draft-pantos-http-live-streaming-23v3.original		draft-pantos-http-live-streaming-23v3.txt
	Informational R. Pantos, Ed.		Independent R. Pantos, Ed.
	Internet-Draft Apple Inc.		Internet-Draft Apple Inc.
	Intended status: Informational W. May		Intended status: Informational W. May
	Expires: November 23, 2017 Major League Baseball Advanced Media		Expires: November 23, 2017 Major League Baseball Advanced Media
	May 22, 2017		May 22, 2017
	HTTP Live Streaming		HTTP Live Streaming
	draft-pantos-http-live-streaming-23		draft-pantos-http-live-streaming-23
	Abstract		Abstract
	skipping to change at page 1, line 46		skipping to change at page 1, line 46
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 IETF Trust and the persons identified as the
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	This document may not be modified, and derivative works of it may not
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	Table of Contents		Table of Contents
	1. Introduction to HTTP Live Streaming . . . . . . . . . . . . . 4		1. Introduction to HTTP Live Streaming . . . . . . . . . . . . . 3
	2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4		2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Media Segments . . . . . . . . . . . . . . . . . . . . . . . 6		3. Media Segments . . . . . . . . . . . . . . . . . . . . . . . 4
	3.1. Supported Media Segment Formats . . . . . . . . . . . . . 6		3.1. Supported Media Segment Formats . . . . . . . . . . . . . 5
	3.2. MPEG-2 Transport Streams . . . . . . . . . . . . . . . . 7		3.2. MPEG-2 Transport Streams . . . . . . . . . . . . . . . . 5
	3.3. Fragmented MPEG-4 . . . . . . . . . . . . . . . . . . . . 7		3.3. Fragmented MPEG-4 . . . . . . . . . . . . . . . . . . . . 6
	3.4. Packed Audio . . . . . . . . . . . . . . . . . . . . . . 8		3.4. Packed Audio . . . . . . . . . . . . . . . . . . . . . . 7
	3.5. WebVTT . . . . . . . . . . . . . . . . . . . . . . . . . 8		3.5. WebVTT . . . . . . . . . . . . . . . . . . . . . . . . . 7
	4. Playlists . . . . . . . . . . . . . . . . . . . . . . . . . . 9		4. Playlists . . . . . . . . . . . . . . . . . . . . . . . . . . 8
	4.1. Definition of a Playlist . . . . . . . . . . . . . . . . 9		4.1. Definition of a Playlist . . . . . . . . . . . . . . . . 8
	4.2. Attribute Lists . . . . . . . . . . . . . . . . . . . . . 10		4.2. Attribute Lists . . . . . . . . . . . . . . . . . . . . . 9
	4.3. Playlist Tags . . . . . . . . . . . . . . . . . . . . . . 12		4.3. Playlist Tags . . . . . . . . . . . . . . . . . . . . . . 11
	4.3.1. Basic Tags . . . . . . . . . . . . . . . . . . . . . 12		4.3.1. Basic Tags . . . . . . . . . . . . . . . . . . . . . 11
	4.3.1.1. EXTM3U . . . . . . . . . . . . . . . . . . . . . 12		4.3.2. Media Segment Tags . . . . . . . . . . . . . . . . . 11
	4.3.1.2. EXT-X-VERSION . . . . . . . . . . . . . . . . . . 12		4.3.3. Media Playlist Tags . . . . . . . . . . . . . . . . . 20
	4.3.2. Media Segment Tags . . . . . . . . . . . . . . . . . 13		4.3.4. Master Playlist Tags . . . . . . . . . . . . . . . . 23
	4.3.2.1. EXTINF . . . . . . . . . . . . . . . . . . . . . 13		4.3.5. Media or Master Playlist Tags . . . . . . . . . . . . 33
	4.3.2.2. EXT-X-BYTERANGE . . . . . . . . . . . . . . . . . 13		5. Key files . . . . . . . . . . . . . . . . . . . . . . . . . . 35
	4.3.2.3. EXT-X-DISCONTINUITY . . . . . . . . . . . . . . . 14		5.1. Structure of Key files . . . . . . . . . . . . . . . . . 35
	4.3.2.4. EXT-X-KEY . . . . . . . . . . . . . . . . . . . . 14		5.2. IV for [AES_128] . . . . . . . . . . . . . . . . . . . . 35
	4.3.2.5. EXT-X-MAP . . . . . . . . . . . . . . . . . . . . 16		6. Client/Server Responsibilities . . . . . . . . . . . . . . . 35
	4.3.2.6. EXT-X-PROGRAM-DATE-TIME . . . . . . . . . . . . . 17		6.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 35
	4.3.2.7. EXT-X-DATERANGE . . . . . . . . . . . . . . . . . 17		6.2. Server Responsibilities . . . . . . . . . . . . . . . . . 35
	4.3.2.7.1. Mapping SCTE-35 into EXT-X-DATERANGE . . . . 19		6.2.1. General Server Responsibilities . . . . . . . . . . . 35
	4.3.3. Media Playlist Tags . . . . . . . . . . . . . . . . . 21		6.2.2. Live Playlists . . . . . . . . . . . . . . . . . . . 38
	4.3.3.1. EXT-X-TARGETDURATION . . . . . . . . . . . . . . 21		6.2.3. Encrypting Media Segments . . . . . . . . . . . . . . 39
	4.3.3.2. EXT-X-MEDIA-SEQUENCE . . . . . . . . . . . . . . 22		6.2.4. Providing Variant Streams . . . . . . . . . . . . . . 40
	4.3.3.3. EXT-X-DISCONTINUITY-SEQUENCE . . . . . . . . . . 22		6.3. Client Responsibilities . . . . . . . . . . . . . . . . . 41
	4.3.3.4. EXT-X-ENDLIST . . . . . . . . . . . . . . . . . . 23		6.3.1. General Client Responsibilities . . . . . . . . . . . 41
	4.3.3.5. EXT-X-PLAYLIST-TYPE . . . . . . . . . . . . . . . 23		6.3.2. Loading the Media Playlist file . . . . . . . . . . . 42
	4.3.3.6. EXT-X-I-FRAMES-ONLY . . . . . . . . . . . . . . . 23		6.3.3. Playing the Media Playlist file . . . . . . . . . . . 43
	4.3.4. Master Playlist Tags . . . . . . . . . . . . . . . . 24		6.3.4. Reloading the Media Playlist file . . . . . . . . . . 44
	4.3.4.1. EXT-X-MEDIA . . . . . . . . . . . . . . . . . . . 24		6.3.5. Determining the next segment to load . . . . . . . . 45
	4.3.4.1.1. Rendition Groups . . . . . . . . . . . . . . 27		6.3.6. Decrypting encrypted Media Segments . . . . . . . . . 45
	4.3.4.2. EXT-X-STREAM-INF . . . . . . . . . . . . . . . . 28		7. Protocol version compatibility . . . . . . . . . . . . . . . 46
	4.3.4.2.1. Alternative Renditions . . . . . . . . . . . 31		8. Playlist Examples . . . . . . . . . . . . . . . . . . . . . . 47
	4.3.4.3. EXT-X-I-FRAME-STREAM-INF . . . . . . . . . . . . 32		8.1. Simple Media Playlist . . . . . . . . . . . . . . . . . . 47
	4.3.4.4. EXT-X-SESSION-DATA . . . . . . . . . . . . . . . 33		8.2. Live Media Playlist, using HTTPS . . . . . . . . . . . . 47
	4.3.4.5. EXT-X-SESSION-KEY . . . . . . . . . . . . . . . . 34		8.3. Playlist with encrypted Media Segments . . . . . . . . . 48
	4.3.5. Media or Master Playlist Tags . . . . . . . . . . . . 34		8.4. Master Playlist . . . . . . . . . . . . . . . . . . . . . 48
	4.3.5.1. EXT-X-INDEPENDENT-SEGMENTS . . . . . . . . . . . 34		8.5. Master Playlist with I-Frames . . . . . . . . . . . . . . 49
	4.3.5.2. EXT-X-START . . . . . . . . . . . . . . . . . . . 35		8.6. Master Playlist with Alternative audio . . . . . . . . . 49
	5. Key files . . . . . . . . . . . . . . . . . . . . . . . . . . 36		8.7. Master Playlist with Alternative video . . . . . . . . . 49
	5.1. Structure of Key files . . . . . . . . . . . . . . . . . 36		8.8. Session Data in a Master Playlist . . . . . . . . . . . . 50
	5.2. IV for [AES_128] . . . . . . . . . . . . . . . . . . . . 36
	6. Client/Server Responsibilities . . . . . . . . . . . . . . . 36
	6.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 36
	6.2. Server Responsibilities . . . . . . . . . . . . . . . . . 36
	6.2.1. General Server Responsibilities . . . . . . . . . . . 36
	6.2.2. Live Playlists . . . . . . . . . . . . . . . . . . . 39
	6.2.3. Encrypting Media Segments . . . . . . . . . . . . . . 40
	6.2.4. Providing Variant Streams . . . . . . . . . . . . . . 41
	6.3. Client Responsibilities . . . . . . . . . . . . . . . . . 42
	6.3.1. General Client Responsibilities . . . . . . . . . . . 42
