Captions workflow and features

[Baptiste Coudurier]

Hi guys,

From the requests page, I can see that quite a few of you are interested
in captions features and workflow.

If you bundle together and gather a funding pool, I could focus on this
feature.

Let's start gathering ideas and features.

--
Baptiste COUDURIER
Key fingerprint 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer http://www.ffmpeg.org

[Alan Hurdle]

Hi,

In Australia broadcast captioning/subtitling requirements revolve around subtitle information carried in teletext pages (801) on VBI line 21.

My main exposure is with the GVG K2 server where captions can be carried 3 ways depending on how it is configured:

• in vision (depreciated)
• 8 bit uncompressed samples using ETSI EN 301 775
• in VANC on an Ancillary data track for SD and HD as a teletext packet

In Australia the teletext packets are constructed according to TV operation standards:

• OP-47 for HD
• OP-42 for analog SD

For the US the following ancillary data standard applies. I am not sure of the European standards that are required.

Our main problem today is the extraction of the teletext packets and converting them to a useful intermediate format.

The most useful (generic) format for teletext reinsertion is an STL file as per EBU TECH. 3264-E.

We have requirements for subtitle file conversion to SAMI and DFXP from the teletext subtitle data.

One of our current bug-bears is the re-insertion of teletext packets into an MPEG-2 transport stream for H.264 VOD files.

I have some prototype C++ code that extracts teletext data from either EN 301 775 packets or an ancillary data track and generates STL files but it is not based on FFMBC.

It isn't pretty but it is functional ;)

Regards,

Alan Hurdle

> Date: Fri, 30 Sep 2011 12:43:00 -0700
> From: baptiste....@gmail.com
> To: ffmbc-...@googlegroups.com; ffmb...@googlegroups.com
> Subject: [ffmbc-discuss] Captions workflow and features

[Kieran Kunhya]

In OBE-VoD, we support CEA-608 captions in SCC files. There's also an
MCC file format for CEA-708 captions which I have the spec for but
haven't implemented yet. The code could be cannibalised for ffmbc if
necessary

As Alan said there really isn't a particularly good workflow apart
from STL files for teletext/DVB subtitles. I think libass could be
used to convert teletext to DVB subtitles but some of the character
sets might be tricky.

[Baptiste Coudurier]

On 09/30/2011 12:43 PM, Baptiste Coudurier wrote:
> Hi guys,
>
> From the requests page, I can see that quite a few of you are interested
> in captions features and workflow.
>
> If you bundle together and gather a funding pool, I could focus on this
> feature.
>
> Let's start gathering ideas and features.
>

All right, let's try to be a bit more specific:

What about SCC file import to SMPTE 436M to go into IMX or XDCAMHD422 ?

[Agustin Goya]

>What about SCC file import to SMPTE 436M to go into >IMX or XDCAMHD422 ?

That would be great!

--
Sent from my phone

-----Original Message-----
From: Baptiste Coudurier
Sent: 06/10/2011 22:17:31
To: ffmbc-...@googlegroups.com; ffmb...@googlegroups.com

Subject: [ffmbc-discuss] Re: Captions workflow and features

On 09/30/2011 12:43 PM, Baptiste Coudurier wrote:
> Hi guys,
>
> From the requests page, I can see that quite a few of you are interested
> in captions features and workflow.
>
> If you bundle together and gather a funding pool, I could focus on this
> feature.
>
> Let's start gathering ideas and features.
>

All right, let's try to be a bit more specific:

[jc]

Hello Baptiste,

Do you still have plan to add this features in ffmbc? Do you hear of
anybody also interested in subtitles?

We could be interested in a solution to add EBU STL subtitles to SMPTE
436 track in XDCAMHD422 and IMX MXF files...

Thank you.
JC

On Oct 7, 2:17 am, Baptiste Coudurier <baptiste.coudur...@gmail.com>
wrote:

[Derek Prestegard]

Yes. SCC into (608 and 708) SMPTE 436M for IMX or XDCAM would be absolutely amazing! The only tool I know that does this properly is CPC's CaptionMaker / MacCaption, and this wasn't really ready for primetime until very recently IMO.

SCC into ATSC A53 would also be quite useful for both MPEG-2 and H.264. Many VOD services require this type of workflow.

Timecode support is definitely a prerequisite (if it's not already implemented). Drop frame and non-drop frame counting are essential.

Derek

[Bouke (VideoToolShed)]

----- Original Message -----
From: "Derek Prestegard" <dpre...@gmail.com>
To: <ffmb...@googlegroups.com>
Cc: <ffmbc-...@googlegroups.com>
Sent: Tuesday, March 20, 2012 8:39 AM
Subject: [ffmbc-discuss] Re: Captions workflow and features

> Yes. SCC into (608 and 708) SMPTE 436M for IMX or XDCAM would be
> absolutely
> amazing! The only tool I know that does this properly is CPC's
> CaptionMaker
> / MacCaption, and this wasn't really ready for primetime until very
> recently IMO.

Problem is, it is (or at least was) patented to use a computer to insert SCC
into video...
(The original patented version used a QT with VITC to wipe over your
video...)
Not sure what that means for open souce code though...

Bouke

[dean...@gmail.com]

I would be very interested in helping to fund the caption feature in ffmbc.  I actually have CPC's Captionmaker HD and the only thing that I have found that it cannot do is insert captions into an SD MXF file.  HD MXF files are no problem.   I need to be able to insert captions that follow the SMPTE 436M standard into a MXF file.  The only problem is, I need this feature yesterday.  Any idea how long it would take to implement something like this and how much $$ you would need to get started?