Hi, Paul,
From: Paul Hammant [mailto:p...@hammant.org] > Markus - I've read your section on deltification and I can see evidence in > what you wrote that you're concurrently in favor of and against it (the > file-suffix exclusion idea). Can you re-read and clarify? >> I agree partly. Skipping compression for known "incompressible" formats like >> mpX, png or gif can come with performance benefits, saving some CPU cycles >> (see the recent performance disccussions on this list) >> However, I'm not sure whether the same amounts for deltification. There are >> editing tasks which do not reencode the whole image / movie, and they can >> profit from deltification, for example: >> - Lossless rotation / cropping of jpeg images. >> - Editing / stripping the EXIF data of jpeg images. >> - Embedding / dropping the preview thumbnail of jpeg images. >> - Lossless MP3 editing (e. G. via mp3DirectCut). >> - Editing MP3 meta data (e. G. Song Title) >> (... and more...) >> In all those cases, skipping deltification can drastically increase storage. To summarize it up: I expect significant benefits in some use cases by skipping the compression, thus I'm +1 if benchmarks prove it's worth the effort. I see the danger of drastically increased bandwith and storage size (transferring/storing the whole mp3 instead of just some changed meta data bytes) in some common use cases when deltification is skipped. Thus, I'm skeptical (count it as -0), and I'd kindly suggest to do some benchmarks for those cases before implementation, and clear documentation of the possible negative effects if it's implemented. Best regards Markus Schaber CODESYS® a trademark of 3S-Smart Software Solutions GmbH Inspiring Automation Solutions 3S-Smart Software Solutions GmbH Dipl.-Inf. Markus Schaber | Product Development Core Technology Memminger Str. 151 | 87439 Kempten | Germany Tel. +49-831-54031-979 | Fax +49-831-54031-50 E-Mail: m.scha...@codesys.com | Web: http://www.codesys.com | CODESYS store: http://store.codesys.com CODESYS forum: http://forum.codesys.com Managing Directors: Dipl.Inf. Dieter Hess, Dipl.Inf. Manfred Werner | Trade register: Kempten HRB 6186 | Tax ID No.: DE 167014915 This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden. Best regards Markus Schaber CODESYS® a trademark of 3S-Smart Software Solutions GmbH Inspiring Automation Solutions ________________________________________ 3S-Smart Software Solutions GmbH Dipl.-Inf. Markus Schaber | Product Development Core Technology Memminger Str. 151 | 87439 Kempten | Germany Tel. +49-831-54031-979 | Fax +49-831-54031-50 E-Mail: m.scha...@codesys.com | Web: codesys.com | CODESYS store: store.codesys.com CODESYS forum: forum.codesys.com Managing Directors: Dipl.Inf. Dieter Hess, Dipl.Inf. Manfred Werner | Trade register: Kempten HRB 6186 | Tax ID No.: DE 167014915 ________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden.
