Archive for category Digital Rights

DVD to mp4

Posted by bumscientist in Computing, Digital Rights on January 26, 2010

$ mplayer -dvd-device /mnt/disk dvd://<title >

$ mplayer dvd://1 -dumpstream -dumpfile dump.vob

ffmpeg -t 15 -i VTS_01_1.VOB -deinterlace -acodec libfaac -ab 160k -vcodec libx264 -vpre hq -b 5000k -threads 0 output.mp4

References

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Checksum

Posted by bumscientist in Computers, Computing, Digital Rights on December 11, 2009

I started backing up all of my DVDs onto my hard drive, but how will I know when my data is corrupted?

The answer is to compute a hash with md5sum or sha1sum. Better yet, use both. md5sum is not considered secure, because hackers can insert bits while retaining the same hash. For random corruption, the md5sum should work fine. For finding out if someone has hacked your files, you should use sha1, which is still considered secure. The thing about cryptography is to not make something secure, but to make something secure for some period of time.

Microsoft has a file check integrity verifier, fciv.exe.

I guess after I compute the sums, I would need to check them every year or so just to make sure my hard drive is still okay.

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PS3 Video Encoding

Posted by bumscientist in Computing, Digital Rights on October 5, 2009

The information for encoding h.264 for PSP on the ffmpeg FAQ is outdated. So I had a hard time encoding h.264 video for my PS3, because both my x264 and ffmpeg are complied from SVN/git.

I kept getting stupid errors about “broken ffmpeg default settings detected” among other errors. I’ve found this blog post helpful and there’s a psp guide. The key was the -vpre hq. Notice the use of Big Buck Bunny, an open-movie project.

ffmpeg -t 10 -i big_buck_bunny_1080p_h264.mov -acodec libfaac -ab 160k \
-vcodec libx264 -vpre hq -b 5000k -threads 0 -s 1920x1080 output3.mp4

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Downloading Video Streams

Posted by bumscientist in Computing, Digital Rights on October 2, 2009

So I’ve been wanting to download some class videos and I’ve lived with 2 problems with these videos for a long time, only one of which I knew about.

I download the stream using mplayer

$ mplayer mms://somehost.com/filename.wmv -dumpstream -dumpfile classlecture.wmv

I usually just watch that wmv in vlc, mplayer or windows media player, but I’m unable to seek. This problem can be fixed by reindexing the wmv. When you dump the stream it is missing the index information. There are two programs that I’ve found to work well in reindexing the stream. One is asfbin and the other is a utility of Windows Media encoder. The upside is that I can now seek and the file size is smaller since the stream actually contains multiple resolutions and audio channels. I can choose which streams to dump in the Windows Media encoder utility.

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Laptop Battery Life Test

Posted by bumscientist in Computing, Digital Rights on November 30, 2007

I was checking the MacBook Pro for battery life and noticed that the most grueling tests are based on playing a DVD since spinning the DVD takes a lot of energy. This is not typical usage at all. If I were to watch a DVD, I would first rip it to my hard drive and watch the mounted iso. This is an excellent exercise in fair use. First, I don’t have worry about the disc skipping. My current laptop has a first generation laptop DVD drive, so sometimes I get skipping when I watch a DVD, which is very unfortunate. To get around this, I have to watch it from my hard drive. I’m willing to wait for the DVD to copy over, which takes just as long as watching the DVD, because it is such a horrible experience to watch a DVD that skips.

The MacBook Pro has everything I want, except for maybe a solid state drive. I’m still weary of those, because they intrinsically have a lot of non-working areas, which gets bypassed by circuitry on the drive. A flash based drive definitely has a shorter retention lifespan than a disk drive, but it should take less power and is shock proof.

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