Changelog - DVR-Scan
Author: Brandon Castellano

Skip to content

#
Changelog

#### Changelog

### 1.8.2 (2026-01-18)

#### Release Notes

Includes several critical bugfixes and improvements when processing multiple input videos.

#### Changelog

- [general] Minimum supported Python version is now 3.10 (Python 3.9 is EOL)
- [general] An error is now displayed when launching the app fails due to an invalid config file #241
- [general] Python package now only depends on `opencv-contrib-python` or `opencv-contrib-python-headless` #251
- [bugfix] Fix `quiet-mode` setting (`-q`/`--quiet` flag) still allowing extraneous output #243
- [bugfix] Fix loading config from file in UI #253
- [bugfix] Fix scan error when enabling "Use PTS" input option with multiple videos #254
- [bugfix] Fix unchecked UI options being turned on in config files #256

### 1.8.1 (2025-08-27)

#### Release Notes

Fixes issue with application not loading config files saved with v1.8.

#### Changelog

- [general] Add `--ignore-user-config` flag to both `dvr-scan` and `dvr-scan-app` commands to allow the application to run even if the user config file is corrupted
- [general] Add new `scan-only` config option to match the UI checkbox and the `--scan-only` CLI flag
- [bugfix] Fix crash on startup when trying to load user config saved with v1.8 #240
  - This was caused by the `scan-only` UI option being emitted but the config file did not support it in v1.8
  - Users who are running into this issue should be able to run DVR-Scan after updating to v1.8.1
  - As a workaround for previous versions, you can manually remove the `scan-only` line in the saved config file

### 1.8 (2025-08-23)

#### Release Notes

DVR-Scan 1.8 includes several UI additions and enhancements, and fixes a long-standing issue with Python packaging dependencies.

#### Changelog

- [general] The Python distribution now correctly requires `opencv-python` #204
  - There is a separate `dvr-scan-headless` package available for servers which requires `opencv-python-headless` and only includes CLI functionality
- [bugfix] Fix bounding box overlay stuck on when using the OpenCV output mode #218
- [feature] UI additions and enhancements:
  - add option for enabling output concatenation #223
  - output folder now opens on completion by default #226
  - input videos can now be sorted by each column
  - add menu button to open DVR-Scan log folder
- [feature] Add `max-area`, `max-width`, and `max-height` options to help suppress improbable motion events, such as those caused by rain or fog #224 (thanks @elvis-epx)
- [bugfix] Log files no longer append to the same file, and now have randomized suffixes to support multiple instances #227
  - Config option changes: logs are no longer appended to the same file, so `max-log-size` is no longer required, and `max-log-files` has been raised from 4 to 15
- [bugfix] Use `pathlib.Path` everywhere for path handling to mitigate issues with ffmpeg output mode on Windows #220
- [bugfix] Fix inaccurate progress bar when using `-st`/`--start-time` #191
- [bugfix] Fix missing log message when processing next video #213
- [improvement] Update default ffmpeg stream mapping to more gracefully handle audio/subtitles #219
- [dist] Update ffmpeg from 7.1 -> 8.0 in binary distributions

### 1.7.0.1 (2025-03-11)

Re-release of Windows distribution that fixes program hanging when starting scan (#209). This was caused due to the way the program was built. There are no code changes, so the Python distribution has not been re-released.

### 1.7 (2025-02-28)

#### Release Notes

DVR-Scan 1.7 ships with a completely new UI, and supports faster video decoders (up to 50% better scanning performance):

The UI can be started by running `dvr-scan-app`, and is installed alongside the existing command line interface `dvr-scan`. Config settings and region files can be shared seamlessly between both. Feedback on the new UI is welcome.

