The SCC reader (ttconv/scc/reader.py) converts SCC documents into
the data model.
The SCC reader accepts as input a Scenarist Closed
Caption document that conforms
to the CEA-608 encoding specification and returns a model.ContentDocument
object.
import ttconv.scc.reader as scc_reader
doc = scc_reader.to_model("src/test/resources/scc/pop-on.scc")
# doc can then manipulated and written out using any of the writer modulesThe input SCC document is read line-by-line. For each line, the time code prefix and following CEA-608 codes (see the
ttconv/scc/codes package) are processed to generate SccCaptionParagraph instances. Each paragraph associates a time and region
with the text (including line-breaks) it contains (see definition in ttconv/scc/content.py). The paragraphs are then converted to
a model.P, part of the output model.ContentDocument (see the SccCaptionParagraph::to_paragraph() method in
ttconv/scc/paragraph.py), following the recommendations specified in SMPTE RP
2052-10:2013.
The paragraph generation is based on the buffer-based mechanism defined in the CEA-608 format: a buffer of caption
content is filled while some other content is displayed. These buffering and displaying processes can be synchronous or
asynchronous, based on the caption style (see ttconv/scc/style.py).
ttconv/scc/utils.py contains utility functions to convert geometrical dimensions of different units,
and ttconv/scc/disassembly.py handles CEA-608 codes conversion to the disassembly format.
The SCC reader can dump SCC content in the Disassemby format, which is an ad-hoc a human-readable description of the SCC content.
import ttconv.scc.reader as scc_reader
print(scc_reader.to_disassembly("src/test/resources/scc/pop-on.scc"))For instance, the following SCC line:
00:00:00:22 9425 9425 94ad 94ad 9470 9470 4c6f 7265 6d20 6970 7375 6d20 646f 6c6f 7220 7369 7420 616d 6574 2c80
is converted to:
00:00:00:22 {RU2}{RU2}{CR}{CR}{1500}{1500}Lorem ipsum dolor sit amet,
This is useful for debugging.
Sample SCC files can be found in the src/test/resources/scc directory.