WebRTC – A viable alternative to Skype

webrtc_logoSkype for Linux 4.3 and upwards requires the use of PulseAudio, which has caused discontent amongst those Linux users who do not use PulseAudio. Although I do use PulseAudio, I recently found out about WebRTC, an API (application programming interface) for browser-based communication offering most of the functions provided by Skype, namely: voice calling, video chat, text chat, file sharing and screen sharing. The official WebRTC site states:

WebRTC is a free, open project that enables web browsers with Real-Time Communications (RTC) capabilities via simple JavaScript APIs. The WebRTC components have been optimized to best serve this purpose.

Our mission: To enable rich, high quality, RTC applications to be developed in the browser via simple JavaScript APIs and HTML5.

WebRTC was originally released by Google but is now a draft standard of the World Wide Web Consortium, and is supported by Chrome, Firefox and Opera browsers. Several commercial Web sites offer WebRTC-based communications to fee-paying customers, but I thought I would try WebRTC by using one of the so-called ‘demo’ WebRTC pages. AppRTC is a WebRTC demo page which can be reached from a link on the official WebRTC site, but I prefer Multi-Party WebRTC Demo by TokBox which offers a more polished experience with better features. Both are free to use and viable substitutes to Skype for video chatting (one-to-one or conference).

So, how do you actually use WebRTC-based sites? Below is a quick guide to get you going.

Text and video chatting

Open the following URL in Chrome or Firefox:

https://opentokrtc.com/

Enter a Room Name that is likely to be unique. I used ‘fitzchat’ (without the quotes), but you can use any name you want.

The other party or parties can do the same thing, i.e. they enter the same Room Name as you, and you will all become connected.

Alternatively, to send an e-mail invitation to someone, click on the URL at the top of the pane on the right-hand side (which is Invite: https://opentokrtc.com/fitzchat in this example, as I chose to name the Room ‘fitzchat’). The partially visible pane at the right-hand side of the browser window will slide into full view when you click on it.

That’s all there is to it. You should see a video window showing each party, and they should see the same. Each party should also be able to hear the other parties. In the top right-hand corner of each video window is an icon (microphone for you; speaker for each of the other parties) which you can click on to mute/un-mute that party.

Click on the partially visible pane at the right-hand side of the browser window. Notice the ‘chat bar’ at the bottom where you enter commands and chat text. Read the grey instructions listed near the top of the pane:

Welcome to OpenTokRTC by TokBox
Type /nick your_name to change your name
Type /list to see list of users in the room
Type /help to see a list of commands
Type /hide to hide chat bar
Type /focus to lead the group
Type /unfocus to put everybody on equal standing

For example, to give myself a meaningful name instead of the default username Guest-0120e48c which was given to me automatically, I entered the following:

/nick Fitz

Screen sharing

I found that screen sharing already works well in Chrome 36.0.1985.125 but is not yet supported in Firefox 31.0. It will be supported in Firefox 32 or 33, apparently, or you can already use Firefox Nightly providing you add the appropriate preferences via about:config.

To be able to share screens in Chrome, I had to perform two steps: enable a Chrome flag and install a Chrome extension. The two steps, which do not need to be repeated, are given below (see Ref. 1).

To enable screen sharing in Chrome, do the following:

  1. Open a new tab or window in Chrome.
  2. Copy the following link: chrome://flags/#enable-usermedia-screen-capture and paste it in the location bar.
  3. Click on the ‘Enable’ link below ‘Enable screen capture support in getUserMedia().’ at the very top of the screen.
  4. Click on the ‘Relaunch Now’ button at the bottom of the page to restart Chrome.

To install the screen sharing extension in Chrome, do the following:

  1. Launch Chrome and click on the Menu icon.
  2. Click on ‘Settings’.
  3. Click on ‘Extensions’.
  4. Click on ‘Get more extensions’ and search for ‘webrtc’.
  5. Download ‘WebRTC Desktop Sharing’.
  6. This places an icon to the right of the URL bar in Chrome.

To share your screen or just a window, do the following in Chrome:

  1. Click on the ‘Share Desktop’ icon to the right of the URL bar and select either ‘Screen’ or the window you wish to share.
  2. Click ‘Share’.
  3. When sharing has started in a new Chrome window, select the URL of the relevant tab in that window and send it to the other parties via the chat pane on the right-hand side of the first browser window.

To stop sharing, click on ‘Stop sharing’ and click on the ‘Share Desktop’ icon to the right of the URL bar to get it to return to displaying the ‘Share Desktop’ icon instead of the || (Pause) icon.

File sharing

I did not bother to try file sharing using WebRTC, but there are various Web sites you can use to do that. One such is ShareDrop, and googling will find others.

Caveats

Chrome 36.0.1985.125 and Firefox 31.0 were used in this trial (I did not try Opera). I found that video chat worked faultlessly when both parties were using Chrome, and when both parties were using Firefox. However, when one of the parties was using Firefox and the other was using Chrome, I could not see myself in one of the video boxes in the browser window (although I could see the other party in the other video box in the browser window). Furthermore, there was a grey bar across the middle of the video images in the AppRTC demo, whereas the Multi-Party WebRTC Demo video images were normal. Other than those two issues, the experience was smooth and straightforward. My recommendation would therefore be to use Multi-Party WebRTC Demo and for all the parties to use the same browser, be it Chrome or Firefox. If you want to share your screen or a window, the logical choice at the moment would be Chrome.

References

1 LiveMinutes Blog – Beta Testers: How To Activate Screen Sharing!

Installing and using the Pipelight browser plug-in with Firefox 30 for Linux

pipelight-logoI use Gentoo Linux (~amd64) on my main laptop. Although I do not use Netflix or any of the other streaming video services that require the Microsoft Silverlight browser plug-in, I do need to use a browser with the Silverlight plug-in to access an office Intranet site. So I was interested in installing the Pipelight plug-in.

Although Pipelight works with most of the Silverlight test sites I have found on the Web, I cannot get it to work with the above-mentioned office Intranet site, which is why I ended up installing Firefox for Windows and Silverlight in WINE (see my previous post). Anyway, below I explain how I installed and configured Pipelight 0.2.7.1 and Firefox 30.0 for Linux. Even if you use a different Linux distribution to me, almost all of this post will still be relevant; only the package installation commands will differ.