	6.3.2. Loading the Media Playlist file . . . . . . . . . . . 43
	6.3.3. Playing the Media Playlist file . . . . . . . . . . . 44
	6.3.4. Reloading the Media Playlist file . . . . . . . . . . 45
	6.3.5. Determining the next segment to load . . . . . . . . 46
	6.3.6. Decrypting encrypted Media Segments . . . . . . . . . 46
	7. Protocol version compatibility . . . . . . . . . . . . . . . 47
	8. Playlist Examples . . . . . . . . . . . . . . . . . . . . . . 48
	8.1. Simple Media Playlist . . . . . . . . . . . . . . . . . . 48
	8.2. Live Media Playlist, using HTTPS . . . . . . . . . . . . 48
	8.3. Playlist with encrypted Media Segments . . . . . . . . . 49
	8.4. Master Playlist . . . . . . . . . . . . . . . . . . . . . 49
	8.5. Master Playlist with I-Frames . . . . . . . . . . . . . . 50
	8.6. Master Playlist with Alternative audio . . . . . . . . . 50
	8.7. Master Playlist with Alternative video . . . . . . . . . 50
	8.8. Session Data in a Master Playlist . . . . . . . . . . . . 51
	8.9. CHARACTERISTICS attribute containing multiple		8.9. CHARACTERISTICS attribute containing multiple
	characteristics . . . . . . . . . . . . . . . . . . . . . 52		characteristics . . . . . . . . . . . . . . . . . . . . . 51
	8.10. EXT-X-DATERANGE carrying SCTE-35 tags . . . . . . . . . . 52
	9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 52		8.10. EXT-X-DATERANGE carrying SCTE-35 tags . . . . . . . . . . 51
	10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 52		9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 51
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 53		10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 51
	12. References . . . . . . . . . . . . . . . . . . . . . . . . . 54		11. Security Considerations . . . . . . . . . . . . . . . . . . . 52
	12.1. Normative References . . . . . . . . . . . . . . . . . . 54		12. References . . . . . . . . . . . . . . . . . . . . . . . . . 53
	12.2. Informative References . . . . . . . . . . . . . . . . . 57		12.1. Normative References . . . . . . . . . . . . . . . . . . 53
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 58		12.2. Informative References . . . . . . . . . . . . . . . . . 56
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 57
	1. Introduction to HTTP Live Streaming		1. Introduction to HTTP Live Streaming
	HTTP Live Streaming provides a reliable, cost-effective means of		HTTP Live Streaming provides a reliable, cost-effective means of
	delivering continuous and long-form video over the Internet. It		delivering continuous and long-form video over the Internet. It
	allows a receiver to adapt the bit rate of the media to the current		allows a receiver to adapt the bit rate of the media to the current
	network conditions in order to maintain uninterrupted playback at the		network conditions in order to maintain uninterrupted playback at the
	best possible quality. It supports interstitial content boundaries.		best possible quality. It supports interstitial content boundaries.
	It provides a flexible framework for media encryption. It can		It provides a flexible framework for media encryption. It can
	efficiently offer multiple renditions of the same content, such as		efficiently offer multiple renditions of the same content, such as
	skipping to change at page 17, line 9		skipping to change at page 16, line 4
	The value is a quoted-string specifying a byte range into the		The value is a quoted-string specifying a byte range into the
	resource identified by the URI attribute. This range SHOULD		resource identified by the URI attribute. This range SHOULD
	contain only the Media Initialization Section. The format of the		contain only the Media Initialization Section. The format of the
	byte range is described in Section 4.3.2.2. This attribute is		byte range is described in Section 4.3.2.2. This attribute is
	OPTIONAL; if it is not present, the byte range is the entire		OPTIONAL; if it is not present, the byte range is the entire
	resource indicated by the URI.		resource indicated by the URI.
	An EXT-X-MAP tag SHOULD be supplied for Media Segments in Playlists		An EXT-X-MAP tag SHOULD be supplied for Media Segments in Playlists
	with the EXT-X-I-FRAMES-ONLY tag when the first Media Segment (i.e.,		with the EXT-X-I-FRAMES-ONLY tag when the first Media Segment (i.e.,
	I-frame) in the Playlist (or the first segment following an		I-frame) in the Playlist (or the first segment following an EXT-
	EXT-X-DISCONTINUITY tag) does not immediately follow the Media		X-DISCONTINUITY tag) does not immediately follow the Media
	Initialization Section at the beginning of its resource.		Initialization Section at the beginning of its resource.
	Use of the EXT-X-MAP tag in a Media Playlist that contains the		Use of the EXT-X-MAP tag in a Media Playlist that contains the EXT-
	EXT-X-I-FRAMES-ONLY tag REQUIRES a compatibility version number of 5		X-I-FRAMES-ONLY tag REQUIRES a compatibility version number of 5 or
	or greater. Use of the EXT-X-MAP tag in a Media Playlist that DOES		greater. Use of the EXT-X-MAP tag in a Media Playlist that DOES NOT
	NOT contain the EXT-X-I-FRAMES-ONLY tag REQUIRES a compatibility		contain the EXT-X-I-FRAMES-ONLY tag REQUIRES a compatibility version
	version number of 6 or greater.		number of 6 or greater.
	4.3.2.6. EXT-X-PROGRAM-DATE-TIME		4.3.2.6. EXT-X-PROGRAM-DATE-TIME
	The EXT-X-PROGRAM-DATE-TIME tag associates the first sample of a		The EXT-X-PROGRAM-DATE-TIME tag associates the first sample of a
	Media Segment with an absolute date and/or time. It applies only to		Media Segment with an absolute date and/or time. It applies only to
	the next Media Segment.		the next Media Segment.
	The date/time representation is ISO/IEC 8601:2004 [ISO_8601] and		The date/time representation is ISO/IEC 8601:2004 [ISO_8601] and
	SHOULD indicate a time zone and fractional parts of seconds:		SHOULD indicate a time zone and fractional parts of seconds:
	skipping to change at page 21, line 15		skipping to change at page 20, line 8
	The END-DATE of an EXT-X-DATERANGE tag containing a SCTE35-IN		The END-DATE of an EXT-X-DATERANGE tag containing a SCTE35-IN
	attribute MUST be the actual (not planned) program date and time of		attribute MUST be the actual (not planned) program date and time of
	that in-point.		that in-point.
	If the actual end date and time is not known when a SCTE35-OUT		If the actual end date and time is not known when a SCTE35-OUT
	attribute is added to the Playlist, the DURATION attribute and the		attribute is added to the Playlist, the DURATION attribute and the
	END-TIME attribute MUST NOT be present; the actual end date of the		END-TIME attribute MUST NOT be present; the actual end date of the
	splice SHOULD be signaled by another EXT-X-DATERANGE tag once it has		splice SHOULD be signaled by another EXT-X-DATERANGE tag once it has
	been established.		been established.
	A canceled splice SHOULD NOT appear in the Playlist as an		A canceled splice SHOULD NOT appear in the Playlist as an EXT-
	EXT-X-DATERANGE tag.		X-DATERANGE tag.
	An EXT-X-DATERANGE tag announcing a splice SHOULD be added to a		An EXT-X-DATERANGE tag announcing a splice SHOULD be added to a
	Playlist at the same time as the last pre-splice Media Segment.		Playlist at the same time as the last pre-splice Media Segment.
