[MPlayer-dev-eng] An Idea - I cannot develop it. Scrap it if it is not any good.

[Loren Merritt]

On Fri, 5 Aug 2005, Oded Shimon wrote:

> On Mon, Jul 25, 2005 at 09:37:59AM -0400, Jason Tackaberry wrote:
>> On Mon, 2005-07-25 at 14:26 +0100, VJ wrote:
>>>   I was just thinking if somebody adds this feature to mencoder
>>> someday - a filter which shows the frames on the screen as they are at
>>> the stage where the filter is added in the chain. It could be used to
>>> show the encoding as it proceeds. It could show all frames or every
>>> nth frame
>>
>> I have developed something like this called vf_outbuf, which writes the
>> contents of the video to a shared memory buffer.  An external
>> application can handle the display portion of it, which is how it should
>> be in mencoder's case anyway.  Although I didn't build it for the type
>> of thing you're describing, it would be possible to use it that way.
>
> That sounds like it would work pretty well... I do wish it would be
> possible to actually preview the ENCODED video while encoding, if it did
> MEncoder would be the first program on earth to support it. :) The obvious
> problem is the keyframing... Solution is to either decode the entire video
> which is wasteful or preview just keyframes which isn't very representative
> of the encode... :/

That's easy: The codec has to decode its own video anyway for motion 
compensation of the next frame. While it's sometimes possible to take 
shortcuts (e.g. with B-frames), in general you could just add an option 
for the codec to export the reconstructed frames.

--Loren Merritt