Screen capture WITH audio in ffmpeg
Solution 1
The solution seems to be to use both a different video and audio encoder. This line works:
FFmpeg/ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+0,0 -f alsa -ac 2 -i pulse -acodec aac -strict experimental output.flv
I couldn't get it to work without -acodec aac -strict experimental
, contrary to the HOWTO on ffmpeg wiki.
The error message I'm getting is:
Output #0, flv, to 'output.flv':
Stream #0:0: Video: flv1 (flv), yuv420p, 1024x768, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
Metadata:
encoder : Lavc56.34.100 flv
Stream #0:1: Audio: adpcm_swf, 0 channels
Metadata:
encoder : Lavc56.34.100 adpcm_swf
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> flv1 (flv))
Stream #1:0 -> #0:1 (pcm_s16le (native) -> adpcm_swf (native))
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height
Neither could I get this to work using:
FFmpeg/ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+0,0 -f alsa -ac 2 -i pulse -acodec copy output.mpeg
which contains -ac 2
probably in the right place. The error I'm getting repeatedly is:
[mp2 @ 0x7faffc007da0] Header missing
This most likely is a bug/regression.
To sum up, I've (probably) found 1 bug in ffmpeg and 1 bug in ffmpeg's wiki. And it looks like I'll have to buy the promised beer to myself ;)
Solution 2
version 4.2.2
get your audio
ffmpeg -list_devices true -f dshow -i dummy
then
ffmpeg -rtbufsize 1500M -f dshow -i audio="Microphone (Realtek High Definition Audio)" -f -y -rtbufsize 100M -f gdigrab -t 00:00:30 -framerate 30 -probesize 10M -draw_mouse 1 -i desktop -c:v libx264 -r 30 -preset ultrafast -tune zerolatency -crf 25 -pix_fmt yuv420p "d:\ffmpeg_testing.mp4"
Solution 3
This works:
ffmpeg -f x11grab -video_size 1280x1024 -framerate 24 -i $DISPLAY -f alsa -i default -af \
acompressor=threshold=0.089:ratio=9:attack=200:release=1000 -vf scale=1280x720 -c:v h264_nvenc -g 24 \
-b:v 2M -preset fast -c:a aac -pix_fmt yuv420p -f otut.flv
Taken from: Stream to Twitch with FFMPEG Y.T.
Adam Kurkiewicz
I'm a co-founder and CEO of Biomage. Our team is building a single-cell genomics platform that's used in cancer and heart disease research. Our customers include Harvard Medical School and University of Glasgow among others. Please get in touch at [email protected]!
Updated on July 09, 2022Comments
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Adam Kurkiewicz almost 2 years
I am using ffmpeg built from source at this revision in Fedora 20.
I am able to record audio perfectly fine with the command:
FFmpeg/ffmpeg -f alsa -ac 2 -i pulse -- output.wav
However, when I try both screen capture and audio, like this:
FFmpeg/ffmpeg -video_size 800x600 -framerate 25 -ac 2 -f x11grab -i :0.0+0,0 -ac 2 -f alsa -i pulse -ac 2 -acodec copy output.mpeg -ac 2
I'm getting a video with 0 audio channels, which I can check running
FFmpeg/ffplay output.mpeg
Input #0, mpeg, from 'output.mpeg': Duration: 00:00:09.44, start: 0.540000, bitrate: 2743 kb/s Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 800x600 [SAR 1:1 DAR 4:3], 104857 kb/s, 25 fps, 25 tbr, 90k tbn, 25 tbc Stream #0:1[0x1c0]: Audio: mp2, 0 channels, s16p 7.26 M-V: 0.000 fd= 0 aq= 0KB vq= 33KB sq= 0B f=0/0
and no audible sound is played. The position of
-ac 2
doesn't change the behaviour, nor does repeating it only once. This is despite ffmpeg claims to record the audio with 2 channels, here is the input:ffmpeg version N-71312-ga66dcfe Copyright (c) 2000-2015 the FFmpeg developers built with gcc 4.8.3 (GCC) 20140911 (Red Hat 4.8.3-7) configuration: libavutil 54. 22.100 / 54. 22.100 libavcodec 56. 34.100 / 56. 34.100 libavformat 56. 29.100 / 56. 29.100 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 13.101 / 5. 13.101 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 1.100 / 1. 1.100 Trailing options were found on the commandline. Input #0, x11grab, from ':0.0+0,0': Duration: N/A, start: 1428348285.201679, bitrate: N/A Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 800x600, 25 fps, 25 tbr, 1000k tbn, 25 tbc Guessed Channel Layout for Input Stream #1.0 : stereo Input #1, alsa, from 'pulse': Duration: N/A, start: 1428348285.225901, bitrate: 1536 kb/s Stream #1:0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s File 'output.mpeg' already exists. Overwrite ? [y/N] y [mpeg @ 0x2d079a0] VBV buffer size not set, using default size of 130KB If you want the mpeg file to be compliant to some specification Like DVD, VCD or others, make sure you set the correct buffer size Output #0, mpeg, to 'output.mpeg': Metadata: encoder : Lavf56.29.100 Stream #0:0: Video: mpeg1video, yuv420p, 800x600, q=2-31, 200 kb/s, 25 fps, 90k tbn, 25 tbc Metadata: encoder : Lavc56.34.100 mpeg1video Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, 1536 kb/s Stream mapping: Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg1video (native)) Stream #1:0 -> #0:1 (copy)
I'm clueless. If anybody can tell me how to get this to work by either:
- fixing my mistakes in the command line flags
- if it's a regression, which revision to build from.
- any other way
I'll buy him/her a pint.
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Ahmad almost 7 yearsWhat is "x11grab" . it shows error when i am using it ?
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Ahmad almost 7 yearsThanks . Do you know any command how to stop this process which i started once ? Actually i am using it in C# code
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Ahmad almost 7 yearsits shows error unkown input format x11grab any solution please ?
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Adam Kurkiewicz almost 7 yearsApologies, I no longer use ffmpeg (I don't even have it installed). You'll be perhaps better off asking another question.
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ipatch almost 4 yearsthere's some great goodies in that command but unfortunately zero expiation of what they do. an external link to the official ffmpeg documentation or even better a quick explanation of what some of the particular settings / flags do would be awesome.
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Michael over 3 years@Ahmad x11grab is for Linux, not Windows
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Ahmad over 3 years@Michael yup thanks for answering I have solved the problem I found alternative of it for windows .
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chovy over 3 yearsi get
[x11grab @ 0x558ce63c7ec0] Cannot open display :0.0+0,0, error 1. :0.0+0,0: Input/output error