Experimental version - 0.8.24 (Page 1 of 2)

I forgot to mention an important change in the way the recording works with regards to the delay feature.

In previous versions of Kinovea, when you started the recording, you would record what was visible on screen. If you had delay in place of say 10 seconds, then the first image of the resulting video would be 10 seconds earlier than the time you pressed record.

This is no longer the case due to the decoupling of the preview and the recording. This means that the configured delay is no longer taken into account when recording. You always record the "live" feed. Minus the base latency between the camera and the computer memory (which depends on the selected stream format by the way).

Many thanks to Joan for the latest version of Kinovea. The ability to make use of hardware compression in the Logitech C920 is very welcome and eases the bandwidth requirements very significantly. In my measurements the data rate decreases by an order of magnitude for this camera. Of course this does not solve all the problems associated with using multiple webcams. I would like to mention a couple of long standing problems and suggest possible modifications to address them.

First let me briefly describe my hardware and use to illustrate the problems although they impact multiple scenarios. For swimming coaching in an Endless Pool, I have an underwater camera connected to a USB rame grabber which runs at 25 fps which is fixed as this is a PAL device. In addition there is a Logitech C920 above the pool and a Microsoft webcam with a front view. Together they allow a three dimensional view of the swimmer. Simultaneous recordings of different pairs of cameras are extremely useful in coaching technique.

The two webcams will only reliably run at 15 fps due to the poor lighting level with auto exposure (auto exposure is useful because of varying lighting levels day/night). This is fast enough for this application and recordings can be made with no dropouts or missing frames with all possible camera pairs at all light levels. The underwater camera provides its own lighting and always achieves good performance at 25 fps.

The first problem is associated with playing back video which is normally done in the 2 playback window mode. There are numerous discussions in the forums about slow playback rates but to illustrate the problem imagine recording 60 seconds of video and then playing it back. Opening video from the two webcams (15 fps) reveals a recording length of 30 seconds whilst the underwater camera (25 fps) video duration is 50 seconds. Clearly Kinovea thinks that all the videos were recorded at 30 fps. I note that the C920 always reports a frame rate of 30, the underwater camera does report 25 fps and I am not sure what the Microsoft camera reports. In all cases Kinovea creates video which includes a frame rate of 30 fps and then plays it back faster than realtime.

When viewing video from the two webcams the problem with linked controls there is not a real problem since the speed can be set to 50% and all is well. When playing video from one webcam (15 fps) and the underwater camera (25fps) then one must unlink the controls to set the appropriate speeds which is not very convenient.

Since Kinovea knows the frame rate selected by the user (even if the camera does not report the selected frame rate correctly), would it be possible to tag the video with the correct frame rate? This would, I think, cause the video to playback at the correct speed. There might be a problem for the underwater camera for which the device properties in the latest version of Kinovea no longer show the frame rate. Previous versions allowed one to select 25 or 30 although this had no effect since it is determine by the camera hardware.

The second problem is really just a long standing inconvenience but since I have spent so long explaining my setup, it can usefully be summarised here. In the two recording mode, one can set the file names to be free text plus auto incrementing number and then set the video names to be something like "John_Camera_A - 1" and "John_Camera_B -1". Subsequent recordings increment the numbers and all is well.

BUT

if you playback the videos and the return to recording, the video file names become the same in the two recording windows e.g. both are "John_Camera_B -8". Clearly the recording name is remembered but there is no provision for the two recordings mode (or it is not read back correctly). It would be very helpful if this could be fixed and might not be too difficult to achieve. Don't you hate it when people say that!

I apologise for the length of the post and perhaps not posting it in the correct place. I would like to say that Kinovea is extremely useful tool and to thank everyone who has contributed to its development.

Many thanks for your considered reply. On the issue of the recording frame rate I do think that your option A would provide the most utility. Whilst it does rely on the user have set the most appropriate frame rate (one that encompasses any auto frame rate adjustment likely to be encountered), they are very unlikely to be any worse off than at present. With the correct choice of frame rate then playback speed will be correct which is something that can at present only be achieved if the user's cameras can all achieve 30 fps. I do agree that B and C are perhaps not the best way forward for the reasons you indicated.

