Commit graph

8 commits

Author SHA1 Message Date
Mathieu Duponchelle
2eab37f231 ccconverter: implement field conversion of CEA 608 control codes
As specified in EIA/CEA-608-B section 8.4:

When closed captioning is used on line 21, field 2, it shall conform
to all of the applicable specifications and recommended practices as
defined for field 1 services with the following differences:

a) The non-printing character of the miscellaneous control-character pairs
  that fall in the range of 14h, 20h to 14h, 2Fh in field 1, shall be replaced
  with 15h, 20h to 15h, 2Fh when used in field 2.
b) The non-printing character of the miscellaneous control-character pairs
  that fall in the range of 1Ch, 20h to 1Ch, 2Fh in field 1, shall be replaced
  with 1Dh, 20h to 1Dh, 2Fh when used in field 2.

This means simply switching the "field" field in the caps isn't enough for
converting raw 608 from one field to another, some control codes also
need to be amended.

+ Adds simple test

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4126>
2023-03-08 10:13:59 +00:00
Mathieu Duponchelle
9e8d1dccb4 ccconverter: add support for advertising / selecting field
Raw 608 caps can now contain a "field" field. On the input side it
signifies that the input raw 608 is attached to either field 0 or 1,
on the output side it allows selecting whether to extract the raw 608
data for field 0 or 1 for field-aware formats.

In addition, it is also allowed to use ccconverter to "convert" 608
field 0 to 608 field 1 (and conversely), this is passthrough as the
change only needs to happen in the caps.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4031>
2023-02-24 19:11:56 +00:00
Matthew Waters
088597b430 closedcaption: move CC buffering to helper object
Move most of the interesting code from ccconverter to this new helper
object.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3211>
2022-11-10 00:52:14 +00:00
Matthew Waters
741cfd18b5 ccconverter: drop data when overflow on extracting cea608 from cc_data
If the buffer overflows, then drop rather than causing a failure and
fropping the output buffer indefinitely.  This may have caused downstream to
be waiting for data the will never arrive.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3211>
2022-11-10 00:52:14 +00:00
Matthew Waters
542060fea7 ccconverter: fix framerate passthrough with malformed input
If an input is malformed (only produces cea608 field 1 cc_data) then
when in passthrough we would effectively be dropping every second cea608
on output as we would not store any unused cea608 data.

Fix by having all code paths go through the framerate conversion code
which will store and retrieve any relevant data across buffers.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3211>
2022-11-10 00:52:14 +00:00
Matthew Waters
2e69886a02 ccconverter: ensure correct ordering of cea608 across output buffers
e.g. if a 60fps output is configured, we can only produce a single field
of cea608 that must alternate between field 1 and field 2.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2019>
2022-03-26 00:00:36 +00:00
Matthew Waters
6977119f99 ccconverter: ignore padding cea608 data even if marked as 'valid'
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2019>
2022-03-26 00:00:36 +00:00
Thibault Saunier
019971a3c7 Move files from gst-plugins-bad into the "subprojects/gst-plugins-bad/" subdir 2021-09-24 16:14:36 -03:00
Renamed from tests/check/elements/ccconverter.c (Browse further)