Page 4 of 25 FirstFirst ... 2345614 ... LastLast
Results 31 to 40 of 246

Thread: HOWTO: Proper Screencasting on Linux

  1. #31
    Join Date
    Mar 2007
    Beans
    Hidden!

    Re: HOWTO: Proper Screencasting on Linux

    Added explanation of "xwininfo" usage as FAQ stub.
    If there is anything you feel this guide is lacking, please tell. Contribution is very welcome.
    Freedom is neither exclusive nor unlimited.

  2. #32
    Join Date
    Mar 2006
    Beans
    Hidden!

    Re: HOWTO: Proper Screencasting on Linux

    This script automating all this is interesting:

    http://github.com/lolilolicon/ffcast

    I found it when looking for some way to select an area with the mouse. The included xrectsel.c does exactly that and it outputs a geometry tuple.

    here’s the manpage:
    Code:
    FFCAST(1)                                                                    FFCAST(1)
    
    
    
    NAME
           ffcast - Take screencast using ffmpeg with the help of xwininfo and xrectsel
    
    SYNOPSIS
           ffcast [options]
    
    DESCRIPTION
           ffcast  is  a screencast script written in bash. It calls ffmpeg to capture any
           specified area on the target X11 display. It supports all video codecs and for‐
           mats  ffmpeg supports. Before ffcast actually calls ffmpeg to record the video,
           it determines the capture area either  by  interactively  asking  the  user  to
           select one, or by reading the geometry defined by command line. In the interac‐
           tive mode, the user can either freely select a rectangle area, or select one or
           more windows by clicking them.
    
    OPTIONS
           -o, --output <outfile>
                  Specify  output  filename.  Filename extension is essential if FORMAT is
                  not set either by config file or from command line  using  --format.  If
                  <outfile>  is  -,  output  goes to standard output, in which case FORMAT
                  must be set.
    
           -d, --display <display>
                  Display to connect  to.  Format:  [hostname]:number.screen_number,  e.g.
                  `:0.1'.  By  default,  ffcast  reads the environment variable DISPLAY as
                  display.
    
           -a, --fullscreen
                  Capture full screen, identical to `--winid root'
    
           -w, --xwininfo
                  Use xwininfo to define capture area, either by click  or  by  specifying
                  window  ids with the --winid option. This is useful for capturing events
                  inside an existing window. You can also select multiple windows,  speci‐
                  fying window number with the --winno option.
    
           -s, --xrectsel
                  Freely select capture area by mouse dragging using xrectsel. When ffcast
                  is triggered with this option, your mouse cursor changes to a cross. You
                  select  your  capture area by dragging your mouse with button 1 pressed.
                  Then, if button 1 is released, capture will start instantly; if keyboard
                  is pressed instead, capture will abort. Think about `scrot -s'.
    
           -j, --xjustcap <geometry>
                  This option enables the user to tell ffcast about the exact capture area
                  using <geometry>, thus no manual selection is performed.  This  is  free
                  selection,  like  --xrectsel,  just  without  the  need of touching your
                  mouse.
    
                  Supported <geometry> formats are:
                  *1) "(x1,y1) (x2,y2)"
                  (x1,y1) and (x2,y2) are the positions of two  diagonal  corners  of  the
                  rectangle area in question.
                  The  comma  between  xN  and  yN  is  required,  but the parentheses are
                  optional.
                  Any of the x1, y1, x2, y2 parameters consists of digits, or  is  a  per‐
                  centage value written as digits%
                  If  any  of  x1,  y1,  x2,  y2 is written as percentage, e.g. 20%, it is
                  equivalent to 20% of the full x or y resolution of you screen.
                  *2) "wxh-x+y gravity"
                  w: Width of the rectangle area.
                  h: Height of the rectangle area.
                  -x: Additional horizontal positioning of the  rectangle,  added  to  the
                  initial positioning by gravity. Optional.
                  +y:  Additional vertical positioning of the rectangle, added to the ini‐
                  tial positioning by gravity. Optional.
                  gravity: Determines the initial positioning of the rectangle. Valid val‐
                  ues are: Northwest, North, Northeast, East, Southeast, South, Southwest,
                  West and Center(or Centre). Optional.
                  Any of w, h, x, y parameters consists of  digits,  or  is  a  percentage
                  value written as digits%
    
           -M, --mod16
                  Force  capture frame size to be mod 16. ffmpeg requires video frame size
                  to be mod 2, which is the default behavior  of  ffcast.  By  using  this
                  option,  you  tell  ffcast  to always adjust capture geometry to mod 16.
                  This may improve video quality for the x264 encoder, but not too much.
    