Google Chrome 34 and onwards does not support NPAPI, so Pipelight does not work any more with Chrome. Actually, Mozilla has disabled some NPAPI support by default in Firefox 30: with the exception of the Flash plug-in you have to explicitly give permission for plug-ins to be activated via Click-to-Activate (also known as Click-to-Play). You can configure how Firefox Click-to-Activate behaves via Open menu > Add-ons > Plugins (choose either ‘Ask to Activate’, ‘Always Activate’ or ‘Never Activate’). See ‘Issues related to plugins – 4.1 Click to Play in Mozilla browser versions 23 and above‘ on the mozillaZine Website and ‘How to always activate a plugin for a trusted website‘ on the Mozilla Support Website.

I updated an existing Pipelight ebuild so that it will install the latest version of Pipelight (0.2.7.1) via a Portage local overlay. You can download the new ebuild from Gentoo Bugzilla Bug Report No. 481596 (see Comment 40). I can only get it to merge by using the -binary-pluginloader USE flag. [Update August 18, 2014: The package is now in the main Portage tree, at least for ~amd64]

Installation

Install Firefox if it has not already been installed:

root # emerge firefox

Install Pipelight (installation fails unless I disable binary-pluginloader):

root # USE="-binary-pluginloader" emerge pipelight

Install WINE with the Compholio patches:

root # USE="pipelight" emerge wine

As you can see below, I have wine-1.7.21 and pipelight-0.7.2.1 installed.

user $ eix -I wine
[I] app-emulation/wine
Available versions: 1.2.3^t (~)1.3.28^t 1.4.1^t 1.6.1^t 1.6.2^t (~)1.7.0^t (~)1.7.3^t (~)1.7.4^t (~)1.7.8^t (~)1.7.9^t (~)1.7.10^t (~)1.7.11^t (~)1.7.12^t (~)1.7.13^t (~)1.7.14^t (~)1.7.15^t (~)1.7.16^t (~)1.7.17^t (~)1.7.18^t (~)1.7.19-r1^t (~)1.7.20^t (~)1.7.21^t **9999^t {+X (+)alsa capi cups custom-cflags dbus dos (+)fontconfig +gecko gnutls gphoto2 gsm gstreamer jack (+)jpeg lcms ldap +mono mp3 nas ncurses netapi nls odbc openal opencl +opengl osmesa (+)oss +perl pipelight (+)png +prelink pulseaudio +realtime +run-exes samba scanner selinux (+)ssl test +threads +truetype (+)udisks v4l +win32 +win64 xcomposite xinerama (+)xml ABI_MIPS="n32 n64 o32" ABI_PPC="32 64" ABI_X86="(+)32 (+)64 x32" ELIBC="glibc" LINGUAS="ar bg ca cs da de el en en_US eo es fa fi fr he hi hr hu it ja ko lt ml nb_NO nl or pa pl pt_BR pt_PT rm ro ru sk sl sr_RS@cyrillic sr_RS@latin sv te th tr uk wa zh_CN zh_TW"}
Installed versions: 1.7.21^t(13:39:36 06/07/14)(X alsa cups fontconfig gecko gphoto2 gsm jpeg lcms mp3 ncurses nls openal opengl perl pipelight png prelink pulseaudio realtime run-exes scanner ssl threads truetype udisks v4l xinerama xml -capi -custom-cflags -dos -gstreamer -ldap -mono -netapi -odbc -opencl -osmesa -oss -samba -selinux -test -xcomposite ABI_MIPS="-n32 -n64 -o32" ABI_PPC="-32 -64" ABI_X86="32 64 -x32" ELIBC="glibc" LINGUAS="en pt_BR -ar -bg -ca -cs -da -de -el -en_US -eo -es -fa -fi -fr -he -hi -hr -hu -it -ja -ko -lt -ml -nb_NO -nl -or -pa -pl -pt_PT -rm -ro -ru -sk -sl -sr_RS@cyrillic -sr_RS@latin -sv -te -th -tr -uk -wa -zh_CN -zh_TW")
Homepage: http://www.winehq.org/
Description: Free implementation of Windows(tm) on Unix
.
user $ eix -I pipelight
[I] www-plugins/pipelight
Available versions: (~)0.2.3[1] (~)0.2.6[2] (~)0.2.7.1[2] {adobereader +binary-pluginloader flash foxitpdf grandstream installation-dialogs npactivex roblox shockwave +silverlight static unity3d}
Installed versions: 0.2.7.1[2](21:57:35 10/07/14)(silverlight -adobereader -binary-pluginloader -flash -foxitpdf -grandstream -installation-dialogs -npactivex -roblox -shockwave -static -unity3d)
Homepage: http://fds-team.de/cms/index.html https://launchpad.net/pipelight
Description: A browser plugin which allows one to use windows-only plugins inside Linux browsers.
.
[1] "sabayon" /var/lib/layman/sabayon
[2] "local_overlay" /usr/local/portage

Now update the dependency-installer script and enable the plug-in:

user $ sudo pipelight-plugin --update # sudo has to be used for this command only.
user $ pipelight-plugin --enable silverlight

Applies to AMD ATI GPUs only: My main laptop has an AMD ATI HD 5850 GPU, and hardware acceleration causes Firefox to hang when the Pipelight plug-in is enabled, so I have to disable hardware acceleration:

user $ cp /usr/share/pipelight/configs/pipelight-silverlight5.1 ~/.config/

Edit the Pipelight configuration file:

user $ nano ~/.config/pipelight-silverlight5.1

In order to force GPU acceleration uncomment the line:
overwriteArg = enableGPUAcceleration=true

In order to disable GPU acceleration (even if your graphic driver is probably supported) uncomment the line:
overwriteArg = enableGPUAcceleration=false

Instead of disabling GPU hardware acceleration in the Pipelight configuration file (pipelight-silverlight5.1), I could have instead done it each time I launch Firefox by entering the following command:

user $ PIPELIGHT_GPUACCELERATION=0 firefox

But I prefer to be able to enter just the following command:

user $ firefox

or to launch Firefox from the as-installed entry for Firefox in the Desktop Environment’s launcher menu.

