Content for TS 26.247 Word version: 18.4.0

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K.1 Introduction K.2 Calculation
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K (Normative) ITU-T P.1203 audio/video MOS estimation |R14| p. 131

K.1 Introduction p. 131

ITU-T P.1203 [49] defines an objective assessment model for Progressive Download and DASH streaming. This model predicts audio only, video only and audio-video MOS on a 5-point Absolute Category Rating scale (see ITU-T P.910 [50]) for monitoring of quality for operation and maintenance purposes. The model can execute in several modes, where Mode 0 is suitable for large-scale network supervision. For more details on this model, please refer to ITU-T P.1203 [49].

K.2 Calculation p. 131

The PSS server should support MOS estimation according to ITU-T P.1203 [49] Mode 0. To enable the MOS estimation, the QoE reporting should include the following metrics in either MPD@metrics or OMA DM QoE Management Object 'metrics':

Initial Playout Delay (clause 10.2.5)
Play List (clause 10.2.7)
MPD Information, unless already available by other means (clause 10.2.8)
Device Information (clause 10.2.10)

The attribute MPD.Metrics.Range@duration or the OMA DM QoE Management Object 'duration' shall be set to a value between 1 and 5 minutes.

The value of MPD.Metrics.Reporting@reportinginterval or OMA DM QoE Management Object 'Interval' shall be larger or equal than the value of MPD.Metrics.Range@duration or OMA DM QoE Management Object 'duration'.

The DASH client reports collected metrics using quality metric reporting protocol defined in clause 10.6.

The mapping between QoE metrics and input to ITU-T P.1203 [49] Mode 0 is provided in Table K-1 to Table K-4 below.

Table K-1: Mapping between QoE metrics and input in ITU-T P.1203 mode 0 model for video stream

Video Metrics needed for ITU-T P.1203 [49] model		QoE metrics defined in clause 10.2		Remark
Description	Value	Metric	Description	Remark
Target Video bit rate	Bit rate in kbps.	Mpdinfo	Provides the MPD information for the representation or subrepresentation identified by representationid and subreplevel, if present. Related attributes: @bandwidth, @width, @height, and @codecs. NOTE: codec attribute includes video codec profile information and video frame rate information.	Target Video bit rate has been supported by @bandwidth attribute. Video frame rate and Video codec and profile have been supported by @ codec attribute. Video encoding resolution has been supported by @width and @height attributes.
Video frame rate	Frame rate in frames per second.
Segment duration	Duration in seconds
Video encoding resolution	Number of pixels (W×H) in transmitted video
Video codec and profile	One of: H264-baseline, H264-high, H264-main
Video codec and profile	One of: H264-baseline, H264-high, H264-main	Playlist	Provides information on when and how long different representations or subrepresentations have been used during the session.	Note that the actual timing of the required input for the P.1203 quality model may be influenced by actions such as play/pause.

Table K-2: Mapping between QoE metrics and input in ITU-T P.1203 mode 0 model for audio stream

Audio Metrics needed for ITU-T P.1203 [49] model		QoE metrics defined in clause 10.2		Remark
Description	Value	Metric	Description	Remark
Target Audio bit rate	Bit rate in kbps.	Mpdinfo	Provides the MPD information for the representation or subrepresentation identified by representationid and subreplevel, if present. Related attributes: @bandwidth, and @codecs. NOTE: codec attribute includes audio codec profile information, audio sampling frequency and Number of audio channels information.	Target Audio bit rate has been supported by @bandwidth attribute. Audio codec, Audio sampling frequency and Number of audio channels have been supported by @ codecs attribute.
Segment duration	Duration in seconds
Audio codec	One of: AAC-LC, AAC-HEv1, AAC-HEv2, AC3
Audio sampling frequency	In Hz
Number of audio channels	2
Number of audio channels	2	Playlist	Provides information on when and how long different representations or subrepresentations have been used during the session.	Note that the actual timing of the required input for the P.1203 quality model may be influenced by actions such as play/pause.

Table K-3: Mapping between QoE metrics and input in ITU-T P.1203 mode 0 model for stalling

Metrics needed for ITU-T P.1203 [49] model		QoE metrics defined in clause 10.2		Remark
Description	Value	Metric	Description	Remark
Buffering event start	The start time of the buffering/stalling event in seconds relative to the start of the original video clip, expressed in media time (not wall clock time) NOTE: This is 0 for initial buffering.	Playlist	The start time of a buffering/stalling event is equal to the end time of a trace entry with the stop reason equal to "rebuffering".	-
Event duration	The duration of the buffering/stalling event in seconds.	Playlist	The duration of each buffer event is calculated from the PlayList according to the example described in the Playlist metric clause.	-

Table K-4: Mapping between QoE metrics and input in ITU-T P.1203 mode 0 model for device information

Metrics needed for ITU-T P.1203 [49] model		QoE metrics defined in clause 10.2		Remark
Description	Value	Metric	Description	Remark
The resolution of the image displayed to the user	Number of pixels (W×H) in displayed video	Device Information	videoWidth and videoHeight	.
The device type on which the media is played	PC or mobile	Device Information	screenWidth × pixelWidth, screenHeight × pixelHeight	P.1203 formally classifies devices up to 10" (diagonal) as mobiles, but to cover most handheld devices (phones and tablets) devices up to 12" could be classified as mobiles.
The size of the video shown	W×H in mm	Device Information	videoWidth × pixelWidth, videoHeight × pixelHeight