feat(rust): add --codec isdb CLI flag for ISDB/ARIB subtitle selection

[pranavshar223]

Extends CCXCodec enum with Isdb variant and wires it to Codec::IsdbCc in the demuxer config, enabling users to explicitly select ISDB/ARIB subtitle streams via:
--codec isdb
--no-codec isdb

The underlying C decoder (isdbsub_decode) and Rust Codec::IsdbCc were already present but had no CLI
entry point. This change completes the wiring.

Relevant for Japanese broadcast (ARIB B-24) support.

In raising this pull request, I confirm the following (please check boxes):

• I have read and understood the contributors guide.
• I have checked that another pull request for this purpose does not exist.
• I have considered, and confirmed that this submission will be valuable to others.
• I accept that this submission may not be used, and the pull request closed at the will of the maintainer.
• I give this submission freely, and claim no ownership to its content.
• I have mentioned this change in the changelog.

My familiarity with the project is as follows (check one):

• I have never used CCExtractor.
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• I am an active contributor to CCExtractor.

---

Summary

Extends CCXCodec enum with Isdb variant and wires it to
Codec::IsdbCc in the demuxer config, enabling users to explicitly
select ISDB/ARIB subtitle streams via:
--codec isdb
--no-codec isdb

Motivation

The underlying C decoder (isdbsub_decode) and Rust Codec::IsdbCc
were already present but had no CLI entry point. This change completes
the wiring for Japanese broadcast (ARIB B-24) support.

Testing

• --codec isdb is now accepted without error
• --no-codec isdb correctly excludes the ISDB stream
• All existing codec tests pass

[ccextractor-bot]

CCExtractor CI platform finished running the test files on linux. Below is a summary of the test results, when compared to test for commit 90128d8...:

Report Name	Tests Passed
Broken	10/13
CEA-708	2/14
DVB	4/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	79/86
Teletext	20/21
WTV	13/13
XDS	34/34

Your PR breaks these cases:

• ccextractor --out=srt --latin1 --autoprogram 73d9313d64...
• ccextractor --out=ttxt --latin1 001dd8cdf7...
• ccextractor --out=srt --latin1 4d4e938ef6...
• ccextractor --service 1 --out=txt --no-bom --no-rollup ea83ff7bcb...
• ccextractor --service 1 --out=txt f17524b53f...
• ccextractor --service 1 --out=txt 80848c45f8...
• ccextractor --service 1 --out=txt --no-bom --no-rollup b5d6aad89f...
• ccextractor --service 1[EUC-KR] --out=txt --no-rollup b5d6aad89f...
• ccextractor --service 1 --out=srt da904de35d...
• ccextractor --service 1 --out=sami da904de35d...
• ccextractor --service 1[EUC-KR] b5d6aad89f...
• ccextractor --service 1[EUC-KR] --no-rollup b5d6aad89f...
• ccextractor --service all da904de35d...
• ccextractor --service all[EUC-KR] b5d6aad89f...
• ccextractor --service 1,2[UTF-8],3[EUC-KR],54 --out=txt da904de35d...
• ccextractor --autoprogram --out=srt --latin1 d41b53b504...
• ccextractor --stdout --quiet --no-fontcolor 79a51f3500...
• ccextractor --stdout --quiet --no-fontcolor 767b546f96...
• ccextractor --service 1 c83f765c66...
• ccextractor --myth c83f765c66...
• ccextractor --in=raw fb79021542...
• ccextractor --mp4vidtrack 5df914ce77...
• ccextractor --startcreditsnotafter 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...
• ccextractor --xmltv=3 --out=null 96efd279cf...
• ccextractor --datapid 2310 --autoprogram --out=srt --latin1 e639e54550...

