It should be possible to specify just an output directory

[mitchellmebane]

Unless I've completely overlooked it (and who knows, maybe I have), there doesn't seem to be a way to change the output directory without also specifying a filename template:

C:\bin>youtube-dl -v -o "D:\\" https://www.youtube.com/watch?v=dQw4w9WgXcQ
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'-v', u'-o', u'D:\\', u'https://www.youtube.com/watch?v=dQw4w9WgXcQ']
[debug] Encodings: locale cp1252, fs mbcs, out cp437, pref cp1252
[debug] youtube-dl version 2015.04.17
[debug] Python version 2.7.8 - Windows-8-6.2.9200
[debug] exe versions: ffmpeg N-71329-g235589e, ffprobe N-71329-g235589e
[debug] Proxy map: {}
[youtube] dQw4w9WgXcQ: Downloading webpage
[youtube] dQw4w9WgXcQ: Extracting video information
[youtube] {43} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {18} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {5} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {36} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {17} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {135} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {244} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {134} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {243} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {133} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {242} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {160} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {140} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] {171} signature length 40.40, html5 player en_US-vflXIPlZ4
[youtube] dQw4w9WgXcQ: Downloading DASH manifest
[debug] Invoking downloader on u'https://r12---sn-vgqs7n7z.googlevideo.com/videoplayback?fexp=900720%2C907263%2C916651%2C929305%2C932627%2C933119%2C934954%2C938028%2C9407115%2C9408347%2C9408406%2C9408707%2C9409174%2C942682%2C947233%2C947601%2C948124%2C948703%2C948802%2C951703%2C952612%2C952637%2C957201%2C961404%2C961406&nh=IgpwcjAyLm9yZDEyKgkxMjcuMC4wLjE&key=yt5&gcr=us&dur=212.834&source=youtube&requiressl=yes&ratebypass=yes&itag=18&expire=1429524879&upn=sBiEm59Wnxk&sver=3&mm=31&id=o-AJBkUUKxs3V0S_Q7vLXJWVFUuiC0CClKKG_NlqXwbToY&mv=m&mt=1429503205&ms=au&ip=75.32.12.90&pl=21&initcwndbps=695000&ipbits=0&sparams=dur%2Cgcr%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Cmime%2Cmm%2Cms%2Cmv%2Cnh%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cupn%2Cexpire&mime=video%2Fmp4&signature=898F6A3963208A382290B512314B28B315CB25EE.84C981582526B6A2498632D6A27F6419B43711E9'
ERROR: unable to open for writing: [Errno 2] No such file or directory: u'D:\\'
Traceback (most recent call last):
  File "youtube_dl\downloader\http.pyo", line 160, in real_download
  File "youtube_dl\utils.pyo", line 248, in sanitize_open
IOError: [Errno 2] No such file or directory: u'D:\\'

If I give a template, it works as expected, but this seems like it shouldn't be necessary when I just want the default:

C:\bin>youtube-dl -o "D:\\%(title)s-%(id)s.%(ext)s" https://www.youtube.com/watch?v=dQw4w9WgXcQ 
[youtube] dQw4w9WgXcQ: Downloading webpage                                                      
[youtube] dQw4w9WgXcQ: Extracting video information                                             
[youtube] dQw4w9WgXcQ: Downloading js player en_US-vflXIPlZ4                                    
[youtube] dQw4w9WgXcQ: Downloading DASH manifest                                                
[download] Destination: D:\Rick Astley - Never Gonna Give You Up-dQw4w9WgXcQ.mp4                
[download] 100% of 16.75MiB in 00:05                                                            

C:\bin>dir /b D:\*.mp4                                                                          
Rick Astley - Never Gonna Give You Up-dQw4w9WgXcQ.mp4                                           

[jaimeMF]

Duplicate of #5043. (Note that if youtube-dl is in your PATH you can just change the working directory)