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Internet Engineering Task Force Audio-Video Transport WG
INTERNET-DRAFT A. Jones, A. Periyannan, D. Singer
draft-ietf-avt-qt-rtp-00 Apple Computer, Inc.
July 22, 1997
Expires: January 22, 1998
RTP Payload Format for QuickTime Media Streams
Status of This Memo
This document is an Internet-Draft. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas,
and its working groups. Note that other groups may also distribute
working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet- Drafts as reference
material or to cite them other than as ``work in progress.''
To learn the current status of any Internet-Draft, please check the
``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow
Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or
ftp.isi.edu (US West Coast).
Distribution of this document is unlimited.
Abstract
This document specifies the payload format for encapsulating
QuickTime media streams in the Realtime Transport Protocol (RTP).
This specification is intended for QuickTime media/codec types that
are not already handled by other RTP payload specifications. Each
QuickTime media track within a movie is sent over a separate RTP
session and synchronized using standard RTP techniques. A static
QuickTime payload type (if assigned) or a dynamic payload type may be
used. A QuickTime header within the RTP payload is defined to carry
the media type and other media specific information. A packetization
scheme is defined for the media data. This specification is intended
for streaming stored QuickTime movies as well as live QuickTime
content.
1 Introduction
This document specifies the payload format for encapsulating
A. Jones, A. Periyannan, D. Singer [Page 1]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
QuickTime media streams in the Realtime Transport Protocol (RTP) [1].
RTP is a generic protocol designed to carry realtime media data along
with synchronization information over a datagram protocol (mostly UDP
over IP). The protocol itself does not address the encapsulation of
specific media types, but instead leaves it to various profile
specifications. An accompanying RTP profile document [2] contains
various payload specifications to carry audio and video over RTP for
conferencing applications and specifies the static payload types for
various audio/video compression schemes. Other documents specify the
encapsulation format used to carry specific compression schemes such
as JPEG, MPEG and H.261 [3,4,5].
The QuickTime file format and architecture support an extensible set
of media types and compression schemes. Many of these are not covered
by the profile specifications available today. Hence, it is desirable
to have an RTP encapsulation scheme that will handle all QuickTime
media/codec types that are not covered by specific RTP payload types.
This specification proposes a scheme to carry QuickTime media/codec
types over RTP. The scheme specified here handles all loss-tolerant
media and a few loss-intolerant media such as text. Support for other
loss-intolerant media such as MIDI and 3D will be added in future.
This specification is intended for streaming stored QuickTime movies
as well as live QuickTime content.
2 QuickTime Overview
QuickTime consists of a software architecture for multimedia
authoring/playback and a movie file format to store multimedia
presentations. These two aspects of QuickTime are independent of each
other but are often combined when referring to QuickTime. It is
possible to playback/author movies in other file formats such as AVI,
AIFF, etc. using QuickTime software. Similarly it is possible to use
QuickTime files independent of the software, for example, streaming
movies over the Internet. The QuickTime movie file format is
specified in [6]. More information on the QuickTime software
architecture can be obtained from [7,8,9].
For the purpose of this document we will mostly be concerned with
streaming QuickTime content using RTP. "QuickTime content" refers to
content as specified in the QuickTime movie file format specification
[6]. This does not preclude live QuickTime content. We merely use the
file format specification as way to specify the format of the
content.
QuickTime movie files contain the media data and synchronization
information for the movie. A movie consists of multiple tracks, each
of which contains a specific media type such as video, sound, MIDI,
A. Jones, A. Periyannan, D. Singer [Page 2]
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text, etc. Not all media types are loss-tolerant. Table 2.1 lists the
common QuickTime media types and whether they are loss-tolerant. The
loss tolerant media can be carried over RTP/UDP in classic RTP-style.
This will not however work for loss-intolerant data. RTP over TCP or
using the Realtime Streaming Protocol (RTSP) [10] are some of the
options for loss-intolerant media data. Another option is to achieve
semi-reliability through redundant transmission. This specification
uses this latter option to handle QuickTime "text" media over RTP.
QuickTime Media TypeLoss Tolerant?
