How to combine/concatenate mp4 videos

In a project similar to the Blender Defender, I am using a Linksys WVC54GCA webcam to monitor my devious cats. The camera has built-in motion detection, and can automatically FTP video files of detected motion to a location of your choice. Unfortunately, the area I’m monitoring has a good deal of exposure to outside lighting, meaning that each day I get hundreds of little videos as light plays across the room.

While messing with the motion sensitivity settings is next on my list, my immediate reaction was to figure out a way to combine the videos. The WVC54GCA lets you use a few different formats, but I chose mp4 since that seemed like the most open format. Some Google searching told me that I needed to use ffmpeg to convert the mp4s to mpg format which is supposedly “concatenatable”.

So first I converted all my mp4s to mpgs (assuming they are stored in a directory called movie_dir):

find movie_dir -name "*.mp4" -exec ffmpeg -i {} -sameq {}.mpg \;

Many posts I found then said that all one needed to do was just cat the mpg files together and you’d end up with one long mpg. That sounded great, but in practice it produced an mpg that caused both QuickTime and VLC to either choke, skip past chunks of video, or otherwise be weird. Going back to the Internet, I found that the solution was to use ffmpeg again to produce a single video:

cat movie_dir/*.mpg | ffmpeg -f mpeg -i - -vcodec copy -acodec copy big_movie.mpg

And this I can enjoy 30 boring minutes of watching the light level change, waiting for that one moment when the cats try to sneak up on the couch. Now I know how a security guard feels.

Fatal flaws with TalkSwitch TS-850i IP phones

I was initially excited at the chance to install and configure a TalkSwitch 240vs PBX phone system. With twelve TalkSwitch 850i cordless phones spread across four base stations, I figured I would have my work empire bathed in telephony goodness. And the price was very low for an IP phone system… too low, as it turns out.

FLAW I: the TalkSwitch Management Software runs on Windows only. This isn’t too big of a deal since I can use VirtualBox on Linux or Parallels on Mac, but the PC-only requirement is still a hassle. I had originally hoped that configuration could be accomplished via a web interface, but apparently not.

FLAW II: conference calling is only 3-way. You can’t have 4+ 850i’s on the same call, nor can you have more than two 850i’s talking to the same outside line. I just assumed that, like a traditional phone system, any number of phones could pick up on an outside line simultaneously. To TalkSwitch’s credit, the system isn’t designed that way because you don’t want people to be able to eavesdrop on conversations. That’s fine, except we need a way to have a “conference” that includes more than three people. You could get around that with a speakerphone, but…

FLAW III: the speakerphone is choppy and cuts in and out due to an overly sensitive mic. This was revealed to be a known flaw when I talked to tech support on the phone. This renders the speakerphone useless, and also takes away a means of working around the 3-way conference limitation (i.e., by having people sit around a speakerphone).

FLAW IV: tech support is painfully slow. I was having trouble updating the firmware on the 850i’s so I filled out a support ticket. After five days I got this response:

This issue would be best dealt with over the phone. Please contact us at 866-393-9960 option 3.

Of course option 3 wasn’t the correct option, and sometimes the tech support line sends you to voicemail instead of queuing you up. Support is not 15-30 minutes away – you’ll wait hours to get any help.

FLAW V: this one is personal. An online vendor who shall rename nameless (because they’ve been decent to me) sold me these phones. They will not take the TalkSwitch system back because I’m past the 30-day return policy limit. But the vendor did contact TalkSwitch and got their VP of sales to call me. I assumed that the call would result in TalkSwitch placating me in some way, even if just some free headsets or something. Instead, the guy said basically nothing and simply confirmed that, yes, conferencing is limited to 3-way, and yes, the speakerphones suck. He was being so useless that at one point I just blurted out, “So… why are you calling me? Are calling to console me?” What a terrible waste of time and money this has been. I thought I’d done my homework on this system before I bought it, but obviously I didn’t dig deep enough. Hopefully this post will help any IT brethren who are considering TalkSwitch; if you’re thinking about buying TalkSwitch, think again.

Solving openSUSE 11.3 mail server problems

Rather than follow an upgrade path, I painstakingly migrated the mail server configuration from an openSUSE 11.0 server to a fresh install on an openSUSE 11.3 server. Here are the problems I ran into and how I solved them:

Problem: “Permission denied” when postfix/lmtp attempted to connect to /var/lib/imap/socket/lmtp

Solution: run vigr to add user postfix to the mail group.