In my use case where I wish to make recordings in a swimming pool which has both artificial and natural light so the illumination can change significantly. Auto exposure is useful because it removes the need for adjustments before recording and I have carried out test which show that 15 fps can be achieved even at night. So option A would be the ideal solution.

I think the situation may be slightly more complex than cameras not reporting actual frame rates. As far as I can see all cameras, including the camera simulator running at 50 fps, result in recordings which have the frame rate set as 30fps, irrespective of the actual frame rates. This according to the tool I used to reveal the video parameters in the recordings. This is, I think, why so many people report problems with playback speeds. I wonder if this is a default setting which is always used?

On the naming pattern for dual cameras topic and specifically the last point:
- have separate prefix/suffix for left/right cameras, etc.
I am uncertain if by left/right you mean a camera alias or the left and right recording windows. I think you mean left/right camera as in stereoscopic.

My suggestion would be the capability to include the camera name or an alias, in the file name. I recall that there was once a capability of assigning an alias to each camera but I can no longer find how to do that. If I could rename/alias my three cameras to be identified as top, front and underwater, and then include that in the filename along with the auto-incrementing number then I think it would make things much more convenient. This would then work whichever way around the cameras appeared in the dual recording window. In the perhaps unusual situation where one is recording two of a possible three or more cameras, then if the incrementing number might refer to the recording rather than the individual camera. So if I recorded my swimmer John with different pairs of cameras I would end up with:
   John_(top)_1 and John_(front)_1                 recorded at the same time, then
   John_(front)_2 and John_(underwater)_2     then,
   John_(underwater)_3                                  just using a single camera, then
   John_(underwater)_4 and John_(top)_4       and so on
Inspection of the file names then allows me to identify which files go with which, the order in which they were made and from which camera the recording originates. I think that some form of suffix is better than a prefix because in this example it allows me to separate all John's recordings from those of Jane. It is the subject that is more important than the camera used so the naming hierarchy should be subject > camera > time

I do not think that there are any downsides to this scheme for the more normal one or two camera use.

Apologies for the length of this post and many thanks for all your hard work on Kinovea.

cmdi035,

I don't think this will help but I saw this type of behaviour when I first installed this version. Subsequently I reinstalled and set the frame rates to appropriate values for my setup. After that it has been well behaved with recordings playing back correctly both individually and two together. I have no idea what caused the initial problem but suspect that it was deleting everything I could find associated with Kinovea and then installing again. Might be worth trying again.

Ahhh.   Yes - it was H.264 content.   I'm ok with the cursor jumping around but the biggest challenge is when there are 2 playback screens and I can't get one to play the video.   

A couple of suggestions or possible feature enhancements: 
1) is there a way to include a "flip" option similar to the mirror option?  Sometimes when I use my Samsung Note 4 to record the video it doesn't automatically orientate the video and when I play the video it's upside down.  I see you have a "mirror" option but would like to see if you can add a "flip" option. 
2)  for the drawing tool, is there a way to make the circle smaller?  It's pretty big and for some highlights I'd like a smaller radius that's about half the size of what's used now
3) is there a way to have the entire video loaded into memory so when we slide the cursor left and right the video advances accordingly?  I use the tool for analyzing baseball swings and many times I'll set the camera up and just record the whole inning.  I'd like to be able to use the cursor advance to find the place in the video where the swing occurs. 

Thanks!

Hello
I am a regular user of Kinovea for golf self training in my basement. I use also commercial software like cSwing, V1, and tried many others. I really think kinovea is the best solution for me now, with the functionality of two cameras (I use Ps3 for the frame rate) and the delay option. So, thanks to everybody behind this project.
I was really happy with the version 8.21.  I tried in a new computer the version 8.24 and there are some improvements but two major problems in my opinion.
1) You can not set the desire format for the video as it is in the previous version. The videos are recorded in MP4 but not being readable by Windows Media player, iTunes or cSwing. I think you have to go back to version 8.21 in that regard, being able to choose for instance, AVI format
2) The new functionality of recording live instead of the delayed video (when delay is applied) I think is a step back and not an improvement!. This is a huge problem for those who like to see in slow motion a previous saved video, but not want to record ALL the swings you do, but just selected ones, (in the new version, with or without delay, one should start recording before you actually hit the ball) . Please go back to version 8.21 in this regard too, or , if some people think is better now (which I doubt), please develop an option to choose either way.
All the best