Sound Yes
Video Yes
Timecode No
Text No
Music (MIDI) No
MPEG Yes
Sprite No
Tween No
3D No
Table 2.1 QuickTime Media Types
QuickTime Timescales
QuickTime has a concept of timescales. A timescale defines the number
of units of time that pass in every second of real time. Any time
value has to be specified with respect to a timescale. A QuickTime
movie has a timescale associated with it. Each of the tracks (medias)
have a timescale associated with them. All of these timescales could
be different. The RTP timestamp will be based on the timescale of the
track associated with the RTP session. The timescale of a track never
changes during its lifetime.
QuickTime Sample Descriptions
Every QuickTime media type has a sample description format associated
with it. The sample description specifies how the sample is
interpreted. For example, the video media sample description
specifies the compression scheme, quality, bit depth and other such
information. The sample description may change during the life of a
track.
QuickTime Track Parameters
Every QuickTime track has a number of parameters associated with it
such as height, width, transformation matrix, etc. These are as
important to the presentation as the sample description.
A. Jones, A. Periyannan, D. Singer [Page 3]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
3 RTP Encapsulation Format
The encapsulation scheme described here requires that each QuickTime
media track within a single movie be sent over a separate RTP session
and be synchronized using standard RTP techniques.
The QuickTime information is carried as payload data within the RTP
protocol. There is a variable length QuickTime header immediately
following the RTP header. The media data is packetized and placed in
the RTP packet following the QuickTime header.
The RTP packet is formatted as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. RTP Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. QuickTime Header... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. QuickTime Media Data... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.1 RTP Header
The format and general usage of the RTP header fields are described
in [1].
The following fields of the RTP header will be used as specified
below:
- The payload type should specify the static QuickTime payload type
(if assigned) or one of the dynamic payload types. (The need for a
static payload type for QuickTime is up for discussion at the IETF
AVT working group.) If a dynamic payload type is used, it should be
agreed upon through some non-RTP means.
- The RTP timestamp is based on the timescale specified in the
QuickTime header. The timestamp encodes the sampling instant of the
first media sample contained in the RTP data packet. Multiple samples
may be contained in one RTP packet or a single sample may require
multiple RTP packets. The packetization rules are specified in a
subsequent section. If a media sample occupies more than one packet,
the timestamp will be the same on all of those packets. Packets
A. Jones, A. Periyannan, D. Singer [Page 4]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
containing different samples must have different timestamps so that
samples may be distinguished by the timestamp. The initial value of
the timestamp is random (unpredictable) to make known-plaintext
attacks on encryption more difficult, see RTP [1].
- The marker bit (M-bit) of the RTP header is set to one in the last
packet of a sample and otherwise, must be zero. If one or more
samples are fully contained within an RTP packet the M-bit must be
set to one. Thus, it is possible to easily detect that a complete
sample has been received and can be decoded and presented.
3.2 QuickTime Header
The QuickTime Header is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| VER |Q|P|S| RES | QuickTime Payload ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. QuickTime Payload Description ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields in the QuickTime Header have the following meanings:
VER: 4 bits
A version field that must be set to zero by transmitters implementing
this specification.
Q bit: 1 bit
The Q-bit is set to one if there is a payload description as part of
this QuickTime header. Otherwise it is set to zero.
P bit: 1 bit
The P-bit is set to one if there are multiple samples which are of
different sizes or durations carried in the payload. Otherwise it is
set to zero. When the P-bit is set, two or more samples are placed
in the QuickTime media data portion of the RTP packet along with
individual timestamp and length information. The format for this
packing is explained in a subsequent section. When the P-bit is not
set, one or more samples or a partial sample is placed directly in
the QuickTime media data portion of the RTP packet.
S bit: 1 bit
The S-bit is set to one if this packet contains data from a sync
A. Jones, A. Periyannan, D. Singer [Page 5]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
sample, i.e. key sample. Otherwise it is set to zero. When the packet
contains more than one sample the S-bit is set to one if the first
sample is a sync sample.
RES: 8 bits
Reserved for future use. Transmitter must set these bits to zero.
Receivers must ignore these bits.
QuickTime Payload ID: 16 bits
A payload identifier that identifies the format of the QuickTime
media data carried in this RTP session. The payload ID associates the
QuickTime payload description (that is transmitted periodically) with
the QuickTime media data. This identifier is changed every time the
payload format changes. Payload IDs are explained further in a
subsequent section.