	The ID attribute of an EXT-X-DATERANGE tag MAY contain a		The ID attribute of an EXT-X-DATERANGE tag MAY contain a
	splice_event_id and/or a segmentation_event_id, but it MUST be unique		splice_event_id and/or a segmentation_event_id, but it MUST be unique
	in the the Playlist. If there is a possibility that a SCTE-35 id		in the the Playlist. If there is a possibility that a SCTE-35 id
	will be reused, the ID attribute value MUST include disambiguation,		will be reused, the ID attribute value MUST include disambiguation,
	such as a date or sequence number.		such as a date or sequence number.
	skipping to change at page 22, line 49		skipping to change at page 21, line 39
	where number is a decimal-integer.		where number is a decimal-integer.
	If the Media Playlist does not contain an EXT-X-DISCONTINUITY-		If the Media Playlist does not contain an EXT-X-DISCONTINUITY-
	SEQUENCE tag, then the Discontinuity Sequence Number of the first		SEQUENCE tag, then the Discontinuity Sequence Number of the first
	Media Segment in the Playlist SHALL be considered to be 0.		Media Segment in the Playlist SHALL be considered to be 0.
	The EXT-X-DISCONTINUITY-SEQUENCE tag MUST appear before the first		The EXT-X-DISCONTINUITY-SEQUENCE tag MUST appear before the first
	Media Segment in the Playlist.		Media Segment in the Playlist.
	The EXT-X-DISCONTINUITY-SEQUENCE tag MUST appear before any		The EXT-X-DISCONTINUITY-SEQUENCE tag MUST appear before any EXT-
	EXT-X-DISCONTINUITY tag.		X-DISCONTINUITY tag.
	See Section 6.2.1 and Section 6.2.2 for more information about		See Section 6.2.1 and Section 6.2.2 for more information about
	setting the value of the EXT-X-DISCONTINUITY-SEQUENCE tag.		setting the value of the EXT-X-DISCONTINUITY-SEQUENCE tag.
	4.3.3.4. EXT-X-ENDLIST		4.3.3.4. EXT-X-ENDLIST
	The EXT-X-ENDLIST tag indicates that no more Media Segments will be		The EXT-X-ENDLIST tag indicates that no more Media Segments will be
	added to the Media Playlist file. It MAY occur anywhere in the Media		added to the Media Playlist file. It MAY occur anywhere in the Media
	Playlist file. Its format is:		Playlist file. Its format is:
	skipping to change at page 24, line 8		skipping to change at page 22, line 46
	#EXT-X-I-FRAMES-ONLY		#EXT-X-I-FRAMES-ONLY
	In a Playlist with the EXT-X-I-FRAMES-ONLY tag, the Media Segment		In a Playlist with the EXT-X-I-FRAMES-ONLY tag, the Media Segment
	duration (EXTINF tag value) is the time between the presentation time		duration (EXTINF tag value) is the time between the presentation time
	of the I-frame in the Media Segment and the presentation time of the		of the I-frame in the Media Segment and the presentation time of the
	next I-frame in the Playlist, or the end of the presentation if it is		next I-frame in the Playlist, or the end of the presentation if it is
	the last I-frame in the Playlist.		the last I-frame in the Playlist.
	Media resources containing I-frame segments MUST begin with either a		Media resources containing I-frame segments MUST begin with either a
	Media Initialization Section (Section 3) or be accompanied by an		Media Initialization Section (Section 3) or be accompanied by an EXT-
	EXT-X-MAP tag indicating the Media Initialization Section so that		X-MAP tag indicating the Media Initialization Section so that clients
	clients can load and decode I-frame segments in any order. The byte		can load and decode I-frame segments in any order. The byte range of
	range of an I-frame segment with an EXT-X-BYTERANGE tag applied to it		an I-frame segment with an EXT-X-BYTERANGE tag applied to it
	(Section 4.3.2.2) MUST NOT include its Media Initialization Section;		(Section 4.3.2.2) MUST NOT include its Media Initialization Section;
	clients can assume that the Media Initialization Section is defined		clients can assume that the Media Initialization Section is defined
	by EXT-X-MAP tag, or is located from the start of the resource to the		by EXT-X-MAP tag, or is located from the start of the resource to the
	offset of the first I-frame segment in that resource.		offset of the first I-frame segment in that resource.
	Use of the EXT-X-I-FRAMES-ONLY REQUIRES a compatibility version		Use of the EXT-X-I-FRAMES-ONLY REQUIRES a compatibility version
	number of 4 or greater.		number of 4 or greater.
	4.3.4. Master Playlist Tags		4.3.4. Master Playlist Tags
	skipping to change at page 28, line 20		skipping to change at page 27, line 12
	corresponding member MUST have identical attributes with the		corresponding member MUST have identical attributes with the
	exception of the URI and CHANNELS attributes.		exception of the URI and CHANNELS attributes.
	Each member in a Group of Renditions MAY have a different sample		Each member in a Group of Renditions MAY have a different sample
	format. For example, an English rendition can be encoded with AC-3		format. For example, an English rendition can be encoded with AC-3
	5.1 while a Spanish rendition is encoded with AAC stereo. However,		5.1 while a Spanish rendition is encoded with AAC stereo. However,
	any EXT-X-STREAM-INF (Section 4.3.4.2) tag or EXT-X-I-FRAME-STREAM-		any EXT-X-STREAM-INF (Section 4.3.4.2) tag or EXT-X-I-FRAME-STREAM-
	INF (Section 4.3.4.3) tag which references such a Group MUST have a		INF (Section 4.3.4.3) tag which references such a Group MUST have a
	CODECS attribute that lists every sample format present in any		CODECS attribute that lists every sample format present in any
	Rendition in the Group, or client playback failures can occur. In		Rendition in the Group, or client playback failures can occur. In
	the example above, the CODECS attribute would include		the example above, the CODECS attribute would include "ac-
	"ac-3,mp4a.40.2".		3,mp4a.40.2".
	4.3.4.2. EXT-X-STREAM-INF		4.3.4.2. EXT-X-STREAM-INF
	The EXT-X-STREAM-INF tag specifies a Variant Stream, which is a set		The EXT-X-STREAM-INF tag specifies a Variant Stream, which is a set
	of Renditions which can be combined to play the presentation. The		of Renditions which can be combined to play the presentation. The
	attributes of the tag provide information about the Variant Stream.		attributes of the tag provide information about the Variant Stream.
	The URI line that follows the EXT-X-STREAM-INF tag specifies a Media		The URI line that follows the EXT-X-STREAM-INF tag specifies a Media
	Playlist that carries a Rendition of the Variant Stream. The URI		Playlist that carries a Rendition of the Variant Stream. The URI
	line is REQUIRED. Clients that do not support multiple video		line is REQUIRED. Clients that do not support multiple video
	skipping to change at page 31, line 31		skipping to change at page 30, line 21
	CLOSED-CAPTIONS		CLOSED-CAPTIONS
	The value can be either a quoted-string or an enumerated-string		The value can be either a quoted-string or an enumerated-string
	with the value NONE. If the value is a quoted-string, it MUST		with the value NONE. If the value is a quoted-string, it MUST
	match the value of the GROUP-ID attribute of an EXT-X-MEDIA tag		match the value of the GROUP-ID attribute of an EXT-X-MEDIA tag
	elsewhere in the Playlist whose TYPE attribute is CLOSED-CAPTIONS,		elsewhere in the Playlist whose TYPE attribute is CLOSED-CAPTIONS,
	and indicates the set of closed-caption Renditions that can be		and indicates the set of closed-caption Renditions that can be
	used when playing the presentation. See Section 4.3.4.2.1.		used when playing the presentation. See Section 4.3.4.2.1.
	If the value is the enumerated-string value NONE, all EXT-X		If the value is the enumerated-string value NONE, all EXT-X -
	-STREAM-INF tags MUST have this attribute with a value of NONE,		STREAM-INF tags MUST have this attribute with a value of NONE,
	indicating that there are no closed captions in any Variant Stream		indicating that there are no closed captions in any Variant Stream
	in the Master Playlist. Having closed captions in one Variant		in the Master Playlist. Having closed captions in one Variant
	Stream but not another can trigger playback inconsistencies.		Stream but not another can trigger playback inconsistencies.
	The CLOSED-CAPTIONS attribute is OPTIONAL.		The CLOSED-CAPTIONS attribute is OPTIONAL.
	4.3.4.2.1. Alternative Renditions		4.3.4.2.1. Alternative Renditions
	When an EXT-X-STREAM-INF tag contains an AUDIO, VIDEO, SUBTITLES, or		When an EXT-X-STREAM-INF tag contains an AUDIO, VIDEO, SUBTITLES, or
	CLOSED-CAPTIONS attribute, it indicates that alternative Renditions		CLOSED-CAPTIONS attribute, it indicates that alternative Renditions
	of the content are available for playback of that Variant Stream.		of the content are available for playback of that Variant Stream.
