[FFmpeg-devel] [PATCH RFC] libavdevice/decklink: Add support for EIA-708 output over SDI

Deron deron at pagestream.org
Wed Oct 18 23:54:49 EEST 2017

On 10/18/17 1:31 PM, Devin Heitmueller wrote:
>> On Oct 6, 2017, at 12:56 PM, Devin Heitmueller <dheitmueller at ltnglobal.com> wrote:
>> From: Devin Heitmueller <dheitmueller at kernellabs.com>
>> Hook in libklvanc and use it for output of EIA-708 captions over
>> SDI.  The bulk of this patch is just general support for ancillary
>> data for the Decklink SDI module - the real work for construction
>> of the EIA-708 CDP and VANC line construction is done by libklvanc.
>> Libklvanc can be found at: https://github.com/stoth68000/libklvanc
>> Signed-off-by: Devin Heitmueller <dheitmueller at ltnglobal.com>
> Any additional technical comments related to this patch, or should I resubmit for merge?
> Devin

I was going to actually test this with some old broadcast equipment I 
have just dying for a purpose, but I don't see how to generate 
AV_PKT_DATA_A53_CC side packet data except using the Decklink capture. I 
have A53 documentation, but it just refers to CEA-708 (or SMPTE 334, or 
... what an unraveling ball of yarn it is. Looks like I could spend a 
months income on standards just trying to learn how this is encoded).

On a side note, can AV_PKT_DATA_A53_CC be used for something besides 
CEA-708? Not sure I understand the line between A53 CC encoding (which 
is at least in part what this generates, right?) and CEA-708 (which is 
what this takes, right?) and why this side data is called A53_CC?

I know these questions are outside the scope that you were asking...


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