MMD OD Query Parameters

MMD OD includes URL query parameters that you can use to control various aspects of playback, such as playback format. Query parameters must be placed at the end of the URL, such as after the list of input files for a dynamic manifest URL.

You can use up to 2048 characters for query parameters.

Server and Client Manifests

The server manifest, which the MMD OD web server module uses, holds information about the available streams, options, and so forth. The webserver module uses the information in the server manifest file to (1) create the various client manifests and playlists and (2) apply any selected options. The webserver module gives the client manifest to the player for playback.

Throughout the remainder of this chapter, the MMD OD web server module will be referred to simply as “the webserver module.”

Timing Parameters

Name	Type / Format	Description / Example
start	Positive integer	Causes the webserver module to begin the client manifests at the given number of seconds from the start of the media. The webserver module will look for the closest segment boundary, so sometimes, the player may start just before the requested time. For a more precise start time, use `fragment_duration` in conjunction with start. Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?start=150` Be sure not to pass a start value that is greater than the actual video duration time.
end	Positive integer	Causes the webserver module to end client manifests at the given number of seconds from the start of the media. The webserver module will look for the closest segment boundary, so sometimes, the player may end just after the requested time. For a more precise end time, use `fragment_duration` in conjunction with end. Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?end=450`
t	Delimited list of positive integers	Causes the webserver module to start, and end-client manifests at the given number of seconds from the start of the media. The webserver module will look for the closest segment boundary, so sometimes, the player may start just before or end just after the requested time. For more precise start and end times, use `fragment_duration` in conjunction with t. Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?t=100;450` You can use any non-numeric character for a delimiter, such as a comma or a semicolon.
fragment_duration	Positive integer	When fragment_duration is provided, it causes the target duration of the generated segments to be as close to the specified `fragment_duration` as possible, depending on the source media’s keyframe frequency. Duration is designated in milliseconds and has the minimum and maximum values of: minimum - 2000 maximum - 10000 Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?fragment_duration=6000`

Supported and Unsupported Input Formats for Timing Parameters

Parameters	Supported Input Formats	Unsupported Input Formats
start, end, t	ism, smil, mp4, ismv	ismd, csmil, ismc, ts Note also that the end parameter is not supported for ism + HDS (Adobe HTTP Dynamic Streaming)
fragment_duration	ismd, csmil	ism, ismc, smil, ts, mp4, ismv

Ordering Parameters

Name	Type / Format	Description / Example
sort_tracks	String	Causes the order of the renditions in the client manifest to be determined by the value of the query parameter. If you don’t provide `sort_tracks` or if the value is invalid, the order of the renditions in the client manifest will be determined by the ordering of the server manifest. `sort_tracks=inc` - Renditions will be ordered from lowest bitrate to highest bitrate `sort_tracks=dec` - Renditions will be ordered from highest bitrate to lowest bitrate Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?` `sort_tracks=inc`
start_index	Positive integer, zero-based	Causes the rendition at the specified index to be moved to the top of the rendition list. The remaining renditions will be unaffected. If you provide `sort_tracks` in conjunction with `start_index`, the `start_index` priority will be applied after the renditions are ordered. The index is zero-based. Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?` `start_index=3`

Filter Parameters

Name	Type / Format	Description / Example
hls_no_audio_only	boolean	Causes the webserver module to exclude audio-only renditions from an HLS client manifest (m3u8). Example: `http://ics-server.com/path/to/content/manifest.m3u8?` `hls_no_audio_only=true`
max_bitrate	integer	Causes the webserver module to exclude from the client manifest any rendition with a system bitrate greater than the specified value. Example: `http://ics-server.com/path/to/content/manifest.mpd?` `max_bitrate=2000000`
min_bitrate	integer	Causes the webserver module to exclude from the client manifest any rendition with a system bitrate less than the specified value. Example: `http://ics-server.com/path/to/content/manifest.mpd?` `min_bitrate=96000`
tracks	comma-delimited strings	Allows the caller to filter the renditions in the client manifest by track name. Causes the webserver module to exclude from the client manifest any track name in the server manifest that does not match one of the supplied values. Example: `http://ics-server.com/path/to/content/manifest.mpd?` `tracks=video,audio`
filter	regular expression (regex)	Determines which tracks in the server manifest file will be added to the client manifest file. When the regex evaluates to true, the track is added to the client manifest file. The appropriate tags must be present in the manifest to filter against a field. Usage The filter expression is passed as a query parameter (`?filter=`) and must be properly escaped (preferably using a standard function from your favorite framework). When testing the URL with a command-line tool like cURL, you must consider the escaping rules for your command-line. For example, for cURL, the ’&’ needs to be escaped in the bash shell: `cURL -v 'http://ics-server/a319/test/usp/smil/` `multi_b.smil/manifest.m3u8?filter=(systemBitrate<1024000%26%26type=="video")'` Simply examining the client manifest file can be misleading; the expression filtered for may be present but absent in the server manifest. For example, this sample adds the `MaxWidth` parameter to a video track in the server manifest: `<video src='mp4:clock-low.mp4'` `systemBitrate='400000'` `title='360p' width='480' height='360'`> `<param name="MaxWidth" value="480"` `valueType="data" />` `</video>` See also: Track Variable Names for the filter Parameter Filter Parameter Samples

Track Variable Names for the `filter` Parameter

The following variables may be used in the filter parameter.

