Video Website Datasheets #5: blip.tv
January 18, 2008
blip.tv allows you to play back uploaded videos back in their original form (assuming say mp4 or QuickTime) as well as in Flash Video format. Unfortunately it is difficult or impossible to embed mp4 videos into blogs (unless privately hosted), although that is likely to change with Flash 9′s native support for playback of mp4.
For the purpose of this post I am reporting on the Flash encoding, as with the earlier posts in the series. Quality with blip.tv encoded flash video is a reasonably pleasing compromise.
blip.tv
A. Output Quality
File Format: flv (Flash video)
Video Codec: On2 VP6
Video Resolution: As source
Video Bitrate: 435 kbps
Max. GOP: 30 frames
Frame-rate: 15 fps
Always re-encoded: No. If source is in flv format it will not be re-encoded.
Audio Format: MPEG-1 Audio layer 3 (mp3)
Audio Channels: mono
Audio Sampling Rate: 44.1 kHz
Audio Resolution: 16 bit
B. Input Flexibility
Input File Formats/Codecs include: Just about anything. Quicktime/Window Media preferred. Uncompressed DV/MPEG2 discouraged.
Max. Video Length: None
Max. File Size: None (100Mb maximum recommended)
C. Comments
- Frame-rate of 15 fps is low, and does lead to some jitteriness, but not as obtrusive as veoh’s 12 fps.
- Overall a good compromise. Reasonably high bitrate and short max. GOP (by video website standards), retention of original resolution, all favour quality. The counterbalance is the low frame-rate.
Summary of just the key data affecting video quality for all websites analysed can be found here.
For all Video Datasheet posts click here.
