[InfoExtractor] Support byte range for DASH

* adapted from https://github.com/ytdl-org/youtube-dl/pull/30279
* thx former GH user kikuyan

test/test_InfoExtractor.py

@@ -1126,6 +1126,72 @@ jwplayer("mediaplayer").setup({"abouttext":"Visit Indie DB","aboutlink":"http:\/
                     'fps': 30,
                 }],
                 {},
+            ), (
+                # https://github.com/ytdl-org/youtube-dl/issues/30235
+                # Bento4 generated test mpd
+                # mp4dash --mpd-name=manifest.mpd --no-split --use-segment-list mediafiles
+                'url_and_range',
+                'http://unknown/manifest.mpd',  # mpd_url
+                'http://unknown/',  # mpd_base_url
+                [{
+                    'manifest_url': 'http://unknown/manifest.mpd',
+                    'fragment_base_url': 'http://unknown/',
+                    'ext': 'm4a',
+                    'format_id': 'audio-und-mp4a.40.2',
+                    'format_note': 'DASH audio',
+                    'container': 'm4a_dash',
+                    'protocol': 'http_dash_segments',
+                    'acodec': 'mp4a.40.2',
+                    'vcodec': 'none',
+                    'tbr': 98.808,
+                }, {
+                    'manifest_url': 'http://unknown/manifest.mpd',
+                    'fragment_base_url': 'http://unknown/',
+                    'ext': 'mp4',
+                    'format_id': 'video-avc1',
+                    'format_note': 'DASH video',
+                    'container': 'mp4_dash',
+                    'protocol': 'http_dash_segments',
+                    'acodec': 'none',
+                    'vcodec': 'avc1.4D401E',
+                    'tbr': 699.597,
+                    'width': 768,
+                    'height': 432
+                }],
+                {},
+            ), (
+                # https://github.com/ytdl-org/youtube-dl/issues/27575
+                # GPAC generated test mpd
+                # MP4Box -dash 10000 -single-file -out manifest.mpd mediafiles
+                'range_only',
+                'http://unknown/manifest.mpd',  # mpd_url
+                'http://unknown/',  # mpd_base_url
+                [{
+                    'manifest_url': 'http://unknown/manifest.mpd',
+                    'fragment_base_url': 'http://unknown/audio_dashinit.mp4',
+                    'ext': 'm4a',
+                    'format_id': '2',
+                    'format_note': 'DASH audio',
+                    'container': 'm4a_dash',
+                    'protocol': 'http_dash_segments',
+                    'acodec': 'mp4a.40.2',
+                    'vcodec': 'none',
+                    'tbr': 98.096,
+                }, {
+                    'manifest_url': 'http://unknown/manifest.mpd',
+                    'fragment_base_url': 'http://unknown/video_dashinit.mp4',
+                    'ext': 'mp4',
+                    'format_id': '1',
+                    'format_note': 'DASH video',
+                    'container': 'mp4_dash',
+                    'protocol': 'http_dash_segments',
+                    'acodec': 'none',
+                    'vcodec': 'avc1.4D401E',
+                    'tbr': 526.987,
+                    'width': 768,
+                    'height': 432
+                }],
+                {},
             ), (
                 'subtitles',
                 'https://sdn-global-streaming-cache-3qsdn.akamaized.net/stream/3144/files/17/07/672975/3144-kZT4LWMQw6Rh7Kpd.ism/manifest.mpd',