	When defining alternative Renditions, the following constraints MUST		When defining alternative Renditions, the following constraints MUST
	be met to prevent client playback errors:		be met to prevent client playback errors:
	o All playable combinations of Renditions associated with an EXT-X		o All playable combinations of Renditions associated with an EXT-X -
	-STREAM-INF tag MUST have an aggregate bandwidth less than or		STREAM-INF tag MUST have an aggregate bandwidth less than or equal
	equal to the BANDWIDTH attribute of the EXT-X-STREAM-INF tag.		to the BANDWIDTH attribute of the EXT-X-STREAM-INF tag.
	o If an EXT-X-STREAM-INF tag contains a RESOLUTION attribute and a		o If an EXT-X-STREAM-INF tag contains a RESOLUTION attribute and a
	VIDEO attribute, then every alternative video Rendition MUST have		VIDEO attribute, then every alternative video Rendition MUST have
	an optimal display resolution matching the value of the RESOLUTION		an optimal display resolution matching the value of the RESOLUTION
	attribute.		attribute.
	o Every alternative Rendition associated with an EXT-X-STREAM-INF		o Every alternative Rendition associated with an EXT-X-STREAM-INF
	tag MUST meet the constraints for a Variant Stream described in		tag MUST meet the constraints for a Variant Stream described in
	Section 6.2.4.		Section 6.2.4.
	The URI attribute of the EXT-X-MEDIA tag is REQUIRED if the media		The URI attribute of the EXT-X-MEDIA tag is REQUIRED if the media
	type is SUBTITLES, but OPTIONAL if the media type is VIDEO or AUDIO.		type is SUBTITLES, but OPTIONAL if the media type is VIDEO or AUDIO.
	If the media type is VIDEO or AUDIO, a missing URI attribute		If the media type is VIDEO or AUDIO, a missing URI attribute
	indicates that the media data for this Rendition is included in the		indicates that the media data for this Rendition is included in the
	Media Playlist of any EXT-X-STREAM-INF tag referencing this		Media Playlist of any EXT-X-STREAM-INF tag referencing this EXT-
	EXT-X-MEDIA tag. If the media TYPE is AUDIO and the URI attribute is		X-MEDIA tag. If the media TYPE is AUDIO and the URI attribute is
	missing, clients MUST assume that the audio data for this Rendition		missing, clients MUST assume that the audio data for this Rendition
	is present in every video Rendition specified by the EXT-X-STREAM-INF		is present in every video Rendition specified by the EXT-X-STREAM-INF
	tag.		tag.
	The URI attribute of the EXT-X-MEDIA tag MUST NOT be included if the		The URI attribute of the EXT-X-MEDIA tag MUST NOT be included if the
	media type is CLOSED-CAPTIONS.		media type is CLOSED-CAPTIONS.
	4.3.4.3. EXT-X-I-FRAME-STREAM-INF		4.3.4.3. EXT-X-I-FRAME-STREAM-INF
	The EXT-X-I-FRAME-STREAM-INF tag identifies a Media Playlist file		The EXT-X-I-FRAME-STREAM-INF tag identifies a Media Playlist file
	skipping to change at page 33, line 52		skipping to change at page 32, line 47
	LANGUAGE		LANGUAGE
	The value is a quoted-string containing a language tag [RFC5646]		The value is a quoted-string containing a language tag [RFC5646]
	that identifies the language of the VALUE. This attribute is		that identifies the language of the VALUE. This attribute is
	OPTIONAL.		OPTIONAL.
	Each EXT-X-SESSION-DATA tag MUST contain either a VALUE or URI		Each EXT-X-SESSION-DATA tag MUST contain either a VALUE or URI
	attribute, but not both.		attribute, but not both.
	A Playlist MAY contain multiple EXT-X-SESSION-DATA tags with the same		A Playlist MAY contain multiple EXT-X-SESSION-DATA tags with the same
	DATA-ID attribute. A Playlist MUST NOT contain more than one EXT-X		DATA-ID attribute. A Playlist MUST NOT contain more than one EXT-X -
	-SESSION-DATA tag with the same DATA-ID attribute and the same		SESSION-DATA tag with the same DATA-ID attribute and the same
	LANGUAGE attribute.		LANGUAGE attribute.
	4.3.4.5. EXT-X-SESSION-KEY		4.3.4.5. EXT-X-SESSION-KEY
	The EXT-X-SESSION-KEY tag allows encryption keys from Media Playlists		The EXT-X-SESSION-KEY tag allows encryption keys from Media Playlists
	to be specified in a Master Playlist. This allows the client to		to be specified in a Master Playlist. This allows the client to
	preload these keys without having to read the Media Playlist(s)		preload these keys without having to read the Media Playlist(s)
	first.		first.
	Its format is:		Its format is:
	#EXT-X-SESSION-KEY:<attribute-list>		#EXT-X-SESSION-KEY:<attribute-list>
	All attributes defined for the EXT-X-KEY tag (Section 4.3.2.4) are		All attributes defined for the EXT-X-KEY tag (Section 4.3.2.4) are
	also defined for the EXT-X-SESSION-KEY, except that the value of the		also defined for the EXT-X-SESSION-KEY, except that the value of the
	METHOD attribute MUST NOT be NONE. If an EXT-X-SESSION-KEY is used,		METHOD attribute MUST NOT be NONE. If an EXT-X-SESSION-KEY is used,
	the values of the METHOD, KEYFORMAT and KEYFORMATVERSIONS attributes		the values of the METHOD, KEYFORMAT and KEYFORMATVERSIONS attributes
	MUST match any EXT-X-KEY with the same URI value.		MUST match any EXT-X-KEY with the same URI value.
	EXT-X-SESSION-KEY tags SHOULD be added if multiple Variant Streams or		EXT-X-SESSION-KEY tags SHOULD be added if multiple Variant Streams or
	Renditions use the same encryption keys and formats. A EXT-X		Renditions use the same encryption keys and formats. A EXT-X -
	-SESSION-KEY tag is not associated with any particular Media		SESSION-KEY tag is not associated with any particular Media Playlist.
	Playlist.
	A Master Playlist MUST NOT contain more than one EXT-X-SESSION-KEY		A Master Playlist MUST NOT contain more than one EXT-X-SESSION-KEY
	tag with the same METHOD, URI, IV, KEYFORMAT, and KEYFORMATVERSIONS		tag with the same METHOD, URI, IV, KEYFORMAT, and KEYFORMATVERSIONS
	attribute values.		attribute values.
	The EXT-X-SESSION-KEY tag is optional.		The EXT-X-SESSION-KEY tag is optional.
	4.3.5. Media or Master Playlist Tags		4.3.5. Media or Master Playlist Tags
	The tags in this section can appear in either Master Playlists or		The tags in this section can appear in either Master Playlists or
	skipping to change at page 36, line 13		skipping to change at page 35, line 13
	If it is missing, its value should be treated as NO.		If it is missing, its value should be treated as NO.
	5. Key files		5. Key files
	5.1. Structure of Key files		5.1. Structure of Key files
	An EXT-X-KEY tag with a URI attribute identifies a Key file. A Key		An EXT-X-KEY tag with a URI attribute identifies a Key file. A Key
	file contains a cipher key that can decrypt Media Segments in the		file contains a cipher key that can decrypt Media Segments in the
	Playlist.		Playlist.
	[AES_128] encryption uses 16-octet keys. If the KEYFORMAT of an		[AES_128] encryption uses 16-octet keys. If the KEYFORMAT of an EXT-
	EXT-X-KEY tag is "identity", the Key file is a single packed array of		X-KEY tag is "identity", the Key file is a single packed array of 16
	16 octets in binary format.		octets in binary format.
	5.2. IV for [AES_128]		5.2. IV for [AES_128]
	[AES_128] REQUIRES the same 16-octet Initialization Vector (IV) to be		[AES_128] REQUIRES the same 16-octet Initialization Vector (IV) to be
	supplied when encrypting and decrypting. Varying this IV increases		supplied when encrypting and decrypting. Varying this IV increases
	the strength of the cipher.		the strength of the cipher.
