Repository: yt-dlp
Issue: --no-overwrites option doesn't work when one uses --convert-thumbnails jpg
Labels: enhancement,core:post-processor

### DO NOT REMOVE OR SKIP THE ISSUE TEMPLATE

- [X] I understand that I will be **blocked** if I remove or skip any mandatory\* field

### Checklist

- [X] I'm reporting a bug unrelated to a specific site
- [X] I've verified that I'm running yt-dlp version **2023.01.06** ([update instructions](https://github.com/yt-dlp/yt-dlp#update)) or later (specify commit)
- [X] I've checked that all provided URLs are playable in a browser with the same IP and same login details
- [X] I've checked that all URLs and arguments with special characters are [properly quoted or escaped](https://github.com/yt-dlp/yt-dlp/wiki/FAQ#video-url-contains-an-ampersand--and-im-getting-some-strange-output-1-2839-or-v-is-not-recognized-as-an-internal-or-external-command)
- [X] I've searched the [bugtracker](https://github.com/yt-dlp/yt-dlp/issues?q=) for similar issues **including closed ones**. DO NOT post duplicates
- [X] I've read the [guidelines for opening an issue](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#opening-an-issue)

### Provide a description that is worded well enough to be understood

The --no-overwrites option doesn't work when one uses --convert-thumbnails jpg. (Of course, the extension could be anything eg png, jpg). 

Example - We will download the description and thumbnail (and convert the thumbnail to jpg) for two different video IDs with the exact same title and upload-date:

> yt-dlp -vU --no-overwrites --ignore-errors --compat-options filename-sanitization --write-description --write-thumbnail --convert-thumbnails jpg --abort-on-unavailable-fragment --skip-download -o "%(upload_date>%Y.%m.%d)s - %(title)s.%(ext)s" "TQqpfNIZ-rc"

> yt-dlp -vU --no-overwrites --ignore-errors --compat-options filename-sanitization --write-description --write-thumbnail --convert-thumbnails jpg --abort-on-unavailable-fragment --skip-download -o "%(upload_date>%Y.%m.%d)s - %(title)s.%(ext)s" "dCRAcRp8SQg"

For both, the downloaded thumbnail is in webp format, which will then be converted to jpg. When downloading the second video ID, the first thumbnail should not be overwritten. Yet it is. The description file however is NOT overwritten. So this problem is exclusive to thumbnails, and to cases where the --convert-thumbnails option is used to convert the thumbnail to another format. Of course, if yt-dlp selects a thumbnail in jpg format from the list of available thumbnails, then the existing thumbnail will not be overwritten, assuming it too is in jpg format.  



### Provide verbose output that clearly demonstrates the problem

- [X] Run **your** yt-dlp command with **-vU** flag added (`yt-dlp -vU <your command line>`)
- [X] Copy the WHOLE output (starting with `[debug] Command-line config`) and insert it below