After launching Firefox for the first time, a series of pop-up windows will show that the Silverlight plug-in is being installed. Once the final pop-up window has closed, install the Firefox extension User Agent Overrider (do not install User Agent Switcher or any other user agent selection extension for Firefox), click on the down-arrow of the User Agent Overrider icon in Firefox and select ‘Windows / Firefox 29′ from the pull-down menu. I also selected ‘Preferences…’ and added another user agent string to the end of the list:

# Custom
Windows / Firefox 15: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20120427 Firefox/15.0a1

Check that the plug-in is installed correctly

Enter about:plugins in the Firefox Address bar to check which plug-ins are installed, their version and current state.

Use the Pipelight diagnostic page to check the plug-in is working.

Pipelight options

To see what commands the Pipelight plug-in supports, enter the following command in a Konsole/Terminal window:

user $ pipelight-plugin --help

Further information

Below are some links to Silverlight tests and other information regarding Pipelight and Silverlight.

Silverlight test pages

Silverlight Version Test

Bubblemark animation test

Silverlight Project Test Page | Deep Zoom

Silverlight DRM Test (Select ‘No DRM’ because the following bug report says that the Silverlight DRM test at the aforementioned Web page is broken and Microsoft will not fix it: Bug 762056.)

Becky’s Silverlight Test Site

Microsoft Silverlight – IIS Smooth Streaming Demo

Experience IIS Smooth Streaming

Silverlight Project Test Page | Deep Zoom Tag Browser

Microsoft Case Studies

Silverlight Demos

Here is an article on Netflix’s intention to dump the awful Silverlight plug-in:
Netflix to dump Silverlight, Microsoft’s stalled technology

Background information on the Pipelight project

This presentation was made by the Pipelight developers:
Pipelight – Windows browser plugins on Linux

Useful pages on the Pipelight Web site

Pipelight | News

This page, about selecting a User Agent String that will work, is important to read if you’re having problems:
Pipelight | Installation – User Agent

Background reading on User Agent Strings

How to Change Your Browser’s User Agent Without Installing Any Extensions

The IE10 User-Agent String

You can find out your current user agent string by using the following link:
What’s My User Agent?

Alternative to using Pipelight

If you still have trouble viewing Web pages that use Silverlight, you might like to try an alternative approach: use Firefox for Windows and the Silverlight plug-in in WINE. See my previous blog post Installing Firefox for Windows and the Silverlight plug-in in WINE.

Bypassing a corporate Web filter when using the command line

or ‘How to bypass a corporate Web filter and download YouTube videos via the command line’

One of the offices where I work uses a Web filter to block access to certain sites, such as YouTube. However, sometimes it is necessary to view blocked Web sites for work purposes. For example, these days a lot of companies or individuals post product reviews on YouTube that are useful for work purposes. In such cases I have used Tor to access the blocked sites in a Web browser such as Firefox, Chrome, Konqueror etc. See my post How to install and use Tor for anonymous browsing or to access country-restricted content from another country for details of how to set up and use Tor with a Web browser.

But sometimes I need to access blocked Web sites from the command line. For example, today I needed to download a YouTube video for work purposes, and I wanted to use youtube-dl to do it. The solution was simple…

First I launched vidalia and polipo as explained in the above-mentioned post on Tor, then I launched another Konsole/Terminal window and entered the commands shown below:

$ # First find out what resolutions are available for the video I want to download:
$ youtube-dl -F https://www.youtube.com/watch?v=T3Rr4CUoTSQ
Setting language
T3Rr4CUoTSQ: Downloading webpage
T3Rr4CUoTSQ: Downloading video info webpage
T3Rr4CUoTSQ: Extracting video information
[info] Available formats for T3Rr4CUoTSQ:
format code extension resolution note
140 m4a audio only DASH audio , audio@128k (worst)
160 mp4 192p DASH video
133 mp4 240p DASH video
134 mp4 360p DASH video
135 mp4 480p DASH video
136 mp4 720p DASH video
17 3gp 176x144
36 3gp 320x240
5 flv 400x240
43 webm 640x360
18 mp4 640x360
22 mp4 1280x720 (best)
$ # Now try to download the video at the resolution I want:
$ youtube-dl -f 22 -o Clevo_W230ST_overview.flv https://www.youtube.com/watch?v=T3Rr4CUoTSQ
Setting language
T3Rr4CUoTSQ: Downloading webpage
T3Rr4CUoTSQ: Downloading video info webpage
T3Rr4CUoTSQ: Extracting video information
ERROR: unable to download video data: HTTP Error 403: Forbidden

As you can see above, the corporate Web filter blocked youtube-dl from downloading the video.

So I informed the shell session about the local HTTP proxy (polipo) running on my laptop, by assigning and exporting the environment variable http_proxy using the following syntax:

export http_proxy=http://server-ip:port/

which in my case meant the following (refer to my article on Tor):

$ export http_proxy=http://127.0.0.1:8123/

and then I was able to download the video from YouTube despite the corporate Web filter:

$ youtube-dl -f 22 -o Clevo_W230ST_overview.flv https://www.youtube.com/watch?v=T3Rr4CUoTSQ
Setting language
T3Rr4CUoTSQ: Downloading webpage
T3Rr4CUoTSQ: Downloading video info webpage
T3Rr4CUoTSQ: Extracting video information
[download] Destination: Clevo_W230ST_overview.flv
[download] 100% of 100.23MiB in 05:50
$

Useful Reference: How To Use Proxy Server To Access Internet at Shell Prompt With http_proxy Variable

Can Linux cope with 24 Hours of Happy?

I enjoyed Pharrell Williams’ feel-good songs in ‘Despicable Me‘ and its sequel, ‘Despicable Me 2‘. ‘Happy‘, a very catchy ditty he wrote for the sequel, also features in the World’s first 24-hour-long music video, ‘24 Hours of Happy‘, shot in and around Los Angeles and released on 21 November last year. The song is played a total of 360 times over the duration of the video, each 4-minute take featuring a different person or persons dancing (improvised) along streets, in petrol stations, through Union Station, in a church, around a school, in a moving school bus, around a supermarket, in a bowling alley, and so on. Each 4-minute performance was filmed in one take using Steadicam, and the location at the end of each take segues into the next take. You see the sun rise; you see the bright sunlight of the morning and the warm sunlight of the afternoon; you see the sun set; you see the twinkling city lights at night. The concept is simple yet brilliant.

Clips from some of the takes were used to create the 4-minute official music video for ‘Happy’, so you can watch that on YouTube to get a flavour of the takes, although it does not do justice to the full video.