	An IV attribute on an EXT-X-KEY tag with a KEYFORMAT of "identity"		An IV attribute on an EXT-X-KEY tag with a KEYFORMAT of "identity"
	specifies an Initialization Vector that can be used when decrypting		specifies an Initialization Vector that can be used when decrypting
	Media Segments encrypted with that Key file. IV values for AES-128		Media Segments encrypted with that Key file. IV values for AES-128
	skipping to change at page 37, line 43		skipping to change at page 36, line 43
	of view of the clients, or playback errors MAY occur.		of view of the clients, or playback errors MAY occur.
	The server MUST NOT change the Media Playlist file, except to:		The server MUST NOT change the Media Playlist file, except to:
	Append lines to it (Section 6.2.1).		Append lines to it (Section 6.2.1).
	Remove Media Segment URIs from the Playlist in the order that they		Remove Media Segment URIs from the Playlist in the order that they
	appear, along with any tags that apply only to those segments		appear, along with any tags that apply only to those segments
	(Section 6.2.2).		(Section 6.2.2).
	Increment the value of the EXT-X-MEDIA-SEQUENCE or EXT-X		Increment the value of the EXT-X-MEDIA-SEQUENCE or EXT-X -
	-DISCONTINUITY-SEQUENCE tags (Section 6.2.2).		DISCONTINUITY-SEQUENCE tags (Section 6.2.2).
	Add an EXT-X-ENDLIST tag to the Playlist (Section 6.2.1).		Add an EXT-X-ENDLIST tag to the Playlist (Section 6.2.1).
	A Media Playlist has further constraints on its updates if it		A Media Playlist has further constraints on its updates if it
	contains an EXT-X-PLAYLIST-TYPE tag. An EXT-X-PLAYLIST-TYPE tag with		contains an EXT-X-PLAYLIST-TYPE tag. An EXT-X-PLAYLIST-TYPE tag with
	a value of VOD indicates that the Playlist file MUST NOT change. An		a value of VOD indicates that the Playlist file MUST NOT change. An
	EXT-X-PLAYLIST-TYPE tag with a value of EVENT indicates that the		EXT-X-PLAYLIST-TYPE tag with a value of EVENT indicates that the
	server MUST NOT change or delete any part of the Playlist file; it		server MUST NOT change or delete any part of the Playlist file; it
	MAY append lines to it.		MAY append lines to it.
	skipping to change at page 38, line 18		skipping to change at page 37, line 18
	NOT change. A typical target duration is 10 seconds.		NOT change. A typical target duration is 10 seconds.
	Playlist changes other than those allowed here can trigger playback		Playlist changes other than those allowed here can trigger playback
	errors and inconsistent client behavior.		errors and inconsistent client behavior.
	Each Media Segment in a Media Playlist has an integer Discontinuity		Each Media Segment in a Media Playlist has an integer Discontinuity
	Sequence Number. The Discontinuity Sequence Number can be used in		Sequence Number. The Discontinuity Sequence Number can be used in
	addition to the timestamps within the media to synchronize Media		addition to the timestamps within the media to synchronize Media
	Segments across different Renditions.		Segments across different Renditions.
	A segment's Discontinuity Sequence Number is the value of the EXT-X		A segment's Discontinuity Sequence Number is the value of the EXT-X -
	-DISCONTINUITY-SEQUENCE tag (or zero if none) plus the number of		DISCONTINUITY-SEQUENCE tag (or zero if none) plus the number of EXT-
	EXT-X-DISCONTINUITY tags in the Playlist preceding the URI line of		X-DISCONTINUITY tags in the Playlist preceding the URI line of the
	the segment.		segment.
	The server MAY associate an absolute date and time with a Media		The server MAY associate an absolute date and time with a Media
	Segment by applying an EXT-X-PROGRAM-DATE-TIME tag to it. This		Segment by applying an EXT-X-PROGRAM-DATE-TIME tag to it. This
	defines an informative mapping of the (wall-clock) date and time		defines an informative mapping of the (wall-clock) date and time
	specified by the tag to the first media timestamp in the segment,		specified by the tag to the first media timestamp in the segment,
	which may be used as a basis for seeking, for display, or for other		which may be used as a basis for seeking, for display, or for other
	purposes. If a server provides this mapping, it SHOULD apply an		purposes. If a server provides this mapping, it SHOULD apply an EXT-
	EXT-X-PROGRAM-DATE-TIME tag to every segment that has an		X-PROGRAM-DATE-TIME tag to every segment that has an EXT-
	EXT-X-DISCONTINUITY tag applied to it.		X-DISCONTINUITY tag applied to it.
	The Server MUST NOT add any EXT-X-PROGRAM-DATE-TIME tag to a Playlist		The Server MUST NOT add any EXT-X-PROGRAM-DATE-TIME tag to a Playlist
	that would cause the mapping between program date and Media Segment		that would cause the mapping between program date and Media Segment
	to become ambiguous.		to become ambiguous.
	The server MUST NOT remove an EXT-X-DATERANGE tag from a Playlist if		The server MUST NOT remove an EXT-X-DATERANGE tag from a Playlist if
	any date in the range maps to a Media Segment in the Playlist.		any date in the range maps to a Media Segment in the Playlist.
	The server MUST NOT reuse the ID attribute value of an		The server MUST NOT reuse the ID attribute value of an EXT-
	EXT-X-DATERANGE tag for any new Date Range in the same Playlist.		X-DATERANGE tag for any new Date Range in the same Playlist.
	Once the Following Range of a Date Range with an END-ON-NEXT=YES		Once the Following Range of a Date Range with an END-ON-NEXT=YES
	attribute is added to a Playlist, the Server MUST NOT subsequently		attribute is added to a Playlist, the Server MUST NOT subsequently
	add a Date Range with the same CLASS attribute whose START-DATE is		add a Date Range with the same CLASS attribute whose START-DATE is
	between that of the END-ON-NEXT=YES range and its Following Range.		between that of the END-ON-NEXT=YES range and its Following Range.
	For Date Ranges with a PLANNED-DURATION attribute, the Server SHOULD		For Date Ranges with a PLANNED-DURATION attribute, the Server SHOULD
	signal the actual end of the range once it has been established. It		signal the actual end of the range once it has been established. It
	can do so by adding another EXT-X-DATERANGE tag with the same ID		can do so by adding another EXT-X-DATERANGE tag with the same ID
	attribute value and either a DURATION or an END-DATE attribute or, if		attribute value and either a DURATION or an END-DATE attribute or, if
	skipping to change at page 39, line 31		skipping to change at page 38, line 31
	provide a clear indication to clients that the Playlist file is no		provide a clear indication to clients that the Playlist file is no
	longer available (e.g. with an HTTP 404 or 410 response). It MUST		longer available (e.g. with an HTTP 404 or 410 response). It MUST
	ensure that all Media Segments in the Playlist file remain available		ensure that all Media Segments in the Playlist file remain available
	to clients for at least the duration of the Playlist file at the time		to clients for at least the duration of the Playlist file at the time
	of removal to prevent interruption of in-progress playback.		of removal to prevent interruption of in-progress playback.
	6.2.2. Live Playlists		6.2.2. Live Playlists
	The server MAY limit the availability of Media Segments by removing		The server MAY limit the availability of Media Segments by removing
	Media Segments from the Playlist file (Section 6.2.1). If Media		Media Segments from the Playlist file (Section 6.2.1). If Media
	Segments are to be removed, the Playlist file MUST contain an EXT-X		Segments are to be removed, the Playlist file MUST contain an EXT-X -
	-MEDIA-SEQUENCE tag. Its value MUST be incremented by 1 for every		MEDIA-SEQUENCE tag. Its value MUST be incremented by 1 for every
	Media Segment that is removed from the Playlist file; it MUST NOT		Media Segment that is removed from the Playlist file; it MUST NOT
	decrease or wrap. Clients can malfunction if each Media Segment does		decrease or wrap. Clients can malfunction if each Media Segment does
	not have a consistent, unique Media Sequence Number.		not have a consistent, unique Media Sequence Number.
	Media Segments MUST be removed from the Playlist file in the order		Media Segments MUST be removed from the Playlist file in the order
	that they appear in the Playlist; otherwise, client playback can		that they appear in the Playlist; otherwise, client playback can
	malfunction.		malfunction.
