On Thu, Jul 23, 2015 at 11:04 AM, tim nicholson < nichot20-at-yahoo....@ffmpeg.org> wrote:
> On 22/07/15 14:29, Matthieu Bouron wrote: > > Hello there, > > > > The following patchset add support for j2ki/mxf files (which store frames > > using the separate fields / segmented frame layouts, ie: fields are > > stored in seperate frames) through the insertion of filters at the > > ffmpeg/ffplay level. It differs from my original attempt which introduced > > modifications at the decoder level, which in my opinion was wrong and > > introduced several limitations, such as: > > > > [..] > > I may be missing something here, as my mind has been on other things. > But currently most mxf material I see that ffmpeg correctly handles is > "frame wrapped" with the frame layout as type 1 (SEPARATE_FIELDS). > Can you provide samples with this layout ? I might have misinterpreted the MXF specs on this one. My understating is that, separated fields (as well as segmented frame) means that the fields are stored in a different "packet" (that might no be the right world for it). Also it might be specific to jpeg2000 (see below), i'll have to look again at the mxf/jpeg2000 spec again. > > AFAIK these do not use filter insertion etc to work. > Are these therefore handled at the decoder level, in which case:- > > a: they will not benefit from doing things at the format level. > > b: J2K will be an exception to the current way of doing things, which > could add confusion. > It might be a jpeg2000 exception and my code will only insert the right filters for the jpeg2000 codec. > > If they are not currently handled at the decoder level, the surely the > format level must already handle this material correctly so why is your > patch needed in this form? > This kind of file is not handled correctly by ffmpeg at the moment as each field is stored in a separate jpeg2000 image. You can find a sample attached to this bug https://trac.ffmpeg.org/ticket/1102 Matthieu _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