#### Changelog

- [feature] New GUI now available across all platforms, can be launched via `dvr-scan-app`
  - Has UI elements for all settings, supports editing motion regions
  - Shows scan progress in real-time
- [feature] Add ability to control video decoder via `input-mode` config option (`opencv`, `pyav`, `moviepy`)
  - Allows switching between `OpenCV` (default), `PyAV`, and `MoviePy` for video decoding
  - Certain backends provide substantial performance benefits, up to 50% in some cases (let us know which one works best!)
- [bugfix] Fix crash on headless systems that don't have `pillow` installed
- [general] The region editor no longer prompts for a save path if one was already specified via the `-s`/`--save-regions` option
- [general] A size-limited logfile is now kept locally, useful for filing bug reports
  - Can be controlled with config file options `save-log` (default: yes), `max-log-size` (default: 20 kB), `max-log-files` (default: 4)
  - Path can be found under help entry for `--logfile` by running `dvr-scan --help` or `dvr-scan-app --help`
- [general] Minimum supported Python version is now 3.9

## DVR-Scan 1.6

### 1.6.2 (2024-12-17)

- [feature] Vastly improved region editor UI:
  - Reimplemented entire UI with Tcl/Tk to provide much more consistent experience across platforms
  - All options now have dedicated UI controls in addition to keyboard shortcuts
  - System-specific shortcuts like undo/redo now work as expected
  - Various performance and usability improvements including zoom/pan and shape selection
- [feature] Add new `variance-threshold` config option to control how MOG2 controls which pixels are described by the current background model #163
- [feature] Add new `--thumbnails` option to extract images from each event, use `--thumbnails highscore` to save frame with highest motion score #159
- [feature] Add `--use-pts` option to allow using presentation time instead of frame number for timestamps #170
- [bugfix] Fix incorrect framerate detection in Windows builds #174
- [general] Updates to Windows distributions:
  - Python 3.9 -> Python 3.12
  - OpenCV 4.10.0.82 -> 4.10.0.84
  - Ffmpeg 6.0 -> 7.1

### 1.6.1 (2024-06-18)

#### Release Notes

DVR-Scan 1.6.1 includes some important fixes and improvements for the region editor. Minimum supported Python version is now 3.8.

#### Changelog

- [bugfix] Corrupt frames are no longer encoded and are skipped when encoding #151
- [bugfix] Fix `region-editor` config file option having no effect #154
- [bugfix] The region editor now always prompts on any unsaved changes #161
- [general] The region editor no longer prompts for a save path if `-s`/`--save-region` was specified
- [general] Regions added via command line are now be merged with those loaded from the `load-region` config option
- [general] Add new `learning-rate` config option to control how fast the background model is updated
  - Value between `0.0` and `1.0` controls how much weight is placed on next frame, or `-1` for auto
  - `0.0` implies no update to the model, `1.0` will re-initialize it completely on each frame
  - Default value of `-1` is for automatic, which is unchanged from previous releases

### 1.6 (2023-11-15)

#### Release Notes

DVR-Scan greatly improves masking capabilities with the new region editor (user guide):

Multiple regions can now be defined with any shape, size, and complexity. Region data can be saved to a file and loaded again. Regions can also be specified by command line.

There are also several other bugfixes and improvements, such as improved seeking performance.

#### Changelog

- [feature] New region editor `-r`/`--region-editor` allows creation of multiple regions without shape restrictions, replaces `-roi`/`--region-of-interest`
- [feature] Multiple regions of interest (rectangular or polygonal) can now be created:
  - Using the new region editor by adding the `-r`/`--region-editor` flag: `dvr-scan -i video.mp4 -r`
  - New `-a`/`--add-region` replaces `-roi`/`--region-of-interest` option: `dvr-scan -i video.mp4 -a 5 5 20 5 20 20 5 20`
  - Regions can now be saved to a file: press S in the region editor or use `-s`/`--save-region`
  - Regions can now be loaded from a file: press O in the region editor or use `-R`/`--load-region`
  - Config files can specify a region file to use by default with the `load-region` option, replaces the `region-of-interest` setting
- [feature] New `-fm` / `--frame-metrics` option draws motion score on each frame to help tune detection parameters
- [cli] Short flag `-v` is now used for `--verbosity`, replaced by `-V` for `--version`
- [cli] `-roi`/`--region-of-interest` is now deprecated, replaced by region editor and add/save/load region flags
  - Specifying this option will display the ROI in the new region format allowing you to update usages more easily
- [general] Improved seeking performance, using `-st`/`--start-time` is now much faster (#92) -detection-parameters)
- [general] Noise reduction kernel can now be disabled by setting `-k`/`--kernel-size` to `0` (#123)
- [general] Include stack traces in logfiles when setting `--verbosity debug`
- [bugfix] Add `max-score` option to config file to fix CNT mode always treating first few frame as motion, default is 255.0 #119
- [bugfix] Fix timecode format `HH:MM:SS[.nnn]` being rejected for start/end time (#141)
- [bugfix] Fix incorrect RGB mapping for config file (values were treated as BGR instead)
- [other] Config option `timecode` has been renamed to `time-code` to match the command-line option
- [other] Config options that started with `timecode-` have been renamed to start with `text-`, and are now shared between the `time-code` and `frame-metrics` overlays:
  - `time-code-margin` is now `text-margin`
  - `time-code-font-scale` is now `text-font-scale`
  - `time-code-font-thickness` is now `text-font-thickness`
  - `time-code-font-color` is now `text-font-color`
  - `time-code-bg-color` is now `text-bg-color`

