id	summary	reporter	owner	description	type	status	priority	component	version	resolution	keywords	cc	blockedby	blocking	reproduced	analyzed
450	Specify the position of -isync more precisely	burek	stefano	"I've figured that the -isync option does not produce the same effect when placed in front of inputs, between the inputs and after the inputs. I just think it would be a good idea to put a little explanation in the documentation about the proper usage of that option.

For example, these 2 examples produce different results:

ffmpeg -f alsa -ac 1 -i hw:1 -isync -f video4linux2 -r 15 -s qqvga -i /dev/video0 -vcodec libx264 -preset ultrafast -g 15 -crf 20 -acodec aac -strict experimental -ar 44100 -ab 96k -ac 1 -f mpegts udp://192.168.25.101:10001

ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -r 15 -s qqvga -i /dev/video0 -isync -vcodec libx264 -preset ultrafast -g 15 -crf 20 -acodec aac -strict experimental -ar 44100 -ab 96k -ac 1 -f mpegts udp://192.168.25.101:10001

(the second example has -isync moved after the 2nd input)"	enhancement	open	normal	documentation	unspecified						0	0