Bug 425960 - Rendering files with only one frame results in 16 minutes of black screen
Summary: Rendering files with only one frame results in 16 minutes of black screen
Status: RESOLVED FIXED
Alias: None
Product: kdenlive
Classification: Applications
Component: Video Display & Export (show other bugs)
Version: 20.08.0
Platform: Microsoft Windows Microsoft Windows
: NOR major
Target Milestone: ---
Assignee: Jean-Baptiste Mardelle
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-08-29 21:09 UTC by KK
Modified: 2021-04-28 19:08 UTC (History)
2 users (show)

See Also:
Latest Commit: https://invent.kde.org/multimedia/kdenlive/commit/b74e65dc299cb38b4498076bb2ac0e735a3f080e
Version Fixed In:
fritzibaby: timeline_corruption+

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Description KK 2020-08-29 21:09:40 UTC 
SUMMARY
Rendering files with only one frame results in 16 minutes of black screen

STEPS TO REPRODUCE
1. Drag a single image/video to the timeline.
2. Use the Razor tool to cut the video in one frame.
3. Render to File

OBSERVED RESULT
The video has 16 minutes of black screen

EXPECTED RESULT
A video with the duration of one frame.

SOFTWARE/OS VERSIONS
Windows: 10

ADDITIONAL INFORMATION
This only happens if the timeline has only one or two frames.
Comment 1 emohr 2020-09-12 10:33:57 UTC 
Please try with version 20.08.1 where some rendering issues are fixed.
Comment 2 Bug Janitor Service 2020-09-27 04:33:14 UTC 
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 3 KK 2020-09-28 17:46:16 UTC 
(In reply to emohr from comment #1)
> Please try with version 20.08.1 where some rendering issues are fixed.

Still same issue on latest version. Tried it a few days ago
Comment 4 emohr 2020-09-28 18:31:37 UTC 
Please upload here your project file so I can have a look.
Comment 5 KK 2020-10-05 04:23:47 UTC 
(In reply to emohr from comment #4)
> Please upload here your project file so I can have a look.


There is no need to send a project file since I can reproduce the bug with a fresh download of the portable version.
Here:
https://youtu.be/7D8YuDrqAJ0
Comment 6 Jean-Baptiste Mardelle 2020-10-05 05:47:19 UTC 
Reproduced, thanks
Comment 7 Jean-Baptiste Mardelle 2020-10-06 11:10:18 UTC 
Just to let you know: I have understood the problem, trying to render only the 1st frame of the project confuses melt, the MLT rendering app. I found a workaround but that interestingly revealed a bug in MLT that currently duplicates the last frame on rendering, making it impossible to render a 1 frame only project. I am working with MLT devs to find a fix for this issue, and will then apply my fix for the 16minutes rendering.
Comment 8 farid 2021-03-22 21:19:19 UTC 
What is the status of this issue?
Comment 9 Jean-Baptiste Mardelle 2021-03-24 08:53:13 UTC 
Git commit b74e65dc299cb38b4498076bb2ac0e735a3f080e by Jean-Baptiste Mardelle.
Committed on 24/03/2021 at 08:52.
Pushed by mardelle into branch 'release/21.04'.

Rendering fixes: fix black frame at end of rendered project, enforce out point to avoid rendering trailing black frames, stop rendering before end guide

M  +10   -2    renderer/kdenlive_render.cpp
M  +18   -12   src/dialogs/renderwidget.cpp

https://invent.kde.org/multimedia/kdenlive/commit/b74e65dc299cb38b4498076bb2ac0e735a3f080e
Comment 10 Jean-Baptiste Mardelle 2021-03-24 08:55:20 UTC 
The main issue is now fixed in git and upcomming 21.04. The last duplicated frame on rendering is still an issue in MLT, see my exchange with Dan (MLT's maintainer) :
https://sourceforge.net/p/mlt/mailman/message/37123029/
Comment 11 KK 2021-04-28 18:51:29 UTC 
Can confirm this bug was fixed in the latest Kdenlive release. Thanks!
Comment 12 emohr 2021-04-28 19:08:01 UTC 
Thank you for the feedback and contribution.