#### Known Issues

- Some prebuilt archives include documentation which references the `load-region` config option with the incorrect name (`region-file`) #153

## DVR-Scan 1.5

###
1.5.1 (2022-08-15)

#### Changelog

- [bugfix] Fix crash when opening multiple input videos (#95)
- [bugfix] Fix incorrect warning regarding frame decode failures at end of video

### 1.5 (2022-07-30)

#### Release Notes

- Significant performance improvements on multicore systems
- Support wildcards/globs as inputs for scanning entire folders (`-i folder/*.mp4`)
- Allow use of ffmpeg for better output quality (`-m ffmpeg`) or codec-copying mode (`-m copy`)
- Configuration files are now supported, see documentation for details
  - Can specify config file path with `-c`/`--config`, or create a `dvr-scan.cfg` file in your user config folder
- Windows binaries are now signed, thanks SignPath.io (certificate by SignPath Foundation)
- Experimental Nvidia CUDA® support has been added (set `-b MOG2_CUDA`)
  - If installing via `pip`, requires manual installation of OpenCV compiled with CUDA support
  - If downloading Windows version, make sure to download the GPU-enabled build (`dvr-scan-1.5-win64-cuda.zip`)
  - CUDA-enabled builds are not code signed, and do not include the `CNT` method
- Minimum supported Python version is now 3.7
- Minimum supported OpenCV version is now 3.x

#### Command-Line Changes

- New options:
  - `-c`/`--config` - set path to config file
  - `-d`/`--output-dir` - set directory to write output files (default is working directory)
  - `-m`/`--output-mode` - set output mode (one of: `opencv`, `ffmpeg`, `copy`)
  - `-mo`/`--mask-output` - path to write motion mask for analysis
  - `--verbosity` and `--logfile` - control output verbosity and path to save output
- `-i`/`--input` now supports globs/wildcards to scan entire folders, e.g. `-i folder/*.mp4`
- Change default value for `-l`/`--min-event-length` to 0.1 seconds, previously was 2 frames
- Long form of `-roi` has been renamed to `--region-of-interest` (previously was `--rectangle-of-interest`)
- `-c` is now used for `--config`, previously was for `--codec`
- Add experimental `MOG2_CUDA` option for `-b`/`--bg-subtractor`
- Rename existing `MOG` option to `MOG2`
- `--codec` has been removed, the value should now be set using a config file

#### Changelog

- [feature] Configuration file support and new `-c`/`--config` argument to specify path to config files (#77)
  - Breaks existing behavior of `-c` (was previously the shortform of `--codec`)
- [feature] Add support for multiple output modes via `-m`/`--output-mode` argument (#27, #42)
- [feature] Experimental support for GPU-based CUDA MOG2 filter (#12)
- [feature] Video encoding and decoding are now done in parallel with the scanning logic leading to improved performance on most systems (#52)
- [feature] Add support for exporting motion masks via `-mo`/`--mask-output` argument
  - Useful for detailed analysis or tuning of detection parameters
  - ffmpeg can be used to generate output videos by specifying `-m ffmpeg`
  - Codec-copy mode, using ffmpeg, can be used by specifying `-m copy`
- [feature] Add `--verbosity` and `--logfile` arguments to provide more control over program output
- [feature] Allow scanning entire folders using wildcards with `-i`/`--input` (#5)
  - Glob expansion is also performed on each input path directly, so quoted globs also function correctly
- [bugfix] Fix incorrect results when `-st`/`--start-time` is set
- [bugfix] Event start times are now correctly calculated when using `-fs`/`--frame-skip` (#68, #70)
  - Note that all skipped frames within the event window are included in motion event, thus the calculated start time may be slightly earlier
- [bugfix] Only get screen resolution when required (was causing issues on headless machines)
- [bugfix] Fix output messages conflicting with progress bar shown during scanning
- [bugfix] Output events now start from 1 to align with the event list
- [bugfix] Event end times now include the presentation duration of the last frame
- [bugfix] Small values for `-l`/`--min-event-length` are now handled correctly, previously would cause an error
- [enhancement] Progress bar now indicates how many events have been detected so far
- [enhancement] Change default value for `min_event_len` to 0.1 seconds, previously was 2 frames (#91)

