Movies from the Minolta DiMage X50

I went to a Pop Will Eat Itself concert recently, and for the first time had a reason to test out the video-recording abilities of the new camera. Given the camera's minimal dimensions and tiny lens, I wasn't expecting great results. However, despite the gloominess of the venue, I was (mostly) pleasantly surprised by the results!

As you can see, the picture quality was fairly good. I had the camera set to record at the maximum settings (320x240 resolution, 30fps). Watching it on the camera was fairly uninspiring, but once I had copied it over to my Mac the apparent quality improved dramatically.

I was however surprised by the size of the video clip. A 2 minute 30 second clip recorded on the camera turned out to be 86.5MB in size. I was curious as to why it was so huge, so I set about doing some investigation. Opening the file in QuickTime Player revealed that the video component was recorded in the Photo-JPEG format! I can only presume that the limited CPU power of the camera limits it to recording in largely uncompressed video and totally uncompressed audio.

The actual settings were:

Photo JPEG video, 320x240, 4700 kbps (!!!!)

PCM audio, 8 bit, mono, 7875Hz, 60 kbps

4700kbps ! That's a higher bitrate than some DVDs for an image less than a quarter of the size! And then to top it all off the audio component is of a ridiculously low quality.

I wanted to save the clip, but in a more efficient way. I also wanted to contrast it to a more modern way of storing video, so I fired up ffmpegX and ran a few conversions:

Converting the clip to an xvid/mp3 of equal dimensions and very similar visual quality resulted in a 10.6MB file comprising an 8.1MB 320x240 30fps 450kbps xvid video stream and a 2.2MB 144kbps mp3 audio stream! Given that 160kbps mp3 is generally considered to be sufficient for virtually CD-quality, you can see how much the Minolta's capabilities could be improved.

Purely out of interest I also used ffmpegX to convert the clip to DVD specifications. My 320x240 86.5MB photo-JPEG clip turned into a 720x480 75.2MB mpeg2 clip. Definitely bloated!

Related entries

One. Slick. Camera. - 3 January 2005
Stop iphoto from importing images - 14 January 2005
Encoding for SmartMovie - 23 May 2004
RealVideo to SmartMovie - 26 August 2004
Real Mplayer - 9 October 2004
From iMovie to YouTube, a.s.a.p. - 28 March 2007
Full screen video on the P800 - 21 May 2004
Fairly major ffmpegX update - 24 January 2005
Converting Ogg (ogm) and Matroska (mkv) video - 15 June 2004