2007/12/10, Herman Robak <[EMAIL PROTECTED]>: > YUV, YUVA, RGB, RGBA or floating point presision color format? > My guess is that 90% of the users ought to use YUVA, so let that > be the default. > Is the difference in memory footprint between YUV and YUVA so big > that it warrants a setting? I'm not sure.
Two things: First, I think in most cases, convinience is more important than trying to save every possible tiny bit of memory. Second, RGBA is 32bit, RGB is 24bit. Most SSE and Fast vector operations in CPUs work on 32bit aligned data. My totally naive guess is that in certain cases, the 32bit alignment of Alpha-Enabled Data might be faster to process. But I won't claim that until properly benchmarked. ;-) > PAL, NTSC or anything else? Firstly, that should depend on what ---8<--- > Interlacing... That's so involved that it belongs in an essay > of its own! Cinelerra must know more about interlacing, so > that the users can get by without know anything about it. > > Aspect ratio. There is not really any setting in Cinelerra ---8<--- So, Framesize, Interlacing and Pixel-Aspect are hard problems. In my humble Opinion the only serious attempt to solve that problem in a fashion that is at least somehow universial, is the following. You need several tools, One Tool would be like the unix "file" utility. A tool that scans a video source and makes a good guess about what kind of Interlacing and Pixel-Aspect is being used. The Second Tool is some kind of machine readable Knowledge-Database, that is filled with rules and heuristics about common frame-sizes, their assorted pixel-aspects, and how and when and when certain formats are used, and how they should be converted to other formats when necessary. This information will likely be useful to the "Source-Analysis-Tool" as well, as mentioned in the paragraph above. Additionally the Knowledge Base should also be sprinkled with human readable information, Such as: "You are exporting a 24p file to 29.97i, a 3:2 Pulldown will be performed for conversion, for more information about that, click here...". Ideally the knowledge base should have information available for most of the common cases. In case there are conflicting rules, or two equally likely options, the database should have enough information available to ask the user the question whether he prefers A or B. Will this work? I think it will, take the debian installer for example, it is very good in asking "clever" human understandable questions, and it provides sensible options as answers. Try it one day, maybe you will understand what I mean. Surely some users might be overwhelmed in some situations, but if it works well, most cases should be covered, so the system could work without interaction. And there could be some option like a "tell me more" button, that will provide the user with detailed information about why a certain conversion algorithm was selected. In short, built an expert system that has all the current knowledge about video conversion compiled into the most usable form. Cheers -Richard -- Are you teaching the What and the How but without the Why and the When? _______________________________________________ Cinelerra mailing list [email protected] https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
