[FFmpeg-devel] [PATCH 7/8] decklink: Add support for SCTE-104 to decklink capture

Devin Heitmueller dheitmueller at ltnglobal.com
Fri Jan 5 21:40:34 EET 2018

> On Dec 30, 2017, at 3:11 AM, Aaron Levinson <alevinsn_dev at levland.net> wrote:
> On 12/29/2017 10:12 AM, Devin Heitmueller wrote:
>> Make use of libklvanc to parse SCTE-104 packets and announce them
>> as a new stream.  Right now we just pass the payload straight
>> through, but once this is hoooked into libklscte35 we'll be able
> "hoooked" -> “hooked"


>> +        }
>> +        st->codecpar->codec_type  = AVMEDIA_TYPE_DATA;
>> +        st->time_base.den         = ctx->bmd_tb_den;
>> +        st->time_base.num         = ctx->bmd_tb_num;
> I wonder if there is any reason to set time_base here.  Aren't the triggers relatively infrequent?

The triggers are relatively infrequent, but we want them to be frame accurate and when they do occur they may happen in bursts over multiple frames, and we want the clock to be accurate enough to ensure they are inserted into the correct video frame.  Putting them on the same clock as the video helps with that.


More information about the ffmpeg-devel mailing list