Williams appears in a different take every hour on the hour, and a few other takes have celebrity cameos, but the vast majority of the participants are unknown extras of all ages, races, shapes, sizes and looks. To quote Williams talking to the Los Angeles Times: “We wanted all humanity in there, not just the model-types you might expect.” Some are good dancers, others not so good. But they all have one thing in common: they’re having fun, so they look good. The joy is infectious, and I found myself watching far longer than I would have expected, having to return to the site again and again. Half the fun is watching the bystanders.

When you open the ’24 Hours of Happy’ site, the take that was in progress at the current time of day starts playing from the beginning. However, you can drag the pointer around the clock dial and watch any take from the 24-hour period. There are also buttons you can click on to jump between takes or to jump to each take featuring Williams. The yellow on-screen controls can be made to disappear by not moving the mouse pointer for 5 seconds.

Still from 24 Hours of Happy, showing on-screen controls

Still from 24 Hours of Happy, showing on-screen controls

The Web site is well-designed and fun to use, so I was not surprised it was voted ‘Site of the Month‘ and ‘Site of the Year Users’ Choice‘ by AWWWARDS, and voted ‘Site of the Month‘ and ‘Site of the Year‘ by TheFWA.

It’s impossible to list them all, but a few of my favourite takes are:

01:36  Very perky woman with ponytail.
05:28  Jogger who has to keep pulling his shorts up!
08:24  Woman on roller skates.
09:52  Very cute little girl.
09:56  Woman with some groovy moves.
10:40  Woman in Union Station. Some of the bystanders are particularly amusing.
11:16  Man with cast on foot.
11:20  Boy with an Afro.
11:36  Three groovy old ladies.
11:44  Chubby guy with style.
12:36  Woman with some groovy moves.
13:32  Dancing couple in pink.
14:20  Two cool guys in dinner jackets inside and outside Union Station.
15:00  Pharrell Williams in a church with a gospel choir.
19:04  Woman with a lizard puppet. The lizard does the lip-synching!
19:36  Guy on stilts.
23:40  Woman with LED hula hoop (love it!).

If you want to start viewing a take made at a specific time of day, you can append the time to the URL, like so:

http://24hoursofhappy.com/09h53am

Obviously I think ’24 Hours of Happy’ is fabulous, but why am I discussing it in a blog predominantly about Linux? Because Firefox 27.0.1 (32-bit) running in Windows 8.1 (64-bit) on my new Acer Aspire XC-600 micro-tower PC (dual-core Intel Pentium G2030 @ 3 GHz & 3 MB cache, 4 GB DDR3 RAM) handles ’24 Hours of Happy’ at 720p with ease, but the story is very different on my main laptop running 64-bit Gentoo Linux with KDE (quad-core Intel Core i7 720QM @ 933 MHz & 6 MB cache, 4 GB DDR3 RAM). Both machines are on my home network, connected to the Internet via high-bandwidth broadband (FTTC).

On my laptop, the latest available versions of Firefox (27.0) and Opera (12.16_p1860-r1) for Gentoo, both 64-bit, do not even complete loading the ’24 Hours of Happy’ site: the black progress bar at the bottom of the home page stops about 7/8th of the way across the page and the KDE Network Monitor widget shows there is no network activity. Clearing Firefox’s Web content cache or increasing the cache’s size to 1 GB make no difference. Konqueror 4.12.2 (configured to use the WebKit browser engine rather than the KHTML engine) loads the site and plays it quite well at 720p to start with, but eventually video becomes choppy and I notice a lot of spawned kio_http processes. The KDE Network Monitor widget shows a continuous 3600 Kib/s data stream, which does not stop when I exit Konqueror. Numerous kio_http processes are spawned and remain after I exit Konqueror, and the 3600 KiB/s activity on the network only ceases when I kill all the kio_http processes. The number of spawned kio_http processes increases if I drag the pointer around the clock to select different takes, and the page just displays ‘LOADING’ ad infinitum if I do this several times. To be fair, if I do this a lot in Firefox running in Windows 8.1, I can get Firefox to stall too. I thought I’d try a lightweight browser and installed NetSurf (3.0-r1), but that couldn’t even render the title on the home page, let alone begin to load the video.

So, does ’24 Hours of Happy’ play nicely in your Linux installation? If it does, what hardware, distribution, desktop environment, browser and quality (360p, 480p, 720p or 1080p) are you using?

Fixing a problem with received video in Skype when using the AMD Catalyst (FGLRX) driver in Linux

Some users of Skype for Linux have reported that the bottom half of the received video image is corrupted in installations that use the closed-source video driver for ATI GPUs (the AMD Catalyst proprietary Linux driver, also known as the ‘FGLRX’ driver). One user described the lower half of the video image as “covered in small coloured squares like a chequer board”.

From what I have read in a few forums, it seems the problem does not occur when the open-source Radeon driver is used. My own experience corroborates that: I use the Radeon driver on one of my laptops, and received video in Skype is fine.

My main laptop has an AMD ATI Mobility Radeon HD 5650 GPU and I am using the Catalyst driver under Gentoo Linux. In this case there was a problem with received video in most Skype sessions. Either of the following effects usually occurred:

Snapshot 1 - Extract of received video image in Skype, showing an example of the corrupted image

Snapshot 1 - Extract of received video image in Skype, showing an example of the corrupted image

Snapshot 2 - Extract of received video image in Skype, showing another example of the corrupted image

Snapshot 2 - Extract of received video image in Skype, showing another example of the corrupted image

As shown in Snapshot 1, the lower half of the received video image was covered in a grid of thin green lines with areas tinged with purple, blue or green, whereas there was no grid of lines in the upper half of the image but some areas were tinged with red or blue.

As shown in Snapshot 2, the lower half of the received video image was covered in a grid of thin red lines, with a purple tinge in some areas, whereas there was no grid of lines in the upper half of the image, which looked reasonable but had some red-, green- or blue-tinged areas.

In all cases Skype’s thumbnail of my Webcam’s video image looked fine, and the person on the other end of the call said the video image received from me looked fine too.

