On Mon, Feb 13, 2012 at 7:04 AM, bettinger cédric <[email protected]> wrote: > Hello, > > I am trying to find out how work the volum filter. I just have some issue to
An early thing you should do is 'grep volume mlt/demo/*' > understand this documentation : > http://mltframework.org/twiki/bin/view/MLT/FilterVolume > > I am using the following propertie : > > identifier: normalise > title: Normalise > type: string > description: | > Normalise the volume to the specified amplitude. > The normalization may be indicated as a floating point > value of the relative volume. > The normalisation may also be indicated as a numeric value > with the suffix "dB" to set the amplitude in decibels. > > > Here is my code which works : > > Mlt::Filter filter(*this->readingVideoProfile, "volume"); > > Mlt::Properties properties(filter.get_properties()); > > properties.set("normalise", "50dB"); considering the default is -12dB, 50dB does not seem very sensible > > this->mainVideoProducer->attach(filter); > > > It seems that the higher "normalise", the lower the volume. But what I'd First, is "normalise" really what you want? The documentation is not clear about this as I only recently improved the sox version of the documentation about normalise, but the "normalise" here is an old attempt of mine at a "dynamic" normalisation for realtime operation as opposed to the traditional two-phase file-oriented normalization. The result it gives is not always so good. But I simply haven't removed or deprecated it. > like to do is to change the initiale volume with a percentage, such as 50%, So, you want to do a fade in? Or you want to make the first N seconds 50% and then jump to 100%? OK, again, look at the demos, or mock this up in Kdenlive or OpenShot and view the XML it generates to learn more. These are general learning techniques when you do not want to consult the source code. > 200%...But I don't understand how is suppose to be the "floating point > value". I tried things like that ".9", "2", "0.1", "1000" but it doesn't For a simple volume adjustment, use the "argument" or "gain" parameter. "argument" is a special parameter that means append it to the service name with a colon (:) in between: volume:0.5. "gain" is not documented, but it appears in the demos and is mapped to the argument in this filter. > seems to work. May be someone know ? Or may be I am suppose to find a > correlation between the volume in percentage and the one in dB ? > > Thank you, > > Cédric -- +-DRD-+ ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Mlt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mlt-devel
