Repository: youtube-dl
Issue: youtube-dl refuses to download if there's a file already present
Labels: question

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## Checklist

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- [ ] I'm reporting a broken site support issue
- [x] I've verified that I'm running youtube-dl version **2024.04.22**
- [x] I've checked that all provided URLs are alive and playable in a browser
- [x] I've checked that all URLs and arguments with special characters are properly quoted or escaped
- [ ] I've searched the bugtracker for similar bug reports including closed ones
- [ ] I've read bugs section in FAQ

## Description

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I tried to download audio (webm) with youtube-dl. Worked fine. Then tried to download video+audio (webm) and youtube-dl refuses, even though it's not the same file.

I have noticed two possible fixes, and I figure both would be good to have:
1) Implement `--force-download`
2) Make overwrite default if it's a different file (compare size)

(The justification for (2) is that `--skip-download` and `--simulate` are available.)

## Verbose log

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Provide the complete verbose output of youtube-dl that clearly demonstrates the problem.
Add the `-v` flag to your command line you run youtube-dl with (`youtube-dl -v <your command line>`), copy the WHOLE output and insert it below. It should look similar to this:
 [debug] System config: []
 [debug] User config: []
 [debug] Command-line args: [u'-v', u'http://www.youtube.com/watch?v=BaW_jenozKcj']
 [debug] Encodings: locale cp1251, fs mbcs, out cp866, pref cp1251
 [debug] youtube-dl version 2021.12.17
 [debug] Python version 2.7.11 - Windows-2003Server-5.2.3790-SP2
 [debug] exe versions: ffmpeg N-75573-g1d0487f, ffprobe N-75573-g1d0487f, rtmpdump 2.4
 [debug] Proxy map: {}
 <more lines>
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```
D:\> youtube-dl --version
2024.04.22

D:\> youtube-dl -F https://www.youtube.com/watch?v=ynPdORrsuZM
[youtube] ynPdORrsuZM: Downloading webpage
[info] Available formats for ynPdORrsuZM:
format code  extension  resolution note
249          webm       audio only audio_quality_low   54k , webm_dash container, opus  (48000Hz), 1.27MiB
250          webm       audio only audio_quality_low   72k , webm_dash container, opus  (48000Hz), 1.70MiB
140          m4a        audio only audio_quality_medium  129k , m4a_dash container, mp4a.40.2 (44100Hz), 3.03MiB
251          webm       audio only audio_quality_medium  142k , webm_dash container, opus  (48000Hz), 3.33MiB
160          mp4        256x108    144p   41k , mp4_dash container, avc1.4d400b, 25fps, video only, 995.16KiB
278          webm       256x108    144p   72k , webm_dash container, vp9, 25fps, video only, 1.69MiB
133          mp4        426x182    240p   97k , mp4_dash container, avc1.4d400d, 25fps, video only, 2.28MiB
242          webm       426x182    240p  125k , webm_dash container, vp9, 25fps, video only, 2.95MiB
134          mp4        640x272    360p  174k , mp4_dash container, avc1.4d4015, 25fps, video only, 4.08MiB
243          webm       640x272    360p  281k , webm_dash container, vp9, 25fps, video only, 6.59MiB
135          mp4        854x364    480p  316k , mp4_dash container, avc1.4d401e, 25fps, video only, 7.40MiB
244          webm       854x364    480p  424k , webm_dash container, vp9, 25fps, video only, 9.94MiB
136          mp4        1280x544   720p  547k , mp4_dash container, avc1.4d401f, 25fps, video only, 12.82MiB
247          webm       1280x544   720p  782k , webm_dash container, vp9, 25fps, video only, 18.31MiB
248          webm       1920x816   1080p 1301k , webm_dash container, vp9, 25fps, video only, 30.47MiB
137          mp4        1920x816   1080p 1926k , mp4_dash container, avc1.640028, 25fps, video only, 45.10MiB
271          webm       2560x1088  1440p 5108k , webm_dash container, vp9, 25fps, video only, 119.61MiB
313          webm       3840x1634  2160p 12595k , webm_dash container, vp9, 25fps, video only, 294.89MiB
18           mp4        640x272    360p  487k , avc1.42001E, 25fps, mp4a.40.2 (44100Hz), 11.41MiB (best)

D:\> del "French 79 - TEENAGERS [Official Video]-ynPdORrsuZM.webm"

D:\> youtube-dl -f 251 https://www.youtube.com/watch?v=ynPdORrsuZM
[youtube] ynPdORrsuZM: Downloading webpage
[dashsegments] Total fragments: 1
[download] Destination: French 79 - TEENAGERS [Official Video]-ynPdORrsuZM.webm
[download] 100% of 3.33MiB in 00:00

D:\> youtube-dl -f 313 https://www.youtube.com/watch?v=ynPdORrsuZM
[youtube] ynPdORrsuZM: Downloading webpage
[download] French 79 - TEENAGERS [Official Video]-ynPdORrsuZM.webm has already been downloaded
[download] 100% of 3.33MiB
```