Allocate an AVHWFramesContext tied to a given device context.
@param device_ctx a reference to a AVHWDeviceContext. This function will make
a new reference for internal use, the one passed to the
function remains owned by the caller.
@return a reference to the newly created AVHWFramesContext on success or NULL
on failure.
Allocate an AVHWFramesContext tied to a given device context.
@param device_ctx a reference to a AVHWDeviceContext. This function will make a new reference for internal use, the one passed to the function remains owned by the caller. @return a reference to the newly created AVHWFramesContext on success or NULL on failure.