#### Known Issues

- Attempting to open multiple input videos will cause DVR-Scan to crash, fixed in v1.5.1 (#95)
- Variable framerate videos (VFR) are not fully supported, and will yield incorrect timestamps (#20)
- Video output when using frame skip and `-m opencv` (default output mode) will result in frames missing from the exported videos (#81)
  - Use `-m ffmpeg` or `-m copy` as a workaround
- Multiple input videos are not supported with `-m ffmpeg` or `-m copy` (#86)
  - Use ffmpeg to concatenate/merge input videos before processing as a workaround
- CUDA builds do not include the `CNT` option for `-b`/`--bg-subtractor`

## DVR-Scan 1.4

### 1.4.1 (2022-02-20)

#### Release Notes

This release includes fixes for incorrect event start/end times when using frame skipping, and improvements to the bounding box overlays.

Important: Aside from critical bugfixes, DVR-Scan 1.4.x is the last minor version supporting Python 2.7. Starting from v1.5, the new minimum supported Python version will be 3.6 (see #83 for details).

#### Changelog

- [bugfix] Event start times are now correctly calculated when using `-fs`/`--frame-skip` (#68, #70)
  - Note that event start/end times may still be off by how many frames are skipped due to loss of context with respect to frame-accurate motion detection
- [bugfix] Event end times now take into account the number of skipped frames if `-fs`/`--frame-skip` if specified (e.g. it is assumed all skipped frames contained motion)
- [bugfix] Bounding box smoothing now takes into account `-fs`/`--frame-skip` (#31)
- [bugfix] Bounding boxes now cover all frames with motion (#31)
  - In v1.4 only the frames after `-l`/`--min-event-length` frames had passed were covered

#### Known Issues

- Variable framerate videos (VFR) are not fully supported, and will yield incorrect timestamps (#20)
- Using `-st`/`--start-time` will yield incorrect results
- If a motion event happens to be exactly the number of frames specified by `-l`/`--min-event-length`, the end timecode will be displayed incorrectly (#90)

### 1.4 (2022-02-08)

#### Release Notes

In addition to several bugfixes, this release of DVR-Scan adds the ability to draw a bounding box around the area in the frame where motion was detected. There are also several improves when using `-fs`/`--frame-skip` and/or `-df`/`--downscale-factor` by ensuring all other option are relative to the original video framerate/resolution.

Important: Aside from critical bugfixes, DVR-Scan 1.4.x is the last minor version supporting Python 2.7. Starting from v1.5, the new minimum supported Python version will be 3.6 (see #83 for details).

#### Changelog

- [feature] Add new `--bb`/`--bounding-box` option to draw rectangle around the area in the video where motion was detected
  - An amount to temporally smooth the box in time can also be specified after `-bb` (e.g. `-bb 0.5s`), where the default is 0.1s
- [bugfix] Processing errors should now return a non-zero exit code
- [bugfix] Allow a maximum window size to be set when using `-roi` (#59):
  - The `-roi` flag now accepts a maximum window size for the ROI selection window (e.g. `-roi 1920 1080`)
  - If the `screeninfo` package is installed, or you are using a Windows build, videos will automatically be resized to the maximum screen size
- [bugfix] Fix frozen timestamp at beginning of video (#68)
- [bugfix] Fix output videos not including all of the duration specified by `-tb`/`--time-before` in certain cases (#68
- [bugfix] Fix event start times not reflecting `-l`/`--min-event-length` and `-tb`/`--time-before` (#68
- [bugfix] Scanning no longer stops suddenly after a frame fails to decode (#62)
  - If more than 1 corrupt frame is found, a warning will be displayed with the number of frame decode failures
  - If more than 5 frames in a row fail to be decoded, processing will stop and display an error
- [bugfix] When no events have been found, an empty file is no longer created if `-o/--output` is specified
- [enhancement] `-k`/`--kernel-size` is now relative to the original video resolution, and will be reduced to adjust for `-df`/`--downscale-factor` if set (#46)
- [bugfix] Output videos now have the correct playback speed when using `-fs`/`--frame-skip` by reducing the framerate (#70)
- [bugfix] The `-l`/`--min-event-length` and `-tp`/`--time-post-event` parameters are now adjusted to compensate for `-fs`/`--frame-skip` if set (#70)
- [bugfix] An erroneus event (false positive) is no longer generated at the beginning of a video when `-l`/`--min-event-length` is equal to 1 frame