Because of a bug in a previous version of the Catalyst driver a few years ago — see my blog posts Playing QuickTime videos in Firefox and Chromium + XVideo bug in AMD Catalyst 11.11 and 11.12 driver and AMD Catalyst for Linux driver 12.2 fixes the XVideo bug that crashed X.Org Server 1.11.x — I happen to know that Sykpe uses X11 overlays with the XVideo extension (xv), rather than using the OpenGL renderer (gl) or X11 with the SHM extension (x11). This made me wonder whether the use of XVideo with the Catalyst driver was causing the current problem. Unlike media players such as MPlayer and VLC, it is not possible to configure Skype to use gl or x11 instead of xv, so I thought it would not be possible to test whether the use of gl or x11 instead of xv would make a difference. Until, that is, I came upon a ‘trick’ posted by openSUSE user queequeg in 2009 during the period when an earlier version of the Catalyst driver had the aforementioned bug:

Skype Video Workaround for ATI

Anybody trying to make a video call with Skype and ATI fglrx drivers has had problems due to Skype using the “xv” video mode with the driver can’t handle. For anyone interested that is affected by this, there is a workaround:

1. Run the xvinfo command and look at the number of xv sessions available. Some cards have only 1, some have as many as 4. This is the number of xv occurances that the card can do at one time.
2. “Use up” all these xv sessions by opening videos in your favorite video player making sure to use xv for the video output. The videos can then be paused.
3. Once this (or they) are open, skype can be started and will default to X11 video and work properly with video calls.

I know this is a goofy way to get around this issue, but until fglrx can handle xv or skype allows an option to choose X11 for video render, I don’t know of any other way to do it.

(From what I hear, the 11.1 fglrx drivers can handle xv, but I haven’t confirmed this.)

So I tried his work-around. I had to launch four media players in order to use all available XVideo sessions. Lo and behold, when I launched Skype and made a video call the received video image was perfect. So it appeared that the Catalyst driver is not able to handle well the XVideo output from Skype. However, playing and pausing four videos every time I want to make a video call in Skype would hardly be practical, would it? And that is not the only downside: when I maximised a Firefox window during the Skype video call, my laptop spontaneously rebooted (I assume the X.Org server crashed).

I did also wonder whether just disabling compositing would solve the problem, so I disabled KWin Desktop Effects, but that didn’t make any difference.

I had also read in several forums that enabling or disabling the TexturedVideo and/or VideoOverlay options in the xorg.conf file have an effect on the video image produced by the Catalyst driver, but I could not find a post mentioning the use of either of those options to fix the specific problem I was seeing. So I decided not to pursue the xorg.conf route.

In my searches of the Web I came across a post somewhere that mentioned using GTK+ UVC Viewer (guvcview) to adjust video properties and improve video in Skype. I thought guvcview was only for adjusting the video image from a Webcam connected to my machine, i.e. adjusting the outgoing video image, and would not have any effect on received video. Nevertheless, I decided to install and launch guvcview to see if I could adjust both incoming and outgoing video properties. To my surprise, guvcview appeared to have fixed the problem with the received video. These are the steps I followed:

  1. I launched Skype and started a video call. The received video image had a grid of thin red lines and purple/green/blue tinting (similar to Snapshot 2).
  2. I Installed guvcview using the package manager.
  3. I launched guvcview in a Konsole (terminal) window. After guvcview created the file /home/fitzcarraldo/.config/guvcview/video0 and checked various video and audio settings it exited because my Webcam was being used by Skype (‘libv4l2: error setting pixformat: Device or resource busy‘).
  4. I clicked on the Webcam icon in the Skype call window, to turn my Webcam off.
  5. I launched guvcview again. The lower half of the received video image in Skype changed from a grid of thin red lines to a continuous green-coloured band, and the upper half of the image now looked reasonable but still had some red- or blue-tinged areas (see Snapshot 3 below).
  6. Snapshot 3 - Extract of received video image in Skype after I launched guvcview again

    Snapshot 3 - Extract of received video image in Skype after I launched guvcview again

  7. On the ‘Image Controls’ tab in the ‘GUVCViewer Controls’ window I changed the video frequency from 60 Hz to 50 Hz then back to 60 Hz again. I was just tinkering, and I believe this had no bearing on the outcome.
  8. I clicked on the ‘Quit’ button in the guvcview window to terminate the application.
  9. I clicked on the Webcam icon in the Skype call window to turn on again the Webcam, and the received Skype video image changed to a perfect image (see Snapshot 4 below).
  10. Snapshot 4 - Extract of received video image in Skype after I turned on again my Webcam in Skype

    Snapshot 4 - Extract of received video image in Skype after I turned on again my Webcam in Skype

It appears that guvcview had an effect on the received video image in Skype, although, if it did, I do not understand how. To check if the fix was permanent I ended the Skype video call, signed out of Skype and quit the application, rebooted and made a new Skype video call. The received video image in Skype was again perfect. I even deleted the guvcview configuration file and repeated this check, just in case the configuration file was somehow being used even though I had not launched guvcview, but the received video in yet another Skype video call was still perfect. I also clicked on the Webcam icon in the Skype call window several times during each call in order to turn my Webcam off and on several times; the received video image of the other person remained perfect.

So there you have it: when using an AMD ATI GPU and the Catalyst driver, it seems that guvcview can be used — at least in my case — to eliminate the type of image corruption in received Skype video shown in Snapshots 1 and 2. So, if you are also using the AMD Catalyst for Linux driver and are experiencing a similar problem, try guvcview. It might just do the trick.

ARTE Live Web videos

The Franco-German cultural Web site ARTE Live Web is an excellent resource for lovers of music (classical, jazz, alternative and World) and dance. The show videos at the site are enjoyable but unfortunately only viewable for a fixed period of time before the site removes them. Back in 2011 I wanted to download the video of a performance I’d attended and loved. I searched for a Linux tool but could not find one, then found a Windows freeware GUI tool called artepupper, and used version 0.2 to download the video. You can read about the tool on the author’s blog pages artepupper 0.1, artepupper 0.2 and artepupper 0.3. The reason for the change from 0.2 to 0.3 was that ARTE Live Web changed the format of an embedded URL inside the XML page for the video on their Web site.

Now, artepupper is based on livewebarte1.1.sh, a 2010 Bash script by Carmelo Ingrao, and a Perl script livewebarte.pl by Juan Domingo based on livewebarte1.1.sh, both of which are still available on line at Carmelo’s download page and which I only discovered after using artepupper in Windows. I tried the Perl script in Linux back in 2011, and it worked for me.

