(Sponsored Request) -> MP4: support of media characteristic (spoken dialog, translation, easy to read...)

[rsmvdl]

Hello,

it appears my old (paid) request has been dropped for some reason, also see:

#1793 (comment)

Now I'm in a Bug situation I can't easily fix myself anymore, nor can I use the old codebase anymore as release repo-mediaarea_1.0-21_all.deb as been dropped from the servers which contained the relevant changes for me!

I really would like to have the output for the additional subtitle metadata like this:

"udta_tagc_public_auxiliarycontent": "Yes",
"udta_tagc_public_subtitles_forcedonly": "Yes",
"udta_tagc_public_accessibility_describesmusicandsound": "Yes",
"udta_tagc_public_auxiliarycontent": "Yes",
"udta_tagc_public_accessibility_transcribesspokendialog": "Yes"
[...]

In the current implementation these fields have been remapped to "tagc", but it appears that the whole implementation is faulty, for example, how can such an output even be possible? Here we have "tagc": "public.auxiliary-content" but "Forced": "Yes"

{
"@type": "Text",
"@typeorder": "1",
"StreamOrder": "3",
"ID": "4",
"Format": "Timed Text",
"MuxingMode": "sbtl",
"CodecID": "tx3g",
"Duration": "6900.932",
"BitRate_Mode": "VBR",
"BitRate": "83",
"FrameRate": "0.465",
"FrameCount": "3212",
"StreamSize": "71970",
"Language": "de",
"Default": "Yes",
"Forced": "Yes",
"AlternateGroup": "2",
"Encoded_Date": "2025-02-27 09:20:43 UTC",
"Tagged_Date": "2025-02-27 09:20:45 UTC",
"Events_Total": "1606",
"extra": {
"Full_Alternative": "4",
"Forced_Alternative": "4",
"tagc": "public.auxiliary-content"
}

Where on the other side placing the exact same forced metadata on the next subtitle we get:

{
"@type": "Text",
"@typeorder": "3",
"StreamOrder": "5",
"ID": "6",
"Format": "Timed Text",
"MuxingMode": "sbtl",
"CodecID": "tx3g",
"Duration": "6900.890",
"BitRate_Mode": "VBR",
"BitRate": "82",
"FrameRate": "0.464",
"FrameCount": "3202",
"StreamSize": "70691",
"Language": "en",
"Default": "No",
"Forced": "Yes",
"AlternateGroup": "2",
"Encoded_Date": "2025-02-27 09:20:43 UTC",
"Tagged_Date": "2025-02-27 09:20:45 UTC",
"Events_Total": "1601",
"extra": {
"Full_Alternative": "6",
"Forced_Alternative": "6",
"tagc": "public.subtitles.forced-only"
}

So here it's "tagc": "public.subtitles.forced-only" and "Forced": "Yes", that does not make much sense when they have exactly the same metadata attached ... besides of that, it's hard for me to remap these fields, please just simply bring back:

"udta_tagc_public_auxiliarycontent": "Yes",
"udta_tagc_public_subtitles_forcedonly": "Yes",
"udta_tagc_public_accessibility_describesmusicandsound": "Yes",
"udta_tagc_public_auxiliarycontent": "Yes",
"udta_tagc_public_accessibility_transcribesspokendialog": "Yes"
[...]

This would really solve all my problems!