speaker-test returns all 6 channels to front speakers

OS: KUBUNTU 19.04 Soundcard: Creative Soundblaster ZxR Sound Setup: front (left/right), center, bass, rear (left/right)

My problem is, that all speaker outputs are played at the front speakers.

I did the following:

  • Set speaker setup at Plasma sound settings to “Analog Surround 5.1-Output + Analog Stereo-Input”
  • If I click on any rear speaker there, to test audio output, they are played on front speakers. The setup seems very faulty:
    • rear right: output on front left and right at the same time
    • rear left: output on front left and right at the same time
    • center: output on front left and right at the same time
    • front left: output on front left (one of two correct speakers)
    • front right: output on front right (one of two correct speakers)
  • I then executed alsamixer and noticed that my NVIDIA Graphics card was initially selected. I switched with F6 to my ZxR and set it up like this: enter image description here
  • I ran speaker-test -Dplug:surround51 -c6 -twav. An error message appeared and I was unable to perform the command: Error when opening the device: -2
  • I googled how to set the default device and so I did cat /proc/asound/cards:
 0 [NVidia         ]: HDA-Intel - HDA NVidia                       HDA NVidia at 0xdf080000 irq 17  1 [Creative       ]: HDA-Intel - HDA Creative                       HDA Creative at 0xdf204000 irq 19 

with kate ~/.asoundrc I set my default device:

defaults.pcm.card 1 defaults.ctl.card 1 defaults.timer.card 1 
  • after a restart speaker-test -Dplug:surround51 -c6 -twav was working: Unfortunately rear left output is on front left, rear right output is on front right, center appears to be on both front (left/right) speakers

Does anyone have any idea how I can fix this?

How could I block or at least detect the use of ultrasonic side channels or Google Nearby Messages API on my smartphone?

My question is about the use of ultrasonic messages that are part of the modern advertising ecosystem and are also used by the Google Nearby Messages API.

When it comes to advertising, the type of ultrasonic messages that I am referring to are described in this Wired article titled “How to Block the Ultrasonic Signals You Didn’t Know Were Tracking You”, from 2016. The article says (emphasis added):

The technology, called ultrasonic cross-device tracking, embeds high-frequency tones that are inaudible to humans in advertisements, web pages, and even physical locations like retail stores. These ultrasound “beacons” emit their audio sequences with speakers, and almost any device microphone—like those accessed by an app on a smartphone or tablet—can detect the signal and start to put together a picture of what ads you’ve seen, what sites you’ve perused, and even where you’ve been.

The Wired article also mentions that:

Now that you’re sufficiently concerned, the good news is that at the Black Hat Europe security conference on Thursday, a group based at University of California, Santa Barbara will present an Android patch and a Chrome extension that give consumers more control over the transmission and receipt of ultrasonic pitches on their devices.

Being that the article was from 2016, I looked at the Black Hat Europe conference from that year for more information about the Android patch. The presentation mentioned in the Wired article seems to be this one.

The presentation slides (available here) led me to the ubeacsec.org website where the researchers do have an android patch as mentioned in the Wired article. Alas that patch is a research prototype made for android-5.0.0_r3.

There is also this research paper from 2017, titled “Privacy Threats through Ultrasonic Side Channels on Mobile Devices”. The authors of this paper found out for example that

  • Advertising platforms such as Google’s Universal Analytics and Facebook’s Conversion Pixel provided services utilizing this technology. The researchers analyzed three commercial solutions: Shopkick, Lisnr and Silverpush.
  • 234 Android applications analyzed by the researchers were constantly listening for ultrasonic beacons.
  • Out of 35 stores visited in European cities, 4 were using ultrasonic beacons at the time of the research.

Anyway my interest is not just about blocking advertising trackers. Even though the marketing departments may be the largest consumer of this technology, it can be utilized in many other ways as well.

And this issue is related to another technology, namely the Google Nearby Messages API. The overview document written by Google about this technology (here) says that (emphasis added):

The Nearby Messages API is a publish-subscribe API that lets you pass small binary payloads between internet-connected Android and iOS devices. The devices don’t have to be on the same network, but they do have to be connected to the Internet.

Nearby uses a combination of Bluetooth, Bluetooth Low Energy, Wi-Fi and near-ultrasonic audio to communicate a unique-in-time pairing code between devices.

The concerns about the Nearby Messages API are:

  1. Its ability to pass small binary payloads, i.e. presumably executable code.
  2. That while it is easy to disable Bluetooth and WiFi on a smart phone, it is not so easy to disable the microphone.

Question:

Are there ways to block or at least detect the use of ultrasonic side channels or Google Nearby Messages API on my smartphone?

Slack not showing unread channels + wrong “No unread” indication

slack webapp have been acting very weird lately.

When I first log into slack, it shows everything correctly, like coloring the unread channels in bold white and providing the correct unread count.

On refresh, slacks stops showing the unread channels in bold white. I can still see them in the All Unreads though, which still makes this tool usable.

But, when I click on any starred channel and then back to All Unreads, I see that all is read, though it isn’t!!!

Again, refresh shows the correct number of unreads but doesn’t show the unread channels.