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --startcreditsforatmost 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed:

  Test 8730

Congratulations: Merging this PR would fix the following tests:

• ccextractor --autoprogram --out=srt --latin1 --quant 0 85271be4d2..., Last passed: Never
• ccextractor --autoprogram --out=ttxt --latin1 --ucla dab1c1bd65..., Last passed: Never
• ccextractor --out=srt --latin1 --autoprogram 29e5ffd34b..., Last passed: Never
• ccextractor --out=spupng c83f765c66..., Last passed: Never
• ccextractor --parsePAT --out=srt c83f765c66..., Last passed: Never
• ccextractor --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsnotbefore 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsforatleast 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --endcreditsforatleast 3 --endcreditstext "CCextractor Ends crdit Testing" addf5e2fc9..., Last passed: Never

It seems that not all tests were passed completely. This is an indication that the output of some files is not as expected (but might be according to you).

Check the result page for more info.

[ccextractor-bot]

CCExtractor CI platform finished running the test files on windows. Below is a summary of the test results, when compared to test for commit e4bcade...:

Report Name	Tests Passed
Broken	10/13
CEA-708	2/14
DVB	4/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	81/86
Teletext	20/21
WTV	13/13
XDS	34/34

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --out=srt --latin1 --autoprogram 73d9313d64..., Last passed:

  Test 8611

• ccextractor --out=ttxt --latin1 001dd8cdf7..., Last passed:

  Test 8611

• ccextractor --out=srt --latin1 4d4e938ef6..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt --no-bom --no-rollup ea83ff7bcb..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt f17524b53f..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt 80848c45f8..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt --no-bom --no-rollup b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1[EUC-KR] --out=txt --no-rollup b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1 --out=srt da904de35d..., Last passed:

  Test 8611

• ccextractor --service 1 --out=sami da904de35d..., Last passed:

  Test 8611

• ccextractor --service 1[EUC-KR] b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1[EUC-KR] --no-rollup b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service all da904de35d..., Last passed:

  Test 8611

• ccextractor --service all[EUC-KR] b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1,2[UTF-8],3[EUC-KR],54 --out=txt da904de35d..., Last passed:

  Test 8611

• ccextractor --autoprogram --out=srt --latin1 d41b53b504..., Last passed:

  Test 8611

• ccextractor --stdout --quiet --no-fontcolor 79a51f3500..., Last passed:

  Test 8611

• ccextractor --stdout --quiet --no-fontcolor 767b546f96..., Last passed:

  Test 8611

• ccextractor --service 1 c83f765c66..., Last passed:

  Test 8611

• ccextractor --myth c83f765c66..., Last passed:

  Test 8611

• ccextractor --in=raw fb79021542..., Last passed:

  Test 8611

• ccextractor --mp4vidtrack 5df914ce77..., Last passed:

  Test 8611

• ccextractor --xmltv=3 --out=null 96efd279cf..., Last passed:

  Test 8611

• ccextractor --datapid 2310 --autoprogram --out=srt --latin1 e639e54550..., Last passed:

  Test 8611

Congratulations: Merging this PR would fix the following tests:

• ccextractor --autoprogram --out=srt --latin1 --quant 0 85271be4d2..., Last passed: Never
• ccextractor --autoprogram --out=ttxt --latin1 --ucla dab1c1bd65..., Last passed: Never
• ccextractor --out=srt --latin1 --autoprogram 29e5ffd34b..., Last passed: Never
• ccextractor --out=spupng c83f765c66..., Last passed: Never
• ccextractor --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsnotbefore 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsnotafter 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsforatleast 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsforatmost 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never

This PR does not introduce any new test failures. However, some tests are failing on both master and this PR (see above).

Check the result page for more info.

[cfsmp3]

The code change looks correct — small and clean wiring.

A few questions before we can move forward:

1. How did you test this? The testing section says --codec isdb is accepted without error, but that just means the CLI parser doesn't reject it. Did you actually test with an ISDB/ARIB sample? If so, which specific sample file did you use?

2. What's the end-to-end use case? Once a user passes --codec isdb, what happens? Does ccextractor actually produce subtitle output from an ISDB stream? What output format? Can you show us the actual output from a real file?

3. Without this flag, what happens with an ISDB stream? Is the codec auto-detected, and this flag is just for forcing selection when there are multiple subtitle streams? Or does ISDB processing not work at all without this flag?

We'd like to understand the practical value before merging — the wiring is correct but we need to know it actually does something useful end-to-end.