Problem: imap[14973]: IOERROR: opening /var/lib/imap/user_deny.db: No such file or directory

Solution: it’s okay to ignore this.

Problem: imap[10976]: SQUAT failed to open index file
imap[10976]: SQUAT failed

Solution: you can either ignore this or build SQUAT indexes.

Problem: postfix/smtp[21515]: connect to localhost[::1]:10024: Connection refused
amavis[21058]: (21058-12) (!!)WARN: all primary virus scanners failed, considering backups

Solution: the Problems I found and fixed section of this Virus scanning post seemed to have the answer. All I needed to do was uncomment the ClamAV-clamd lines in /etc/amavisd.conf

How to recommend movies to friends on Netflix

Do you remember when Netflix used to have a Netflix Community feature where you could add friends and recommend movies to one another? I was just now about to make a recommendation when I realized I could no longer find that feature, nor a listing of my Netflix friends.

If you peruse this forum, then you’ll find that Netflix has removed all of their “community” features. A poster in that forum recommended calling Netflix customer service (1-866-716-0414) to request the return of this feature.

I really liked that feature so I gave them a call. The rep was very friendly and told me they removed the community stuff because less than 2% of their customers were using it. Unfortunately I can’t really argue against those numbers. Still, the rep was kind enough to pass on the “re-feature” request to their dev team. Who knows, maybe if they get enough calls then they will bring it back. Personally, I think if they worked a bit harder to promote the community (read: social networking) aspect of their site, then those features would see heavier usage.

The only problem is, what would Netflix gain? The best answer I could come up with is that as a business you would remain “hip to the times” and stay ahead of your competition. If a customer has a social network built up within Netflix, then they are much less likely to change services.

So anyway, I’ve been watching Dexter and it’s freaking awesome.

The fate of the Blue Carbuncle

Everyone seems to have a favorite movie that they watch during the holidays – mine is The Blue Carbuncle (1984). Jeremy Brett seems as if he were born to play Sherlock Holmes, and I have watched every episode in which he has starred. Not only is The Blue Carbuncle one of my favorites, but it takes place during Christmas which makes it perfect for holiday viewing.

One question that came up this year was whether Holmes kept the jewel, or wound up returning it to the police or the Countess. In the show, he says something about adding it to his private museum, and we see him lock the Blue Carbuncle in a desk drawer along with a brief glimpse of his cocaine syringe.

I decided to settle the matter by opening my copy of The Original Illustrated Sherlock Holmes by Arthur Conan Doyle. I found the answer on page 100:

I’ll lock it up in my strong box now, and drop a line to the Countess to say that we have it.

Another mystery solved!

The League: a television flop

The League is a sitcom about a group of 30-something adults who are in a fantasy football league. After seeing the promo (and being a fantasy football addict), I raced to the DVR to acquire some League action. I’ve since slogged my way through six episodes and am now at the point where I just cannot bear to punish myself anymore.

I thought I was going to get a comedy that satirizes both fantasy football and the people who are involved with this national obsession. Instead, The League is a poor attempt at TV-for-guys-who-like-TV, composed of painful caricatures, pointless vulgarity, the occasional NFL player cameo, “zany” scenarios that have nothing to do with fantasy football, and a few flat jokes about the game itself.

The premise is solid, the acting is fine, but the plot lines and writing are miserable. Every now and then the show gets a chuckle out of me, but that’s just kind of like how a stopped clock is right twice a day. At the moment when the characters were in a car, screaming and yelling as a monkey was jumping frenetically around the interior, I hit the stop button, deleted the episode, and decided I was done with The League.

If you really want to bring out the comedy in the fantasy football craze, you can’t just toss together a crappy sitcom, make a few fantasy football references, and expect to bask in rays of accolades. If I had the resources and the opportunities, here is how I would do it:

Ditch the sitcom paradigm and move to something closer to sketch comedy – a Daily Show or SNL model, if you will. The drama of the NFL and weekly fantasy impact hold so much material that you could put out a show every, say, Wednesday. If actual NFL footage could be incorporated into the show, then you could have something really huge. The point is that the comedy would be focused on fantasy football and it would be current – the show would be extremely relevant to the millions who are playing this game.

A number of blogs exist that combine humor, analysis, and fantasy football fallout, but for a medium like television, The League should be disbanded.

