mp4 recode broken

[EricBelanger]

Recoding the video to mp4 using ffmpeg doesn't work:

$ youtube-dl --recode-video=mp4 http://www.youtube.com/watch?v=iiFWoXQPOJc
[youtube] Setting language
[youtube] iiFWoXQPOJc: Downloading video webpage
[youtube] iiFWoXQPOJc: Downloading video info webpage
[youtube] iiFWoXQPOJc: Extracting video information
[download] Destination: Work Done by Isothermic Process-iiFWoXQPOJc.flv
[download] 100.0% of 21.94MiB at 864.23KiB/s ETA 00:00
[ffmpeg] Converting video from flv to mp4, Destination: Work Done by Isothermic Process-iiFWoXQPOJc.mp4
ERROR: The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

[jaimeMF]

This is working for me, could you post the output of youtube-dl -v and ffmpeg -version

[EricBelanger]

My guess is that I'm using a newer ffmpeg. Anyway here's the info:

$ ffmpeg -version
ffmpeg version 1.2.1
built on May 10 2013 16:31:05 with gcc 4.8.0 (GCC) 20130502 (prerelease)
configuration: --prefix=/usr --disable-debug --disable-static --enable-avresample --enable-dxva2 --enable-fontconfig --enable-gpl --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-postproc --enable-runtime-cpudetect --enable-shared --enable-vdpau --enable-version3 --enable-x11grab
libavutil 52. 18.100 / 52. 18.100
libavcodec 54. 92.100 / 54. 92.100
libavformat 54. 63.104 / 54. 63.104
libavdevice 54. 3.103 / 54. 3.103
libavfilter 3. 42.103 / 3. 42.103
libswscale 2. 2.100 / 2. 2.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 2.100 / 52. 2.100

$ youtube-dl -v --recode-video=mp4 http://www.youtube.com/watch?v=iiFWoXQPOJc
[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['-v', '--recode-video=mp4', 'http://www.youtube.com/watch?v=iiFWoXQPOJc']
[debug] youtube-dl version 2013.07.19
[debug] Python version 3.3.2 - Linux-3.10.1-1-ARCH-x86_64-with-arch
[debug] Proxy map: {}
[youtube] Setting language
[youtube] iiFWoXQPOJc: Downloading video webpage
[youtube] iiFWoXQPOJc: Downloading video info webpage
[youtube] iiFWoXQPOJc: Extracting video information
[download] Destination: Work Done by Isothermic Process-iiFWoXQPOJc.flv
[download] 100.0% of 21.94MiB at 611.91KiB/s ETA 00:00
[ffmpeg] Converting video from flv to mp4, Destination: Work Done by Isothermic Process-iiFWoXQPOJc.mp4
ERROR: The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

[jaimeMF]

The problem is with libfaac, which can only be build if the nonfree option is included. Adding -strict -2 may solve the problem but I haven't managed to get it to work.

[EricBelanger]

It seems like youtube-dl autodownloads as mp4 now:

$ youtube-dl --recode-video=mp4 http://www.youtube.com/watch?v=iiFWoXQPOJc
[youtube] Setting language
[youtube] iiFWoXQPOJc: Downloading video webpage
[youtube] iiFWoXQPOJc: Downloading video info webpage
[youtube] iiFWoXQPOJc: Extracting video information
[download] Destination: Work Done by Isothermic Process-iiFWoXQPOJc.mp4
[download] 100% of 14.56MiB in 00:19
[ffmpeg] Not converting video file Work Done by Isothermic Process-iiFWoXQPOJc.mp4 - already is in target format mp4

So I guess this can be closed.

[jaimeMF]

No, we have a problem with youtube not serving all the itags (#1578), so now the best quality available is a mp4 file. But the problem is still there, you'll get the same ffmpeg error if you try to recode to mp4 a flv video.

