Commit bc09d8cc changed gstmpdparser to put the entire
<ContentProtection> element in the "value" field, so that DRMs
other than PlayReady could make use of the data inside this
element.
However, the data in the "value" field does not include any
XML namespace declarations that are used within the element. This
causes problems for a namespace aware XML parser that wants to
make use of this data.
This commit modifies the way the XML is converted to a string
so that XML namespaces are preserved in the output.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2487>
Some manifests use the ContentProtection node to store additional information
such as the license server url. Our MPD parser used to process the
ContentProtection node, extracting Playready PSSH boxes. However for other DRM
systems, only the `value` attribute was passed down to the protection event, so
for example, Widevine data was not parsed at all and "Widevine" was passed to
the event, which is not very useful for decryptors that require a PSSH init
data.
Parsing should now be done by decryptors which will receive the entire
ContentProtection XML node as a string. This gives more "freedom" to the
decryptor which can then detect and parse custom nodes as well.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2400>
Add static or dynamic mpd with:
- baseURL
- period
- adaptation_set
- representaton
- SegmentList
- SegmentURL
- SegmentTemplate
Support multiple audio and video streams.
Pass conformance test with DashIF.org
The start of each segment is relative to the Period start, minus
the presentation time offset.
As specified in section 5.3.9.6 of the MPEG DASH specification:
The value of the @t attribute minus the value of the
@presentationTimeOffset specifies the MPD start time of
the first Segment in the series.
Several tests use a Period@start value of 10 seconds, which either
needs to be taken into account when calculating expected timestamps
or have that attribute removed.
This commit uses a mix of updating the timestamps and removing the
start attribute, so that both the case of its presence and absence
is tested.
The start of each segment is relative to the Period start, minus
the presentation time offset.
As specified in section 5.3.9.6 of the MPEG DASH specification:
The value of the @t attribute minus the value of the
@presentationTimeOffset specifies the MPD start time of
the first Segment in the series.
dashdemux was not taking account of presentationTimeOffset and in
some methods was not taking into account the Period start time.
This commit modifies the segment->start value to always be
relative to the MPD start time (zero for VOD,
availabilityStartTime for live streams). This makes all uses of
the segment list consistent.
Fixes#841
Section 5.3.3 in ISO/IEC 23009-1:2014 defines that invalid references
(e.g., invalide URI or cannot be resolved) specified by "@xlink:href" attribute
shall be removed. That means, we should play it without error,
and just ignore the corresponding element.
It's similar to "urn:mpeg:dash:resolve-to-zero:2013".
https://bugzilla.gnome.org/show_bug.cgi?id=774463
External xml could have empty, one or multiple top-level "Period" elements.
Because xml parser cannot parse the multiple top-level elements
(i.e., no root element), we need to wrap a xml in order to make root element.
See also ISO/IEC 23009-1:2014 5.3.2.2
https://bugzilla.gnome.org/show_bug.cgi?id=774357
Add a test of the gst_mpd_client_get_maximum_segment_duration() function
to check that it first checks the MPD@maxSegmentDuration and then falls
back to checking all of the segment durations.
https://bugzilla.gnome.org/show_bug.cgi?id=753751
The function actually returns the segment availability start time (as defined by the standard).
That is at the end of the segment, but it is called availability start time.
Availability end time is something else (the time when the segment is no longer
available on the server). The function name was misleading.
https://bugzilla.gnome.org/show_bug.cgi?id=757655
gst_mpdparser_parse_utctiming_node does not validate the parsed values completely. The following scenarios are incorrectly accepted:
- elements with no schemeIdUri property should be rejected
- elements with unrecognized UTCTiming scheme should be rejected
- elements with empty values should be rejected
The last one triggers a division by 0 in gst_dash_demux_poll_clock_drift:
clock_drift->selected_url = clock_drift->selected_url % g_strv_length (urls);
because it urls is a valid pointer to an empty array.
https://bugzilla.gnome.org/show_bug.cgi?id=759547
The standard does not seem to make any particular explicit not
implicit reference to the signedness of durations, and the code
does not rely on such, nor on the negativity of the -1 value
that's used as a placeholder when a duration property is not
present in the XML.
https://bugzilla.gnome.org/show_bug.cgi?id=750847
According to the standard:
"SegmentBase, SegmentTemplate and SegmentList shall inherit
attributes and elements from the same element on a higher level.
If the same attribute or element is present on both levels,
the one on the lower level shall take precedence over the one
on the higher level."
gst_mpdparser_parse_segment_list_node will now discard any inherited
segment URLs if the parsed element defines some too.
https://bugzilla.gnome.org/show_bug.cgi?id=751832
If MPD@suggestedPresentationDelay is not present in the manifest,
dashdemux selects the fragment closest to the most recently generated
fragment. This causes a playback issue because this choice does not allow
the DASH client to build up any buffer of downloaded fragments without
pausing playback. This is because by definition new fragments appear on
the server in real-time (e.g. if segment duration is 4 seconds, a new
fragment will appear on the server every 4 seconds). If the starting
playback position was n*segmentDuration seconds behind "now", the DASH
client could download up to 'n' fragments faster than realtime before it
reached the point where it needed to wait for fragments to appear on the
server.
The MPD@suggestedPresentationDelay attribute allows a content publisher
to provide a suggested starting position that is behind the current
"live" position.
If the MPD@suggestedPresentationDelay attribute is not present, provide
a suitable default value as a property of the dashdemux element. To
allow the default presentation delay to be specified either using
fragments or seconds, the property is a string that contains a number
and a unit (e.g. "10 seconds", "4 fragments", "2500ms").
Corrected the parsing of a segment template string.
Added unit tests to test the segment template parsing.
All reported problems are now correctly handled.
https://bugzilla.gnome.org/show_bug.cgi?id=751735
When building the media segment list using a SegmentList node, the
gst_mpd_client_setup_representation function will iterate through the
list of S nodes and will expect to find a matching SegmentUrl node. If
one does not exist, the code made an illegal memory access.
https://bugzilla.gnome.org/show_bug.cgi?id=752496
