Is there a previous frame hotkey?

[fourierJAM]

OK, we have noted that you don't care about consuming memory to keep all decoded video frames. Keeping frames for Full HD video only requires about 100 megabytes/second. And they're stored on the GPU RAM. What could possibly go wrong...

And I don't take moral lesson from an hypocrit who feels like they can demand work from "toxic" volunteers and even state that they are not there to do any actual work.

This matter has been considered more than a decade ago by several VLC developers, as well as other experts from VideoLAN. It is not generally possible. If you think it is possible, explain exactly how. Evasive references to mpv or other software does not count as an explanation.

If dev X says something Y is not generally possible, it's only natural for [user here] to reason that Y can't be impossible if [VLC alternative here] can do it with ease. I can open MPC-HC and easily frame scrub through rapid-paced parts of a video, where with VLC I have to resort to going back several seconds if I frame scrub forwards a little too far. Is that not an incentive for the veteran developers to figure something out? Something, anything. 100mb is barely a drop of disk space in 2023.

[filmeditor]

Sorry for interventing. VLC does support Left button to rewind 10 sec back, right?
So, I believe, it is possible to have function like this:

function GO_ONE_FRAME_BACK()
{
GO_BACK_FOR_10_SECONDS();
any_pointer = start_caching();
REBUILD_NEXT_10_SECONDS();
frames_cached = stop_caching();
show(any_pointer[frames_cached-2]);
}

[Rémi Denis-Courmont]

That won't work with infinite GOP nor with formats that can't seek accurately. This was already mentioned several times

[MichaelPulis]

How about adding the previous frame feature, but only enabling it on supported formats, thus allowing the constraints of unknown formats to be lifted? I am using VLC for work, and frame-by-frame analysis is a crucial part of the process. I assumed I would be able to do it using VLC but I was surprised that it only worked one way for MP4. I understand that the problem is difficult, and I understand that compressed video doesn't store sequential images but only the changes, but aside from all this I feel that there should be a way to enable this feature for a select few formats.

I don't know the distribution of use cases, but I imagine something like 80-90% of files opened by VLC are covered by 4-5 file formats, so maybe enabling this feature for a select few file formats where the assumptions can be lifted would be really helpful.

[afdaf]

How about adding the previous frame feature, but only enabling it on supported formats, thus allowing the constraints of unknown formats to be lifted? I am using VLC for work, and frame-by-frame analysis is a crucial part of the process. I assumed I would be able to do it using VLC but I was surprised that it only worked one way for MP4. I understand that the problem is difficult, and I understand that compressed video doesn't store sequential images but only the changes, but aside from all this I feel that there should be a way to enable this feature for a select few formats.

I don't know the distribution of use cases, but I imagine something like 80-90% of files opened by VLC are covered by 4-5 file formats, so maybe enabling this feature for a select few file formats where the assumptions can be lifted would be really helpful.

Let's say you find an image editor. You try it, it's great, but it doesn't save to PNG. You go to the forum and the devs say "yeah, we could implement PNG, but it's possible to create images that aren't compressed by the PNG algo, so we won't."

The correct answer is not "whoa, that sounds kinda bonkers, FECKIN' IMPLEMENT IT!" The correct answer is "whoa, that sounds kinda bonkers, I'ma go download one of the other projects that does support the feature with 99.9999% of the files out there, using less than all resources and infinite time." Going from complaint to solution is quick and the rate of success goes from near zero to near perfect, so it's great for everyone with no insight into this particular project + it's source code + the history of the feature request + it's devs.

Also, wtf are you using a player instead of an editor for actual work?
Also, here's for the people who want a small cache: Step one frame forward, press print screen (or for extra safety, reverse the order of operations). Your desired previous frame is easily accessible using ctrl+v as long as you don't overwrite the buffer.
Also, here's an ffmpeg command to extract 48 frames (2 seconds worth if the framerate is the common 24000/1001) from timestamp 15:23, it takes no time at all, so just customize it for your use-case or write a shell script (look into ffprobe if you want to find the framerate automagically): ffmpeg.exe -ss 00:15:23 -i "path/to/video/file/example.mkv" -frames:v 48 "path/to/save/images/frame_%02d.bmp"

There. Four simple, quick, and efficient solutions to an impossible problem.

