ffmpeg good ogv command

Author: cirosantilli

buildroot.md

@@ -32,6 +32,18 @@ Tested on Ubuntu 16.04.
     # cat board/qemu/x86_64/readme.txt
     qemu-system-x86_64 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append root=/dev/vda -net nic,model=virtio -net user
 
+### QEMU x86 nographic
+
+https://www.hiroom2.com/2016/05/20/ubuntu-16-04-build-buildroot-and-run-qemu/
+
+`qemu -nographic -append 'console=ttyS0'`
+
+At Buildroot 7e85734709e0da78cc399c1b85655528e2d5f209 requires:
+
+    sed -i -e 's/BR2_TARGET_GENERIC_GETTY_PORT="tty1"/BR2_TARGET_GENERIC_GETTY_PORT="ttyS0"/g' .config
+
+TODO: but why does it work on: https://github.com/cirosantilli/linux-kernel-module-cheat/tree/b8f190cc24b4f7474894b68a5510a8f3d767843d even without changing it? Buildroot version difference?
+
 ## ARM
 
 Full QEMU command documented under `board/qemu/*/readme.txt`.

docker/README.md

@@ -21,33 +21,46 @@ Docker was developed by a company called dotCloud Inc, and open sourced. dotClou
 
 ## Getting started
 
-List all commands:
+Download Ubuntu image, and create a new container from it named `ub16`:
 
-    sudo docker help
+    sudo docker run --name ub16 -it ubuntu:16.04 bash
 
-Get help on one command:
+Write a file there:
 
-    sudo docker help build
+    date >f
 
-Good info on the manpages:
+Ctrl + D kills the VM, as can be seen by the empty:
 
-    man docker
-    man docker-run
+    sudo docker ps
 
-Status of the currently running VMs:
+which lists all containers. To get turn it back on:
 
-    sudo docker info
+    sudo docker start -ai ub16
+
+To detach without turning it off enter `Ctrl-P Ctrl-Q`: <https://stackoverflow.com/questions/19688314/how-do-you-attach-and-detach-from-dockers-process>
+
+To open a new shell in a running container <https://stackoverflow.com/questions/39794509/how-to-open-multiple-terminals-in-docker> run:
+
+    sudo docker exec -it bash
+
+And check that `f` is present:
+
+    cat f
+
+## Help
+
+List all commands:
 
-Run a hello world and exit:
+    sudo docker help
 
-    docker run hello-world
+Get help on one command:
 
-Run Ubuntu shell: TODO which is the default version:
+    sudo docker help build
 
-    sudo docker run -it ubuntu bash
-    sudo docker run -it ubuntu:16.04 bash
+Good info on the manpages:
 
-Ctrl + D exits shell, `sudo docker info` says it is still running, how to exit?
+    man docker
+    man docker-run
 
 ## Images
 
@@ -178,13 +191,33 @@ Same goes for a bare `CMD nginx`, since by default Nginx turns itself into a bac
 
 Share directory between guest and host:
 
-    sudo docker run -v /tmp ubuntu date > /tmp/docker
-    cat /tmp/docker
+    sudo docker run -v path/in/host:/full/path/in/guest ubuntu date > /full/path/in/guest/mydate
+    cat path/in/host/mydate
+
+It gets updated immediately.
+
+Can only take absolute paths on guest. Efficient for large files, unlike some VM schemes. The paths get created if they don't exist.
+
+Only works for new containers: <https://stackoverflow.com/questions/28302178/how-can-i-add-a-volume-to-an-existing-docker-container>
+
+### GUI apps
+
+https://stackoverflow.com/questions/16296753/can-you-run-gui-apps-in-a-docker-container
+
+    sudo docker run --net=host
+
+Then in guest:
+
+    apt-get install x11vnc xvfb
+
+Then in host:
+
+    sudo apt-get install vinagre
+    vinagre localhost:5900
 
-    date > /tmp/docker
-    sudo docker run -v /tmp ubuntu cat /tmp/docker
+## Port forwarding
 
-Can only take absolute paths. Efficient for large files, unlike some VM schemes.
+https://stackoverflow.com/questions/17770902/forward-host-port-to-docker-container
 
 ## ps
 

ffmpeg.md

@@ -199,10 +199,14 @@ Best command:
 - <http://ffmpeg.org/faq.html#How-can-I-concatenate-video-files>
 - <http://stackoverflow.com/questions/7333232/concatenate-two-mp4-files-using-ffmpeg>
 
-Best command:
+Did not upload correctly to YouTube in 2018:
 
     ffmpeg -i concat:"in1.ogv|in2.ogv" -c copy out.ogv
 
+but the other method did:
+
+    ffmpeg -i in1.ogv -i in2.ogv -filter_complex "[0:v] [0:a] [1:v] [1:a] concat=n=2:v=1:a=1 [v] [a]" -map "[v]" -map "[a]" out.ogv
+
 ## Merge audio and video
 
 <http://superuser.com/questions/277642/how-to-merge-audio-and-video-file-in-ffmpeg>

qemu.md

@@ -117,6 +117,16 @@ How to access the QEMU monitor there (Ctrl + Alt + 1/2 on GUI): <http://stackove
 
     quit
 
+## Display
+
+### vnc
+
+    ./qemu-system-x86_64 -vnd :0
+
+Then on host:
+
+    vinagre localhost:5900
+
 ## Increase screen size
 
 TODO