rule #1: thou shalt remember to use the cross-compiled GDB when debugging remote embedded targets! in other words, use “arm-none-eabi-gdb” not “gdb”
starting:
arm-none-eabi-gdb ELF-FILENAME connect to openocd: <code> target remote localhost:3333
control the processor:
monitor halt monitor reset monitor resume continue Ctrl-C
sniffing around:
info registers info locals x/32wx ADDRESS
To add a specific vid/pid combination to the ftdi_sio driver, without having to recompile it:
echo "VID PID" > /sys/bus/usb-serial/drivers/ftdi_sio/new_id
Recording screen to mp4 on ubuntu with ffmpeg/avconv
avconv -f x11grab -r 25 -s 900x900 -i :0.0+1280,100 -vcodec libx264 -pre lossless_ultrafast -threads 0 test.mp4
Extract DV from mpeg-4, to go to iMovie:
ffmpeg -y -i INPUT.m4v -map 0.0:0.0 -f dv -vcodec dvvideo -b 25000 -aspect 16:9 -r ntsc -g 240 -qmin 2 -qmax 15 -acodec pcm_s16le -ab 1411 -ar 48000 -ac 2 -map 0.1:0.1 -target ntsc-dv -ss START_TIME -t LENGTH OUTPUT.dv
Extract images from a movie (at a reduced framerate):
ffmpeg -i INPUT.avi -r 2 -f image2 %05d.png
Assemble images into a movie:
ffmpeg -i %05d.png -sameq OUTPUT.mp4
Encode movie without audio:
ffmpeg -i INPUT -an [LOTS_OF_FLAGS] OUTPUT
Take screenshots with mplayer:
mplayer -vf screenshot MOVIEFILE
MPEG4 encoding using ffmpeg:
ffmpeg -i INPUT -mbd rd -flags +4mv+aic -b BITRATE -trellis 2 -cmp 2 -subcmp 2 -g 300 -pass 1/2 -ss 0.5 OUTPUT.mp4
Windows Media encoding using ffmpeg (for powerpoint, etc.)
ffmpeg -i INPUT -b BITRATE -vcodec wmv2 -acodec wmav2 OUTPUT.wmv
Export an openshot sequence as a series of images. Actually, this doesn't seem to work, as the audio stream seems to be interpolated in the image stream. The GUI works, though.
openshot-render -i -F OUTPUT_DIRNAME -f png -o "OUTPUT_STEM_%d" INPUT.osp
Assemble sequence of images into a widescreen mp4:
ffmpeg -i INPUT_STEM_%05d.png -b BITRATE -aspect 16:9 -trellis 2 -cmp 2 -subcmp 2 -g 300 -ss 0.5 OUTPUT.mp4
Assemble sequence of images into a widescreen mp4, add a soundtrack file, and stop encoding when the video is done (since the soundtrack/music may be longer than the video):
ffmpeg -i INPUT_IMAGE_STEM_%05d.png -i AUDIO_FILE -map 0:0 -map 1:0 -b 4000000 -aspect 16:9 -trellis 2 -cmp 2 -subcmp 2 -g 300 -ss 0.5 -acodec libmp3lame -t 64 OUTPUT.mp4
View a specific revision of a file
svn cat -r REVISION filename | vim -
Add users to apache auth:
sudo htpasswd PASSWD-FILE USERNAME
roslaunch /etc/ros/robot.cturtle.launch rosrun pr2_tuckarm tuck_arms.py b roslaunch pr2_teleop teleop_joystick.launch
on laptop:
export ROS_MASTER_URI=http://stair4a:11311/ rosrun rviz rviz