	The server MUST NOT remove a Media Segment from a Playlist file		The server MUST NOT remove a Media Segment from a Playlist file
	without an EXT-X-ENDLIST tag if that would produce a Playlist whose		without an EXT-X-ENDLIST tag if that would produce a Playlist whose
	skipping to change at page 40, line 7		skipping to change at page 39, line 7
	When the server removes a Media Segment URI from the Playlist, the		When the server removes a Media Segment URI from the Playlist, the
	corresponding Media Segment MUST remain available to clients for a		corresponding Media Segment MUST remain available to clients for a
	period of time equal to the duration of the segment plus the duration		period of time equal to the duration of the segment plus the duration
	of the longest Playlist file distributed by the server containing		of the longest Playlist file distributed by the server containing
	that segment. Removing a Media Segment earlier than that can		that segment. Removing a Media Segment earlier than that can
	interrupt in-progress playback.		interrupt in-progress playback.
	If the server wishes to remove segments from a Media Playlist		If the server wishes to remove segments from a Media Playlist
	containing an EXT-X-DISCONTINUITY tag, the Media Playlist MUST		containing an EXT-X-DISCONTINUITY tag, the Media Playlist MUST
	contain an EXT-X-DISCONTINUITY-SEQUENCE tag. Without the EXT-X		contain an EXT-X-DISCONTINUITY-SEQUENCE tag. Without the EXT-X -
	-DISCONTINUITY-SEQUENCE tag, it can be impossible for a client to		DISCONTINUITY-SEQUENCE tag, it can be impossible for a client to
	locate corresponding segments between Renditions.		locate corresponding segments between Renditions.
	If the server removes an EXT-X-DISCONTINUITY tag from the Media		If the server removes an EXT-X-DISCONTINUITY tag from the Media
	Playlist, it MUST increment the value of the EXT-X-DISCONTINUITY-		Playlist, it MUST increment the value of the EXT-X-DISCONTINUITY-
	SEQUENCE tag so that the Discontinuity Sequence Numbers of the		SEQUENCE tag so that the Discontinuity Sequence Numbers of the
	segments still in the Media Playlist remain unchanged. The value of		segments still in the Media Playlist remain unchanged. The value of
	the EXT-X-DISCONTINUITY-SEQUENCE tag MUST NOT decrease or wrap.		the EXT-X-DISCONTINUITY-SEQUENCE tag MUST NOT decrease or wrap.
	Clients can malfunction if each Media Segment does not have a		Clients can malfunction if each Media Segment does not have a
	consistent Discontinuity Sequence Number.		consistent Discontinuity Sequence Number.
	skipping to change at page 40, line 50		skipping to change at page 39, line 50
	If an encrypted Media Segment is followed by one or more unencrypted		If an encrypted Media Segment is followed by one or more unencrypted
	Media Segments in the Playlist, the unencrypted Media Segments MUST		Media Segments in the Playlist, the unencrypted Media Segments MUST
	have an EXT-X-KEY tag whose METHOD is NONE applied to them.		have an EXT-X-KEY tag whose METHOD is NONE applied to them.
	Otherwise, the client will misinterpret those segments as encrypted.		Otherwise, the client will misinterpret those segments as encrypted.
	If the encryption METHOD is AES-128 and the Playlist does not contain		If the encryption METHOD is AES-128 and the Playlist does not contain
	the EXT-X-I-FRAMES-ONLY tag, AES encryption as described in		the EXT-X-I-FRAMES-ONLY tag, AES encryption as described in
	Section 4.3.2.4 SHALL be applied to individual Media Segments.		Section 4.3.2.4 SHALL be applied to individual Media Segments.
	If the encryption METHOD is AES-128 and the Playlist contains an		If the encryption METHOD is AES-128 and the Playlist contains an EXT-
	EXT-X-I-FRAMES-ONLY tag, the entire resource MUST be encrypted using		X-I-FRAMES-ONLY tag, the entire resource MUST be encrypted using
	AES-128 CBC with PKCS7 padding [RFC5652]. Encryption MAY be		AES-128 CBC with PKCS7 padding [RFC5652]. Encryption MAY be
	restarted on 16-byte block boundaries, unless the first block		restarted on 16-byte block boundaries, unless the first block
	contains an I-frame. The IV used for encryption MUST be either the		contains an I-frame. The IV used for encryption MUST be either the
	Media Sequence Number of the Media Segment or the value of the IV		Media Sequence Number of the Media Segment or the value of the IV
	attribute of the EXT-X-KEY tag, as described in Section 5.2. These		attribute of the EXT-X-KEY tag, as described in Section 5.2. These
	constraints allow a client to load and decrypt individual I-frames		constraints allow a client to load and decrypt individual I-frames
	specified as sub-ranges of regular encrypted Media Segments, and		specified as sub-ranges of regular encrypted Media Segments, and
	their Media Initialization Sections.		their Media Initialization Sections.
	If the encryption METHOD is SAMPLE-AES, media samples MAY be		If the encryption METHOD is SAMPLE-AES, media samples MAY be
	skipping to change at page 42, line 18		skipping to change at page 41, line 18
	duration.		duration.
	If any Media Playlists have an EXT-X-PLAYLIST-TYPE tag, all Media		If any Media Playlists have an EXT-X-PLAYLIST-TYPE tag, all Media
	Playlists MUST have the EXT-X-PLAYLIST-TYPE tag with the same		Playlists MUST have the EXT-X-PLAYLIST-TYPE tag with the same
	value.		value.
	If the Playlist contains an EXT-X-PLAYLIST-TYPE tag with the value		If the Playlist contains an EXT-X-PLAYLIST-TYPE tag with the value
	of VOD, the first segment of every Media Playlist in every Variant		of VOD, the first segment of every Media Playlist in every Variant
	Stream MUST start at the same media timestamp.		Stream MUST start at the same media timestamp.
	If any Media Playlist in a Master Playlist contains an EXT-X		If any Media Playlist in a Master Playlist contains an EXT-X -
	-PROGRAM-DATE-TIME tag, then all Media Playlists in that Master		PROGRAM-DATE-TIME tag, then all Media Playlists in that Master
	Playlist MUST contain EXT-X-PROGRAM-DATE-TIME tags with consistent		Playlist MUST contain EXT-X-PROGRAM-DATE-TIME tags with consistent
	mappings of date and time to media timestamps.		mappings of date and time to media timestamps.
	Each Variant Stream MUST contain the same set of Date Ranges, each		Each Variant Stream MUST contain the same set of Date Ranges, each
	one identified by EXT-X-DATERANGE tag(s) with the same ID		one identified by EXT-X-DATERANGE tag(s) with the same ID
	attribute value and containing the same set of attributes / value		attribute value and containing the same set of attributes / value
	pairs.		pairs.
	In addition, for broadest compatibility, Variant Streams SHOULD		In addition, for broadest compatibility, Variant Streams SHOULD
	contain the same encoded audio bitstream. This allows clients to		contain the same encoded audio bitstream. This allows clients to
	skipping to change at page 45, line 15		skipping to change at page 44, line 15
	account; if it does not the client MAY assume the time to be local.		account; if it does not the client MAY assume the time to be local.
	Note that dates in Playlists can refer to when the content was		Note that dates in Playlists can refer to when the content was
	produced (or to other times), which have no relation to the time of		produced (or to other times), which have no relation to the time of
	playback.		playback.
	If the first EXT-X-PROGRAM-DATE-TIME tag in a Playlist appears after		If the first EXT-X-PROGRAM-DATE-TIME tag in a Playlist appears after
	one or more media segment URIs, the client SHOULD extrapolate		one or more media segment URIs, the client SHOULD extrapolate
	backward from that tag (using EXTINF durations and/or media		backward from that tag (using EXTINF durations and/or media
	timestamps) to associate dates with those segments. To associate a		timestamps) to associate dates with those segments. To associate a
	date with any other media segment that does not have an EXT-X		date with any other media segment that does not have an EXT-X -
	-PROGRAM-DATE-TIME tag applied to it directly , the client SHOULD		PROGRAM-DATE-TIME tag applied to it directly , the client SHOULD
	extrapolate forward from the last EXT-X-PROGRAM-DATE-TIME tag		extrapolate forward from the last EXT-X-PROGRAM-DATE-TIME tag
	appearing before that segment in the Playlist.		appearing before that segment in the Playlist.
	6.3.4. Reloading the Media Playlist file		6.3.4. Reloading the Media Playlist file
	The client MUST periodically reload a Media Playlist file to learn		The client MUST periodically reload a Media Playlist file to learn
	what media is currently available, unless it contains an EXT-X		what media is currently available, unless it contains an EXT-X -
	-PLAYLIST-TYPE tag with a value of VOD, or a value of EVENT and the		PLAYLIST-TYPE tag with a value of VOD, or a value of EVENT and the
	EXT-X-ENDLIST tag is also present.		EXT-X-ENDLIST tag is also present.