I tried signing out and in. Tried clearing the cookies.

I’m using a fresh install on Ubuntu 18.04 on chrome v 75.0.3770.100. Same issue on firefox as well.

enter image description here

How do I enable or bond the 80mHz channels on a Cisco 3502i AP in autonomous mode?

I have a Cisco AIR-CAP3502I-A-K9 using F/W ap3g1-k9w7-xx-153-3.JF5 in autonomous mode. I have tried everything I can think of (Google has NOT been my friend) to configure the 5gHz radio to use 300mBps? I have I can get the additional channels configured using:

speed 6.0 9.0 12.0 18.0 24.0 36.0 48.0 54.0 m0. m1. m2. m3. m4. m5. m6. m7. m8. m9. m10. m11. m12. m13. m14. m15.

CLI command but the most I get on a speed test is about 27 Mbps using an iPhone 7 plus with only 2 clients connected to the AP.

I have also followed the following Serverfault page with no luck either – YES, this is a post I posted, and at the time, it “appeared” to work, but NOT really: What is the correct way of enabling 300mbps on a cisco 3502i?

So what am I Missing?

My AP configuration with masked fields follows.

! ! Last configuration change at 17:59:43 -0700 Sun Jun 9 2019 by Cisco ! NVRAM config last updated at 17:59:47 -0700 Sun Jun 9 2019 by Cisco ! NVRAM config last updated at 17:59:47 -0700 Sun Jun 9 2019 by Cisco version 15.3 no service pad service timestamps debug datetime msec service timestamps log datetime msec service password-encryption ! hostname ap ! ! logging rate-limit console 9 enable secret XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ! no aaa new-model clock timezone -0700 -7 0 no ip source-route no ip cef ip domain name XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ! ! ! ! dot11 pause-time 100 dot11 syslog ! dot11 ssid 4ff0-58    authentication open     authentication key-management wpa version 2    guest-mode    infrastructure-ssid    wpa-psk ascii XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ! dot11 ssid 7ab0-24    authentication open     authentication key-management wpa version 2    guest-mode    infrastructure-ssid    wpa-psk ascii XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ! ! ! no ipv6 cef ! ! username Cisco password XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ! ! bridge irb ! ! ! interface Dot11Radio0  no ip address  !  encryption mode ciphers aes-ccm   !  ssid XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  !  antenna gain 0  speed  basic-11.0 6.0 9.0 12.0 18.0 24.0 36.0 48.0 54.0 m0. m1. m2. m3. m4. m5. m6. m7. m8. m9. m10. m11. m12. m13. m14. m15.  channel 2462  station-role root  no dot11 extension aironet  world-mode dot11d country-code US indoor  bridge-group 1  bridge-group 1 subscriber-loop-control  bridge-group 1 spanning-disabled  bridge-group 1 block-unknown-source  no bridge-group 1 source-learning  no bridge-group 1 unicast-flooding ! interface Dot11Radio1  no ip address  !  encryption mode ciphers aes-ccm   !  ssid XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  !  antenna gain 0  peakdetect  dfs band 3 block  speed  basic-6.0 9.0 12.0 18.0 24.0 36.0 48.0 54.0 m0. m1. m2. m3. m4. m5. m6. m7. m8. m9. m10. m11. m12. m13. m14. m15.  channel width 40-above  channel 5180  station-role root  no dot11 extension aironet  world-mode dot11d country-code US indoor  bridge-group 1  bridge-group 1 subscriber-loop-control  bridge-group 1 spanning-disabled  bridge-group 1 block-unknown-source  no bridge-group 1 source-learning  no bridge-group 1 unicast-flooding ! interface GigabitEthernet0  no ip address  duplex auto  speed auto  bridge-group 1  bridge-group 1 spanning-disabled  no bridge-group 1 source-learning ! interface BVI1  mac-address 70ca.9b98.f5bf  ip address dhcp client-id GigabitEthernet0  ipv6 address dhcp  ipv6 address autoconfig ! ip forward-protocol nd ip http server no ip http secure-server ip http help-path http://www.cisco.com/warp/public/779/smbiz/prodconfig/help/eag ! ! bridge 1 route ip ! ! ! line con 0 line vty 0 4  login local  transport input all ! sntp server 132.163.96.1 sntp broadcast client end 

How to search a YouTube channel’s videos by duration

I’m trying really hard to find a specific video on a YouTube channel that has nearly 1000 videos. The channel has a lot of short videos (<10 minutes), but the video I’m looking for was at least 20 or 30 minutes long. I’ve tried everything from a metadata grabber that crawls all the videos and compiles their metadata into an excel spreadsheet, but the data includes everything but duration. I’ve tried culling the videos based on their titles but there’s still too many to go through. I really need a way to either search or sort the channel’s videos by duration, but I’ve had no such luck.

I know YouTube lets you do a general search by either short, medium, or long duration, but I can’t find any way to do this search only for only the videos of a specific channel.

I also know I watched the video at some point in the past year and a half or so, so if there’s any way to find it in my own watch history I’d be glad to do that, too. Again, though, there’s too many videos in my history to go through them without sorting first by the specific channel and then by duration.

Any help is greatly appreciated.