### Complete Verbose Output

```shell
[debug] Command-line config: ['-vU', '--no-overwrites', '--ignore-errors', '--compat-options', 'filename-sanitization', '--write-description', '--write-thumbnail', '--convert-thumbnails', 'jpg', '--abort-on-unavailable-fragment', '--skip-download', '-o', '%(upload_date>%Y.%m.%d)s - %(title)s.%(ext)s', 'TQqpfNIZ-rc']
[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8, error utf-8, screen utf-8
[debug] yt-dlp version 2023.01.06 [6becd25] (zip)
[debug] Compatibility options: filename-sanitization
[debug] Python 3.8.10 (CPython x86_64 64bit) - Linux-5.4.72-microsoft-standard-WSL2-x86_64-with-glibc2.29 (OpenSSL 1.1.1f  31 Mar 2020, glibc 2.31)
[debug] exe versions: ffmpeg n4.4-154-g79c114e1b2-20210923 (setts)
[debug] Optional libraries: certifi-2019.11.28, secretstorage-2.3.1, sqlite3-2.6.0, websockets-10.3
[debug] Proxy map: {}
[debug] Loaded 1760 extractors
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
Latest version: 2023.01.06, Current version: 2023.01.06
yt-dlp is up to date (2023.01.06)
[youtube] Extracting URL: TQqpfNIZ-rc
[youtube] TQqpfNIZ-rc: Downloading webpage
[youtube] TQqpfNIZ-rc: Downloading android player API JSON
[debug] Sort order given by extractor: quality, res, fps, hdr:12, source, vcodec:vp9.2, channels, acodec, lang, proto
[debug] Formats sorted by: hasvid, ie_pref, quality, res, fps, hdr:12(7), source, vcodec:vp9.2(10), channels, acodec, lang, proto, filesize, fs_approx, tbr, vbr, abr, asr, vext, aext, hasaud, id
[debug] Default format spec: bestvideo*+bestaudio/best
[info] TQqpfNIZ-rc: Downloading 1 format(s): 248+251
[info] Writing video description to: 2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.description
[info] Downloading video thumbnail 41 ...
[info] Writing video thumbnail 41 to: 2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp
[ThumbnailsConvertor] Converting thumbnail "2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp" to jpg
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -f image2 -pattern_type none -i 'file:2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp' -update 1 -bsf:v mjpeg2jpeg -movflags +faststart 'file:2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.jpg'
Deleting original file 2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp (pass -k to keep)


[debug] Command-line config: ['-vU', '--no-overwrites', '--ignore-errors', '--compat-options', 'filename-sanitization', '--write-description', '--write-thumbnail', '--convert-thumbnails', 'jpg', '--abort-on-unavailable-fragment', '--skip-download', '-o', '%(upload_date>%Y.%m.%d)s - %(title)s.%(ext)s', 'dCRAcRp8SQg']
[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8, error utf-8, screen utf-8
[debug] yt-dlp version 2023.01.06 [6becd25] (zip)
[debug] Compatibility options: filename-sanitization
[debug] Python 3.8.10 (CPython x86_64 64bit) - Linux-5.4.72-microsoft-standard-WSL2-x86_64-with-glibc2.29 (OpenSSL 1.1.1f  31 Mar 2020, glibc 2.31)
[debug] exe versions: ffmpeg n4.4-154-g79c114e1b2-20210923 (setts)
[debug] Optional libraries: certifi-2019.11.28, secretstorage-2.3.1, sqlite3-2.6.0, websockets-10.3
[debug] Proxy map: {}
[debug] Loaded 1760 extractors
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
Latest version: 2023.01.06, Current version: 2023.01.06
yt-dlp is up to date (2023.01.06)
[youtube] Extracting URL: dCRAcRp8SQg
[youtube] dCRAcRp8SQg: Downloading webpage
[youtube] dCRAcRp8SQg: Downloading android player API JSON
[debug] Loading youtube-nsig.97ea7458 from cache
WARNING: [youtube] dCRAcRp8SQg: nsig extraction failed: You may experience throttling for some formats
         Install PhantomJS to workaround the issue. Please download it from https://phantomjs.org/download.html
         n = 3DDdmlQqOZdXrS ; player = https://www.youtube.com/s/player/97ea7458/player_ias.vflset/en_US/base.js
[debug] [youtube] Signature function returned an exception; please report this issue on  https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using  yt-dlp -U
[debug] Sort order given by extractor: quality, res, fps, hdr:12, source, vcodec:vp9.2, channels, acodec, lang, proto
[debug] Formats sorted by: hasvid, ie_pref, quality, res, fps, hdr:12(7), source, vcodec:vp9.2(10), channels, acodec, lang, proto, filesize, fs_approx, tbr, vbr, abr, asr, vext, aext, hasaud, id
[debug] Default format spec: bestvideo*+bestaudio/best
[info] dCRAcRp8SQg: Downloading 1 format(s): 136+251
[info] Video description is already present
[info] Downloading video thumbnail 45 ...
[info] Writing video thumbnail 45 to: 2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp
[ThumbnailsConvertor] Converting thumbnail "2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp" to jpg
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -f image2 -pattern_type none -i 'file:2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp' -update 1 -bsf:v mjpeg2jpeg -movflags +faststart 'file:2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.jpg'
Deleting original file 2021.02.04 - Depression Signs Symptoms and Causes Part 3 of 4.webp (pass -k to keep)
```