test/testdata/mpd/range_only.mpd

@@ -0,0 +1,35 @@
+<?xml version="1.0"?>
+<!-- MPD file Generated with GPAC version 1.0.1-revrelease at 2021-11-27T20:53:11.690Z -->
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" minBufferTime="PT1.500S" type="static" mediaPresentationDuration="PT0H0M30.196S" maxSegmentDuration="PT0H0M10.027S" profiles="urn:mpeg:dash:profile:full:2011">
+ <ProgramInformation moreInformationURL="http://gpac.io">
+  <Title>manifest.mpd generated by GPAC</Title>
+ </ProgramInformation>
+
+ <Period duration="PT0H0M30.196S">
+  <AdaptationSet segmentAlignment="true" maxWidth="768" maxHeight="432" maxFrameRate="30000/1001" par="16:9" lang="und" startWithSAP="1">
+   <Representation id="1" mimeType="video/mp4" codecs="avc1.4D401E" width="768" height="432" frameRate="30000/1001" sar="1:1" bandwidth="526987">
+    <BaseURL>video_dashinit.mp4</BaseURL>
+    <SegmentList timescale="90000" duration="900000">
+     <Initialization range="0-881"/>
+     <SegmentURL mediaRange="882-876094" indexRange="882-925"/>
+     <SegmentURL mediaRange="876095-1466732" indexRange="876095-876138"/>
+     <SegmentURL mediaRange="1466733-1953615" indexRange="1466733-1466776"/>
+     <SegmentURL mediaRange="1953616-1994211" indexRange="1953616-1953659"/>
+    </SegmentList>
+   </Representation>
+  </AdaptationSet>
+  <AdaptationSet segmentAlignment="true" lang="und" startWithSAP="1">
+   <Representation id="2" mimeType="audio/mp4" codecs="mp4a.40.2" audioSamplingRate="48000" bandwidth="98096">
+    <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
+    <BaseURL>audio_dashinit.mp4</BaseURL>
+    <SegmentList timescale="48000" duration="480000">
+     <Initialization range="0-752"/>
+     <SegmentURL mediaRange="753-124129" indexRange="753-796"/>
+     <SegmentURL mediaRange="124130-250544" indexRange="124130-124173"/>
+     <SegmentURL mediaRange="250545-374929" indexRange="250545-250588"/>
+    </SegmentList>
+   </Representation>
+  </AdaptationSet>
+ </Period>
+</MPD>
+

test/testdata/mpd/subtitles.mpd

@@ -0,0 +1,351 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Created with Unified Streaming Platform (version=1.10.18-20255) -->
+<MPD
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns="urn:mpeg:dash:schema:mpd:2011"
+  xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-DASH_schema_files/DASH-MPD.xsd"
+  type="static"
+  mediaPresentationDuration="PT14M48S"
+  maxSegmentDuration="PT1M"
+  minBufferTime="PT10S"
+  profiles="urn:mpeg:dash:profile:isoff-live:2011">
+  <Period
+    id="1"
+    duration="PT14M48S">
+    <BaseURL>dash/</BaseURL>
+    <AdaptationSet
+      id="1"
+      group="1"
+      contentType="audio"
+      segmentAlignment="true"
+      audioSamplingRate="48000"
+      mimeType="audio/mp4"
+      codecs="mp4a.40.2"
+      startWithSAP="1">
+      <AudioChannelConfiguration
+        schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011"
+        value="2" />
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main" />
+      <SegmentTemplate
+        timescale="48000"
+        initialization="3144-kZT4LWMQw6Rh7Kpd-$RepresentationID$.dash"
+        media="3144-kZT4LWMQw6Rh7Kpd-$RepresentationID$-$Time$.dash">
+        <SegmentTimeline>
+          <S t="0" d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="96256" r="2" />
+          <S d="95232" />
+          <S d="3584" />
+        </SegmentTimeline>
+      </SegmentTemplate>
+      <Representation
+        id="audio=128001"
+        bandwidth="128001">
+      </Representation>
+    </AdaptationSet>
+    <AdaptationSet
+      id="2"
+      group="3"
+      contentType="text"
+      lang="en"
+      mimeType="application/mp4"
+      codecs="stpp"
+      startWithSAP="1">
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle" />
+      <SegmentTemplate
+        timescale="1000"
+        initialization="3144-kZT4LWMQw6Rh7Kpd-$RepresentationID$.dash"
+        media="3144-kZT4LWMQw6Rh7Kpd-$RepresentationID$-$Time$.dash">
+        <SegmentTimeline>
+          <S t="0" d="60000" r="9" />
+          <S d="24000" />
+        </SegmentTimeline>
+      </SegmentTemplate>
+      <Representation
+        id="textstream_eng=1000"
+        bandwidth="1000">
+      </Representation>
+    </AdaptationSet>
+    <AdaptationSet
+      id="3"
+      group="2"
+      contentType="video"
+      par="960:409"
+      minBandwidth="100000"
+      maxBandwidth="4482000"
+      maxWidth="1689"
+      maxHeight="720"
+      segmentAlignment="true"
+      mimeType="video/mp4"
+      codecs="avc1.4D401F"
+      startWithSAP="1">
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main" />
+      <SegmentTemplate
+        timescale="12288"
+        initialization="3144-kZT4LWMQw6Rh7Kpd-$RepresentationID$.dash"
+        media="3144-kZT4LWMQw6Rh7Kpd-$RepresentationID$-$Time$.dash">
+        <SegmentTimeline>
+          <S t="0" d="24576" r="443" />
+        </SegmentTimeline>
+      </SegmentTemplate>
+      <Representation
+        id="video=100000"
+        bandwidth="100000"
+        width="336"
+        height="144"
+        sar="2880:2863"
+        scanType="progressive">
+      </Representation>
+      <Representation
+        id="video=326000"
+        bandwidth="326000"
+        width="562"
+        height="240"
+        sar="115200:114929"
+        scanType="progressive">
+      </Representation>
+      <Representation
+        id="video=698000"
+        bandwidth="698000"
+        width="844"
+        height="360"
+        sar="86400:86299"
+        scanType="progressive">
+      </Representation>
+      <Representation
+        id="video=1493000"
+        bandwidth="1493000"
+        width="1126"
+        height="480"
+        sar="230400:230267"
+        scanType="progressive">
+      </Representation>
+      <Representation
+        id="video=4482000"
+        bandwidth="4482000"
+        width="1688"
+        height="720"
+        sar="86400:86299"
+        scanType="progressive">
+      </Representation>
+    </AdaptationSet>
+  </Period>
+</MPD>

