Recording video on a server

[justheuristic]

Recording video on a server

[sytelus]

I got this error with Ubuntu 18.04 while using Monitor class in OpenAI Gym. You need correct versions of ffmpeg and x264 encoder. To get them, I used following and it worked:

conda install x264=='1!152.20180717' ffmpeg=4.0.2 -c conda-forge

[mimoralea]

In 2019, the solution by @sytelus down 2 comments is what worked for me. He has exact versions which work well! Leaving this comment for context only

For those using conda (and my future self,) I solved a similar issue by:

1. Installing x264:
   conda install x264

2. Upgrading ffmpeg:
   conda install ffmpeg==4.0

[DanielTakeshi]

This error also happens on OS X 10.11.6 (El Capitan). In that case, the solution is to reinstall ffmpeg with the -x265 (not -x264...) library:

brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-libass --with-libquvi --with-libvorbis --with-libvpx --with-opus --with-x265

(From the ffmpeg docs, though I had to get rid of --with-libass to get this to work.)

[gdb]

I'm slightly surprised that there isn't a nicer error message for you, but does using the xvfb command recommended here help: https://gist.github.com/joschu/e42a050b1eb5cfbb1fdc667c3450467a?

I'll re-open the other issue so we can chat there about readability. Sorry, think we missed that the first time around!

[tlbtlbtlb]

Most likely ffmpeg is failing. Can you try this:

dd if=/dev/zero bs=750000 count=50 | ffmpeg -nostats -loglevel error -y -r 60 -f rawvideo -s:v 500x500 -pix_fmt 'rgb24' -i /dev/stdin -vcodec libx264 -pix_fmt yuv420p /tmp/foo.mp4

and see if it's able to generate a /tmp/foo.mp4 video file (of all black pixels). If not, the error message should give a clue.

[justheuristic]

Thanks a lot. It said id doesn't know about libx264.

dd if=/dev/zero bs=750000 count=50 | ffmpeg -nostats -loglevel error -y -r 60 -f rawvideo -s:v 500x500 -pix_fmt 'rgb24' -i /dev/stdin -vcodec libx264 -pix_fmt yuv420p /tmp/foo.mp4
Unknown encoder 'libx264'

This did not help (still getting the same error)

sudo apt-get update
sudo apt-get install libav-tools
sudo apt-get install libavcodec-extra-53

However, doing the same thing with avconv worked

dd if=/dev/zero bs=750000 count=50 | avconv -nostats -loglevel error -y -r 60 -f rawvideo -s:v 500x500 -pix_fmt 'rgb24' -i /dev/stdin -vcodec libx264 -pix_fmt yuv420p /tmp/foo.mp4
50+0 records in
50+0 records out
37500000 bytes (38 MB) copied, 0,141512 s, 265 MB/s

Yet the error in the game monitoring stays the same.
It may actually be due to weirdness of that server, so if you have no idea why such behaviour may happen and no one can reproduce it, i believe it's worth simply closing the thing.

[tlbtlbtlb]

The video_recorder logic is

        if distutils.spawn.find_executable('ffmpeg') is not None:
            self.backend = 'ffmpeg'
        elif distutils.spawn.find_executable('avconv') is not None:
            self.backend = 'avconv'

Try deleting the ffmpeg executable so it will use avconv instead. Use:
sudo apt-get remove ffmpeg

I suspect we should prefer avconv over ffmpeg, since it is more predictable.

[justheuristic]

Thank you, that finally worked 👍

[avivrosenberg]

In case this helps someone, this issue got resolved for me by specifying ffmpeg>4.1 in my environment.yml file (using conda). It installed 4.1.3. My gym version is 0.12.1.

Before this I had ffmpeg 4.0 which didn't work.

[hagh]

I get the same error with Ray RLlib when setting the video recording on.
I tried both methods, i.e. conda install x264=='1!152.20180717' ffmpeg=4.0.2 -c conda-forge (and also the newer versions), as well as installing x265 instead of x264.
Both method worked for me in the sense that I don't get the error any more. However, many of the recorded videos are corrupted and cannot be played. I am wondering if people may have experienced the same problem? any suggestion to fix this later issue?

EDIT: Source of my problem should be something else. I tested these in a container and all worked fine.

[avivrosenberg]

I encountered this issue again after updating packages.
It works with: ffmpeg=4.2.2, x264=1!157.20191217, gym=0.17.3.
The problem occurred with ffmpeg=4.3 and disappeared when downgrading to 4.2.2.

[nhanph]

I got this error with Ubuntu 18.04 while using Monitor class in OpenAI Gym. You need correct versions of ffmpeg and x264 encoder. To get them, I used following and it worked:

conda install x264=='1!152.20180717' ffmpeg=4.0.2 -c conda-forge

This works for gym==0.18.3 python==3.7.10 torch=1.7.1 with Ubuntu 20.04.