	However the client MUST NOT attempt to reload the Playlist file more		However the client MUST NOT attempt to reload the Playlist file more
	frequently than specified by this section, in order to limit the		frequently than specified by this section, in order to limit the
	collective load on the server.		collective load on the server.
	When a client loads a Playlist file for the first time or reloads a		When a client loads a Playlist file for the first time or reloads a
	Playlist file and finds that it has changed since the last time it		Playlist file and finds that it has changed since the last time it
	was loaded, the client MUST wait for at least the target duration		was loaded, the client MUST wait for at least the target duration
	before attempting to reload the Playlist file again, measured from		before attempting to reload the Playlist file again, measured from
	skipping to change at page 48, line 13		skipping to change at page 47, line 13
	contains:		contains:
	o The KEYFORMAT and KEYFORMATVERSIONS attributes of the EXT-X-KEY		o The KEYFORMAT and KEYFORMATVERSIONS attributes of the EXT-X-KEY
	tag.		tag.
	o The EXT-X-MAP tag.		o The EXT-X-MAP tag.
	A Media Playlist MUST indicate a EXT-X-VERSION of 6 or higher if it		A Media Playlist MUST indicate a EXT-X-VERSION of 6 or higher if it
	contains:		contains:
	o The EXT-X-MAP tag in a Media Playlist that does not contain		o The EXT-X-MAP tag in a Media Playlist that does not contain EXT-
	EXT-X-I-FRAMES-ONLY.		X-I-FRAMES-ONLY.
	A Master Playlist MUST indicate a EXT-X-VERSION of 7 or higher if it		A Master Playlist MUST indicate a EXT-X-VERSION of 7 or higher if it
	contains:		contains:
	o "SERVICE" values for the INSTREAM-ID attribute of the EXT-X-MEDIA		o "SERVICE" values for the INSTREAM-ID attribute of the EXT-X-MEDIA
	tag.		tag.
	The EXT-X-MEDIA tag and the AUDIO, VIDEO and SUBTITLES attributes of		The EXT-X-MEDIA tag and the AUDIO, VIDEO and SUBTITLES attributes of
	the EXT-X-STREAM-INF tag are backward compatible to protocol version		the EXT-X-STREAM-INF tag are backward compatible to protocol version
	1, but playback on older clients may not be desirable. A server MAY		1, but playback on older clients may not be desirable. A server MAY
	consider indicating a EXT-X-VERSION of 4 or higher in the Master		consider indicating a EXT-X-VERSION of 4 or higher in the Master
	Playlist but is not required to do so.		Playlist but is not required to do so.
	The PROGRAM-ID attribute of the EXT-X-STREAM-INF and the EXT-X-I		The PROGRAM-ID attribute of the EXT-X-STREAM-INF and the EXT-X-I -
	-FRAME-STREAM-INF tags was removed in protocol version 6.		FRAME-STREAM-INF tags was removed in protocol version 6.
	The EXT-X-ALLOW-CACHE tag was removed in protocol version 7.		The EXT-X-ALLOW-CACHE tag was removed in protocol version 7.
	8. Playlist Examples		8. Playlist Examples
	8.1. Simple Media Playlist		8.1. Simple Media Playlist
	#EXTM3U		#EXTM3U
	#EXT-X-TARGETDURATION:10		#EXT-X-TARGETDURATION:10
	#EXT-X-VERSION:3		#EXT-X-VERSION:3
	skipping to change at page 54, line 40		skipping to change at page 53, line 37
	Encryption keys are specified by URI. The delivery of these keys		Encryption keys are specified by URI. The delivery of these keys
	SHOULD be secured by a mechanism such as HTTP Over TLS [RFC2818]		SHOULD be secured by a mechanism such as HTTP Over TLS [RFC2818]
	(formerly SSL) in conjunction with a secure realm or a session token.		(formerly SSL) in conjunction with a secure realm or a session token.
	12. References		12. References
	12.1. Normative References		12.1. Normative References
	[AC_3] Advanced Television Systems Committee, "ATSC Standard:		[AC_3] Advanced Television Systems Committee, "ATSC Standard:
	A/52:2010: Digital Audio Compression (AC-3) (E-AC-3)		A/52:2010: Digital Audio Compression (AC-3) (E-AC-3)
	Standard", November 2010, <http://atsc.org/wp-content/		Standard", November 2010, <http://atsc.org/wp-
	uploads/2015/03/A52-201212-17.pdf>.		content/uploads/2015/03/A52-201212-17.pdf>.
	[AES_128] U.S. Department of Commerce/National Institute of
	Standards and Technology, "Advanced Encryption Standard
	(AES), FIPS PUB 197", November 2001, <http://csrc.nist
	.gov/publications/fips/fips197/fips-197.pdf>.
	[CEA608] Consumer Electronics Association, "CEA-608-E: Line 21 Data		[CEA608] Consumer Electronics Association, "CEA-608-E: Line 21 Data
	Services", April 2008, <http://www.ce.org/Standards/		Services", April 2008, <http://www.ce>.
	Standard-Listings/R4-3-Television-Data-Systems
	-Subcommittee/Line-21-Data-Service.aspx>.
	[CEA708] Consumer Electronics Association, "CEA-708-E (ANSI):		[CEA708] Consumer Electronics Association, "CEA-708-E (ANSI):
	Digital Television (DTV) Closed Captioning", August 2013,		Digital Television (DTV) Closed Captioning", August 2013,
	<http://www.ce.org/Standards/Standard-Listings/		<http://www.ce.org/Standards/Standard-Listings/
	R4-3-Television-Data-Systems-Subcommittee/CEA-708-D.aspx>.		R4-3-Television-Data-Systems-Subcommittee/CEA-708-D.aspx>.
	[COMMON_ENC]		[COMMON_ENC]
	International Organization for Standardization, "ISO/IEC		International Organization for Standardization, "ISO/IEC
	23001-7:2016; Information technology -- MPEG systems		23001-7:2016; Information technology -- MPEG systems
	technologies -- Part 7: Common encryption in ISO base		technologies -- Part 7: Common encryption in ISO base
	media file format files", February 2016, <http://www.iso		media file format files", February 2016, <http://www>.
	.org/iso/catalogue_detail.htm?csnumber=68042>.
	[HDCP] Digital Content Protection LLC, "High-bandwidth Digital
	Content Protection System - Mapping HDCP to HDMI",
	February 2013, <http://www.digital-cp.com/sites/default/
	files/specifications/
	HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf>.
	[H_264] International Telecommunications Union, "Advanced video		[H_264] International Telecommunications Union, "Advanced video
	coding for generic audiovisual services", January 2012,		coding for generic audiovisual services", January 2012,
	<http://www.itu.int/rec/T-REC-H.264>.		<http://www.itu.int/rec/T-REC-H.264>.
	[ISOBMFF] International Organization for Standardization, "ISO/IEC		[HDCP] Digital Content Protection LLC, "High-bandwidth Digital
	14496-12:2015; Information technology -- Coding of audio-		Content Protection System - Mapping HDCP to HDMI",
	visual objects -- Part 12: ISO base media file format",		February 2013, <http://www.digital-
	December 2015, <http://www.iso.org/iso/		cp.com/sites/default/files/specifications/
	catalogue_detail.htm?csnumber=68960>.		HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf>.
	[ISO_13818]		[ISO_13818]
	International Organization for Standardization, "ISO/IEC		International Organization for Standardization, "ISO/IEC
	International Standard 13818; Generic coding of moving		International Standard 13818; Generic coding of moving
	pictures and associated audio information", October 2007,		pictures and associated audio information", October 2007,
	<http://www.iso.org/iso/catalogue_detail?csnumber=44169>.		<http://www.iso.org/iso/catalogue_detail?csnumber=44169>.
	[ISO_13818_3]		[ISO_13818_3]
	International Organization for Standardization, "ISO/IEC		International Organization for Standardization, "ISO/IEC
	International Standard 13818-3:1998; Generic coding of		International Standard 13818-3:1998; Generic coding of
	moving pictures and associated audio information - Part 3:		moving pictures and associated audio information - Part 3:
	Audio", April 1998, <http://www.iso.org/iso/home/store/		Audio", April 1998,
	catalogue_tc/catalogue_detail.htm?csnumber=26797>.		<http://www.iso.org/iso/home/store/catalogue_tc/
			catalogue_detail.htm?csnumber=26797>.
