Downmux to 2-channel AAC without recoding video stream

Get Win64 build of ffmpeg here.

ffmpeg.exe -i input.mp4 -c:v copy -ac 2 -c:a aac -vbr 3 output.mp4

ESPCLOCK3 - The Final Version

Overview This is the latest, and probably final iteration of my ESPCLOCK project. You can find ESPCLOCK1 here, and ESPCLOCK2 here.

The main differences between ESPCLOCK3 and ESPCLOCK2 are:
Use barebones ESP-07 instead of WeMOS D1 Mini to reduce deep sleep power draw.Use PCF8563 RTC to clock the ATtiny85. PCF8563 is chosen over the more popular DS3231 RTC due its vastly lower power consumption. Using a RTC to clock the ATtiny85 allow us to use the POWER_DOWN instead of IDLE sleep mode, which minimizes power draw. As a result, the ATtiny85 code is also vastly simplified because we don't have to play with Timer1 to get an accurate 1Hz signal.Use diode clamp to limit the voltage pulsing the analog clock. Connecting to the analog clock directly using the ATtiny85 pins running at ~3V requires the clock pulse to be longer (~200ms) and increases power draw (due to reduced MCU sleep time). In addition, the higher voltage causes ticks to miss occasionally. The diode clamp limits the pulses …

Newly formatted SD card not working in Ender 3

I quick-formatted an old 2GB SD card using Windows and popped it into the Ender 3, but it was not recognized.

I also tried a full format based on what others have mentioned on Reddit, but that didn't work as well.

Finally, what worked was quick-formatting the SD card using the SD Memory Card Formatter by the SD Association.

Free method to migrate HDD to a smaller SSD

I have run into this enough times, I thought I should make a mental note for myself.

Make sure the actual content on the HDD is able to fit onto the smaller SSD. If the HDD contains 900GB worth of data, it is not going to fit onto a 512GB SSD.

Check to see if the SSD manufacturer have some free software that can be downloaded for the task. Frequently they might have a restricted version of some commercial software that will only work with their SSD. That should be the easiest way forward.

If this option is not available, most supposed free version of disk imaging or cloning software will have a few restrictions in place so that you will upgraded to their paid software. For example, they might only clone to a drive of the same capacity.

Here is one way of migrating the HDD to a smaller SSD for free.

1. Use MiniTool Partition Wizard to resize your HDD to a size that is smaller than your SSD. The partition move/resize functions of this software is free, but the cloning function is only a…

Mass removal of NTFS ADS

How to mass remove all NTFS ADS (Alternate Data Stream) from files in a folder and all its subfolders:

stream -d -s *.*

Filament Joiner Part 2 (With Display and Knob)

Thanks to the current corona-virus crisis, the parts I ordered for the filament joiner project were taking forever to arrive. But now that they have finally arrived, I can put them to good use.

These were the parts ordered:
0.96" OLED display SSD1306Rotary switch encoder KY-040 Here is the final circuit diagram:
The OLED display is connected to the SCK and SDA pins of the Nano (A2 and A3 respectively), and powered by 5V and GND.

The rotary switch encoder is connected as follows:
VCC => 5VGND = > GNDCLK => D9DT => D8SW => D2 My prototype board now looks like this:

The updated code for driving the knob and display is available in heater-with-display.ino in the Github repository.

We now have a fairly compact (about 7cm x 5cm) and independent filament joiner (no need to connect to PC) that is driven solely by a 12V power supply.

Here's how to use it to join printer filaments.

More usage details in my previous post.

3D Printer Filament Joiner

I have been looking at various ways of joining 3D printing filaments.

One method involves running one end of a filament through a short PTFE tubing, melting it with a lighter or candle, retracting it back into the tubing and immediately plunging the filament to be fused into the tubing:

One problem with this method is that you can't really control the temperature at which you melt the filament, so you frequently end up with a brittle joint that breaks upon the slightest bend.

Aliexpress even sells a contraption that works along the same line. As it uses a lighter or candle as well, it suffers from the same weakness. I am not even sure why you need a special contraption when a short PTFE tubing will work just as well.

Another method involves using shrink tubing/aluminium foil, and a heat gun:

But a heat gun is rather expensive, so I wanted to explore other alternatives.

The candle + PTFE tubing method actually works quite well when you happen to melt it at the right temperature. It…