> On 16 Sep 2015, at 9:11 PM, Andy Furniss <[email protected]> wrote: > > Andy Furniss wrote: >> Moritz Barsnick wrote: >>> On Wed, Sep 16, 2015 at 05:38:30 +0800, Rick C. wrote: >>>> Output #0, dvd, to '/Users/mahalko/Desktop/output.vob': >>> [...] >>>> Stream #0:1: Audio: ac3, 0 channels, 128 kb/s >>> >>> And I'm not sure I understand the concept of zero channel audio >>> streams. ;-) >> >> There are valid uses in wav at least though ffmpeg doesn't like >> them. >> >> The case I am thinking of is ambisonic formats where 0 channels >> indicates not for speakers (I beleive DTS and MPEH-H can also handle >> this). > > Having had more time to remember old tests and look at the wav spec I > think that what was 0 was the dwChannelMask in the wav. > > From the microsoft site > > http://msdn.microsoft.com/en-us/windows/hardware/gg463006.aspx > > If, for example in a multi-channel audio authoring application, no > speaker location is desired on any of the mono streams, the > dwChannelMask should explicitly be set to 0. A dwChannelMask of 0 tells > the audio device to render the first channel to the first port on the > device, the second channel to the second port on the device, and so on. > This also means that if the device doesn't know how to process the raw > audio streams, it should not accept the multi-channel stream with a > dwChannelMask of 0. A device like a digital mixer or a digital audio > storage device (hard disk, ADAT, and so on) might want to accept formats > without particular speaker locations. > > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
Just want to say thanks for all the replies and help :-) _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