[Solution-Based]

And yet another solution to the impossible problem, without a technical lecture you don't need to hear. This worked for me:

- Update VLC to 3.0 if you haven't, file structure changed since the last version I had.
- Download 'Jump to Time Previous Frame v3'. Install instructions on the page:
https://addons.videolan.org/p/1154013
You can access the extension's menu under the View tab when it's added.
- Set the skip speed to multiples of whatever camera fps it shot at - my vids were shot at 30 fps, so 1/30th skips gives me frame by frame if I need to scan a vid on a PC.
- Alt+F/Alt+B let you go forward and back a frame. Doesn't matter how it's different from a built-in frame skip.

For technical reasons, you can't use the hotkeys with the video clicked on. You need to be clicked on the extension's menu. This is unfortunate because you likely want to scan at full screen - there's a workaround for that too!
- First, change the player shortcut keys for 'Crop/Uncrop one pixel' to something else besides Alt+F/Alt+B. You'll accidentally click on the player by mistake a few times, takes a problem away.
- Then, open the extension so you can control the frames with the hotkeys
- Then double-click your video to make it full-screen.
- Then press the computer's taskbar key (windows key on mine, how it works on your OS may vary), hover on VLC, and click the extension menu window.
When you move your mouse cursor off the extension, it should move back behind the full-screen video, but still be selected so you can hotkey back & forth.

A bit wonky, but problem solved! "(Simple explanation) --> (Simple Solution)" is such a quick and easy way to help people, isn't it? Bye forever, hope it spared future searchers.
I'm reminded of someone who once worked the phone line at a towing company. Expected upset people. So was pre-emptively rude, disrespectful, and insulting, regardless of how the other person started. Naturally prompted people to respond in kind, lost any goodwill or civility they might have started with. Then she complained about the attitude of the people she had to deal with afterward, refusing to acknowledge she -caused- the behavior she complained about. Even though the people being helpful/pleasant were getting the outcomes she complained she didn't. The cognitive dissonance was staggering. But it's too emotionally costly for them to accept they continue prompting what they say they hate and what they claim they want people to stop.

[sleerfnivek]

Looks like I timed this perfectly. lol
I have to say, I'm rather mystified at all the drama. Either that or I'm just missing something critical...

Using SHIFT, ALT, CTRL, and CTRL+ALT with the left and right cursor moves the time corresponding to settings for VERY SHORT JUMP, SHORT JUMP, MEDIUM JUMP, and LONG JUMP. These correspond to settings under In TOOLS/PREFERENCES/INTERFACE/Hotkeys Settings. By default, I think the settings were 3 seconds, 10 seconds, 30 seconds, and 1 minute but I changed this so long ago that I really can't remember. I have mine set to 1 second, 3 seconds, 7 seconds, and 15 seconds. Anything longer and I'll just drag it.

This isn't frame by frame. At 30fps that's a lot of content in that one second but it's important to remember that frames don't actualy exist in any of the standard media files. If you need to work at the frame level then you should probably be using a true purpose-built editor and not a media player. But it really isn't that much of a hassle to jump back to just before the desired frame and then roll forward, one frame at a time.

For the devs, I am curious if this couldn't be a bit further refined. Maybe allowing the input of a decimal which would allow the user make adjustments and further refine it. The result would be through trial and error on the user's part....garbage in/garbage out.

With that said, what I can't seem to figure out is why the dev(s) feel so combative about people asking for more fine-tuned control. It seems to me that someone a little more skilled at PR should be handling such issues. Since there doesn't appear to be such a person in the company, and since I've enjoyed the benefit of using VLC's FREE player since it first launched, I'm going to go ahead and write a response that can be copied, edited, and pasted anywhere that it makes sense the next time it comes up.

