Re: [gentoo-user] [OT] using ffmpeg for screen cast
On 26 June 2011, at 19:54, Mick wrote: ... ffmpeg -f x11grab -s xga -r 25 -i :0.0 -aspect 4:3 /tmp/out.mpg but the result is rather blurred as you can see in the attached screenshot, when I play it with mplayer. ... Try passing -sameq WOW! Exceptional improvement in a single stroke! Thanks! :) Why is it that ffmpeg degrades the quality with default settings? What does it assume that the setting is? (sorry for the newbie Qs, but this area is until now outside my cognitive map! ;-) I don't know about the default settings, but I would interpret the file extension of your original command as telling mplayer that the destination file should be encoded as mpeg2. This is a pretty poor codec by today's standards. I could well be wrong, though. Do you know what format the output file is? IMO you're best encoding to h264 (in an mp4 container) for distribution, but I think it's possible the encoding load of that might affect your screencast. So you might wish to use sameq or the r210 or rawvideo codecs and then transcode to h264 (or WebM or whatever) afterwards. Now, I hope I'm not getting greedy, but how do I add voice recording to the above stanza? Or do I have to record voice and then package it along with the video in a container as a separate step? EXAMPLES Video and Audio grabbing FFmpeg can grab video and audio from devices given that you specify the input format and device. ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg Note that you must activate the right video source and channel before launching FFmpeg with any TV viewer such as xawtv (http://linux.bytesex.org/xawtv/) by Gerd Knorr. You also have to set the audio recording levels correctly with a standard mixer. Audacity is widely used for simple audio editing. Stroller.
Re: [gentoo-user] [OT] using ffmpeg for screen cast
On Monday 27 Jun 2011 12:08:17 Stroller wrote: On 26 June 2011, at 19:54, Mick wrote: Try passing -sameq WOW! Exceptional improvement in a single stroke! Thanks! :) Why is it that ffmpeg degrades the quality with default settings? What does it assume that the setting is? (sorry for the newbie Qs, but this area is until now outside my cognitive map! ;-) I don't know about the default settings, but I would interpret the file extension of your original command as telling mplayer that the destination file should be encoded as mpeg2. This is a pretty poor codec by today's standards. I could well be wrong, though. Do you know what format the output file is? No, I have no idea. I assume it is capturing my desktop in some raw video format - whatever that means. What would X11 feed to x11grab? IMO you're best encoding to h264 (in an mp4 container) for distribution, but I think it's possible the encoding load of that might affect your screencast. So you might wish to use sameq or the r210 or rawvideo codecs and then transcode to h264 (or WebM or whatever) afterwards. I changed the output file to mp4 and it transcodes it accordingly! :) ffmpeg -f x11grab -s xga -r 25 -i :0.0 -sameq -aspect 4:3 /tmp/out.mp4 FFmpeg version SVN-r25767, Copyright (c) 2000-2010 the FFmpeg developers built on Jan 30 2011 17:04:59 with gcc 4.4.4 configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 -- mandir=/usr/share/man --enable-static --enable-shared --cc=x86_64-pc-linux- gnu-gcc --enable-gpl --enable-version3 --enable-postproc --enable-avfilter -- disable-stripping --disable-debug --disable-doc --disable-network --disable- static --disable-vdpau --enable-libmp3lame --enable-libvorbis --enable-libx264 --enable-libxvid --enable-libfaac --enable-nonfree --disable-indev=v4l -- disable-indev=oss --disable-indev=jack --enable-x11grab --disable-outdev=oss --enable-libopencore-amrwb --enable-libopencore-amrnb --enable-librtmp -- disable-altivec --cpu=core2 --enable-hardcoded-tables libavutil 50.33. 0 / 50.33. 0 libavcore 0.13. 0 / 0.13. 0 libavcodec52.96. 0 / 52.96. 0 libavformat 52.84. 0 / 52.84. 0 libavdevice 52. 2. 2 / 52. 2. 2 libavfilter1.62. 0 / 1.62. 0 libswscale 0.12. 0 / 0.12. 0 libpostproc 51. 2. 0 / 51. 2. 