Thanks for that. I suspected that bit-rate was a factor, too. I don't actually specify bit rate anywhere; I've just followed the cookbook.
Bit rate is implicitly set, I expect, by the '-target ntsc-dvd' option on ffmpeg; and I suppose that the 'YUV4MPEG Stream' and 'ffmpeg pipe' settings determine the bit rate that Cinelerra will generate. So, now I need to figure out where to throttle the bit-rate without conflicting with, or overriding, any other parameters that I should care about. If 2-5 MB/s can produce acceptable video, that's certainly worth being told. This puts me on a path! Thanks again! (To be clear, my 'half-an-hour' estimate is based on actual experience using high street '4.7 GB' media.) On 2009-02-23 03:54, mskala wrote: > On Sun, 22 Feb 2009, John Detwiler wrote: > > 3. Standard DVD+R have 4.7 GB capacity, and hold about half an hour of > > mpg's. My finished project (including 'feature' and 'extras') will be > > at least 60-90 minutes altogether. > > DVD+R discs don't hold "half an hour" of MPEG video. They hold 4.7G, and > how much time that is depends entirely on the bit rate. There isn't one > standard bit rate that everybody uses. In order to fill a DVD in half an > hour you must be using a bit rate of about 20Mbps, which is almost > certainly *much* too high. Many decoders won't even operate properly when > fed such a high-rate stream; I think the spec sets a maximum of about > 10Mbps. Commercially published DVDs routinely fit several hours on a > single regular-density 4.7G disc, with bit rates as low as 2Mbps. Try > reducing your bit rate by a factor of at least five. > > Is it possible you're estimating based on the space consumption of > uncompressed video, or the output of some kind of camcorder that does > some other kind of compression, like DV? > > _______________________________________________ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
