Frame advance - Frame by Frame - Bugzilla?

Feature requests for VLC.
FrameByFrame

Frame advance - Frame by Frame - Bugzilla?

Postby FrameByFrame » 30 Jul 2005 15:37

Should someone open a feature request in bugzilla? Is anyone considering this trivial change?

I would look myself in the code, I am hoping it wouldn't be too easy if I see where the play/pause event is handled, and the way the speed it used to advance frames.

A frame by frame is not just important, but vital for this media player!

I am shocked how every version of Microsoft Media player was more cut down than the last, except for their really annoying interfaces (REALLY annoying).

For instance: Media Player - space bar used to pause/play. Can you guess what it does now? NOTHING! Well done the idiots at redmond.

Anyway, I agree with the many people I saw here and on google search, can someone add a frame advance/retreat using the right/left arrow keys, or interface buttons.

Thanks!!!!!!!!!!!!!

FrameByFrame

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Postby dionoea » 30 Jul 2005 15:47

frame by frame is far (i repeat far) from being trival in VLC (i would say near impossible considering VLC's network orriented conception)
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chaunceychu

Postby chaunceychu » 25 Aug 2005 10:50

I second the frame advance/retreat. Makes life easier to get the "perfect" screencap from a vid.

Guest No. 11

Agreed 100%

Postby Guest No. 11 » 28 Aug 2005 21:04

Impossible? It doesn't have to be a global command, but would be essential for us users who use VLC as our default media player. I've been trying to capture specific frames all day long today and using the spacebar is such an imperfect way to step through a video for that specific frame you need, that sometimes I had to play a sequence 10-20 times (depending on the video source and how it was encoded, some frames move faster than others - especially for those of us on lower spec machines, I imagine...)

The only media player I know of that allows you to advance frame by frame (forward works great, reverse is iffy) is Jiao MPEGPlayer, which is a bit outdated for playing a lot of newer media. Are there any others (that don't require XP or .NET)?

Guest

Re: Agreed 100%

Postby Guest » 01 Sep 2005 17:57

Impossible? It doesn't have to be a global command, but would be essential for us users who use VLC as our default media player. I've been trying to capture specific frames all day long today and using the spacebar is such an imperfect way to step through a video for that specific frame you need, that sometimes I had to play a sequence 10-20 times (depending on the video source and how it was encoded, some frames move faster than others - especially for those of us on lower spec machines, I imagine...)

The only media player I know of that allows you to advance frame by frame (forward works great, reverse is iffy) is Jiao MPEGPlayer, which is a bit outdated for playing a lot of newer media. Are there any others (that don't require XP or .NET)?
Have you tried Media Player Classic?
I'm pretty sure it does

Guest No. 11

Re: Agreed 100%

Postby Guest No. 11 » 03 Sep 2005 01:02

[quote="Anonymous"]
Have you tried Media Player Classic?
I'm pretty sure it does[/quote]
I stand corrected. I just recently installed MPC and have been wrestling with the video overlay and a few other niggles, so didn't notice that feature. Thanks. Still, no frame grab in MPC and only partially in vlan (I assume; the other thread got no response, so I dunno if that prob is on my end of vlan's end...)

Guest

Postby Guest » 21 Dec 2005 00:51

frame by frame is far (i repeat far) from being trival in VLC (i would say near impossible considering VLC's network orriented conception)
The OS X DVD Player can do it (step forward, anyway). Most stand alone DVD players can do it.

If VLC is to be a worthwhile replacement to evil, non-free DVD players on the desktop (and pardon my impertinence, but wasn't that the original reason for its development?), it needs to have a frame-by-frame/step feature.

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Postby dionoea » 21 Dec 2005 18:04

VLC isn't like other players ... it was meant to read network streams. So it has no notion of what a frame is (except when displaying it) and can't skip 1 frame, go back one frame and stuff like that.b
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Willie

Frame by frame

Postby Willie » 18 Jan 2006 04:53

Well that's too bad then. It makes it rather useless for those of us who just want to play files saved on our computer.
It has skip forward and back functionality (press Alt + Arrows, or Shift + Arrows). Why not just make that happen in the smallest increments possible?

Obviously, for a network stream, this may not be possible. However, I'm sure for a local file, VLC can handle reading back a few frames to reconstruct the one frame I want to see.

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Postby The DJ » 18 Jan 2006 15:36

You don't understand. The very concept of doing that is not part of the design of VLC. it would require huge changes to the way VLCs inners work. It's not gonna happen any time soon.
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Frame advance - Frame by Frame - Bugzilla?

Postby mathieu44 » 15 Feb 2007 00:33

OK, it seems that VLC's design makes it very complicated to play one frame forward or backward.

I think that going one frame backward would be more complicated than going one frame forward (because of the network streaming design of VLC).

But would it be possible to go one frame forward ONLY (and not backward) ?

I mean: a playNextFrame function would be very great.

Along with a GetCurrentFrame (or GetCurrentPicture or GetSnapshot or another name) function to capture the current frame, these two functions (playNextFrame and GetCurrentFrame) would enable VLC to be used in many more various applications than "only" video playing/recording/streaming.

Indeed, many image and video processing applications could be developped using VLC for decoding/networking/saving purposes.

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Postby CloudStalker » 15 Feb 2007 01:05

Yes, this is one of the things that I would like to see as well. I used to use my PowerDVD to take snapshots, and being able to go one frame backwards/forwards to obtain the perfect snapshot was very useful.

Well it’s been over a year since a developer has responded to this thread; maybe VLC can do some things now that it couldn’t before.

