[FFmpeg-user] ffmpeg and two (2) logitech 920 webcams

Frank Belson frankbelson2 at gmail.com
Mon May 28 19:07:24 EEST 2018 

I am using the following line to preview my webcam:

ffmpeg -s 1280x720 -framerate 30 -pix_fmt yuv420p -rtbufsize 100MB -f dshow
-i video="Logitech Cam#1" -c:v copy -an -f sdl "WebCAM Preview"

this line works fine with cam #1, however when try it with cam #2, I get
the error:

[dshow @ 00000000002d8920] Could not set video options video=Logitech
Cam#2: I/O error

Can anyone tell me why this is happening. I would like to able to preview
both webcams at the same time?

Thanks, Frank

On Wed, May 23, 2018 at 2:49 PM, Frank Belson <frankbelson2 at gmail.com>
wrote:

> DopeLabs,
>
>    Thanks for the advice, Unfortunately, I have tried both suggestions to
> no avail. No sure if i mentioned it but both webcams are the same make and
> model (Logitech 920) I change the names initially as i figured two cams
> with the same name was the issue. Any further suggestions would be greatly
> appreciated as the current program I am using to view both camera is a CPU
> hog.
>
> Thanks, Frank
>
> On Tue, May 22, 2018 at 12:57 PM, DopeLabs <dopelabs at dubstep.fm> wrote:
>
>> you could try using the alternate names.. examples are shown here
>>
>> https://www.ffmpeg.org/ffmpeg-devices.html#dshow
>>
>>
>> is it always that specific camera?
>>
>> if you connect the one that isnt working first so that its listed as #1,
>> will it work?
>>
>> have you tried connecting the 2nd camera to a separate USB bus?
>>
>> you can use the following tool to get usb bus info on your system
>>
>> https://github.com/Microsoft/Windows-driver-samples/tree/mas
>> ter/usb/usbview
>>
>>
>>
>> > On May 22, 2018, at 9:35 03AM, Frank Belson <frankbelson2 at gmail.com>
>> wrote:
>> >
>> > The following is the output from ffmpeg -list_devices true -f dshow -i
>> dummy
>> >
>> > ffmpeg version N-87353-g183fd30 Copyright (c) 2000-2017 the FFmpeg
>> > developers
>> >  built with gcc 7.2.0 (GCC)
>> >  configuration: --enable-gpl --enable-version3 --enable-cuda
>> > --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx
>> > --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig
>> > --enable-frei0r --enable-gnutls --enable-iconv --enable-libass
>> > --enable-libbluray --enable-libbs2b --enable-libcaca
>> --enable-libfreetype
>> > --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug
>> > --enable-libmp3lame --enable-libopencore-amrnb
>> --enable-libopencore-amrwb
>> > --enable-libopenh264 --enable-libopenjpeg --enable-libopus
>> --enable-librtmp
>> > --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora
>> > --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc
>> > --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp
>> > --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid
>> > --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib
>> >  libavutil      55. 76.100 / 55. 76.100
>> >  libavcodec     57.106.101 / 57.106.101
>> >  libavformat    57. 82.101 / 57. 82.101
>> >  libavdevice    57.  8.101 / 57.  8.101
>> >  libavfilter     6.105.100 /  6.105.100
>> >  libswscale      4.  7.103 /  4.  7.103
>> >  libswresample   2.  8.100 /  2.  8.100
>> >  libpostproc    54.  6.100 / 54.  6.100
>> > [dshow @ 00000000002f6c00] DirectShow video devices (some may be both
>> video
>> > and audio devices)
>> > [dshow @ 00000000002f6c00]  "Logitech Cam#1"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_pnp_\\?\usb#vid_046d&pid_082d&mi_00#6&10047afe&0&00
>> 00#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{bbefb6c7-2fc4-413
>> 9-bb8b-a58bba724083}"
>> > [dshow @ 00000000002f6c00]  "Logitech Cam#2"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_pnp_\\?\usb#vid_046d&pid_082d&mi_00#6&3a78d907&0&00
>> 00#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global"