0 [x11grab @ 0x1a52510] device: :0.0 - display: :0.0 x: 0 y: 0 width: 1024 height: 768 [x11grab @ 0x1a52510] shared memory extension found [x11grab @ 0x1a52510] Estimating duration from bitrate, this may be inaccurate Input #0, x11grab, from ':0.0': Duration: N/A, start: 1309180986.812527, bitrate: 629145 kb/s Stream #0.0: Video: rawvideo, bgra, 1024x768, 629145 kb/s, 25 tbr, 1000k tbn, 25 tbc [buffer @ 0x1a7db80] w:1024 h:768 pixfmt:bgra [ffsink @ 0x1a7ddf0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out' [scale @ 0x1a7e110] w:1024 h:768 fmt:bgra - w:1024 h:768 fmt:yuv420p flags:0xa004 Output #0, mp4, to '/tmp/out.mp4': Metadata: encoder : Lavf52.84.0 Stream #0.0: Video: mpeg4, yuv420p, 1024x768 [PAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25 tbn, 25 tbc Stream mapping: Stream #0.0 - #0.0 Press [q] to stop encoding frame= 14 fps= 0 q=0.0 size= 702kB time=0.68 bitrate=8454.1kbits/s dup=frame= 27 fps= 25 q=0.0 size=1056kB time=1.20 bitrate=7212.1kbits/s dup=frame= 40 fps= 25 q=0.0 size=1411kB time=1.72 bitrate=6720.9kbits/s dup= [snip...] Then it plays it as such: mplayer /tmp/out.mp4 MPlayer SVN-r32624-4.4.4 (C) 2000-2010 MPlayer Team Playing /tmp/out.mp4. libavformat file format detected. [lavf] stream 0: video (mpeg4), -vid 0 VIDEO: [MP4V] 1024x768 24bpp 25.000 fps 5798.3 kbps (707.8 kbyte/s) Clip info: major_brand: isom minor_version: 512 compatible_brands: isomiso2mp41 encoder: Lavf52.84.0 == Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4) == Audio: no sound Starting playback... Movie-Aspect is 1.33:1 - prescaling to correct movie aspect. VO: [xv] 1024x768 = 1024x768 Planar YV12 V: 19.1 0/ 0 5% 0% 0.0% 0 0 Exiting... (End of file) Not sure how to define the vcodec to be h264. Is ffodivx the same as h264? Now, I hope I'm not getting greedy, but how do I add voice recording to the above stanza? Or do I have to record voice and then package it along with the video in a container as a separate step? EXAMPLES Video and Audio grabbing FFmpeg can grab video and audio from devices given that you specify the input format and device. ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg Note that you must activate the right video source and channel before launching FFmpeg with any TV viewer such as xawtv
Re: [gentoo-user] [OT] using ffmpeg for screen cast
2011/6/27 Mick michaelkintz...@gmail.com On Monday 27 Jun 2011 12:08:17 Stroller wrote: On 26 June 2011, at 19:54, Mick wrote: Try passing -sameq WOW! Exceptional improvement in a single stroke! Thanks! :) Why is it that ffmpeg degrades the quality with default settings? What does it assume that the setting is? (sorry for the newbie Qs, but this area is until now outside my cognitive map! ;-) I don't know about the default settings, but I would interpret the file extension of your original command as telling mplayer that the destination file should be encoded as mpeg2. This is a pretty poor codec by today's standards. I could well be wrong, though. Do you know what format the output file is? No, I have no idea. I assume it is capturing my desktop in some raw video format - whatever that means. What would X11 feed to x11grab? IMO you're best encoding to h264 (in an mp4 container) for distribution, but I think it's possible the encoding load of that might affect your screencast. So you might wish to use sameq or the r210 or rawvideo codecs and then transcode to h264 (or WebM or whatever) afterwards. I changed the output file to mp4 and it transcodes it accordingly! :) ffmpeg -f x11grab -s xga -r 25 -i :0.0 -sameq -aspect 4:3 /tmp/out.mp4 FFmpeg version SVN-r25767, Copyright (c) 2000-2010 the FFmpeg developers built on Jan 30 2011 17:04:59 with gcc 4.4.4 configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 -- mandir=/usr/share/man --enable-static --enable-shared --cc=x86_64-pc-linux- gnu-gcc --enable-gpl --enable-version3 --enable-postproc --enable-avfilter -- disable-stripping --disable-debug --disable-doc --disable-network --disable- static --disable-vdpau --enable-libmp3lame --enable-libvorbis --enable-libx264 --enable-libxvid --enable-libfaac --enable-nonfree --disable-indev=v4l -- disable-indev=oss --disable-indev=jack --enable-x11grab --disable-outdev=oss --enable-libopencore-amrwb --enable-libopencore-amrnb --enable-librtmp -- disable-altivec --cpu=core2 --enable-hardcoded-tables libavutil 50.33. 0 / 50.33. 0 libavcore 0.13. 0 / 0.13. 0 libavcodec52.96. 0 / 52.96. 0 libavformat 52.84. 0 / 52.84. 0 libavdevice 52. 2. 2 / 52. 2. 2 libavfilter1.62. 0 / 1.62. 0 libswscale 0.12. 0 / 0.12. 0 libpostproc 51. 2. 0 / 51. 2. 