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Postby Jean-Baptiste Kempf » 15 Feb 2007 08:46

Well, no... It cannot.
The thing is that VLC is a packet-based player, which is great for networking play, read unfinished files, read broken files, etc...

However, it is difficult to have this frame by frame thing. One way would be to do a play-pause, very quickly, but I don't know yet if this is doable...
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Postby CloudStalker » 15 Feb 2007 09:10

Well the pause feature is already a little bit delayed, so I don’t see this working too well either, unless it has been fixed for version 0.9.0

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Postby BlackShark » 05 Mar 2007 17:11

Hello (first post)
I'm also very interested in that feature, an other thing i've noticed is that lag when using the play/pause button.
I'm not a programmer, i can't even read the code but what i understand just by watching the advanced options is that VLC is a hungry beast which can't stop "eating" (processing) video data unless the source cache is empty. And the play/pause button only controls how the cache is filled instead of how that cache is read.

So would it be possible to lock the last buffer right before the video is displayed in order to have at least some kind of "instant pause" while the source cache empties in the background and fills up again from the corrected position. It would take some time to switch between frames but at least a "next frame" function would be doable.

Am I right or is what i said a complete nonsense ?

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Postby glossolalie » 15 Mar 2007 15:22

I was wondering too if a plugin would handle this kind of feature.
I mean an access plugin (i don't really know what kind it could be) that buffered some frames and could display/save/process it with the hability to go forward and backward in his buffer....

I just say this cause if it could, i mean if this a good way to handle frame by frame seeking
I WILL start to write some code just now.

I really need this kind of features.

Right now i am using ffmpeg with some modifications in order to get frame by frame random access. But I would really like to have it on vlc player because it contain large more codecs and lot of more appealing stuff.

So is it possible.??? Got my fingers burning on the keyboard ... Get Set.... Ready....? go ?

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Re: Frame advance - Frame by Frame - Bugzilla?

Postby jenumba » 13 Jan 2008 05:34

I've been waiting and hoping that VLC would implement a frame step feature for a long time.

I'm an animation student and being able to view animation files frame by frame is absolutely imperative to understanding and learning how an animated scene works. I'd love to make VLC my one and only player, but without frame stepping capabilities VLC is absolutely useless concerning a large portion of my media playing needs and practices. Until frame by frame viewing is implemented, I need to keep players like Windows Media Player Classic and GOM player handy on my desktop.

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Re: Frame advance - Frame by Frame - Bugzilla?

Postby Jean-Baptiste Kempf » 13 Jan 2008 07:26

Yes, but this is still the same problem, we know that, but noone has the time to do it.
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Re: Frame advance - Frame by Frame - Bugzilla?

Postby jenumba » 13 Jan 2008 23:48

Yes, but this is still the same problem, we know that, but noone has the time to do it.
No one has time, or it's not a priority? The first post was from 2005, and there's been plenty of VLC player updates since then.

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Re: Frame advance - Frame by Frame - Bugzilla?

Postby Jean-Baptiste Kempf » 13 Jan 2008 23:55

It is really complex, and needs almost a full rewrite to have some correct frame by frame accuracy. Some trick could be done like a fast play/pause... But this hasn't been implemented.
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Re: Frame advance - Frame by Frame - Bugzilla?

Postby sfed » 05 Feb 2008 14:03

Forgive my ignorance, but for frame advance, couldn't a flag be developed/set to have the playback decode paused on the next decoded/displayed picture? When in that mode play would then just advance to the next (decoded) picture. It would allow at least frame by frame advance - understand that frame back is much more difficult as it would require the stream to be re-parsed from some prior point (can be a long way with some long distances between I frames). If this is not possible, I suppose it is due to the way/point at which stream decoding is blocked during a pause being behind the display decoding, i.e. does pause operate on the stream (blocks) being decoded or the picture being displayed? If the former then it would not necessarily be possible to even pause on any particular still frame in the video.

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Re: Frame advance - Frame by Frame - Bugzilla?

Postby Jean-Baptiste Kempf » 05 Feb 2008 18:53

OK. Do it.
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Re: Frame advance - Frame by Frame - Bugzilla?

Postby sfed » 06 Feb 2008 12:48

Lol, i understand if you have more important matters to attend to. I'll take a look if I get some free time - i've just started to peruse the source. Seriously i have not looked at the asynchronous event chain in the application, and I understand the disconnected nature of the stream processing and not wanting to rewrite the application from the ground up, but was just looking for comment as to the plausibility of adding such an automatic block for having the output paused at a particular frame, either in the input or output decoding / processing stages. This could also be used for freezing on the last or first frame of selected video which is another useful function for multimedia playback in displays or interactive applications.

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Re: Frame advance - Frame by Frame - Bugzilla?

Postby bwwd » 11 Feb 2008 15:48

why you just dont slowdown video and press space?

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Re: Frame advance - Frame by Frame - Bugzilla?

Postby bugmenot » 29 Mar 2008 22:14

why you just dont slowdown video and press space?
Because that will not work for many videos, specifically videos that are very compressed and require more work to decode. Try doing it with a DVD; that won’t work either because of the delay of reading it off the disc. If you set playback too slow, the video won’t even resume at all, it will just sit there “stuck”. If you set it too fast, then by the time the video resumes playing, many frames have already passed and it is a couple of seconds ahead.

VLC’s lack of a frame step feature has been a thorn in my side for a long time. I use it to compare an original video with a compressed version when authoring DVDs to see if the results are satisfactory, but that requires comparing exact frames which is a HUGH headache in VLC. MPC has a step feature but cannot playback videos from DVD files. The closest thing I can think of is to read the VOBs into VDub which gives me nice control, but then I have to read in 4GB of data which is at least as much of a pain. :(


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