Merging video+audio. Output video wrong.

[degtyaryov]

Hello.

$ youtube-dl -c --format 137+141 "http://www.youtube.com/watch?v=u3riQ3eHDy0" -o test.mp4

$ du -h test.mp4 
278M    test.mp4

Manually merging:

$ youtube-dl -c --format 137 "http://www.youtube.com/watch?v=u3riQ3eHDy0" -o test_video.mp4
$ du -h test_video.mp4
621M    test_video.mp4

$ youtube-dl -c --format 141 "http://www.youtube.com/watch?v=u3riQ3eHDy0" -o test_audio.mp4
$ du -h test_audio.mp4
52M     test_audio.mp4

$ ffmpeg -y -i test_video.mp4 -i test_audio.mp4 -c copy -map 0:v:0 -map 1:a:0 -shortest test_manually.mp4
$ du -h test_manually.mp4
278M    test_manually.mp4

Merging without -shortest:

$ ffmpeg -y -i test_video.mp4 -i test_audio.mp4 -c copy -map 0:v:0 -map 1:a:0 test_manually_without_shortest.mp4
$ du -h test_manually_without_shortest.mp4
672M    test_manually_without_shortest.mp4

Duration Video < Duration Audio:

$ ffprobe test_video.mp4 2>&1 | grep Duration
  Duration: 00:27:58.96, start: 0.000000, bitrate: 3099 kb/s
$ ffprobe test_audio.mp4 2>&1 | grep Duration
  Duration: 00:27:59.06, start: 0.000000, bitrate: 255 kb/s

$ ffprobe test_manually.mp4 2>&1 | grep Duration
  Duration: 00:27:59.06, start: 0.000000, bitrate: 1384 kb/s
$ ffprobe test_manually_without_shortest.mp4 2>&1 | grep Duration
  Duration: 00:27:59.06, start: 0.000000, bitrate: 3355 kb/s

How to remove -shortest?

[clb92]

I have a merge problem too. Maybe it's the same as this? In the merged output file the video cuts off (well, gets stuck on one frame) for the last 1/3 of the video. Is that what you're describing too?

It's a bit annoying to find out, that things went wrong, after downloading/archiving ~2000 videos.

[degtyaryov]

yes. 1/3 video and 3/3 audio.

[clb92]

See also issue #4220 if you haven't already.

[jaimeMF]

It seems to work with ffmpeg 2.5.2, could you post the full output of youtube-dl -c --format 137+141 "http://www.youtube.com/watch?v=u3riQ3eHDy0" -o test.mp4 --verbose?

[clb92]

My full output of that command is:

DiskStation> youtube-dl -c --format 137+141 "http://www.youtube.com/watch?v=u3riQ3eHDy0" -o test.mp4 --verbose
[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['-c', '--format', '137+141', 'http://www.youtube.com/watch?v=u3riQ3eHDy0', '-o', 'test.mp4', '--verbose']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2014.12.17.2
[debug] Python version 2.7.9 - Linux-3.2.40-i686-with-glibc2.0
[debug] exe versions: ffmpeg 2.0.2
[debug] Proxy map: {}
[youtube] u3riQ3eHDy0: Downloading webpage
[youtube] u3riQ3eHDy0: Extracting video information
[youtube] u3riQ3eHDy0: Downloading DASH manifest
[debug] Invoking downloader on 'https://r4---sn-cgxqc55oq-caae.googlevideo.com/videoplayback?id=bb7ae24377870f2d&itag=137&source=youtube&requiressl=yes&mm=31&ms=au&mv=m&ratebypass=yes&mime=video/mp4&gir=yes&clen=650467330&lmt=1410840519374013&dur=1678.960&signature=6181F4AECDA3F426BBBB803BA340AEF990C9CE30.8F47CA63D1CC3FB12C70F4B5D3E97382704C189B&fexp=900718,927622,932404,9405581,9405619,943917,947209,947218,948124,952302,952605,952901,955301,957103,957105,957201&sver=3&upn=v6S01HMbO40&mt=1420040098&key=dg_yt0&ip=78.143.106.133&ipbits=0&expire=1420061756&sparams=ip,ipbits,expire,id,itag,source,requiressl,mm,ms,mv,ratebypass,mime,gir,clen,lmt,dur'
[download] Destination: test.f137.mp4
[download] 100% of 620.33MiB in 01:48
[debug] Invoking downloader on 'https://r4---sn-cgxqc55oq-caae.googlevideo.com/videoplayback?id=bb7ae24377870f2d&itag=141&source=youtube&requiressl=yes&mm=31&ms=au&mv=m&ratebypass=yes&mime=audio/mp4&gir=yes&clen=53532367&lmt=1410840440884345&dur=1679.058&signature=1C28EB8CAE138E503F7F003B4A2BE5FEBEF65210.45D28C8DA2F0553BB1B8AA65F7BBCCB72679425A&fexp=900718,927622,932404,9405581,9405619,943917,947209,947218,948124,952302,952605,952901,955301,957103,957105,957201&sver=3&upn=v6S01HMbO40&mt=1420040098&key=dg_yt0&ip=78.143.106.133&ipbits=0&expire=1420061756&sparams=ip,ipbits,expire,id,itag,source,requiressl,mm,ms,mv,ratebypass,mime,gir,clen,lmt,dur'
[download] Destination: test.f141.mp4
[download] 100% of 51.05MiB in 00:17
[ffmpeg] Merging formats into "test.mp4"
[debug] ffmpeg command line: ffmpeg -y -i test.f137.mp4 -i test.f141.mp4 -c copy -map 0✌️0 -map 1🅰️0 -shortest test.mp4
DiskStation>

How do I upgrade my ffmpeg? Does youtube-dl have it bundled or should I upgrade the regular one installed on my system?

[jaimeMF]

youtube-dl doesn't bundle ffmpeg, so you should upgrade the regular one.

[clb92]

That's going to be a problem then, I think. It's a Synology box with no real package manager except Synology's own "Package Center". Two community repositories have an ffmpeg package. One is version 2.2.1-1 and the other says 1.0-0005.

[jaimeMF]

version 2.2 could work, try with it.

Since it's causing problems and it's not really needed (I think) we could remove the -shortest option.

[clb92]

The ffmpeg command still starts the old 2.0.2 version that comes default on the box.

[clb92]

I got it. I just moved /usr/local/bin in front of /usr/bin in the PATH variable. Now it uses the correct ffmpeg.

Will post with the youtube-dl download result in a minute...

[clb92]

And it works! The video stream now works all the way to the end.

Thank you very much for your help, and have a happy new years eve!

[jaimeMF]

In the next version it won't use the -shortest option.