0 [x11grab @ 0x1a52510] device: :0.0 - display: :0.0 x: 0 y: 0 width: 1024 height: 768 [x11grab @ 0x1a52510] shared memory extension found [x11grab @ 0x1a52510] Estimating duration from bitrate, this may be inaccurate Input #0, x11grab, from ':0.0': Duration: N/A, start: 1309180986.812527, bitrate: 629145 kb/s Stream #0.0: Video: rawvideo, bgra, 1024x768, 629145 kb/s, 25 tbr, 1000k tbn, 25 tbc [buffer @ 0x1a7db80] w:1024 h:768 pixfmt:bgra [ffsink @ 0x1a7ddf0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out' [scale @ 0x1a7e110] w:1024 h:768 fmt:bgra - w:1024 h:768 fmt:yuv420p flags:0xa004 Output #0, mp4, to '/tmp/out.mp4': Metadata: encoder : Lavf52.84.0 Stream #0.0: Video: mpeg4, yuv420p, 1024x768 [PAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25 tbn, 25 tbc Stream mapping: Stream #0.0 - #0.0 Press [q] to stop encoding frame= 14 fps= 0 q=0.0 size= 702kB time=0.68 bitrate=8454.1kbits/s dup=frame= 27 fps= 25 q=0.0 size=1056kB time=1.20 bitrate=7212.1kbits/s dup=frame= 40 fps= 25 q=0.0 size=1411kB time=1.72 bitrate=6720.9kbits/s dup= [snip...] Then it plays it as such: mplayer /tmp/out.mp4 MPlayer SVN-r32624-4.4.4 (C) 2000-2010 MPlayer Team Playing /tmp/out.mp4. libavformat file format detected. [lavf] stream 0: video (mpeg4), -vid 0 VIDEO: [MP4V] 1024x768 24bpp 25.000 fps 5798.3 kbps (707.8 kbyte/s) Clip info: major_brand: isom minor_version: 512 compatible_brands: isomiso2mp41 encoder: Lavf52.84.0 == Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4) == Audio: no sound Starting playback... Movie-Aspect is 1.33:1 - prescaling to correct movie aspect. VO: [xv] 1024x768 = 1024x768 Planar YV12 V: 19.1 0/ 0 5% 0% 0.0% 0 0 Exiting... (End of file) Not sure how to define the vcodec to be h264. Is ffodivx the same as h264? Now, I hope I'm not getting greedy, but how do I add voice recording to the above stanza? Or do I have to record voice and then package it along with the video in a container as a separate step? EXAMPLES Video and Audio grabbing FFmpeg can grab video and audio from devices given that you specify the input format and device. ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg Note that you
Re: [gentoo-user] [OT] using ffmpeg for screen cast
On Monday 27 Jun 2011 15:14:28 Leonardo Guilherme wrote: This link was very helpful to me, maybe it can be to you: http://verb3k.wordpress.com/2010/01/26/how-to-do-proper-screencasts-on-linu x/ This is excellent info. Just what I was looking for, with a lot of detailed explanation and examples too. Thanks for sharing! -- Regards, Mick signature.asc Description: This is a digitally signed message part.
Re: [gentoo-user] [OT] using ffmpeg for screen cast
On Sun, Jun 26, 2011 at 1:28 PM, Mick michaelkintz...@gmail.com wrote: Hi All, I was trying to record my desktop using: ffmpeg -f x11grab -s xga -r 25 -i :0.0 -aspect 4:3 /tmp/out.mpg but the result is rather blurred as you can see in the attached screenshot, when I play it with mplayer. Is there some other option (codec) I should add to improve the quality of the captured image? -- Regards, Mick I have used recordmydesktop and received good results; recordmydesktop -device hw:1 --width 1200 --height 800 -x 1900 -y 30 -o test.ogv control alt p to pause control alt s to stop Adjust to taste that is on a dual screen. HTH David
Re: [gentoo-user] [OT] using ffmpeg for screen cast
On Sunday, June 26 at 18:28 (+0100), Mick said: Hi All, I was trying to record my desktop using: ffmpeg -f x11grab -s xga -r 25 -i :0.0 -aspect 4:3 /tmp/out.mpg but the result is rather blurred as you can see in the attached screenshot, when I play it with mplayer. Is there some other option (codec) I should add to improve the quality of the captured image? Try passing -sameq -a
Re: [gentoo-user] [OT] using ffmpeg for screen cast
On Sunday 26 Jun 2011 19:09:40 Albert Hopkins wrote: On Sunday, June 26 at 18:28 (+0100), Mick said: Hi All, I was trying to record my desktop using: ffmpeg -f x11grab -s xga -r 25 -i :0.0 -aspect 4:3 /tmp/out.mpg but the result is rather blurred as you can see in the attached screenshot, when I play it with mplayer. Is there some other option (codec) I should add to improve the quality of the captured image? Try passing -sameq -a WOW! Exceptional improvement in a single stroke! Thanks! :) Why is it that ffmpeg degrades the quality with default settings? What does it assume that the setting is? (sorry for the newbie Qs, but this area is until now outside my cognitive map! ;-) Thank you both for your suggestions. The recordmydesktop looks good, but I am not sure if I will have to transcode it to make sure that it would also work for MSWindows users? Is ogg MSWindows 'compatible'? Now, I hope I'm not getting greedy, but how do I add voice recording to the above stanza? Or do I have to record voice and then package it along with the video in a container as a separate step? Once I achieve that how can I go back and edit the voice part? -- Regards, Mick signature.asc Description: This is a digitally signed message part.
