yt-dl does not always pull the 'best' version by default, or even when commanded.

[LTIOfficial]

• I've verified and I assure that I'm running youtube-dl 2018.11.07

• At least skimmed through the README, most notably the FAQ and BUGS sections

• Searched the bugtracker for similar issues including closed ones

• Checked that provided video/audio/playlist URLs (if any) are alive and playable in a browser

• Bug report (encountered problems with youtube-dl)

---

It appears that yt-dl is not always pulling the 'best' version by default, or even when commanded.

# youtube-dl -F w7q6Nevfm_M
[youtube] w7q6Nevfm_M: Downloading webpage
[youtube] w7q6Nevfm_M: Downloading video info webpage
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[info] Available formats for w7q6Nevfm_M:
format code  extension  resolution note
139          m4a        audio only DASH audio   53k , m4a_dash container, mp4a.40.5@ 48k (22050Hz), 5.85MiB
140          m4a        audio only DASH audio  132k , m4a_dash container, mp4a.40.2@128k (44100Hz), 15.59MiB
160          mp4        256x144    DASH video  108k , mp4_dash container, avc1.4d400b, 25fps, video only
133          mp4        426x240    DASH video  242k , mp4_dash container, avc1.4d400c, 25fps, video only
134          mp4        640x360    DASH video  274k , mp4_dash container, avc1.4d401e, 25fps, video only, 14.45MiB
136          mp4        1280x720   DASH video 1125k , mp4_dash container, avc1.4d401f, 25fps, video only, 57.78MiB
135          mp4        854x480    DASH video 1155k , mp4_dash container, avc1.4d4014, 25fps, video only
17           3gp        176x144    small , mp4v.20.3, mp4a.40.2@ 24k, 8.39MiB
36           3gp        320x180    small , mp4v.20.3, mp4a.40.2, 24.85MiB
18           mp4        640x360    medium , avc1.42001E, mp4a.40.2@ 96k, 42.89MiB
43           webm       640x360    medium , vp8.0, vorbis@128k, 46.31MiB
22           mp4        1280x720   hd720 , avc1.64001F, mp4a.40.2@192k (best)

For the longest time, I fully assumed that a command for a merged version of the 'best mp4' and 'best m4a' would produce an absolute 'best video possible' end result, but that's not the case here (or with many other videos).

# youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/mp4' w7q6Nevfm_M
[youtube] w7q6Nevfm_M: Downloading webpage
[youtube] w7q6Nevfm_M: Downloading video info webpage
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[dashsegments] Total fragments: 202
[download] Destination: /files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M**.f135**.mp4
[download] 100% of 34.89MiB in 02:52
[dashsegments] Total fragments: 207
[download] Destination: /files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M**.f140**.m4a
[download] 100% of 15.59MiB in 00:27
[ffmpeg] Merging formats into "/files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M.mp4"

According to the -F readout, .f136 is the 'best' separate video, not .f135. So why didn't it grab .f136 instead? Additionally, .f22 appears to have the best video and audio already in single-file form.

So I tested the defaults to see what it would grab:

# youtube-dl w7q6Nevfm_M
[youtube] w7q6Nevfm_M: Downloading webpage
[youtube] w7q6Nevfm_M: Downloading video info webpage
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[dashsegments] Total fragments: 202
[download] Destination: /files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M**.f135**.mp4
[download] 100% of 34.89MiB in 02:52
[dashsegments] Total fragments: 207
[download] Destination: /files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M**.f140**.m4a
[download] 100% of 15.59MiB in 00:27
[ffmpeg] Merging formats into "/files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M.mp4"

Same deal. It tries to grab the apparent 'second best' of the individual, separate components, fully ignoring the higher quality 'single-file' option that's available (.f22).

The only way to get the truly 'best' version of this, and many others, is to specifically call for it:

# youtube-dl -f 22 w7q6Nevfm_M
[youtube] w7q6Nevfm_M: Downloading webpage
[youtube] w7q6Nevfm_M: Downloading video info webpage
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[youtube] w7q6Nevfm_M: Downloading MPD manifest
[download] Destination: /files/public/ytdl/Peter Joseph 'Train of Thought' ZDay 2017-w7q6Nevfm_M.mp4
[download] 100% of 143.21MiB in 00:27

The problem here is that automating the task (where there can be no review of the # youtube-dl -F xxxxxxxxx results ) becomes a bit of a crapshoot, where we end up with only 'some' of the videos satisfying the need for truly 'best' versions.

Is there a way to instruct yt-dl to make a determination of 'true best' by comparing the best complete video with the best individual components (i.e. make it a little smarter)?

[dstftw]

Bitrate is preferred over height.

[LTIOfficial]

It appears to me that .f22 has the highest bitrate (mp4a.40.2@192k) compared to either of the audio-only options (mp4a.40.5@ 48k or mp4a.40.2@128k), while it's video component is HD720, as opposed to .f135's lesser 480 format. yt-dl also has .f22 marked as (best), but then ignores that when using the defaults.

Which is why I'm still asking:
Is there a way to instruct yt-dl to make a determination of 'true best' by comparing the best complete video with the best individual components (i.e. make it a little smarter)?