Heyyyy-oooo!

D&D: Is Sneak Attack damage maximized on critical hits?

Is Sneak Attack damage maximized on critical hits? Short answer: yes.

For the long answer, first read what the Players Handbook says about critical hits on pg. 278:

Maximum Damage: Rather than roll damage, determine the maximum damage you can roll with your attack. This is your critical damage. (Attacks that don’t deal damage still don’t deal damage on a critical hit.)

Extra Damage: Magic weapons and implements, as well as high crit weapons, can increase the damage you deal when you score a critical hit. If this extra damage is a die roll, it’s not automatically maximum damage; you add the result of the roll.

Furthermore, according to this FAQ:

10. Which dice do I maximize when scoring a critical hit?

Only the dice you would normally roll to calculate damage are maximized. If another bonus (like from a weapon or feat) causes you to roll extra damage dice when scoring a critical hit, those dice are rolled as normal.

Given all this, I think that Sneak Attack damage is maximized on critical hits. The main point being that the definition of “Extra Damage” in this context refers to damage that occurs as a result of the critical; Sneak Attack occurs whether the attack is critical or not, therefore it is maximized.

The rules are clear, but I decided to write up this explicit answer given the confusion I’ve seen in various forums about this question.

fdisk problems with large partitions

I recently upgraded my 3ware 9550SX-8LP RAID5 array from 250 GB drives to 1 TB drives. After the lengthy RAID initialization process, I tried to create a partition using fdisk. Unfortunately, fdisk seemed to only create a partition size of about 400 GB instead of the 6+ TB that I expected. For reference:

  • fdisk version: v2.12q
  • OS: SuSE Linux 9.3 (x86-64)
  • kernel: 2.6.11.4-21.14-smp

After searching around for awhile, I came across Linux Creating a Partition Size Larger than 2TB by Vivek Gite. The article recommended using parted; my system had GNU Parted 1.6.21 and it worked just fine. Do remember that you need to mklabel gpt. And now df -h lists the partition at a hearty “6.4 T”.

For some reason I have the urge to do a little jig and sing “Mo’ money, mo’ money, mo’!”

D&D Character Builder crashes under Parallels

I had the D&D Character Builder running fine under a Parallels 5 Windows XP Pro virtual machine. But then a few weeks ago I ran a bunch of updates – both Windows and Parallels updates. Following the updates, the Character Builder would crash after trying to perform an update or launching the program. All of the following failed to fix the problem:

I didn’t have any useful snapshots of the virtual machine, so going back in time was not an option. At last I got fed up and installed a completely new Windows XP virtual machine, ran all the Windows updates, installed the Parallels Tools, then installed the Character Builder. SUCCESS!

When the Character Builder installs, it first automatically downloads and installs the .NET Framework. My guess is that the updates I ran somehow introduced an incompatibility between the .NET Framework and Parallels or the Character Builder. If I had it to do over again I would have tried this:

  1. uninstall Character Builder
  2. uninstall .NET Framework
  3. install Character Builder, allowing it to install .NET Framework itself

I’ll bet that would have worked, but I’ve already spent way too much time on this and don’t feel like testing my theory. Hopefully this blog post will help out anyone who finds themselves faced with this same irritating problem.

Dead EMACS R3U-6460P power modules

Following a power outage that outlasted our UPS’s, I noticed that two out of the three modules (MIN-6250P) in one of our server’s EMACS R3U-6460P power supply were dead. And the fan on the one module that still had an active LED was not spinning. Switching out the fans from the dead modules, I found that all the fans (SUNON KDE1204PKVX) were not functional. The working module was painfully hot when I removed it from the machine – no doubt due to the lack of heat dissipation.

So in terms of the modules dying, the following progression makes sense to me: 1) fan dies, 2) module overheats, 3) some critical component melts/fries.

However, I have a hard time believing that the power outage somehow fried the fans. More likely is that the fans were already dead or dying, and perhaps the power outage and loss of A/C were the straw that broke the camel’s back?

I am going to buy a new fan for the working module, then see if it will spin up. If it works, then that would imply that the fans are just kind of shoddy – even though they are around 5 years old. If the new fan does not spin up, then I would have to assume that somehow the power outage wreaked havoc with the modules.

UPDATE (2011-02-28): finally got around to installing a new fan in the working module; it began whirring away with no problems. So with a little splicing I’ve managed to rescue this $150 power module.