#### Known Issues

- Variable framerate videos (VFR) are not fully supported, and will yield incorrect timestamps (#20)
- When using `-fs`/`--frame-skip`, event start times do not include all of `-tb`/`--time-before-event` (#68, #70)
- When using `-bb`/`--bounding-box`, the amount of time covered by `-l`/`--min-event-length` will be missing bounding box overlays (#31)
- Using `-st`/`--start-time` will yield incorrect results
- If a motion event happens to be exactly the number of frames specified by `-l`/`--min-event-length`, the end timecode will be displayed incorrectly (#90)

## DVR-Scan 1.3

### 1.3 (2021-06-23)

#### Release Notes

This version of DVR-Scan includes a new, faster background subtraction algorithm (`-b CNT`). Results may be slightly different when using this method, so any feedback is most welcome.

#### Changelog

- [feature] Add new `-b`/`--bg-subtractor` argument to allow selecting between the MOG and CNT background subtractor types (e.g. `dvr-scan -b CNT`). Resolves #48. The following background subtractor types are available:
  - `MOG` is the default
  - `CNT` is a newer, faster algorithm (feedback is welcome)
- [bugfix] When using the `-o`/`--output` argument, a file is no longer written to disk if no motion events are found in the input file (#50)

#### Known Issues

- Variable framerate videos (VFR) are not fully supported, and will yield incorrect timestamps (#20)
- Using the `-roi` flag with high resolution videos can result in the window exceeding the size of the monitor (#59)
- When using `-tc`/`--time-code` the start of the video may have a frozen timestamp (#68)
- The kernel size must be manually adjusted when using `-df`/`--downscale-factor` (#46)
- When using `--frame-skip`, the `--min-event-length` parameter must be manually adjusted, and exported clips will have the wrong playback speed

## DVR-Scan 1.2

### 1.2 (2021-03-10)

#### Changelog

- [bugfix] Fix quiet mode (`-q/--quiet`) not working correctly (#19, #35)
- [bugfix] Fix downscale factor (`-df`/`--downscale-factor`) having no effect (#46)
- [api] Swap order of `fps` and `timecode` arguments in `FrameTimecode` constructor to match that of PySceneDetect (#33)
- [api] Refactor ScanContext class for better usage from Python (#33)
- [api] Use named logger rather than print statements (#35)

#### Known Issues

- When using the `-o`/`--output` argument, a file is still written to disk even if no motion events are discovered in the input file (#50)
- Variable framerate videos (VFR) are not fully supported, and will yield incorrect timestamps (#20)

## DVR-Scan 1.1

### 1.1 (2020-07-12)

#### Changelog

- [feature] Add new `-roi` argument to allow specifying a rectangular detection window, can select graphically or specify x/y/w/h via command line (thanks @klucsik)
- [bugfix] Fixed broken OpenCV compatibility layer causing issues with OpenCV 3.0+
- [general] Released project on pip, pinned OpenCV version requirement

#### Known Issues

- Quiet mode (`-q/--quiet`) does not work correctly
- Variable framerate videos (VFR) are not fully supported, and will yield incorrect timestamps (#20)

## DVR-Scan 1.0

### 1.0.1 (2017-01-12)

- [bugfix] unhandled exception affecting users running source distributions under Python 2.7 environments

### 1.0 (2017-01-11)

- [feature] detects motion events with configurable sensitivity and noise removal thresholds
- [feature] output events to individual video files, or as a single-file compilation
- [feature] allows input seeking, frame skipping, and output suppression mode
- [feature] configurable detection windows and pre/post-event inclusion length

#### In Development

## DVR-Scan 1.9

- [general] Modernize project branding and logos, improve legibility at smaller sizes