Variable Name	Type/Description	Example
AudioTag	number The format tag of the audio	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest?filter=(type==%22audio%22%26%26AudioTag==255)'`
avc_level	number The AVC level	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(type=="video"%26%26avc_level>=30)'`
avc_profile	constant The AVC profile: AVC_PROFILE_BASELINE, AVC_PROFILE_MAIN, AVC_PROFILE_HIGH	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest?filter=(type==%22video%22%26%26avc_` `profile==AVC\_PROFILE\_MAIN)'`
BitsPerSample	number The resolution of the audio samples	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest?filter=(type==%22audio%22%26%26BitsPerSample==16)'`
channels	number The number of audio channels	`curl 'http://mymmdod.llnds.net/component/ism/` `m2.ism/manifest.m3u8?filter=` `(type=="audio"%26%26channels==2)%7C%7C(type=="video")'`
DisplayHeight	number The display height (in pixels)	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest?filter=(type==%22video%22%26%26DisplayHeight==360)'`
DisplayWidth	number The display width (in pixels)	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(type=="audio"%7C%7CDisplayWidth>500)'`
FourCC	string The FourCC code of the track: AVC1, AACL, TTML, JPEG, dtse, ac-3, hvc1	`curl http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(FourCC=="AVC1")` `curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(FourCC=="AACL")'`
Maxheight	number The coded height (in pixels)	`curl'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8? <br />filter=(type=="video"%26%26Maxheight==480)'`
MaxWidth	number The coded width (in pixels)	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(type=="video"%26%26MaxWidth==480)'`
SamplingRate	number Audio sampling rate (in Hz)	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?` `filter=(type=="audio"%26%26SamplingRate==44100)'`
systemBitrate	number System bitrate in Kbps	`curl 'http://mymmdod.llnds.net/usp/smil/multi_b.smil/manifest.m3u8?filter=(systemBitrate<1024000%26%26type=="video")'`
systemLanguage	string 3-character language code	`curl http://mymmdod.llnds.net/usp/smil/` `multi_b.smil/manifest.m3u8?filter=(systemBitrate<1024000%26%26systemLanguge=="eng")`
TimeScale	number The timescale	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?` `filter=(TimeScale!=1000)'`
trackID	number Track ID	`curl "http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(trackID==2)"`
trackname	string Track name	`curl 'http://mymmdod.llnds.net/component/ism/m2.ism/` `manifest.m3u8?filter=(trackname=="audio")'`
type	string The type of the track: audio, video, textstream, data	`curl 'http://mymmdod.llnds.net/usp/smil/` `1video_2audio.smil/manifest.m3u8?filter=(type=="video")'` `curl 'http://mymmdod.llnds.net/usp/smil/` `1video_2audio.smil/`

`filter` Parameter Samples

The following examples explain which tracks from the server manifest file will be added to the client manifest file.

Filter Expression	Description
true	Adds all tracks.
type != “video” \| systemBitrate < 400000	Adds all tracks where the video tracks must be at least 400 Kbps.
systemLanguage == “eng”	Adds only audio/video/text tracks with the English language.
FourCC != “AVC1” \| AVC_PROFILE == AVC_PROFILE_BASELINE	Adds all tracks where the video tracks must use the `BASELINE` profile.
(FourCC == “AACL” && SamplingRate == 48000) \| (FourCC == “AVC1” && AVC_LEVEL >= 31)	Adds all AAC audio tracks with a `SamplingRate` of 48KHz and all AVC video tracks with a minimum of 3.1.

Other Parameters

Name	Type / Format	Description / Example
base_path	String	Absolute path (and protocol) to the HLS content on the customer origin. Causes the HLS client manifest to use the base_path parameter value as the absolute path to the HLS content on the customer origin. The protocol used for the initial request must match the protocol provided in the base_path value. For example, when base_path is provided, and HTTPS is the protocol used to access the client manifest, “HTTPS” should be the base_path protocol. Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?base_path=HTTP`
hls_client_manifest_version	Integer in the range 1 through 7	The optional output protocol version of the HLS client manifest (.m3u8) file. Defaults to 1, which specifies protocol version 1. Example: `http://mmd-od-server.com/path/to/content/manifest.mpd?hls_client_manifest=1` Two values to note are: `1`: Causes the client manifest rendition order to mirror the order in the server manifest. `7`: (default value): causes audio tracks always to be placed in the middle of the client manifest. For additional information, see this Apple Technical Q&A Website that explains the `EXT-X-VERSION` tag.