On Wed, 5 Nov 2014 03:19:04 +0100 Michael Niedermayer <michae...@gmx.at> wrote:
> On Wed, Nov 05, 2014 at 02:59:45AM +0100, wm4 wrote: > > On Wed, 5 Nov 2014 02:44:12 +0100 > > Michael Niedermayer <michae...@gmx.at> wrote: > > > > > On Wed, Nov 05, 2014 at 02:13:29AM +0100, wm4 wrote: > > > > The header pixfmt.h contains the following comment in the pixel format > > > > list doxygen: > > > > > > > > * @note > > > > * Make sure that all newly added big-endian formats have (pix_fmt & 1) > > > > == 1 > > > > * and that all newly added little-endian formats have (pix_fmt & 1) == > > > > 0. > > > > * This allows simpler detection of big vs little-endian. > > > > > > > > > > > This is currently broken for the following formats: nv20le/be > > > > gbrap16le/be > > > > > > yes > > > > > > > > > > > > > > Obviously, this can't be fixed until the next ABI bump. But more > > > > > > can you post a patch which does make sure it gets fixed then? > > > and or that documentation corrected > > > > As I said, I could write a patch that adds a proper flag, which the > > user can use to determine endian properties. I'd also adjust the > > documentation and inform the user that the old way doesn't work anymore. > > iam fine with that but you might run into some obstacles > the flags are uint8_t and all used > adding a new field might require some care to ensure ABI compatibility > and might need accessor functions I didn't realize that. It sort of ruins the idea. I see two solutions without breaking ABI: - add a "flags2" member, which contains the flags; duplicate it, and deprecate the old "flags" member - store the high bits of the "flags" member in a new "flags2" member, and add an accessor which returns the full flags There's also the deprecated av_pix_fmt_descriptors[] variable - if we care about this, extending AVPixFmtDescriptor is not possible without breaking ABI. And currently this symbol is actually exported. > > > > > I'm not so much interested in creating big ifdef messes. > > neither am i > > [...] > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
