# Sequence order issue - 2 steps forward, one step backwards **URL:** \ **Category:** Imagery, data, and integrations\ **Created:** [October 9, 2022, 1:46pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453 "2022-10-09T13:46:12Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![TSquared](https://avatars.discourse-cdn.com/v4/letter/t/a698b9/32.png) [@TSquared](https://forum.mapillary.com/u/TSquared)\ **Post date:** [October 9, 2022, 1:46pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/1 "2022-10-09T13:46:12Z")
Uploading sequences from a GoPro 5 Black. Sequence uploaded with the desktop Mapillary Uploader app. Example sequence… [https://www.mapillary.com/app/?pKey=654224036290387](https://www.mapillary.com/app/?pKey=654224036290387) If you step through that sequence (or hit the play button) you will see it jump two images forward and then one image back often throughout the sequence. It’s like it’d doing the Texas Two Step or something. I can’t see anything in the file names or EXIF data the looks wrong. Anybody seen this before or have any ideas? ---
**Author:** ![filipc](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.mapillary.com/filipc/32/1103_2.png) [@filipc](https://forum.mapillary.com/u/filipc)\ **Post date:** [October 10, 2022, 12:40pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/2 "2022-10-10T12:40:21Z")
I had something similar with my Garmin Virb XE > **[Mapillary](https://www.mapillary.com/app/user/filipc?lat=51.204823013333&lng=4.4557781516667&z=17&focus=photo&pKey=233292728592478&menu=false&username%5B%5D=filipc&dateTo=2018-10-01)** > > Mapillary is the street-level imagery platform that scales and automates mapping using collaboration, cameras, and computer vision. ---
**Author:** ![TSquared](https://avatars.discourse-cdn.com/v4/letter/t/a698b9/32.png) [@TSquared](https://forum.mapillary.com/u/TSquared)\ **Post date:** [October 10, 2022, 3:04pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/3 "2022-10-10T15:04:38Z")
> [@filipc](#): > > I had something similar with my Garmin Virb XE > [Mapillary](https://www.mapillary.com/app/user/filipc?lat=51.204823013333&lng=4.4557781516667&z=17&focus=photo&pKey=233292728592478&menu=false&username%5B%5D=filipc&dateTo=2018-10-01) I see that. Perhaps a significant difference between my sequence and yours… You can see the jumping back and forth in the lines connecting the points in your sequence. In my sequence - on the other hand - everything looks normal. What caused your sequence to be laid like that IDK. On mine each point is where it should be in the sequence and the connecting lines look right. It’s just that stepping through - or playing - the sequence doesn’t work right (you get the Texas Two Step action). ---
**Author:** ![filipc](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.mapillary.com/filipc/32/1103_2.png) [@filipc](https://forum.mapillary.com/u/filipc)\ **Post date:** [October 10, 2022, 3:11pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/4 "2022-10-10T15:11:30Z")
I know, mine looks more like the procession of Echternach. ---
**Author:** ![tao](https://avatars.discourse-cdn.com/v4/letter/t/f9ae1b/32.png) [@tao](https://forum.mapillary.com/u/tao)\ **Post date:** [October 12, 2022, 5:08pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/5 "2022-10-12T17:08:15Z")
It looks like an issue with the EXIF timestamp (capture time). Can you reproduce the issue with [Release v0.9.4 · mapillary/mapillary\_tools · GitHub](https://github.com/mapillary/mapillary_tools/releases/tag/v0.9.4) If you could, would be great to share `mapillary_image_description.json` here. ---
**Author:** ![TSquared](https://avatars.discourse-cdn.com/v4/letter/t/a698b9/32.png) [@TSquared](https://forum.mapillary.com/u/TSquared)\ **Post date:** [October 13, 2022, 2:55am UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/6 "2022-10-13T02:55:22Z")
> [@tao](#): > > It looks like an issue with the EXIF timestamp (capture time). > > Can you reproduce the issue with [Release v0.9.4 · mapillary/mapillary\_tools · GitHub](https://github.com/mapillary/mapillary_tools/releases/tag/v0.9.4) > > If you could, would be great to share `mapillary_image_description.json` here. Done. Ran it with version 0.9.4. No duplicate detection was commanded. Just… _mapillary\_tools-0.9.4-win-64bit process “E:\GoPro Capture\100722 - Original\104GOPRO” --interpolate\_directions_ … because I’m assuming that’s all the desktop Mapillary Uploader app would have done and I used the desktop app to upload this sequence. Apparently you can’t attach a file to a post on this forum? Plan B - you can access it here… [https://drive.google.com/file/d/1fWK3ZZujVJKFP5rPOPvxEaVk4k5ZuZXM/view?usp=sharing](https://drive.google.com/file/d/1fWK3ZZujVJKFP5rPOPvxEaVk4k5ZuZXM/view?usp=sharing) One additional thing I noticed… The issue only seems to occur when using the back/play/forward controls at the top of the page. The controls on the road seem to step through the sequence correctly. ![image](https://us1.discourse-cdn.com/flex015/uploads/mapillary/original/3X/6/5/65445f79cadf14eb0ed006bee6496f91082ea776.jpeg) Also should note… I sent an email to support for this issue. I got a response back and a response number (23323) from **Navjyot Sandhu**. In my reply I also provided him all the original images of the sequence which you can find here… [https://drive.google.com/file/d/1l6OQILDoNpiCR49m-FVq6xpGEpgp3f2o/view?usp=sharing](https://drive.google.com/file/d/1l6OQILDoNpiCR49m-FVq6xpGEpgp3f2o/view?usp=sharing) ---
**Author:** ![tao](https://avatars.discourse-cdn.com/v4/letter/t/f9ae1b/32.png) [@tao](https://forum.mapillary.com/u/tao)\ **Post date:** [November 7, 2022, 8:22pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/7 "2022-11-07T20:22:16Z")
Thanks. It’s because the image timestamps have no sub-seconds (milliseconds) stored. Here is an sample: ```auto ❯ exiftool -time:all 104GOPRO/G0017329.JPG Date/Time Original : 2022:10:07 13:13:13 Create Date : 2022:10:07 13:13:13 GPS Time Stamp : 17:13:11 GPS Date Stamp : 2022:10:07 GPS Date/Time : 2022:10:07 17:13:11Z ❯ exiftool -time:all 104GOPRO/G0017330.JPG Date/Time Original : 2022:10:07 13:13:13 Create Date : 2022:10:07 13:13:13 GPS Time Stamp : 17:13:11 GPS Date Stamp : 2022:10:07 GPS Date/Time : 2022:10:07 17:13:11Z ``` As you can see both images have the same timestamp. The Web player does not know which one it should step first. In this case, we can interpolate sub-seconds to make sure they are sorted as expected. Will fix it at mapillary\_tools side. ---
**Author:** ![Gary42](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.mapillary.com/gary42/32/71557_2.png) [@Gary42](https://forum.mapillary.com/u/Gary42)\ **Post date:** [November 8, 2022, 2:49am UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/8 "2022-11-08T02:49:20Z")
One obvious solution that would probably work most of the time would be to sort/index the sequence first by timestamp and then by image name. Most cameras (all that I have worked with) name the images sequentially. If you are fixing this in mapillary\_tools, does that mean that sequences that are already uploaded won’t be fixed? I use the Windows mapillary uploader. Will it be fixed there? ---
**Author:** ![tao](https://avatars.discourse-cdn.com/v4/letter/t/f9ae1b/32.png) [@tao](https://forum.mapillary.com/u/tao)\ **Post date:** [November 9, 2022, 7:04pm UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/9 "2022-11-09T19:04:41Z")
> One obvious solution that would probably work most of the time would be to sort/index the sequence first by timestamp and then by image name. Most cameras (all that I have worked with) name the images sequentially. It makes sense. However, most images might not have the “filename” information for sorting, also it takes some backend effort. > If you are fixing this in mapillary\_tools, does that mean that sequences that are already uploaded won’t be fixed? I use the Windows mapillary uploader. Will it be fixed there? Yes DU uses mapillary\_tools underneath, so it will be fixed too. ---
**Author:** ![bob3bob3](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.mapillary.com/bob3bob3/32/68393_2.png) [@bob3bob3](https://forum.mapillary.com/u/bob3bob3)\ **Post date:** [November 14, 2022, 9:01am UTC](https://forum.mapillary.com/t/sequence-order-issue-2-steps-forward-one-step-backwards/6453/10 "2022-11-14T09:01:59Z")
I get this behaviour regularly from BlackVue mp4 direct uploads. ie just press the play button in the GUI and it is nice and smooth for maybe 30 images, then jerks back one before continuing. I just assumed it was a browser quirk or temporary loss of stream.