Recently I wanted to download another video from the ARTE Live Web site and found that, although artepupper 0.3 in Windows worked, the Perl script livewebarte.pl no longer worked. Presumably this was because of the aforementioned change to the embedded URL. However, I found that the Bash script livewebarte1.1.sh still worked. Actually, I had to edit the script to replace “./rtmpdump” with “rtmpdump“, as I had installed the command-line tool rtmpdump using the Linux distribution’s package manager and the executable is not stored in the same directory as the Bash script. But, apart from that, it worked.

Carmelo is a star for having deciphered how to access and download videos from the site. However, looking at his Bash script, the part where he parses a line in the XML code and extracts a string between the delimiters “MP4″ and “mp4″ is based on a hard-coded character position, which could change if the Web site’s owners change the format of the URL. So I decided to modify the Bash script to avoid using character positions to extract a string. The Bash script livewebarte1.2.sh is an updated version of Carmelo’s livewebarte1.1.sh script.

#!/bin/bash
# Script pour récupérer les vidéos FLV du site liveweb.arte.tv
# par Carmelo Ingrao <carmelo42@gmail.com> http://c.ingrao.free.fr/code/
# version 1.0
# release date 21 février 2010
## modified by Fitzcarraldo 24 April 2013
## version 1.2
## release date 24 April 2013
# licence : GPLv2
# rtmpdump compilé doit être dans le même répertoire que le script
## rtmpdump must be installed and in user's $PATH (e.g. I have it in /usr/bin/)
# utilisation du script :
#
# ./script.sh url fichier.flv
# _______________

# url --> $1
# fichier --> $2

# fichier de sortie
# on efface l'écran avant de commencer
clear

# on affiche les infos sur le script
echo "livewebarte.sh version 1.0."
echo "(c) 2010 Carmelo Ingrao; License : GPL"
echo "livewebarte.sh version 1.2."
echo "updated from version 1.1 by Fitzcarraldo on 24 April 2013; License : GPL"
echo "usage : ./livewebarte.sh url_concert_sur_liveweb.arte.tv fichier.flv"
echo "rtmpdump must be installed and in your path."

# on télécharge le code source de la page streamant le concert dans le fichier sourceconcert.html
wget $1 -O sourceconcert.html

# on récupère le numéro d'event et on le copie dans eventok.txt
#cat sourceconcert.html | grep "new LwEvent" > event.txt
#cat event.txt | cut -b "15 16 17" > eventok.txt
grep "new LwEvent" sourceconcert.html | grep -E -o -e "[0-9]+" > eventok.txt

# on prend le fichier XML d'arte et on crée l'url avec le bon numéro d'event
# xmloriginal="http://arte.vo.llnwd.net/o21/liveweb/events/event-610.xml"

# url du xml sans le numéro d'event original (pour faciliter)
xmloriginal2="http://arte.vo.llnwd.net/o21/liveweb/events/event-"

# on assigne à la variable b le contenu de eventok.txt --> numéro correct d'event
b=$(cat eventok.txt)

# on créer l'url correct du fichier XML qu'on téléchargera
xmlok=$(echo $xmloriginal2$b)
finxml=".xml"
xmlfinal=$(echo $xmlok$finxml)

# on télécharge le bon XML
wget $xmlfinal -O xmlok.xml
echo "Fichier XML téléchargé"

## I have changed the code in this part:
# on extrait le nom du fichier MP4 depuis le fichier xmlok.xml
mp4hd=$(cat xmlok.xml | grep "urlHd")
# on efface le début de l'url du MP4
# on efface le surplus à la fin du nom du MP4 et on sauve le nom dans la variable mp4hdcut2
mp4hdcut2=${mp4hd#*MP4}
mp4hdcut2=${mp4hdcut2%%mp4*}
mp4hdcut2="MP4"$mp4hdcut2"mp4"
## end of my changes to evaluate mp4hdcut2

# on lance la commande rtmpdump avec les paramètres
# rappel :
# $2 = nom du fichier de sortie
# $mp4hdcut2 = nom du fichier MP4

## Carmelo had ./rtmpdump here, but I removed the "./"
rtmpdump -r rtmp://arte.fcod.llnwd.net:1935/a2306/o25 -a a2306/o25 -f LNX 10,0,45,2 -W http://liveweb.arte.tv/flash/player.swf -t rtmp://arte.fcod.llnwd.net:1935/a2306/o25 -p http://liveweb.arte.tv/ -o $2 -y $mp4hdcut2

# on efface les fichiers crées
rm sourceconcert.html
#rm event.txt
rm eventok.txt
rm xmlok.xml

# Affichage des infos de fin
echo "________"
echo "Voilà, le téléchargement est terminé."
echo "Le fichier se trouve ici :"
echo " "
echo $2
echo " "
echo "Bon visionnage"
echo " "
echo " "
exit 0

Save it in your home directory and make it executable:

$ chmod +x livewebarte1.2.sh

Also make sure you have the package rtmpdump installed and that it is in your $PATH.

Then you can browse the ARTE Live Web site and select the performance video you wish to download. Hover the mouse pointer over the video pane and click on “INTEGRER LA VIDEO” to find the URL for that video, which will be of the form http://liveweb.arte.tv/fr/video/foo/, where “foo” is some string of characters (not literally “foo”, of course). The command to download it is then as shown below. I’ll use a file name foo.flv here, but any prefix would do:

$ ./livewebarte1.2.sh http://liveweb.arte.tv/fr/video/foo/ foo.flv

Note that it is essential to include the forward slash at the end of the URL. The file will be downloaded to your home directory and you can watch it in VLC or any other Linux media player that plays Flash video.

So there you have it; currently you can use artepupper 0.3 in Windows or livewebarte1.2.sh in Linux to download from ARTE Live Web a video of a performance you attended and loved.

Using Bombono DVD in Linux to create a DVD-Video disc from a MKV file

I had a .mkv file and associated .srt subtitles file, and wanted to create a DVD-Video disc so that I could play it in my stand-alone DVD player and watch the film on my TV set. I tried to create a DVD-Video disc by using Avidemux and following the procedure in Formatting an MKV container into DVD format with Avidemux, Mkvtoolnix, dvdauthor, and K3B, but both Avidemux and Avidemux2 crashed, displaying the error message “Crash. Segfault at line 0, file ??ADM_backTrack”.

