Dealing with ffmpeg -i output that contains commas in the format string

This patch allows this line to parse cleanly: 

`Stream #0:1(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 960x540, 6520 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 48k tbc (default)`