           -n, --winno <number>
                  Number of window(s) to be captured. Only effective with --xwininfo,  and
                  without  --winid  option. This enables capturing multiple windows. Think
                  about the GIMP, and you'll find this option useful.
    
           -i, --winid <idlist>
                  Specify windows to be capture by window  ids.  <idlist>  is  a  list  of
                  whitespace  seperated  window ids quoted inside double or single quotes,
                  e.g. "0x80000a 0x800039 0x160003c". see xwininfo(1) -id option.
    
           -b, --borderless
                  Ignore borders of window(s).
    
           -B, --border
                  Do not ignore borders. This, as well as --borderless, is only  effective
                  with --xwininfo, obviously.
    
           -c, --codec <codec>
                  Force  Output  Video  Codec.  Default value: 'x264'. Use ? or list for a
                  list. Use '' to let ffmpeg guess video codec from output extension.
    
           -f, --format <format>
                  Force Output Format. Default value: 'h264'. Use ? or list  for  a  list.
                  Use '' to let ffmpeg guess video format from output extension.
    
           -p, --preset <ffpreset>
                  x264  preset.  Default value: 'lossless_slow'. Use ? or list for a list.
                  Dive into /usr/share/ffmpeg/*.ffpreset for details.  See  ffmpeg(1)  for
                  more info (`Preset files' section).
    
           -r, --rate <fps>
                  Set frame rate (fps). Default value: 15. Set it to a higher level if you
                  find your video choppy.
    
           -t, --duration <time>
                  Restrict cast video duration in seconds. hh:mm:ss[.xxx] format  is  also
                  fully supported. This is useful for usage in scripts. It's also reported
                  by lazy people how this has saved there lives by escaping them from  the
                  final [q] press.
    
           --printcmd
                  Don't  actually call ffmpeg, but print the ffmpeg command line and exit.
                  You can then further customize this command and then run it directly  to
                  do the real job. It is meant for slightly advanced users or curious peo‐
                  ple who likes to experiment.
    
           -v, --debug
                  Print verbose debug info to standard error.
    
           --nocolor
                  Disable colors in messages.
    
           -h, --help
                  Print help message, then exit.
    
           --version
                  Print version info, then exit.
    
    CONFIGURATION
           At  start  up,  ffcast  reads  user   configurations   defined   in   $XDG_CON‐
           FIG_HOME/ffcast/ffcast.conf,  if  $XDG_CONFIG_HOME  is not defined, $HOME/.con‐
           fig/ffcast/ffcast.conf is read instead.  An  example  configuration  file  with
           default     values     and     comments     can     be     found    at    $PRE‐
           FIX/share/ffcast/doc/ffcast.conf, where  $PREFIX  is  usually  either  /usr  or
           /usr/local as per build-time settings.  Configuration options in the configura‐
           tion file are all available from the command line, and  will  be  overriden  by
           command line options.
    
    ENVIRONMENT
           DISPLAY To get the default host and display number.
    
    EXAMPLE
           I  want  to  test  a  new  window  manager  inside a window. So I first edit my
           ~/.xinitrc to tell startx to run it instead of my current wm.
    
           Then I start a new X session inside a new window with
    
                  startx -- /usr/bin/Xephyr :2
    
           Then I'd like to record this window by clicking it with
    
                  ffcast -d :2.0 -o wmtest.mp4
    
    NOTES
           GIF output is huge and uncompressed due to very limited gif support  from  ffm‐
           peg.  It's best not to use gif output. But if you must, a workaround for now is
           piping output to convert (from ImageMagick):
    
                  ffcast -s -t 6 -r 3 -f gif -o - | convert gif:- ffcast.gif
    
    FILES
           /usr/bin/ffcast
           /usr/bin/xrectsel
           /usr/share/ffcast/doc/ffcast.conf
           Locations may differ due to make settings.
    
    SEE ALSO
           ffmpeg(1), xwininfo(1)
    
    AUTHORS
           ffcast is written by lolilolicon<lolilolicon@gmail.com>
    
    
    
    ffcast 0.2                            2009-11-25                             FFCAST(1)
    Last edited by hugmenot; May 2nd, 2010 at 12:05 AM.