So I installed Bombono DVD (package name bombono-dvd) and GNOME Subtitles (package name gnome-subtitles), required by Bombono DVD if you want it to create a DVD-Video disc with subtitles, and was able to burn a DVD-Video disc as follows:

1.  If you want subtitles, open the .srt subtitles file in a GUI text editor to check the character encoding. As I use KDE, I opened the .srt file in KWrite, selected Tools > Encoding, and found that ISO 8859-15 was the character set used in the particular .srt file that I had downloaded from the Web.

2.  Launch Bombono DVD as follows:

$ export VIDEO_FORMAT=PAL && bombono-dvd

(Replace ‘PAL’ with ‘NTSC’ if you want to create an NTSC DVD-Video disc.)

3.  In the top right corner of the Bombono DVD window, select the DVD-Video disc size. In my case, I had a 7.9 GB MKV file which I wished to transcode and burn to a 4.7 GB capacity DVD+R, so I selected ‘DVD 4.3 GB’.

4.  Select ‘Project’ > ‘Preferences…’

4.1  Select ‘Default project type’ as ‘PAL/SECAM’ (or ‘NTSC’ if you want to create an NTSC DVD-Video disc).

4.2  Under ‘Play authoring result in’ select ‘Xine’ (or ‘Totem’, if you use that media player).

4.3  I have a quad-core CPU so I selected ‘4’ for ‘Multi-core CPU support’.

4.4  Click ‘Close’.

5.  Click on the ‘Source’ tab.

5.1  Click on the ‘+’ sign and select the MKV file you want to transcode and burn to DVD.

5.2  Right-click on the resulting entry in ‘Media List’ and select ‘Adjust Bitrate to Fit to Disc’.

5.3  If you also have a subtitles file you wish to use, right-click on the entry in ‘Media List’ and select ‘Add Subtitles…’

5.3.1  Select the subtitles file.

5.3.2  Tick ‘Turn on subtitles by default’.

5.3.3  Select the character encoding. In my case I selected ‘ISO-8859-15′ (see Step 1 above).

6.  Click on the ‘Output’ tab.

6.1  Select ‘Write disc image’ and enter a Disc label of up to 15 letters.

6.2  Click on ‘Build DVD-Video’.

If the transcoding, subtitle addition and ISO file creation processes complete successfully, Bombono DVD will pop-up a window informing you and asking if you want to burn the image to a DVD. Make sure a blank DVD is in your optical R/W drive and then click on the appropriate button.

AMD Catalyst for Linux driver 12.2 fixes the XVideo bug that crashed X.Org Server 1.11.x

Just a brief ‘heads up’ for users of the closed-source FGLRX driver in Linux: In a previous blog post I mentioned a bug in the AMD Catalyst driver for Linux that caused X.Org Server 1.11.x to crash if you tried to play a video and your media player was configured to use XVideo (Xv) output. The bug also meant that people talking to you via Skype could not enable their Web cams or X.Org Server 1.11.x would crash on your machine, as Skype uses XVideo.

The problem occurred with versions 11.11, 11.12 and 12.1 of the FGLRX driver (the package x11-drivers/ati-drivers). Well, today I installed version 12.2 of the driver and am pleased to report that I can again set media players to use Xv output without causing the X.Org Server to crash (I’m currently using xorg-server-1.11.4). Likewise, other people who I am talking to via Skype can again enable their Web cams without causing the X.Org Server on my machine to crash.

Playing QuickTime videos in Firefox and Chromium + XVideo bug in AMD Catalyst 11.11 and 11.12 driver

Video problems seem to be perennial in Linux. The latest two to affect me were:

1) Firefox and Chromium could no longer play QuickTime videos on the Apple iTunes Movie Trailers Web site;

2) a bug in the latest two releases of the closed-source ATI FGLRX driver (AMD Catalyst 11.11 and 11.12 for Linux) that causes the X.Org Server to crash when I try to play .mov files using XVideo (Xv) output in media players such as SMPlayer, VLC, GNOME-MPlayer etc. (see e.g. Gentoo Bug Report No. 391193).

The reason I mention these two problems in the same breath is because I encountered the second whilst trying to fix the first. Anyway, below I explain what I did to resolve the two problems.

I first had a problem displaying QuickTime movie trailers in Firefox a couple of years ago. The solution then was to install the User Agent Switcher add-on for Firefox and create a user agent to fool the Apple Web site into thinking Firefox was using Apple’s QuickTime browser plugin instead of mplayerplug-in for Linux. But within a few days Firefox again could not play movie trailers on the Apple Web site. I had to uninstall mplayerplug-in and install the then latest version of its successor, gecko-mediaplayer (which uses gnome-mplayer). All was good again until…

Several months ago I found that, yet again, Firefox could not play movie trailers on the Apple Web site. I tried to view the trailers in Chromium instead but had the same problem. Both browsers just displayed a black box where the video should be playing. A little searching on the Web led me to the conclusion that the problem lay with the latest version of gecko-mediaplayer and gnome-mplayer that I was using at the time, so I gave up and decided to wait for new versions of gecko-mediaplayer and gnome-mplayer to be released.

Now, yesterday I wanted to watch a particular trailer on the Apple Web site, but, despite having installed the latest version of gecko-mediaplayer and gnome-mplayer anyway a few days ago, neither Firefox nor Chromium would display the trailer. A little searching on the Web suggested that I should try mozplugger instead of gecko-mediaplayer, so I uninstalled the latter, installed mozplugger and… the black box in the browser was replaced by a white box displaying the QuickTime ‘Q’ logo and a message that I needed to install QuickTime. Argghh!

So I uninstalled mozplugger and reinstalled gecko-mediaplayer and gnome-mplayer (the same versions that I installed recently, you inderstand). This time my attempts to watch trailers on the Apple Web site resulted in Firefox and Chromium displaying grey boxes and appearing to download the QuickTime videos, but then the X.Org Server crashed, restarted and the Desktop Environment’s login screen appeared. Furthermore, when I tried playing .mov videos in VLC, the same thing happened. Perhaps now you may understand why I mentioned above the bug with the FGLRX driver? It took me a few hours to realise there were two separate problems here.

The work-around to the second problem was to configure media players to use a different output driver rather than the XVideo (Xv) output driver. For example, in VLC this is done via Tools > Preferences > Video and selecting ‘GLX video output (XCB)’ as the Output under Video Settings. For SMPlayer this is done via Options > Preferences > General and selecting ‘gl (fast – ATI cards)’ as the Output driver under the Video tab.