QuickTime Payload Description: variable length
This field is present only if the Q-bit is set to one. It contains
the QuickTime payload format description such as media type,
timescale, sample size, compression information, etc. The header must
be padded to a 32-bit boundary.
The QuickTime Payload Description is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|C| RES | QuickTime Payload Desc Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QuickTime Media Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timescale |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. QuickTime TLVs ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields in the QuickTime Payload Description have the following
meanings:
A bit: 1 bit
The A-bit is set to one if all samples are sync (key) samples for
this payload description. Otherwise it is set to zero.
RES: 7 bits
Reserved for future use. Transmitter must set these bits to zero.
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Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
Receivers must ignore these bits.
QuickTime Payload Description Length: 16 bits
Number of bytes in the QuickTime payload description (not including
padding of 0 to 3 bytes). The QuickTime Media Data starts at the RTP
data offset plus the QuickTime fixed header of 4 bytes plus the
payload description length plus padding (of 0 to 3 bytes).
QuickTime Media Type: 32 bits
A 4 character media type that identifies the QuickTime media [6],
example: 'vide' for video, 'soun' for sound, etc.
Timescale: 32 bits
The number of units of time that pass in 1 second of real time for
this QuickTime payload ID. This is the timescale used by the RTP
timestamp for this session.
QuickTime TLVs: variable length
One or more QuickTime parameters that describes this payload. The
parameters are expressed as a Type-Length-Value triplet. The TLVs are
not padded and can begin at any byte boundary.
A QuickTime TLV is formatted as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QuickTime TLV Length | QuickTime TLV Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. QuickTime TLV Value ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields in a QuickTime TLV have the following meanings:
QuickTime TLV Length: 16 bits
Number of bytes in the QuickTime TLV. The next QuickTime TLV starts
at the offset of the current TLV plus the current TLV length.
QuickTime TLV Type: 16 bits
A 2 character TLV type that identifies the QuickTime parameter.
QuickTime TLV Value: variable length
The value of the TLV as specified by the type. Values must be sent in
network byte-order (i.e. big-endian format).
Note: Section 3.3 lists the set of currently defined TLVs. Some TLVs
A. Jones, A. Periyannan, D. Singer [Page 7]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
are mandatory and must be present if the QuickTime Payload
Description is being sent. Other TLVs will assume their default
values if they are not sent. Any TLV not recognized by a receiver
must be ignored and skipped over.
3.3 QuickTime TLVs
Sample Description (mandatory)
Type: 'sd'
Length: variable length
Media-specific QuickTime sample description. The format for this TLV
for each of the currently defined media types can be found in [6]
(starting pg. 59).
Default: none
QuickTime Atom
Type: 'qt'
Length: variable
Default: none
This TLV is used to transparently send a QuickTime Atom as defined in
[6] (pg. 3). For example, this can be used to send User Data Atoms,
Track Reference Atoms, Track Input Map Atoms, etc. The QuickTime
atoms sent depends on the media type associated with the QuickTime
payload description.
Track ID
Type: 'ti'
Length: 8
Default: 0
Track ID as defined in [6] (pg. 18).
Layer
Type: 'ly'
Length: 6
Default: 0
Layer as defined in [6] (pg. 18).
Volume
Type: 'vo'
Length: 6
Default: 255
Volume as defined in [6] (pg. 18).
Matrix
Type: 'mx'
Length: 40
Default: identity matrix
A. Jones, A. Periyannan, D. Singer [Page 8]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
Matrix as defined in [6] (pg. 18 and 77).
Translation Matrix
Type: 'tr'
Length: 8
Default: identity matrix
h, v -- two 16-bit signed numbers indicating translation values (in
pixels).This TLV is sent instead of the Matrix TLV when only
translation is required.
Track Width
Type: 'tw'
Length: 8
Default: 0
Track Width as defined in [6] (pg. 19).
Track Height
Type: 'th'
Length: 8
Default: 0
Track Height as defined in [6] (pg. 19)
Language
Type: 'la'
Length: 6
Default: 0
Language as defined in [6] (pg. 32 and 75).
3.4 Media Data Packetization
The RTP packetization for QuickTime is designed to take into account
the needs of a varied set of media types and compression schemes.
Hence, 3 different packetization schemes are defined.
The following pieces of information are required at the transmission
end to make packetization decisions:
- Maximum QuickTime Media Data size (MQD) that can be accommodated
in a single RTP packet.