  3. #33
    Join Date
    May 2010
    Beans
    3

    Re: HOWTO: Proper Screencasting on Linux

    Hi everyone,

    I have a special application. That is I need to use VNC Client to login server and control the server to do something. Then I need to record my VNC screen. So, I used the command "sudo ffmpeg -f x11grab -r 30 -s 800x600 -i :0.0 -vcodec libx264 -vpre hq -threads 0 out1.avi" to record screen, but the video content is server screen not my VNC screen.

    I check my export variable and get the DISPLAY variable is ":2.0". So I change my command to record ":2.0" and there is error occur. The following is error message.

    [alex@taipei:~$] export | grep DISPLAY
    declare -x DISPLAY=":2.0"
    [alex@taipei:~$] sudo ffmpeg -f x11grab -r 30 -s 800x600 -i :2.0 -vcodec libx264 -vpre lossless_ultrafast -threads 0 out1.avi

    FFmpeg version SVN-r23008, Copyright (c) 2000-2010 the FFmpeg developers
    built on May 3 2010 11:42:42 with gcc 4.4.1
    configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libx264 --enable-libxvid --enable-x11grab
    libavutil 50.15. 0 / 50.15. 0
    libavcodec 52.66. 0 / 52.66. 0
    libavformat 52.62. 0 / 52.62. 0
    libavdevice 52. 2. 0 / 52. 2. 0
    libswscale 0.10. 0 / 0.10. 0
    libpostproc 51. 2. 0 / 51. 2. 0
    [x11grab @ 0xaa38420]device: :2.0 -> display: :2.0 x: 0 y: 0 width: 800 height: 600
    Xlib: extension "Generic Event Extension" missing on display ":2.0".
    [x11grab @ 0xaa38420]shared memory extension found
    Segmentation fault
    [alex@taipei:~$]

    Could anyone give some suggestions for this problem. Thanks a lot!!

  4. #34
    Join Date
    Mar 2007
    Beans
    Hidden!

    Re: HOWTO: Proper Screencasting on Linux

    Guide updated.
    Removed libvorbis installation instructions as FFmpeg's building guide was updated to include it. Also, expanded the FAQ section.
    Freedom is neither exclusive nor unlimited.

  5. #35
    Join Date
    Mar 2007
    Location
    Your Closet
    Beans
    380
    Distro
    Ubuntu 10.04 Lucid Lynx

    Re: HOWTO: Proper Screencasting on Linux

    Using what I believe to be the latest ffmpeg and I'm getting this error when trying to record from pulse. I've also updated alsa using the upgrade script http://ubuntuforums.org/showthread.php?p=6589810.
    Code:
    ffmpeg -f alsa -ac 2 -i pulse test.mp3
    FFmpeg version SVN-r23603, Copyright (c) 2000-2010 the FFmpeg developers
      built on Jun 14 2010 07:11:00 with gcc 4.4.3
      configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab
      libavutil     50.19. 0 / 50.19. 0
      libavcodec    52.76. 0 / 52.76. 0
      libavformat   52.68. 0 / 52.68. 0
      libavdevice   52. 2. 0 / 52. 2. 0
      libavfilter    1.20. 0 /  1.20. 0
      libswscale     0.11. 0 /  0.11. 0
      libpostproc   51. 2. 0 / 51. 2. 0
    ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM pulse
    [alsa @ 0x3104470]cannot open audio device pulse (No such file or directory)
    pulse: Input/output error
    Code:
    aplay -l
    **** List of PLAYBACK Hardware Devices ****
    card 0: Intel [HDA Intel], device 0: ALC888 Analog [ALC888 Analog]
      Subdevices: 1/1
      Subdevice #0: subdevice #0
    card 0: Intel [HDA Intel], device 1: ALC888 Digital [ALC888 Digital]
      Subdevices: 1/1
      Subdevice #0: subdevice #0
    card 1: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
      Subdevices: 0/1
      Subdevice #0: subdevice #0
    This command works but it's 100% silent.
    Code:
    ffmpeg -f alsa -ac 2 -i hw:0,0 test.mp3
    If I try to use hw:1,3 which is my hdmi I believe according to aplay I get this.
    Code:
    ffmpeg -f alsa -ac 2 -i hw:1,3 test.mp3
    FFmpeg version SVN-r23603, Copyright (c) 2000-2010 the FFmpeg developers
      built on Jun 14 2010 07:11:00 with gcc 4.4.3
      configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab
      libavutil     50.19. 0 / 50.19. 0
      libavcodec    52.76. 0 / 52.76. 0
      libavformat   52.68. 0 / 52.68. 0
      libavdevice   52. 2. 0 / 52. 2. 0
      libavfilter    1.20. 0 /  1.20. 0
      libswscale     0.11. 0 /  0.11. 0
      libpostproc   51. 2. 0 / 51. 2. 0
    [alsa @ 0x1eb7470]cannot open audio device hw:1,3 (No such file or directory)
    hw:1,3: Input/output error
    Any help would be greatly appreciated, thank you.

