1080p WebM YouTube video filesize is smaller than 720p version

[fturco]

I'm using youtube-dl-2013.09.10 on a Gentoo Linux system. I noted that a 1080p WebM (-f 46) YouTube video filesize is smaller than the 720p version (-f 45). The video is http://www.youtube.com/watch?v=1e8xgF0JtVg. I often download 720p/1080p WebM videos from YouTube, but this problem never happened to me. I asked in the youtube-dl IRC channel and a person said it's probably not a youtube-dl problem but a YouTube one, in that it may have re-encoded the original 1080p version to 720p using a wrong bitrate (too high). I opened this issue just to be sure. Thank you.

[fturco]

I forgot to tell you that the 1080p version is 48 MiB while the 720p version is 106 MiB in size.

[xanadu]

itag 45 is supposed to be about 1Mbps, and 46 is about 2Mbps, so the
estimated file size should be 31MB / 61MB. More likely an YouTube trans
code rate control issue in itag 45 (or something done by your internet
provider).

On Sat, Sep 14, 2013 at 12:35 PM, fturco notifications@github.com wrote:

I forgot to tell you that the 1080p version is 48 MiB while the 720p
version is 106 MiB in size.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/1427#issuecomment-24456420
.

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[fturco]

I think this bug can be closed because YouTube switched from WebM to Dash format. Now Dash video at 1080p is 42 MiB while the 720p version is 24 MiB. Everything is OK now.