On Thu, May 9, 2019 at 1:52 AM Nicolas George <geo...@nsup.org> wrote:
> Jun Li (12019-05-06): > > I agree with it that the patch can't solve the case that "not all frames > > have the same orientation". > > The only way I can think of (correct me if I am wrong) is a filter that > > dynamic do tranformation per frame. > > > > From a technical perspective, this kind of media is absolutely possible. > > For example motion jpeg consists of jpg with different orientations. > > But I assume it is rare with my limited knowledge. What do you think? > > I think they can be quite common: imagine somebody trying to make a > slideshow from vacation photos. > > A filter that applies the transform on each frame based on the metadata > would be my first idea too. We already have the filter: the one that > does the transform right now. It needs to be adapter to change the > transform on a per-frame basis. That should be easy. > > But it is a bit harder than that: lavfi does not support real > reconfiguration of the stream properties. Therefore, this filter must be > added to the small list of "temporary" exceptions in the framework. And > the user will need to insert scale/pad/crop to normalize the output. > That needs to be documented. > > Regards, > > -- > Nicolas George > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". Hi Nicolas, Thanks for the input, I will take a look at the transform filter. The image's exif ("orientation") info is kept inside of frame metadata, maybe the filter can directly read from frame, instead of re-config the stream level metadata ? How about that ? Best Regards, Jun _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
