A couple of remarks about XBMC scraper development

I’m a big fan of XBMC. One of its most important features is gathering metadata from various websites (a process called scraping), depending on the type of content (e.g. IMDB for movies, TheTVDB for TV shows etc.). I’ve been using smuto’s Filmweb scraper for scraping movie information for a while now without any major problems. Yet recently Filmweb changed their layout (again…), rendering the scraper useless. I got tired of waiting for an updated version of smuto’s scraper and started developing my own from scratch. It turned out it wasn’t as easy as I would like it to be.

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WMM and delays on TP-LINK routers

I was quite puzzled recently when, after unpacking a TP-LINK TL-WR740N router, plugging it in and configuring a wireless network on it, ICMP ping delays between the router and a laptop connected to it via Wi-Fi were reaching 100 milliseconds, despite a mere distance of a couple of meters between the two devices (without any obstacles). Changing channels and supported speeds didn’t help. It turned out that the reason was WMM (Wi-Fi MultiMedia) which is enabled by default.

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Sony Ericsson Elm, YouTube and TP-LINK routers

If you have a Sony Ericsson Elm J10i2 phone (the issue probably applies to other models as well) and you’re trying to watch YouTube videos via your home WiFi while accessing the Internet through a TP-LINK router, it probably won’t work. The TP-LINK TL-WR541G V4 (probably other models as well) performs NAT in a way that makes it impossible for the RTSP protocol, which is used for streaming YouTube videos on some Sony Ericsson phones (the Android app uses HTTP), to work.

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Non-Latin characters in archive files

I was recently moving files whose names contained non-Latin characters between Linux and Windows. Using Samba (version 3.4), everything worked fine. Yet creating a ZIP or TAR archive on Linux and extracting it on Windows resulted in mangled filenames. As it turns out, this is an expected behavior: neither ZIP nor TAR format allows including character encoding information in the archive. As a result, creating an archive in a system which uses e.g. UTF-8 (most modern Linux systems) and extracting it in Windows causes weird characters to appear in filenames due to the lack of conversion between UTF-8 and Windows’ codepage during extraction. The same goes for creating an archive in Windows and extracting it in Linux. The solution is to use a format which saves character encoding information in the archive (e.g. 7z) or to use Samba (which is able to automatically convert filenames between different encodings) for moving the data.

Trunks on old Cisco switches

When dealing with older Cisco switches it is worth remembering that ISL was once the default trunking protocol on these devices. You can check the trunking protocol used on a given interface using the show interface [interface_name] switchport command. To force a specific protocol, use the switchport trunk encapsulation [dot1q|isl] interface configuration mode command. I’ve come across this problem while trying to setup a trunk between Cisco WS-C3524-XL and HP 1700-24 switches (the latter uses 802.1q by default).