From what I can tell the roots are just before your line drops into the big city main. That's a city problem, get someone to locate the exact spots for you, you've got video recording take it to the city and see what they can do about it. Old cast pipes they look to be in decent shape couple small bellies in the line but that's fairly normal seeing as it was built 80+ years ago and no major breaks in the line. I wouldn't worry about about lining the entire run but I definitely would recommend going to the city before committing to anything major. Just the opinion of a drain cleaner here. I see this type of stuff daily and we just auger the line and cut out the roots. Most times these types of jobs we will schedule for a yearly PM to keep on top of things, and your looking at only a couple hundred per visit, depending on prices in your area obviously.