  6. #36
    Join Date
    Mar 2007
    Beans
    Hidden!

    Re: HOWTO: Proper Screencasting on Linux

    If you say this works:
    ffmpeg -f alsa -ac 2 -i hw:0,0 test.mp3
    but is silent, then maybe it's an issue with your microphone or input volume?
    That usually happens. You can verify if the file has recorded audio but with very low volume by playing it in mplayer and amplifying the audio:

    Code:
    mplayer test.mp3 -af volume=60
    Still this won't work if the input volume is muted.

    If this doesn't help, sorry, but this is uncharted waters for me; I really may not be able to help with this. If no one can help you in this thread, then you'll surely get support in FFmpeg's official support channel on IRC: #ffmpeg @ irc.freenode.net.

    If you ever manage to figure it out, please post how you did it. This will be a good reference in the future for users who might encounter the same problem.
    Last edited by verb3k; June 14th, 2010 at 05:29 PM.
    Freedom is neither exclusive nor unlimited.

  7. #37
    Join Date
    Sep 2006
    Beans
    548

    Re: HOWTO: Proper Screencasting on Linux

    Is pulseaudio running on your system? Did you change any of the pulse or alsa config files, such as the ~/.asoundrc file?

  8. #38
    Join Date
    Mar 2007
    Location
    Your Closet
    Beans
    380
    Distro
    Ubuntu 10.04 Lucid Lynx

    Re: HOWTO: Proper Screencasting on Linux

    Following this guide http://wiki.xbmc.org/?title=HOW-TO_s...20%2C_or_GT240

    Installed latest alsa snapshot.

    Added below line to /etc/modprobe.d/alsa-base.conf
    options snd-hda-intel enable_msi=0 probe_mask=0xffff,0xfff2

    Added below line to /etc/pulse/default.pa
    load-module module-alsa-sink device=hw:1,3

    Added my user to the necessary groups.

    Unmuted the s/pdif audio channels and changed my output device to hdmi in the sound preferences.

    Pulse works perfectly with rythmbox, mplayer, vlc, xine, aplay etc.

    Code:
    ffmpeg -f alsa -ac 2 -i pulse test.mp3
    FFmpeg version SVN-r23603, Copyright (c) 2000-2010 the FFmpeg developers
      built on Jun 14 2010 07:11:00 with gcc 4.4.3
      configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab
      libavutil     50.19. 0 / 50.19. 0
      libavcodec    52.76. 0 / 52.76. 0
      libavformat   52.68. 0 / 52.68. 0
      libavdevice   52. 2. 0 / 52. 2. 0
      libavfilter    1.20. 0 /  1.20. 0
      libswscale     0.11. 0 /  0.11. 0
      libpostproc   51. 2. 0 / 51. 2. 0
    ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM pulse
    [alsa @ 0x2a2b470]cannot open audio device pulse (No such file or directory)
    pulse: Input/output error
    Code:
    cat /proc/asound/version
    Advanced Linux Sound Architecture Driver Version 1.0.23.
    Compiled on Jun  8 2010 for kernel 2.6.32-22-generic (SMP).
    Maybe the correct place to ask would be an alsa thread? But I'm confused since it seems to work fine for everything else and I have the latest ffmpeg and alsa. I'm so confused lol. Thanks for the help.
    Last edited by bashologist; June 16th, 2010 at 06:18 AM.

  9. #39
    Join Date
    Mar 2007
    Location
    Your Closet
    Beans
    380
    Distro
    Ubuntu 10.04 Lucid Lynx

    Re: HOWTO: Proper Screencasting on Linux

    On another computer it's working fine except the sound's very low and sounds terrible. Is it supposed to sound like that?

  10. #40
    Join Date
    Mar 2007
    Beans
    Hidden!

    Re: HOWTO: Proper Screencasting on Linux

    UPDATES:
    *Expanded FAQ section to cover recording on systems which do not use PulseAudio. I think this can still be improved a lot, but a stub is better than nothing
    Freedom is neither exclusive nor unlimited.

Page 4 of 25 FirstFirst ... 2345614 ... LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •