Streaming with ffmpeg?

Area for discussing streaming over the Internet, especially as it relates to ATV
Forum rules
This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.

Thank you
vk4ea
Posts: 4
Joined: Sun Sep 02, 2018 3:19 am

Re: Streaming with ffmpeg?

Post by vk4ea » Mon Sep 03, 2018 8:22 am

Hi Dave,
I'm guessing a bit as to what the filtergraph parameter is contained in the "$CAPTION""$SCALE" variables.

I've pored through the rather detailed and extensive ffmpeg doco without learning what should reasonable values?
Cheers,
Peter - VK4EA

G8GKQ
Site Admin
Posts: 1237
Joined: Sun Mar 22, 2009 1:21 pm

Re: Streaming with ffmpeg?

Post by G8GKQ » Mon Sep 03, 2018 9:10 am

Hi Peter

You can safely leave out the string

Code: Select all

-vf "$CAPTION""$SCALE"yadif=0:1:0
for testing. The formatting of this particular parameter is very critical and it is easier to get something working without it, and then add it later.

$CAPTION contains the code to put a callsign caption in the top right hand corner, $SCALE contains code that can be used to force 16:9 format from a PAL 4:3 source, and yadif=0:1:0 changes the frame interlace order which seems to be set wrongly for PAL in the EasyCap driver (it's OK for NTSC, but not reversed, like it needs to be, for PAL).

Dave

M0DTS
Posts: 383
Joined: Sun Feb 24, 2008 9:03 pm

Re: Streaming with ffmpeg?

Post by M0DTS » Thu Sep 06, 2018 9:54 am

This is my streaming command at present for GB3KM, uses a Hauppauge capture device.

ffmpeg -v 0 -f mpeg -i /dev/video1 -c:a aac -strict experimental -s 640x480 -ac 2 -b:a 48k -f flv -r 25 -vcodec libx264 -preset fast -vf crop=685:546:20:0 -b:v 375k -minrate 375k -maxrate 375k -bufsize 400k "rtmp://rtmp.batc.org.uk/live/gb3km-xxxxxx"


The minrate/maxrate is used to limit the data rate if encoding noise, it just stalls the encoder otherwise.

Rob

Post Reply

Return to “Streaming”