test/testdata/mpd/url_and_range.mpd

@@ -0,0 +1,32 @@
+<?xml version="1.0" ?>
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" profiles="urn:mpeg:dash:profile:isoff-live:2011" minBufferTime="PT10.01S" mediaPresentationDuration="PT30.097S" type="static">
+  <!-- Created with Bento4 mp4-dash.py, VERSION=2.0.0-639 -->
+  <Period>
+    <!-- Video -->
+    <AdaptationSet mimeType="video/mp4" segmentAlignment="true" startWithSAP="1" maxWidth="768" maxHeight="432">
+      <Representation id="video-avc1" codecs="avc1.4D401E" width="768" height="432" scanType="progressive" frameRate="30000/1001" bandwidth="699597">
+        <SegmentList timescale="1000" duration="10010">
+          <Initialization sourceURL="video-frag.mp4" range="36-746"/>
+          <SegmentURL media="video-frag.mp4" mediaRange="747-876117"/>
+          <SegmentURL media="video-frag.mp4" mediaRange="876118-1466913"/>
+          <SegmentURL media="video-frag.mp4" mediaRange="1466914-1953954"/>
+          <SegmentURL media="video-frag.mp4" mediaRange="1953955-1994652"/>
+        </SegmentList>
+      </Representation>
+    </AdaptationSet>
+    <!-- Audio -->
+    <AdaptationSet mimeType="audio/mp4" startWithSAP="1" segmentAlignment="true">
+      <Representation id="audio-und-mp4a.40.2" codecs="mp4a.40.2" bandwidth="98808" audioSamplingRate="48000">
+        <AudioChannelConfiguration schemeIdUri="urn:mpeg:mpegB:cicp:ChannelConfiguration" value="2"/>
+        <SegmentList timescale="1000" duration="10010">
+          <Initialization sourceURL="audio-frag.mp4" range="32-623"/>
+          <SegmentURL media="audio-frag.mp4" mediaRange="624-124199"/>
+          <SegmentURL media="audio-frag.mp4" mediaRange="124200-250303"/>
+          <SegmentURL media="audio-frag.mp4" mediaRange="250304-374365"/>
+          <SegmentURL media="audio-frag.mp4" mediaRange="374366-374836"/>
+        </SegmentList>
+      </Representation>
+    </AdaptationSet>
+  </Period>
+</MPD>
+