>> > [dshow @ 00000000002f6c00]  "Kodak S101 Webcam"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_pnp_\\?\usb#vid_0979&pid_0206&mi_00#6&2455fd16&0&00
>> 00#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global"
>> > [dshow @ 00000000002f6c00] DirectShow audio devices
>> > [dshow @ 00000000002f6c00]  "Microphone (4- Kodak S101 Micro"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\Microphone (4- Kodak
>> > S101 Micro"
>> > [dshow @ 00000000002f6c00]  "Line (WsAudio_Device)"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\Line
>> (WsAudio_Device)"
>> > [dshow @ 00000000002f6c00]  "Microphone (2- HD Pro Webcam C9"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\Microphone (2- HD
>> Pro
>> > Webcam C9"
>> > [dshow @ 00000000002f6c00]  "Microphone (HD Pro Webcam C920)"
>> > [dshow @ 00000000002f6c00]     Alternative name
>> > "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\Microphone (HD Pro
>> > Webcam C920)"
>> > dummy: Immediate exit requested
>> >
>> >
>> > On Tue, May 22, 2018 at 6:59 AM, DopeLabs <dopelabs at dubstep.fm> wrote:
>> >
>> >> what is the output of
>> >>
>> >> $ ffmpeg -list_devices true -f dshow -i dummy
>> >>
>> >>
>> >> if you have multiple entries of a webcam named "Logitech Cam", you can
>> >> specify which using -video_device_number
>> >>
>> >> the following would select the 2nd identical device (as numbers for
>> >> devices start at 0)
>> >>
>> >> $ ffmpeg -f dshow -video_device_number 1 -i video="Logitech Cam"
>> >>
>> >>
>> >> im also curious.. would this work? video="Logitech Cam#0"
>> >>
>> >> (please include complete uncut console output)
>> >>
>> >> running the latest version of ffmpeg?
>> >>
>> >>
>> >>> On May 19, 2018, at 3:34 17PM, Brenda Spinner <
>> brendaspinner at gmail.com>
>> >> wrote:
>> >>>
>> >>> I am using the following line to preview my webcam:
>> >>>
>> >>> ffmpeg -s 1280x720 -framerate 30 -pix_fmt yuv420p -rtbufsize 100MB -f
>> >> dshow
>> >>> -i video="Logitech Cam#1" -c:v copy -an -f sdl "WebCAM Preview"
>> >>>
>> >>> this line works fine with cam #1, however when try it with cam #2, I
>> get
>> >>> the error:
>> >>>
>> >>> [dshow @ 00000000002d8920] Could not set video options video=Logitech
>> >>> Cam#2: I/O error
>> >>>
>> >>> Can anyone tell me why this is happening. I would like to able to
>> preview
>> >>> both webcams at the same time?
>> >>>
>> >>> Thanks, Frank
>> >>>
>> >>> <https://www.avast.com/sig-email?utm_medium=email&utm_
>> >> source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon>
>> >>> Virus-free.
>> >>> www.avast.com
>> >>> <https://www.avast.com/sig-email?utm_medium=email&utm_
>> >> source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
>> >>> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>> >>> _______________________________________________
>> >>> ffmpeg-user mailing list
>> >>> ffmpeg-user at ffmpeg.org
>> >>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>> >>>
>> >>> To unsubscribe, visit link above, or email
>> >>> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>> >>
>> >> _______________________________________________
>> >> ffmpeg-user mailing list
>> >> ffmpeg-user at ffmpeg.org
>> >> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>> >>
>> >> To unsubscribe, visit link above, or email
>> >> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>> >>
>> > _______________________________________________
>> > ffmpeg-user mailing list
>> > ffmpeg-user at ffmpeg.org
>> > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>> >
>> > To unsubscribe, visit link above, or email
>> > ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>>
>> _______________________________________________
>> ffmpeg-user mailing list
>> ffmpeg-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>>
>
>

More information about the ffmpeg-user mailing list