A local news station provides good video directly from TV but they strangely take 50MB for just a few minutes of video. The files should be more like 10MB in size.
Where the heck are you getting the "should be" figure? Video file sizes can vary widely depending on format, compression, color model, resolution, and a number of other factors.
DVCPRO50 (the standard format most TV News stations use for Standard Def content) uses 50 Mbits/sec, which works out to roughly 510MB per minute of record time. DVCPRO HD (where many ENG facilities are moving, along with DVCAM and XDCAM) is 100 Mbits/sec, or roughly 1GB per minute. Even these file sizes are compressed immensely (and not losslessly -- almost all video compression is lossy, certainly including DV compression).
Anything less than that
is being compromised in quality in some way (and in most cases in
MANY ways). You can certainly recompress whatever files they're giving you, but be aware that this is effectively the same thing as recompressing a 32kbps MP3 into a 12kbps MP3. You aren't going to get very good results. A much better option would be, of course, to use the original source files to create the lower-bitrate version, but you aren't going to have access to those. I'm sure the TV station compresses them to a file size that they feel provides an appropriate level of quality (and, I'm sure, has a balanced impact on their bandwidth capabilities).
That's not to say you can't recompress the video, but be aware of what you're doing. I'm only disputing the fact that you said it "should be" a certain size. Uncompressed Standard Def video runs about 1440 MB/minute, anything less is making some sort of compromise.
Author
Topic: What types of video conversion? (Read 1119 times)