youtube_dl/extractor/common.py

@@ -183,6 +183,8 @@ class InfoExtractor(object):
                                             fragment_base_url
                                  * "duration" (optional, int or float)
                                  * "filesize" (optional, int)
+                                 * "range" (optional, str of the form "start-end"
+                                            to use in HTTP Range header)
                     * preference Order number of this format. If this field is
                                  present and not None, the formats get sorted
                                  by this field, regardless of all other values.
@@ -2296,15 +2298,27 @@ class InfoExtractor(object):
             def extract_Initialization(source):
                 initialization = source.find(_add_ns('Initialization'))
                 if initialization is not None:
-                    ms_info['initialization_url'] = initialization.attrib['sourceURL']
+                    ms_info['initialization_url'] = initialization.get('sourceURL') or base_url
+                    initialization_url_range = initialization.get('range')
+                    if initialization_url_range:
+                        ms_info['initialization_url_range'] = initialization_url_range
 
             segment_list = element.find(_add_ns('SegmentList'))
             if segment_list is not None:
                 extract_common(segment_list)
                 extract_Initialization(segment_list)
                 segment_urls_e = segment_list.findall(_add_ns('SegmentURL'))
-                if segment_urls_e:
-                    ms_info['segment_urls'] = [segment.attrib['media'] for segment in segment_urls_e]
+                segment_urls = traverse_obj(segment_urls_e, (
+                    Ellipsis, T(lambda e: e.attrib), 'media'))
+                if segment_urls:
+                    ms_info['segment_urls'] = segment_urls
+                segment_urls_range = traverse_obj(segment_urls_e, (
+                    Ellipsis, T(lambda e: e.attrib), 'mediaRange',
+                    T(lambda r: re.findall(r'^\d+-\d+$', r)), 0))
+                if segment_urls_range:
+                    ms_info['segment_urls_range'] = segment_urls_range
+                    if not segment_urls:
+                        ms_info['segment_urls'] = [base_url for _ in segment_urls_range]
             else:
                 segment_template = element.find(_add_ns('SegmentTemplate'))
                 if segment_template is not None:
@@ -2443,6 +2457,11 @@ class InfoExtractor(object):
                     def location_key(location):
                         return 'url' if re.match(r'^https?://', location) else 'path'
 
+                    def calc_segment_duration():
+                        return float_or_none(
+                            representation_ms_info['segment_duration'],
+                            representation_ms_info['timescale']) if 'segment_duration' in representation_ms_info else None
+
                     if 'segment_urls' not in representation_ms_info and 'media' in representation_ms_info:
 
