True Closed Caption support in VLC

[mm55la]

Hello guys,

I did some digging around and found several topics on CC support in VLC. I see there is some support for EIA-608 captions and basic EIA-708 in an MPEG2. From my experiences, it seems that VLC supports EIA-608 and SCTE-20 CC's very well. EIA-708, not so much.

Another thing I notice is that if an MPEG-2 (TS) has dual captions (ATSC/a53 + SCTE 20), VLC decodes both at the same time, which manifests itself as garbled CC's.

What is the roadmap for true EIA-708, true EIA-608 and SCTE-20 support in MPEG-2 (TS) of the MPEG-2 and AVC codec flavors?

Currently VLC (1.1.11) displays Service 1 - 4 captions (CC1, CC2, CC3, CC4) in VLC > Video > Subtitles Tracks

Can there be an additional option be added in the GUI under Video that is specifically for Closed Captions?

Then, add support for EIA-708, EIA-608 and the different SCTE-20 CC services (1-4).

I don't know the feasibility of my request, but any help or feedback would be greatly appreciated.

[Jean-Baptiste Kempf]

First, please try VLC 1.2.0-git and not 1.1.11.
Then, there are no roadmaps on VLC, just people who come and submit code to fix support.
Finally, we don't have the specs usually, so it is done the best we can.

So, EIA-608 and SCTE-20 work except when they are together, right?
And EIA-708 is broken?
I have seen a sample for the first case, but not for EIA-708. Please give some sample and a bugreport.

To get a fix, either wait, or sponsor the bug solving.

Can there be an additional option be added in the GUI under Video that is specifically for Closed Captions?

What is that supposed to mean?

[mm55la]

First, please try VLC 1.2.0-git and not 1.1.11.
Then, there are no roadmaps on VLC, just people who come and submit code to fix support.
Finally, we don't have the specs usually, so it is done the best we can.

Understood. What do you mean by "we don't have the specs usually..."? I assume the ATSC/A53 and SCTE 20 specs?

So, EIA-608 and SCTE-20 work except when they are together, right?

They work if one or the other is in the user data of MPEG2 or AVC. However, if the file has dual captions, they still decode - at the same time, which looks garbled.

And EIA-708 is broken?
I have seen a sample for the first case, but not for EIA-708. Please give some sample and a bugreport.

Doesn't seem to be broken IF there is 608 encapsulated in a 708 container. However, I am looking for true 708 support.

To get a fix, either wait, or sponsor the bug solving.

I am pretty sure I can sponsor the feature request. What is involved in starting the process please.

Can there be an additional option be added in the GUI under Video that is specifically for Closed Captions?

What is that supposed to mean?

Currently, to decode CC's in VLC 1.1.11 GUI - a user has to go to: Video > Subtitles Track >

What I am proposing is a new section. Something like: Video > Closed Captions >
Open File...
___________
Disable
___________
EIA-708
EIA-608
__________
Closed Captions 1
Closed Captions 2
Closed Captions 3
Closed Captions 4

I can provide samples and am creating some now that are:
ONLY true EIA-708
ONLY EIA-608 in an encapsulated 708
ONLY SCTE-20 (CC1)

I can also provide:
ONLY EIA-608 + SCTE-20 (CC1) (dual captions)
All 3 standards in one file

What codec is preferred, AVC or MPEG2?

Note that this would be a Transport Stream.

Anything else needed, let me know.

[Jean-Baptiste Kempf]

First, please try VLC 1.2.0-git and not 1.1.11.
Then, there are no roadmaps on VLC, just people who come and submit code to fix support.
Finally, we don't have the specs usually, so it is done the best we can.

Understood. What do you mean by "we don't have the specs usually..."? I assume the ATSC/A53 and SCTE 20 specs?

Yes. Not important.

So, EIA-608 and SCTE-20 work except when they are together, right?

They work if one or the other is in the user data of MPEG2 or AVC. However, if the file has dual captions, they still decode - at the same time, which looks garbled.

So, we agree the issue is with dual captions.
Samples, please.

And EIA-708 is broken?
I have seen a sample for the first case, but not for EIA-708. Please give some sample and a bugreport.

Doesn't seem to be broken IF there is 608 encapsulated in a 708 container. However, I am looking for true 708 support.

Ok. I never heard about that, to be honest.
Samples, please.

To get a fix, either wait, or sponsor the bug solving.

I am pretty sure I can sponsor the feature request. What is involved in starting the process please.

Usually, start by opening good bugreports and mail the mailing list.

Can there be an additional option be added in the GUI under Video that is specifically for Closed Captions?

What is that supposed to mean?

Currently, to decode CC's in VLC 1.1.11 GUI - a user has to go to: Video > Subtitles Track >

What I am proposing is a new section. Something like: Video > Closed Captions >

Look at the VLC 1.2.0-git UI, please.

I can provide samples and am creating some now that are:

We need samples. Most cases should be covered. Upload on our HTTP or ftp.

[Jean-Baptiste Kempf]

ping

[mm55la]

ping

Hello Jean, sorry for the delayed response...

I will start by filling out a bug report and joining / mailing the mail list (is it the vlc-devel list??), since I already asked in the feature request forums.

Obviously you will need samples which I have been sitting on

By the way, would the PC or Mac version be easier to implement this CC request ?

Anyway, I know I can sponsor the fix, so let's do this

[VLC_help]

Mac version is easier to build than Windows version. And yes, vlc-devel is used for developer discussions (specially for patch bashing).

[Jean-Baptiste Kempf]

ping

Hello Jean, sorry for the delayed response...

I will start by filling out a bug report and joining / mailing the mail list (is it the vlc-devel list??), since I already asked in the feature request forums.

Obviously you will need samples which I have been sitting on

By the way, would the PC or Mac version be easier to implement this CC request ?

Anyway, I know I can sponsor the fix, so let's do this

Samples is the most important... And specifications too