[PATCH] shm: Allow caps to change in PLAYING state

Submitted by Joshua M. Doe

Link to original bug (#699352)

Description

I'd like to extend shmsrc/shmsink to support changing of caps while in the PLAYING state, though I'm really only interested in width and height changing. A new ShmPipe command would be needed, such as COMMAND_NEW_CAPS, which would include a string set by gst_caps_to_string in shmsink. Upon shmsrc receiving this command, in 0.10 the new caps would just be set to the subsequent buffers, and in 1.0 a CAPS event would be sent. Certainly this breaks API compatibility somewhat, but this could be mitigated by adding an allow-reconfigure property to shmsink that defaults to FALSE. Is any of this reasonable?