- Whether all samples for this media type are of constant size? (CQS)
- Whether all samples for this media type are of constant duration?
(CQD)
- Sample size of all samples (when they are constant) (CSS).
- Sample size of a specific sample (SS).
Based on the above pieces of information, one of the following
packetization schemes is adopted:
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Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
Scheme I : (CQS=true) AND (CQD=true) AND (CSS <= 0.5*MQD)
Multiple samples are packed into one RTP packet. The RTP header M-bit
is set to one on all packets. The QuickTime header P-bit is set to
zero on all packets.
Scheme II: ( (CQS=false) OR (CQD=false) ) AND (SS <= 0.5*MQD)
Multiple samples are packed into the QuickTime Media Data portion of
an RTP packet. The RTP header M-bit is set to one in this packet. The
QuickTime header P-bit is set to one.
The samples are packed using the format illustrated below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sample Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sample Timestamp |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. Sample Data ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sample Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sample Timestamp |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. Sample Data ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. ...... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields in the QuickTime Media Data have the following meanings:
Sample Length: 32 bits
Number of bytes in the sample data (not including the length field,
timestamp field and padding).
Sample Timestamp: 32 bits
This field contains the timestamp for this sample in the timescale
associated with this QuickTime payload ID. The first timestamp must
be the same as the timestamp in the RTP header.
Sample Data: variable length
This field contains the sample data. The data must be padded to a
A. Jones, A. Periyannan, D. Singer [Page 10]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
32-bit boundary.
All receivers are required to handle this scheme. A transmitter may
choose to not implement this scheme in which case it will default to
scheme III.
Note: This scheme leads to more efficient packing than scheme III for
certain media/codec types. However, there is a trade-off between
efficiency and losing multiple samples when a packet is lost.
Scheme III: Cases not covered by schemes I and II
A single sample is placed in one or more RTP packets. The RTP header
M-bit is set to one in the last packet and is otherwise set to zero.
The QuickTime header P-bit is set to zero in every packet.
The packetization boundaries may be chosen intelligently to respect
the compression/decompression algorithm requirements. However, this
is not a requirement. When intelligent boundaries are not chosen, a
single packet loss will lead to the entire sample being lost in the
case of multi-packet samples.
3.5 Payload Information
Payload ID
The QuickTime payload ID identifies the format of the QuickTime media
data carried in an RTP session. It associates the QuickTime payload
description (that is transmitted periodically) with the QuickTime
media data. This identifier is an arbitrary 16-bit number that is
changed every time the payload format changes. When streaming
QuickTime movie tracks, the payload format changes usually when the
sample description changes during the life of the track.
The following restrictions apply when picking payload IDs,
- The payload ID must be unique among all QuickTime RTP sessions
originating from a given source canonical name. This is to ensure
efficient mapping of payload IDs to payload descriptions using a
single receiver-side table per canonical name.
- A payload ID must not be reused for a different payload description
during the lifetime of the session. This allows receivers to cache
the payload descriptions for the duration of the session.
Payload Description
The QuickTime payload descriptions are transmitted as part of the
A. Jones, A. Periyannan, D. Singer [Page 11]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
QuickTime header. The payload descriptions specify the format of the
QuickTime media data. The information for the specific fields in a
payload description can be found in [6]. These fields do not include
all of the information associated with a QuickTime track. For
example, information on transformation matrices, layers, etc. is not
included. This information needs to be communicated through non-RTP
means.
Payload Description Transmission
The payload description must be transmitted in the first RTP packet
which contains media samples that require the payload description.
After the first packet, the payload description must be retransmitted
at a periodic interval until the format of the media samples changes.
The maximum retransmission interval should be 1 second, unless
packets are being transmitted at less than 1 packet/second in which
case the payload description must be transmitted with each packet.
The retransmission interval may be negotiated to an arbitrary value
through non-RTP means. Note: This includes the case in which the
payload descriptions are never sent over RTP, i.e. a retransmission
interval of infinity. In this case the payload descriptions are
communicated through some non-RTP means.
A transmitter may send an RTP packet that contains only a payload
description and no QuickTime media data. This payload description
must be cached by the receiver and used to interpret data that may
arrive in the future.
