Various audio formats require an audio lead-in to decode it properly.
Most parsers would take care of it, but when a container like matroska is
involved, the demuxer handles the seeking and without its own lead-in
handling would never even pass the lead-in data to the parser.
This commit provides an initial implementation of that for audio/mpeg,
audio/x-ac3 and audio/x-eac3 by calculating the worst case lead-in time
needed from known samplerate, potential lead-in frames need and the
maximum blocksize possible for the format (as we don't parse that out
exactly in matroskademux) and seeking that much earlier in case of
accurate seeks. This is especially important for NLE use-cases with GES.
If accurate seeking to a position that happens to have a video keyframe,
it'll go back to the previous keyframe than needed, but with typical
video files that's the best we can do anyway without falling back to
scanning the clusters, as typically only keyframes are indexed in
Cueing Data.
If the media doesn't have a CUE, then we bisect for the cluster to seek
to with the same modified time as well in case of accurate seeking,
ensuring sufficient lead-in. This code path is typically hit only with
(suboptimal) audio-only matroska files, e.g. when created with ffmpeg,
which doesn't add a CUE for audio-only mkv muxing.
This patch enables matroskademux to receive seeks before it reaches
GST_MATROSKA_READ_STATE_DATA.
Closes https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/issues/514
This also enables receiving seeks in the element READY state.
When such a seek is received, it is stored to be later handled when
GST_MATROSKA_READ_STATE_DATA is reached.
Add property instead of hardcoding it in the code.
In some scenarios such as CCTV variable fps and extra long GOPs are
used to minimise storage space, for example. In those cases there might
not be any keyframes for many minutes, so provide a property to override
the max allowed distance.
https://bugzilla.gnome.org/show_bug.cgi?id=790696
This is useful for reverse playback/trickmodes
without an index, and will also be useful in the
seek handler if we need to scan back to find a cluster
that starts with a keyframe.
https://bugzilla.gnome.org/show_bug.cgi?id=790696
Instead of constantly querying upstream, just cache the last duration,
and in the unlikelyness we might have gone over query again before
deciding we are EOS.
Cut 15% cpu off matroskademux streaming thread (srsly...)
Support for TAG_IMAGE and TAG_ATTACHMENT is commented out; this requires caps
on buffers which is gone from 0.11.
Segment handling in the demuxer is a bit complex; I added some FIXME comments
in places where I'm not yet sure if I ported correctly.
matroskademux performs segment tricks to skip gaps in streams,
notably at start for non 0 based files. There may however be
cases when full presentation (including intermediate gaps) is
desired, so a property allows to configure as of which gap
to act (or not at all).
API: GstMatroskaDemux::max-gap-time
Fixes#659009.
Move the following function to matroska-read-common.[ch] from
matroska-demux.c and matroska-parse.c:
- gst_matroska_{demux,parse}_parse_attachments
https://bugzilla.gnome.org/show_bug.cgi?id=650877
Replace the following functions with their gst_matroska_read_common_*
counterparts:
- gst_matroska_{demux,parse}_parse_index
- gst_matroska_{demux,parse}_parse_skip
- gst_matroska_{demux,parse}_stream_from_num
Introduce GstMatroskaReadCommon to contain those members of
GstMatroskaDemux and GstMatroskaParse that were used by the above
functions.
https://bugzilla.gnome.org/show_bug.cgi?id=650877
That is, in files that have no index (Cue), perform seek by scanning for
nearest cluster with timecode before requested position. Scanning is done
as a combination of interpolation and sequential scan.
Fixes#617368.
Original commit message from CVS:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_reset),
(gst_matroska_demux_element_send_event),
(gst_matroska_demux_handle_seek_event), (gst_matroska_demux_loop):
* gst/matroska/matroska-demux.h:
Close the current segment if we're doing a non-flushing seek and send
the close-segment and the new segment of the seek from the streaming
thread.
Original commit message from CVS:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_finalize),
(gst_matroska_demux_class_init), (gst_matroska_demux_init),
(gst_matroska_demux_combine_flows), (gst_matroska_demux_reset),
(gst_matroska_demux_stream_from_num),
(gst_matroska_demux_tracknumber_unique),
(gst_matroska_demux_add_stream), (gst_matroska_demux_send_event),
(gst_matroska_demux_handle_seek_event),
(gst_matroska_demux_sync_streams),
(gst_matroska_demux_parse_blockgroup_or_simpleblock),
(gst_matroska_demux_loop):
* gst/matroska/matroska-demux.h:
Allow an infinite number of stream inside Matroska containers and use
a GPtrArray for storing them instead of allowing "only" 127 streams.
Original commit message from CVS:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_reset),
(gst_matroska_demux_handle_src_query),
(gst_matroska_demux_parse_info),
(gst_matroska_demux_loop_stream_parse_id):
* gst/matroska/matroska-demux.h:
Don't set the segment duration to the duration from the Matroska
header as this value could be wrong and is just informational.
Original commit message from CVS:
* gst/matroska/Makefile.am:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_reset),
(gst_matroska_demux_parse_attached_file),
(gst_matroska_demux_parse_attachments),
(gst_matroska_demux_parse_contents_seekentry),
(gst_matroska_demux_loop_stream_parse_id):
* gst/matroska/matroska-demux.h:
* gst/matroska/matroska-ids.c: (gst_matroska_register_tags):
* gst/matroska/matroska-ids.h:
* gst/matroska/matroska.c: (plugin_init):
Parse Attachments and post them as GST_TAG_IMAGE if we detect
it as image and otherwise as GST_TAG_ATTACHMENT. Include filename
and description of the attachments in the caps. Fixes bug #537622.
Original commit message from CVS:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_reset),
(gst_matroskademux_do_index_seek),
(gst_matroska_demux_parse_index_cuetrack),
(gst_matroska_demux_parse_index_pointentry),
(gst_matroska_index_compare), (gst_matroska_demux_parse_index),
(gst_matroska_demux_parse_metadata):
* gst/matroska/matroska-demux.h:
* gst/matroska/matroska-ids.h:
Use a GArray for storing the Cue (i.e. seek) information, store
the CueTrackPositions for every track, store the block number
and optimize searching in the array by sorting it after the last
element was added.
Fix a small memory leak when trying to parse a tags element that was
already parsed.
Original commit message from CVS:
* gst/matroska/ebml-read.c:
* gst/matroska/ebml-read.h:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_reset),
(gst_matroska_demux_parse_metadata):
* gst/matroska/matroska-demux.h:
Make sure that every Tags element is only parsed once and it's
containing tags are only posted once.
Original commit message from CVS:
* gst/matroska/matroska-demux.c: (gst_matroska_demux_reset),
(gst_matroska_demux_parse_tracks),
(gst_matroska_demux_parse_index), (gst_matroska_demux_parse_info),
(gst_matroska_demux_parse_attachments),
(gst_matroska_demux_parse_chapters),
(gst_matroska_demux_parse_contents_seekentry),
(gst_matroska_demux_loop_stream_parse_id):
* gst/matroska/matroska-demux.h:
Only parse Tracks, SeekHead and SegmentInfo elements once but allow
Tags multiple times. The first ones can appear more than once but must
contain the same content as the first for backup purposes so we ignore
all but the first one. Tags can appear multiple times with different
content.
Jump to all elements except Clusters that are available from a
SeekHead to make it more likely to have all required informations
before getting to the first Clusters.
Add dummy functions for parsing Attachments and Chapters.
