On Wed, 25 May 2011, Sylwester Nawrocki wrote: > Hi Guennadi, > > On 05/25/2011 12:11 PM, Guennadi Liakhovetski wrote: > > Hi Scott > > > > On Wed, 25 May 2011, Scott Jiang wrote: > > > >> Hi Hans and Laurent, > >> > >> I got fmt info from a video data source subdev, I thought there should > >> be a helper function to convert these two format enums. > >> However, v4l2_fill_pix_format didn't do this, why? Should I do this in > >> bridge driver one by one? > > > > Because various camera hosts (bridges) can produce different pixel formats > > in memory from the same mediabus code. However, there is a very common way > > to handle such video data in the bridge: store it in RAM in a "natural" > > way. This mode is called in soc-camera the pass-through mode and there is > > an API to handle this mode in drivers/media/video/soc_mediabus.c. If this > > Sorry about getting off the topic a bit. > > As some media bus formats require different conversion process in the bridge > to obtain specific format in memory (fourcc) I was wondering whether it would > be reasonable to indicate the "natural" fourccs for the applications when > enumerating formats supported by the bridge/DMA with VIDIOC_ENUM_FMT? > So applications are aware what are the "natural" formats and which require > lossy conversion. And in this way could choose formats that yield better > quality. Yes, in principle this seems like a good idea to me. Of course, somebody will have to teach the user-space to use this information:) > Now there are following flags available for struct v4l2_fmtdesc::flags > > V4L2_FMT_FLAG_COMPRESSED > V4L2_FMT_FLAG_EMULATED > > I thought about something like V4L2_FMT_HW_EMULATED or V4L2_FMT_FLAG_LOW_QUALITY. > > I not happy with those exact names but I hope that gives a basic idea what > I am talking about. > Possibly I am missing other ways to achieve the same. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