"I'm sorry. VLC is first and foremost a video player, not an editor. We have built-in a wide variety of tools over the years to allow for an enormous amount of customization when viewing while providing support and features that far exceed any other in the market. Since inception, our primary goal has always been to combine the greatest possible compatibility and reliability in a product that anyone can use on nearly any platform for FREE. For comparison with other players, check out he Wikipedia article that compares video player software at https://en.wikipedia.org/wiki/Compariso ... r_software . The article covers nearly 30 video players and 151 different attributes laid out in 13 categories. Of those, we hit roughly 112 (there are roughly 20 question marks and plugins likely expand it even further). The closest any of the others get is 96. It drops off quickly from there. We win in nearly every category. In the few categories that we don't win, we're still no more than 1-2 items off (or maybe not when you consider plugins) while the winner fails to rank highly at all in other categories. For instance, in the "Production video format ability" there are only three players. We are one of them. We're nearly matched with the other two and neither of those is our next closes competitor in other categories.

There are several players on the list that must be purchased, or worse, subscribed to with regular repeated payments. In addition, there are a number of things not covered in the comparison, likely because there is little else to compare to. The ability to work with damaged files and repair them without having to be use an editor is something that we're extremely proud of. Often VLC can play right through a damaged file without the user noticing there is damage until they try to play it in another player and it fails. It can also repair and export into other formats. The number of API bindings, browser plugins, and the number of plugins and skins available is nothing short of amazing. On Windows, Linux, macOS, and some other Unix-like platforms, VLC also provides an NPAPI plugin, which enables users to view QuickTime, Windows Media, MP3, and Ogg files embedded in websites without using additional software.

Along with several additional unique attributes, VLC is by far the most capable player available...and we provide it at the bargain-basement cost of "FREE". This broad support for features, including repair capabilities and control over the rendering leads some people to assume that VLC is an editor. It is not.

While it may technically be possible to render individual "frame-by-frame" control for select formats on select platforms, doing so would require significant work, greater product diversion across platforms, and changes to a platform that has long been considered the most stable and capable player available and would likely cause more problems and bugs. Also, once we open that door we would then be subject to "feature creep" on one end while trying to maintain more complex compatibility and playability on the other. It simply doesn't make sense to risk breaking the superior compatibility and reliability of VLC as a PLAYER to allow a small handful of people that want to edit when there are free purpose-built tools available for editing that we could never expect to keep up with. Most video editors control the chaos by limiting the compatibility and playback features.

While we would love to be everything to everyone, it just doesn't make sense to go down this path. The last thing we want to do is give up being the master of playback to become a Jack-of-all-trades. Since there are plenty of tools out there designed specifically around editing, our advice is to let VLC do the playing and for editing, get an editor."

I know this response needs work. This is particularly true with the comparison numbers as I believe many of the places where VLC is not marked as a feature are simply because the authors didn't know for sure, or the feature may be available with a plugin which widens the gap even further. I just wanted to give you an example of a proper response to this debate that didn't have to be a debate. The responses went from slightly rude to outright self-righteous contempt which is never good even if you are providing VLC for free.

Anyways, time for work. Gotta run.

[Paralyses6216]

Every time I setup a new PC as I get older, I try VLC, because everyone says it's so great. The first thing I get annoyed with is I can't click the video to pause it. And of course there's no option for it. So I go through the obnoxious setup of downloading an extension and messing around in preferences for 5 minutes until it works. The next thing I get annoyed with is no frame backward. Which is really the state of VLC: backward. It works however it wants without any concern for how most videos are interacted with in modern times. I'll never understand the appeal of VLC, in any case.

Anyways, back to MPC-BE for the next X years.

[robcat2075]

The recent text accompanying the recent VLC update had something about improvements to "frame by frame" operations.

Is there a real single frame forward/back now in VLC? Where is it?

Using search I found only a smattering of long-ago requests/discussions about single frame forward/back but they always seem to devolve into either "You just don't understand how HARD that is!" or "If it's so simple why don't YOU do it?"

What I do understand is that small apps like the Quicktime player had working single frame accurate forward/back and freely interactive scrubbing of the timeline that worked decades ago and works for almost any codec, even complexly compressed ones, including h.264 that is the basis of so much video today. The only real limitation seemed to be a hard drive's ability to serve up what you were scrubbing to in a timely fashion.

that is why I still have Quicktime installed today... I need that single framing... but Quicktime has been deprecated for its ostensible security risks. However, I doubt that single frame forward/back is the cause of the security trouble.

If VLC is going to be the widely-adopted open source solution that deters all other video player attempts, single frame forward/back is a sorely-needed feature.

Something to do with caching, perhaps?