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Kinovea - Forums → Posts by joan
Yes, I had thought of this but the mere fact of saving to file is adding burden to the CPU from the extra copy of images and access to disk, so an average computed before recording starts would still overestimate the true framerate of the capture…
A more ambitious solution would be to record in a dedicated format with timestamps associated with each image and honoring the timestamps at playback time. It would break compatibility with other softwares though.
You can right click the lines, choose "persistence", uncheck "use default", and check "always visible".
Alternatively, you can do that for all drawings ever from the global preferences in Drawings > Persistence.
From what I gather the persistence feature is one of the main usability issue with drawings and bites newcomers. It's not obvious that it's there or how to use it. Any feedback on improving this is appreciated.
For your scenario you might be interested in the "Posture" tool from the custom tools (long click the Goniometer to make the extra tools appear).
Hi,
The "playback is too fast" problem arise when we select a framerate but we do not receive the frames at the advertised rate.
Due to something else, PC being busy, camera giving wrong info, etc. we receive images at a lower rate. We still save the advertised framerate in the file metadata for a lack of a better value. So when played back, it plays at the advertised framerate even though frames were captured at slower rate. Hence the speeding up of the action.
If you use 0.8.21, the actual framerate at which frames are received is displayed in the top bar above the viewport. You will probably see a lot of variability when choosing higher framerates, and more stability for lower framerates.
At the moment I do not know how to mitigate this problem. Saving the actual framerate seen when the record button is hit is not really an option since it's very variable. Maybe keeping the average of the framerate of the sequence and using this, but the issue is that the metadata is written before the capture starts…
Thanks for the feedback!
@Amus:
capture do not work at all
Can you be more specific ? Do you have an error message ? Do you see thumbnails of your cameras in the cameras panel ? What camera brands/model do you have ?
no frame by frame possibility in two playback screen mode using arrow keys left and right (sometimes works, usually not)
I can't reproduce the problem for now. Is there anything special about the videos ?
sometimes program lost sync point in two playback screen mode
Can you pinpoint a scenario leading to the loosing of the sync point ?
Thanks
Bonjour,
Merci pour le rapport.
Je reproduis un plantage en lançant une vidéo dans un dossier alors que le dossier n'a pas fini de charger toutes les vignettes.
Pour tester cette hypothèse pouvez-vous faire plusieurs essais sur les deux scénarios, avant/après la fin du chargement de toutes les vignettes.
Merci
Hi,
Great points.
Have you tried the delay slider ? If you don't care about saving each swing it may be enough.
Ideas about capture-replay scenarios have been floating around.
My fear is that a function only available through a keyboard shortcut will be virtually non-existant to 90% of users.
Barring a unique "most popular" replay scenario, what would be needed is to turn this into a mini macro "language" so you can create a macro command by picking actions like "close capture screen", "open playback screen", "launch last captured file", "close playback screen", "open capture on last used camera", etc.
Obviously this is a different beast altogether, if only to make sure the list of commands is coherent.
5. A swing "trigger" would be ideal. Foresight sells a swing trigger, but it costs $4,000. It is a box that starts the video when you begin your backswing and stops the video when the swing ends.
Implementing trigger by microphone level would be feasible.
Combined with the delay feature and a new function to specify a preset duration for recording, it could be used to record the full swing by hearing when the ball is hit, without touching the computer…
Hi,
The magnifier expected behavior is to stay visible until you explicitly hide it. Are you experiencing it differently ?
Le besoin existe car les distorsions de la caméra posent des problèmes pour la précision des mesures et donc impactent toutes les fonctions d'analyse quantitative…
Avec la GoPro3 qui filme en 720p à 120fps ça vaudrait le coup de pouvoir rectifier les images.
Un peu sur le même principe, un stabilisateur de vidéos filmées sans trépied est également possible (en tout cas pour les vidéos sans pan ni zoom). Même topo : la fonction peut être implémentée sans trop de difficultés sur une suite d'images données mais pour faire du temps réel c'est plus compliqué.
Version expérimentale, merci de remonter toutes les regressions éventuelles !
Installeur: Kinovea.Setup.0.8.21.exe
Experimental version feedback needed ! 
Beware of regressions and report anything suspicious. Do not assume the issue is known.
Installer: Kinovea.Setup.0.8.21.exe
Highlights:
General
- Catalan and Serbian (latin) locales.
- Keyboard shortcuts can be customized.
Capture
- New "cameras" panel.
- Common controls in capture.
- New viewport (drawings outside image, movable image, better zoom).
Analysis
- Video pagination (jump by 10% or 1% increments).
- Human model tool with center of mass.
I did a video to highlight the changes:
[video]http://www.youtube.com/watch?v=o8aZCaNOiqs[/video]
Thanks!
Hi pgendreau,
Be aware that you cannot really make speed measurements as in post #2 unless the various points of the trajectory are all on the same plane and this plane is perpendicular to the camera optical axis.
Tennis serve and stroke have many rotational component, it will be impossible to measure this in a 2D software. You may get better results with a pure side view.
I concur on what Chas said regarding zoom and shutter speed if your camera support changing these parameters. If you are using a webcam or similar device, place it so that what you want to see fills most of the image.
If you plan on making measurements, another important aspect is the calibration of the space. To make accurate measurements you should either make sure the camera is perfectly perpendicular to the plane on which you make all your measurements, or use the perspective grid to map a physical rectangle and make the measurements on that plane.
I'll try to do a more in depth post to compare the errors that can be expected from both calibration methods.
Hi everyone,
I apologize for the relative lack of news during the past months.
It doesn't mean there hasn't been new developments, quite the contrary actually.
There has been 177 revisions to the source code repository, the most ever between two versions.
A lot of changes, many under the hood, and many visible. The experimental version 0.8.21 is ready, I'm currently waiting for Avast antivirus to fix a false positive in their new virus signatures that put Kinovea into quarantine.
I'll do a video presentation of the changes because it'll be easier than a written description.
Some highlights:
- new cameras management (thumbnails, name aliases).
- new capture screen (dual recording, drawings outside image, free moving of the image, better zooming)
- custom keyboard shortcuts.
- human model with center of mass tool.
And more things that I'll describe in the video.
Cheers!
in ver 8.20 when I try to track the point tool, the tracking box does not appear and the trace line does not happen. The marker does track the point correctly but it does not leave a line trace behind for visualizing the path.
Yes. The point tool (cross marker) is now using the same tracking system as the other tools. To get back the trajectory tool you need to directly right click the object you want to track and choose "Track path". Do not add the cross marker.
Bonjour,
J'avais fait des tests sur le sujet il y a quelques temps sans que cela ne débouche sur une fonctionnalité, mais si je me souviens bien sur le principe c'était tout à fait faisable.
À l'heure actuelle les filtres (contraste, niveaux, etc.) sont uniquement disponibles en mode analyse, ce qui en limite sévèrement l'utilité. L'avantage étant qu'ils sont appliqués une fois pour toute sur l'ensemble de la séquence et qu'on ne fait pas le calcul à chaque image, donc pas de perte de performances.
Je ne sais pas si l'application d'un ou plusieurs filtre en temps réel autoriserait la visu à vitesse normale…
Kinovea - Forums → Posts by joan