                         media_template = prepare_template('media', ('Number', 'Bandwidth', 'Time'))
@@ -2512,45 +2531,68 @@ class InfoExtractor(object):
                                         'duration': duration,
                                     })
                                     segment_index += 1
-                            representation_ms_info['fragments'] = fragments
-                        elif 'segment_urls' in representation_ms_info:
+                        elif 'segment_urls_range' in representation_ms_info:
+                            # Segment URLs with mediaRange
+                            # Example: https://kinescope.io/200615537/master.mpd
+                            # https://github.com/ytdl-org/youtube-dl/issues/30235
+                            # or any mpd generated with Bento4 `mp4dash --no-split --use-segment-list`
+                            segment_duration = calc_segment_duration()
+                            for segment_url, segment_url_range in zip(
+                                    representation_ms_info['segment_urls'], representation_ms_info['segment_urls_range']):
+                                fragments.append({
+                                    location_key(segment_url): segment_url,
+                                    'range': segment_url_range,
+                                    'duration': segment_duration,
+                                })
+                        else:
                             # Segment URLs with no SegmentTimeline
                             # Example: https://www.seznam.cz/zpravy/clanek/cesko-zasahne-vitr-o-sile-vichrice-muze-byt-i-zivotu-nebezpecny-39091
                             # https://github.com/ytdl-org/youtube-dl/pull/14844
-                            fragments = []
-                            segment_duration = float_or_none(
-                                representation_ms_info['segment_duration'],
-                                representation_ms_info['timescale']) if 'segment_duration' in representation_ms_info else None
+                            segment_duration = calc_segment_duration()
                             for segment_url in representation_ms_info['segment_urls']:
-                                fragment = {
+                                fragments.append({
                                     location_key(segment_url): segment_url,
-                                }
-                                if segment_duration:
-                                    fragment['duration'] = segment_duration
-                                fragments.append(fragment)
-                            representation_ms_info['fragments'] = fragments
-                        # If there is a fragments key available then we correctly recognized fragmented media.
-                        # Otherwise we will assume unfragmented media with direct access. Technically, such
-                        # assumption is not necessarily correct since we may simply have no support for
-                        # some forms of fragmented media renditions yet, but for now we'll use this fallback.
-                        if 'fragments' in representation_ms_info:
-                            f.update({
-                                # NB: mpd_url may be empty when MPD manifest is parsed from a string
-                                'url': mpd_url or base_url,
-                                'fragment_base_url': base_url,
-                                'fragments': [],
-                                'protocol': 'http_dash_segments',
+                                    'duration': segment_duration,
+                                })
+                        representation_ms_info['fragments'] = fragments
+
+                    # If there is a fragments key available then we correctly recognized fragmented media.
+                    # Otherwise we will assume unfragmented media with direct access. Technically, such
+                    # assumption is not necessarily correct since we may simply have no support for
+                    # some forms of fragmented media renditions yet, but for now we'll use this fallback.
+                    if 'fragments' in representation_ms_info:
+                        base_url = representation_ms_info['base_url'] 
+                        f.update({
+                            # NB: mpd_url may be empty when MPD manifest is parsed from a string
+                            'url': mpd_url or base_url,
+                            'fragment_base_url': base_url,
+                            'fragments': [],
+                            'protocol': 'http_dash_segments',
+                        })
+                        if 'initialization_url' in representation_ms_info and 'initialization_url_range' in representation_ms_info:
+                            # Initialization URL with range (accompanied by Segment URLs with mediaRange above)
+                            # https://github.com/ytdl-org/youtube-dl/issues/30235
+                            initialization_url = representation_ms_info['initialization_url']
+                            f['fragments'].append({
+                                location_key(initialization_url): initialization_url,
+                                'range': representation_ms_info['initialization_url_range'],
                             })
-                            if 'initialization_url' in representation_ms_info:
-                                initialization_url = representation_ms_info['initialization_url']
-                                if not f.get('url'):
-                                    f['url'] = initialization_url
-                                f['fragments'].append({location_key(initialization_url): initialization_url})
-                            f['fragments'].extend(representation_ms_info['fragments'])
-                        else:
-                            # Assuming direct URL to unfragmented media.
-                            f['url'] = base_url
-                        formats.append(f)
+                        elif 'initialization_url' in representation_ms_info:
+                            initialization_url = representation_ms_info['initialization_url']
+                            if not f.get('url'):
+                                f['url'] = initialization_url
+                            f['fragments'].append({location_key(initialization_url): initialization_url})
+                        elif 'initialization_url_range' in representation_ms_info:
+                            # no Initialization URL but range (accompanied by no Segment URLs but mediaRange above)
+                            # https://github.com/ytdl-org/youtube-dl/issues/27575
+                            f['fragments'].append({
+                                location_key(base_url): base_url,
+                                'range': representation_ms_info['initialization_url_range'],
+                            })
+                        f['fragments'].extend(representation_ms_info['fragments'])
+                        if not period_duration:
+                            period_duration = sum(traverse_obj(representation_ms_info, (
+                                'fragments', Ellipsis, 'duration', T(float_or_none))))
                     else:
                         # Assuming direct URL to unfragmented media.
                         f['url'] = representation_ms_info['base_url']