3.6 Loss-intolerant Media Types
Loss-intolerant media types can not be easily handled within the
standard RTP framework. Hence, we may need to use some non-RTP
techniques to transmit these media types. However, some of the media
types, notably Text and Tween media can be sent over RTP by the use
of redundant transmissions. (Tween media is used to alter the
characteristics of other media streams. For example, Tween samples
may contain a series of values that change the volume of an audio
stream.) The use of this technique is experimental.
Redundant Transmissions
The redundant transmission technique is one in which the RTP packet
is retransmitted multiple times within the duration of the sample.
The RTP packet is resent as a whole with the same RTP sequence
number, timestamp and other information, i.e. it is an identical
packet when seen on the wire. This technique is not bandwidth
friendly when used with high bandwidth media types. Hence it will be
A. Jones, A. Periyannan, D. Singer [Page 12]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
used only with the low bandwidth media types such as "text" and
"tween" media.
The rationale for using the same RTP sequence numbers in the
retransmitted packets is as follows: If the sequence numbers were
incremented for each of the retransmitted packets we would require an
additional field to identify the duplicate samples. In the proposed
scheme, the receiver can discard duplicates by simply keeping track
of the sequence numbers of the packets received.
The interval between retransmissions depends on the media type and
the current congestion situation in the network. This interval can be
a simple fixed interval, say 4 retransmissions equally spaced within
the duration of the sample, or it could be more complex, say
exponentially increasing intervals within the duration of the sample.
This specification does not currently recommend a preferred scheme to
use for determining the retransmission interval.
4 Open Issues
The following open issues need to be resolved:
- How to handle loss-intolerant media with "key" and "update"
samples?
Loss-intolerant media samples can be retransmitted multiple times
with fixed or variable intervals between transmission. The samples
can be classified as key samples and update samples and handled
appropriately. Update samples need not be periodically retransmitted.
For example, in sprite media, key samples will contain the sprite
image and update samples will contain the motion vectors. Whereas, in
text media, all samples will be key samples.
- What is the appropriate interval between redundant
transmissions for "text" and "tween" media samples?
- Should there be sample size TLV (that specifies bits per
sample)?
Acknowledgments
The authors would like to thank Joe Pallas (of Apple ATG) and all the
members of the QuickTime Streaming team, Jay Geagan, Andy Grignon,
Sylvain Rouze and Kevin Gong for their valuable input in writing this
proposal.
A. Jones, A. Periyannan, D. Singer [Page 13]
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References
[1] H. Schulzrinne, et. al., "RTP : A Transport Protocol for Real-
Time Applications", IETF RFC 1889, January 1996.
[2] H. Schulzrinne, et. al., "RTP Profile for Audio and Video
Conference with Minimal Control", IETF RFC 1890, January 1996.
[3] L. Berc, et. al., "RTP Payload Format for JPEG-compressed Video",
IETF RFC 2035, October 1996.
[4] D. Hoffman, et. al., "RTP Payload Format for MPEG1/MPEG2 Video",
IETF RFC 2038, October 1996.
[5] T. Turletti, C. Huitema, "RTP Payload Format for H.261 Video
Streams", IETF RFC 2032, October 1996.
[6] Apple Computer, Inc., "QuickTime File Format Specification", May
1996.
[7] Apple Computer, Inc., "Inside Macintosh: QuickTime", Addison
Wesley Press.
[8] Apple Computer, Inc., "Inside Macintosh: QuickTime Components",
Addison Wesley Press.
[9] Apple Computer, Inc., "QuickTime 2.5 Developer Guide", Developer
Press.
[10] H. Schulzrinne, et. al., "Real Time Streaming Protocol", IETF
Draft ietf-mmusic-rtsp-02.txt, March 24 1994, Expires: August 20
1997.
Authors' Contact Information
Alagu Periyannan
Email: alagu@apple.com
Tel: (408) 862 5387
Fax: (408) 974 0234
Anne Jones
Email: astoria@apple.com
Tel: (408) 862 1170
David Singer
Email: singer@apple.com
Tel: (408) 974 3162
A. Jones, A. Periyannan, D. Singer [Page 14]
Internet Draft draft-ietf-avt-qt-rtp-00 July 22 1997
Apple Computer, Inc.
One Infinite Loop, MS:302-3MT
Cupertino CA 95014
USA
A. Jones, A. Periyannan, D. Singer [Page 15]