[DavidS]

This is still happening:

david@zion:/net/Multimedia/Movies/yt$ youtube-dl --recode-video=mp4 https://www.youtube.com/watch?v=DDDD --verbose
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'--recode-video=mp4', u'https://www.youtube.com/watch?v=DDDD', u'--verbose']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2015.06.04.1
[debug] Python version 2.7.10 - Linux-4.1.0-1-amd64-x86_64-with-debian-stretch-sid
[debug] exe versions: avconv 11.4-6, avprobe 11.4-6, rtmpdump 2.4
[debug] Proxy map: {}
[youtube] DDDD: Downloading webpage
[youtube] DDDD: Extracting video information
[youtube] DDDD: Downloading DASH manifest
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[download] DDDD.mkv has already been downloaded and merged
[ffmpeg] Converting video from mkv to mp4, Destination: DDDD.mp4
[debug] ffmpeg command line: avconv -y -i 'DDDD.mkv' 'DDDD.mp4'
ERROR: Add '-strict experimental' if you want to use it.
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/youtube_dl/YoutubeDL.py", line 1548, in post_process
    files_to_delete, info = pp.run(info)
  File "/usr/lib/python2.7/dist-packages/youtube_dl/postprocessor/ffmpeg.py", line 302, in run
    self.run_ffmpeg(path, outpath, [])
  File "/usr/lib/python2.7/dist-packages/youtube_dl/postprocessor/ffmpeg.py", line 152, in run_ffmpeg
    self.run_ffmpeg_multiple_files([path], out_path, opts)
  File "/usr/lib/python2.7/dist-packages/youtube_dl/postprocessor/ffmpeg.py", line 148, in run_ffmpeg_multiple_files
    raise FFmpegPostProcessorError(msg)
FFmpegPostProcessorError

david@zion:/net/Multimedia/Movies/yt$ 

This is a pretty current Debian testing:

david@zion:~$ avconv -version
avconv version 11.4-6:11.4-2, Copyright (c) 2000-2014 the Libav developers
  built on Jun  3 2015 22:51:42 with gcc 4.9.2 (Debian 4.9.2-19)
avconv 11.4-6:11.4-2
libavutil     54.  3. 0 / 54.  3. 0
libavcodec    56.  1. 0 / 56.  1. 0
libavformat   56.  1. 0 / 56.  1. 0
libavdevice   55.  0. 0 / 55.  0. 0
libavfilter    5.  0. 0 /  5.  0. 0
libavresample  2.  1. 0 /  2.  1. 0
libswscale     3.  0. 0 /  3.  0. 0
david@zion:~$ youtube-dl --version
2015.06.04.1
david@zion:~$ 

running the recoding step manually with avconv -y -i 'DDDD.mkv' -strict experimental 'DDDD.mp4' worked.

[yan12125]

@DavidS I guess the following command works:

youtube-dl --recode-video=mp4 https://www.youtube.com/watch?v=DDDD --verbose --postprocessor-args "-strict experimental"

[dashed]

@yan12125 thanks. The following: --postprocessor-args "-strict experimental" fixed my issue:

ERROR: audio conversion failed: Or use the non experimental encoder 'libfaac'.

[yan12125]

Closing as the problem is solved with the newly added flag --postprocessor-args. Feel free to open a new issue if the problem is still when the flag mentioned above is used.

[dashed]

I wasn't sure how to resolve the error at first.

Perhaps, youtube-dl should suggest resolving using --postprocessor-args flagg?

[yan12125]

experimental indicates that the feature should not be enabled by default. By the way, in the latest ffmpeg, aac encoder is no longer marked as experimental. [1] You may want to upgrade ffmpeg.

[1] http://ffmpeg.org/index.html#aac_encoder_stable

[faxotherapy]

For unknown reasons to me, I now get the following error:

ERROR: audio conversion failed: Or use the non experimental encoder 'libfaac'.

I had no problem in the past. How can I circumvent this? If I use mp3, it works, but I would rather use either m4a or aac, but none of the last two work.

[yan12125]

@faxotherapy Upgrade your ffmpeg or use the command in #1027 (comment)

[chibicode]

I used homebrew to install ffmpeg, so this worked for me:

# Reinstall ffmpeg with faac support
brew reinstall ffmpeg --with-faac

# Convert using --prefer-ffmpeg
youtube-dl -x ... --audio-format m4a --prefer-ffmpeg