After Effects error:RAM preview needs 2 or more frames to playback
 
“RAM preview requires 2 or more frames for playback “or” explained that memory capacity is too small”
 
 
Another small finding was that WHEN AE rendered by pressing the “0” button, if it said “After Effects Error :RAM Preview needs 2 or more frames to Playback “, the popular online message was that it was running out of memory, so just release it. In fact, there is a small side door, which is to check the From Current Time check box on the right. Accidentally discovered..

 
I used the English version and noticed that the RAM preview changed when I adjusted to different Settings.

in the AE menu, you can follow the following steps to find out the RAM preview memory configuration options:

so if you set the adjustment bar to the far right for the fastest preview speed, press 0 again, the following prompt may appear:

“After Effects Error :RAM Preview needs 2 or more Frames to Playback”, so this graphical option should be adjusted to avoid this error.

the other RAM preview also have different options:

I am will adjust the tie rod moved to the far left, anyway, large memory capacity (64 – bit Windows 7 of 8 gb of memory), then I am chose “From the current frame” this option, the English meaning is From now this frame (start preview), activate this option has the advantage of, avoid to start From scratch every time.

then I first move the pointer of the timeline to the place I want to review, and then press the 0 key of the keypad to start the rendering, I found that the RAM render preview can be accumulated.
although rendered will likely stop somewhere, if you press the keypad 0, can timely preview with audio clips, and then if you press the keypad 0, if memory allocation is reasonable, can also continue to accumulate, every rendering is tight as the last rendering the end point, this section after accumulation, the green line of time online will have different rendering process with time, gradually accumulate, until will run out the allocation of memory. This allows you to view long rendered content.

also:

render after press 0 can only play the part of the green line, if it is a green line between the blue line or blank, then press 0 when the preview will be stopped on the blue line starting point (or starting point of the blank, the end of the green), if you would turn it into green and sustainable, in former time pointer positioned in the green line, and choose “” From the current frame”, continue to press the keypad 0, and the green line in the middle of the blue lines or fill blank section was JiCheng green. It is recommended that you always use the 0 key of the keypad, so that you can watch long segments of accumulated content with sound. When viewing the RAM preview, if you reach the key point, press the * key on the keypad to mark, which is useful for audio editing in the future.

preview window has the “SHIFT+RAM” option, which can be rendered every other frame preview, generally defined in the project default resolution about half of the definition, and for the frame-by-frame jump preview. Also associated with this is the option “SKIP”, which allows you to choose how many frames you want to render in to save time. Above SHIFT + RAM is to skip a frame.
, of course, selects 0 to render everything (no omitted interval frames). The above two items should be noted: because some people may like to keep RAM rendering content, but you should pay attention to the interval frame parameters (1 and 2 or 0?). And possible audio spacing issues. Note that select 0: is all the spaceless render!

(CTRL+ keyboard 0 can save RAM preview content)

with audio preview, might as well CTRL+4 to activate the audio level indicator to see if the audio is overloaded…

preview has a lot to play with… As long as you stick to the zero key on your keypad, you’ll iterate over the steps, render, play, accumulate render…
green line is part of the timeline can be spliced together, mainly is the stitching together of the persistent green line, can real-time with audio playback preview, if you insist on cumulative preview render, allocated memory segment will make the corresponding adjustment, is likely to be behind the rendering gradually turn green, and in front of the green line is gradually becoming blue…