And, most importantly, in order to enable gecko-mediaplayer to display those Apple QuickTime trailers in Firefox and Chromium I had to launch gnome-mplayer, select Edit > Preferences, click on the Player tab and select ‘gl’ as the Video Output under Adjust Output Settings. Actually, clicking on the MPlayer tab and entering “-vo gl” (without the quotes) in the ‘Extra Options to MPlayer:’ box achieves the same result. By the way, the tickboxes QuickTime Emulation, RealPlayer Emulation, Windows Media Player Emulation and DIVX Player Emulation were already ticked on the Plug-in tab.

So, there you have it. After several hours of searching and tinkering I can again watch movie trailers on the Apple Web site. Don’t you just love Linux?

For the sake of completeness, below I list the versions of the applicable packages currently installed on my main laptop:

firefox-9.0
chromium-16.0.912.63
gecko-mediaplayer-1.0.5_beta1_p20111207
gnome-mplayer-1.0.5_beta1
mplayer-1.0_rc4_p20111215
ffmpeg-0.9
libquicktime-1.2.3-r1
xorg-server-1.11.2-r2
ati-drivers-11.12

EDIT (January 2, 2012): I’ve just had a thought: When I used Skype for Linux a few days ago, my laptop rebooted spontaneously as soon as the person at the other end enabled her Webcam in Skype for Windows. This was reproducible consistently. However, I could enable my Webcam, she could see me in Skype on her PC, and I could also see video of me in Skype’s ‘myself preview’ on my laptop. Now, it could be a coincidence but I wonder if the reboot occurred because Skype for Linux uses XVideo? Skype’s Web page for Skype for Linux lists “Video card driver with Xv support” as one of the hardware requirements, which looks pretty conclusive to me. However, this leaves a couple of niggling questions: a) If Skype does indeed use XVideo, why didn’t the ‘myself preview’ video in the Skype for Linux window crash the X.Org Server?. b) If the FGLRX driver bug is the cause, why did my laptop reboot instead of just the X.Org Server crashing, restarting and displaying the Desktop Environment login screen? Furthermore, Skype’s Options > Video Devices > Test does work correctly on my laptop. So perhaps the rebooting problem is caused by a different bug. Suspicious, though. Unfortunately, as far as I know there is no way of switching Skype to use OpenGL instead of XVideo, so I cannot prove that XVideo is the cause of this particular problem I’m experiencing with Skype.

How to play MSS2 codec (Windows Media Video 9 Screen) .wmv files in 64-bit Linux

One type of legacy .wmv file uses the ‘Windows Media Video 9 Screen’ MSS2 codec (“DMO-based codec, optimized for low-bitrate sequential screen captures or screencasts”, according to Wikipedia). Now, it is not possible to use win32codecs with the 64-bit versions of Linux multimedia players, so they cannot play .wmv files that use the MSS2 codec. However, there is a way around this: use the Windows version of SMPlayer in WINE. Below I explain the procedure I used to enable me to play .wmv files that use the MSS2 codec.

1. I surfed over to the download page of the MPlayer Web site and downloaded to ~/Desktop/ the installer for the latest version of SMPlayer for Windows (smplayer-0.6.9-win32.exe at the time of writing).

2. I configured WINE and installed SMPlayer for Windows:

$ cd
$ export WINEPREFIX=$HOME/.wine-smplayer
$ export WINEARCH="win32"
$ winecfg
$ cd .wine-smplayer/drive_c/
$ cp ~/Desktop/smplayer-0.6.9-win32.exe .
$ wine smplayer-0.6.9-win32.exe

3. I launched SMPlayer for Windows:

As I had opted to use a WINEPREFIX, to launch SMPlayer (Windows version) from the command line I would need to enter the following command under my normal user account:

env WINEPREFIX="/home/fitzcarraldo/.wine-smplayer" WINEARCH="win32" wine /home/fitzcarraldo/.wine-smplayer/drive_c/Program\ Files/SMPlayer/smplayer.exe

Instead it was easier for me to edit the Desktop Configuration File that was created on the Desktop, and also edit the menu entry that was created in the Kickoff menu, to execute the above command for me. Now all I need to do to launch SMPlayer for Windows is either to select it from Kickoff > Applications > Wine > Programs > SMPlayer > SMPlayer or to double-cick on the SMPlayer for Windows icon on my Desktop.

EDIT (December 11, 2012): OK, for those of you having trouble seeing the video component and only hearing the audio component of a .wmv file using MSS2, you need to do the following:

When you launch the SMPlayer 0.6.9 Setup program (wine smplayer-0.6.9-win32.exe) and click on Next and accept the Licence Agreement, make sure Binary Codecs (under MPlayer Components) is ticked.

When you launch SMPlayer for Windows and open the .wmv file, click on Options > Preferences to open the Preferences window. Click on General in the left pane, then click on the Video tab in the main pane and select “directx (fast)” or “directx(slow)” as the Output driver. I have just done this again (I’m currently using WINE 1.5.18) and I’m watching a MSS2-encoded .wmv file ‘Kai_Software2.wmv’ as I type this, as shown in the information listed by SMPlayer for Windows:

Kai_Software2.wmv
General
File H:/Kai_Software2.wmv
Size 3193 KB (3 MB)
Length 00:04:33
Demuxer asf

Video
Resolution 883 x 720
Aspect ratio 1.22639
Format MSS2
Bitrate 100 kbps
Frames per second 1000.000
Selected codec wmsdmod

Initial Audio Stream
Format 353
Bitrate 16 kbps
Rate 22050 Hz
Channels 1
Selected codec ffwmav2

Audio Streams
# 0
Language
Name
ID 1

Just to recap:

$ cd
$ export WINEPREFIX="/home/fitzcarraldo/.wine-smplayer"
$ export WINEARCH="win32"
$ winecfg
$ cd /home/fitzcarraldo/.wine-smplayer/drive_c/
$ cp ~/Downloads/smplayer-0.6.9-win32.exe ~/.wine-smplayer/drive_c/
$ wget http://winetricks.org/winetricks
$ chmod +x ./winetricks
$ ./winetricks # 'Select the default wineprefix' + OK first then 'Install a Windows DLL or component' + OK and tick 'allcodecs' and OK.
$ wine smplayer-0.6.9-win32.exe # Make sure Binary Codecs is ticked.

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