	[ISO_13818_7]		[ISO_13818_7]
	International Organization for Standardization, "ISO/IEC		International Organization for Standardization, "ISO/IEC
	International Standard 13818-3:2006; Generic coding of		International Standard 13818-3:2006; Generic coding of
	moving pictures and associated audio information - Part 7:		moving pictures and associated audio information - Part 7:
	Advanced Audio Coding (AAC)", January 2006,		Advanced Audio Coding (AAC)", January 2006,
	<http://www.iso.org/iso/home/store/catalogue_tc/		<http://www.iso.org/iso/home/store/catalogue_tc/
	catalogue_detail.htm?csnumber=43345>.		catalogue_detail.htm?csnumber=43345>.
	[ISO_14496]		[ISO_14496]
	International Organization for Standardization, "ISO/IEC		International Organization for Standardization, "ISO/IEC
	14496-3:2009 Information technology -- Coding of audio-		14496-3:2009 Information technology -- Coding of audio-
	visual objects -- Part 3: Audio", 2009,		visual objects -- Part 3: Audio", 2009,
	<http://www.iso.org/iso/catalogue_detail?csnumber=53943>.		<http://www.iso.org/iso/catalogue_detail?csnumber=53943>.
	[ISO_8601]		[ISO_8601]
	International Organization for Standardization, "ISO/IEC		International Organization for Standardization, "ISO/IEC
	International Standard 8601:2004; Data elements and		International Standard 8601:2004; Data elements and
	interchange formats -- Information interchange --		interchange formats -- Information interchange
	Representation of dates and times", December 2004,		--Representation of dates and times", December 2004,
	<http://www.iso.org/iso/catalogue_detail?csnumber=40874>.		<http://www.iso.org/iso/catalogue_detail?csnumber=40874>.
			[ISOBMFF] International Organization for Standardization, "ISO/IEC
			14496-12:2015; Information technology -- Coding of audio-
			visual objects -- Part 12: ISO base media file format",
			December 2015, <http://www.iso.org/iso/
			catalogue_detail.htm?csnumber=68960>.
	[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail		[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
	Extensions (MIME) Part Two: Media Types", RFC 2046,		Extensions (MIME) Part Two: Media Types", RFC 2046,
	November 1996.		DOI 10.17487/RFC2046, November 1996,
			<http://www.rfc-editor.org/info/rfc2046>.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.		Requirement Levels", BCP 14, RFC 2119,
			DOI 10.17487/RFC2119, March 1997,
			<http://www.rfc-editor.org/info/rfc2119>.
	[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.		[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
			DOI 10.17487/RFC2818, May 2000,
			<http://www.rfc-editor.org/info/rfc2818>.
	[RFC2964] Moore, K. and N. Freed, "Use of HTTP State Management",		[RFC2964] Moore, K. and N. Freed, "Use of HTTP State Management",
	BCP 44, RFC 2964, October 2000.		BCP 44, RFC 2964, DOI 10.17487/RFC2964, October 2000,
			<http://www.rfc-editor.org/info/rfc2964>.
	[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO		[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
	10646", STD 63, RFC 3629, November 2003.		10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
			2003, <http://www.rfc-editor.org/info/rfc3629>.
	[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66, RFC		Resource Identifier (URI): Generic Syntax", STD 66,
	3986, January 2005.		RFC 3986, DOI 10.17487/RFC3986, January 2005,
			<http://www.rfc-editor.org/info/rfc3986>.
	[RFC5646] Phillips, A. and M. Davis, "Tags for Identifying		[RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
	Languages", BCP 47, RFC 5646, September 2009.		Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
			September 2009, <http://www.rfc-editor.org/info/rfc5646>.
	[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,		[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
	RFC 5652, September 2009.		RFC 5652, DOI 10.17487/RFC5652, September 2009,
			<http://www.rfc-editor.org/info/rfc5652>.
	[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,		[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,
	April 2011.		DOI 10.17487/RFC6265, April 2011,
			<http://www.rfc-editor.org/info/rfc6265>.
	[RFC6381] Gellens, R., Singer, D., and P. Frojdh, "The 'Codecs' and		[RFC6381] Gellens, R., Singer, D., and P. Frojdh, "The 'Codecs' and
	'Profiles' Parameters for "Bucket" Media Types", RFC 6381,		'Profiles' Parameters for "Bucket" Media Types", RFC 6381,
	August 2011.		DOI 10.17487/RFC6381, August 2011,
			<http://www.rfc-editor.org/info/rfc6381>.
	[RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data		[RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
	Interchange Format", RFC 7159, March 2014.		Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
			2014, <http://www.rfc-editor.org/info/rfc7159>.
	[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer		[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
	Protocol (HTTP/1.1): Message Syntax and Routing", RFC		Protocol (HTTP/1.1): Message Syntax and Routing",
	7230, DOI 10.17487/RFC7230, June 2014,		RFC 7230, DOI 10.17487/RFC7230, June 2014,
	<http://www.rfc-editor.org/info/rfc7230>.		<http://www.rfc-editor.org/info/rfc7230>.
	[SCTE35] Society of Cable Telecommunications Engineers, "SCTE-35		[SCTE35] Society of Cable Telecommunications Engineers, "SCTE-35
	(ANSI/SCTE): Digital Program Insertion Cueing Message for		(ANSI/SCTE): Digital Program Insertion Cueing Message for
	Cable", August 2014, <http://www.scte.org/documents/pdf/		Cable", August 2014,
	Standards/ANSI_SCTE%2035%202014.pdf>.		<http://www.scte.org/documents/pdf/Standards/
			ANSI_SCTE%2035%202014.pdf>.
	[US_ASCII]		[US_ASCII]
	American National Standards Institute, "ANSI X3.4-1986,		American National Standards Institute, "ANSI X3.4-1986,
	Information Systems -- Coded Character Sets 7-Bit American		Information Systems -- Coded Character Sets 7-Bit American
	National Standard Code for Information Interchange (7-Bit		National Standard Code for Information Interchange (7-Bit
	ASCII)", December 1986.		ASCII)", December 1986.
	[WebVTT] World Wide Web Consortium (W3C), "WebVTT: The Web Video
	Text Tracks Format", July 2013,
	<http://dev.w3.org/html5/webvtt/>.
	12.2. Informative References		12.2. Informative References
	[CMAF] International Organization for Standardization, "ISO/IEC		[CMAF] International Organization for Standardization, "ISO/IEC
	23000-19; Information technology -- Multimedia application		23000-19; Information technology -- Multimedia application
	format (MPEG-A) -- Part 5: Common media application format		format (MPEG-A) -- Part 5: Common media application format
	(CMAF) for segmented media", <https://www.iso.org/		(CMAF) for segmented media", <https://www.iso.org/
	standard/71975.html/>.		standard/71975.html/>.
	[ID3] ID3.org, "The ID3 audio file data tagging format",
	<http://www.id3.org/Developer_Information>.
	[M3U] Nullsoft, Inc., "The M3U Playlist format, originally
	invented for the Winamp media player",
	<http://wikipedia.org/wiki/M3U>.
	[SampleEnc]		[SampleEnc]
	Apple Inc., "MPEG-2 Stream Encryption Format for HTTP Live		Apple Inc., "MPEG-2 Stream Encryption Format for HTTP Live
	Streaming", <https://developer.apple.com/library/ios/		Streaming",
	documentation/AudioVideo/Conceptual/		<https://developer.apple.com/library/ios/documentation/
	HLS_Sample_Encryption/>.		AudioVideo/Conceptual/HLS_Sample_Encryption/>.
	[UTI] Apple Inc., "Uniform Type Identifier",		[UTI] Apple Inc., "Uniform Type Identifier", <http://developer.a
	<http://developer.apple.com/library/ios/#documentation/		pple.com/library/ios/#documentation/general/conceptual/
	general/conceptual/DevPedia-CocoaCore/		DevPedia-CocoaCore/UniformTypeIdentifier.html>.
	UniformTypeIdentifier.html>.
	Authors' Addresses		Authors' Addresses
	Roger Pantos (editor)		Roger Pantos (editor)
	Apple Inc.		Apple Inc.
	Cupertino, California		Cupertino, California
	United States		United States
	Email: http-live-streaming-review@group.apple.com		Email: http-live-streaming-review@group.apple.com
End of changes. 52 change blocks.
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