707" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="264835" codecs="avc1.4d4015" height="240" id="5" mimeType="video/mp4" width="426">
+        <BaseURL>http://example.com/video-6.mp4</BaseURL>
+        <SegmentBase indexRange="672-1147">
+          <Initialization range="0-671" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="100000" codecs="avc1.4d4015" height="144" id="5" mimeType="video/mp4" width="256">
+        <BaseURL>http://example.com/video-5.mp4</BaseURL>
+        <SegmentBase indexRange="671-1146">
+          <Initialization range="0-670" />
+        </SegmentBase>
+      </Representation>
+    </AdaptationSet>
+    <AdaptationSet>
+      <ContentComponent contentType="audio" id="2" />
+      <Representation bandwidth="127236" codecs="mp4a.40.2" id="6" mimeType="audio/mp4" numChannels="2" sampleRate="44100">
+        <BaseURL>http://example.com/audio-1.mp4</BaseURL>
+        <SegmentBase indexRange="592-851">
+          <Initialization range="0-591" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="255236" codecs="mp4a.40.2" id="7" mimeType="audio/mp4" numChannels="2" sampleRate="44100">
+        <BaseURL>http://example.com/audio-2.mp4</BaseURL>
+        <SegmentBase indexRange="592-851">
+          <Initialization range="0-591" />
+        </SegmentBase>
+      </Representation>
+      <Representation bandwidth="31749" codecs="mp4a.40.5" id="8" mimeType="audio/mp4" numChannels="1" sampleRate="22050">
+        <BaseURL>http://example.com/audio-0.mp4</BaseURL>
+        <SegmentBase indexRange="592-851">
+          <Initialization range="0-591" />
+        </SegmentBase>
+      </Representation>
+    </AdaptationSet>
+  </Period>
+</MPD>

sample_archive/text_content/sample_hls.m3u8

@@ -0,0 +1,16 @@
+#EXTM3U
+#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="WebVTT",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,URI="https://example.com/subtitles/"
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=610000,RESOLUTION=640x360,CODECS="avc1.66.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_1.m3u8
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=416000,RESOLUTION=400x224,CODECS="avc1.66.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_2.m3u8
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=797000,RESOLUTION=640x360,CODECS="avc1.66.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_3.m3u8
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1002000,RESOLUTION=640x360,CODECS="avc1.77.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_4.m3u8
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2505000,RESOLUTION=1280x720,CODECS="avc1.77.30, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_5.m3u8
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=4495000,RESOLUTION=1920x1080,CODECS="avc1.640028, mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/video_6.m3u8
+#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=38000,CODECS="mp4a.40.2",SUBTITLES="WebVTT"
+http://example.com/audio_0.m3u8