RDF language Updated 2025-07-16
Secure Shell Updated 2025-07-16
FFmpeg filter graph Updated 2025-07-16
Filter graphs are a thing of great beauty. What an amazingly obscure domain-specific language, but which can produce striking results with very little!!!
A quick example from stackoverflow.com/questions/59551013/how-to-generate-stereo-sine-wave-using-ffmpeg-with-different-frequencies-for-eac/77730492#77730492 illustrates some of the fundamentals:
ffplay -autoexit -nodisp -f lavfi -i '
sine=frequency=500[a];
sine=frequency=1000[b];
[a][b]amerge, atrim=end=2
' +--------+
[sine=frequency=500]--->[a]-->| |
| amerge |-->[atrim]-->[output]
[sine=frequency=1000]-->[b]-->| |
+--------+So we see the following syntax patterns:
sine,amergeandatrimare filterssine=frequency=500: the first=says "araguments follow";: separates statements[a],[b]: sets the name of an edge,: creates unnamed edge between filters that have one input and one output
A list of all filters can be obtained ith:and parameters for a single filter can be obtained with:Related question: stackoverflow.com/questions/69251087/in-ffmpeg-command-line-how-to-show-all-filter-settings-and-their-parameters-bef
ffmpeg -filtersffmpeg --help filter=sineTODO dump graph to ASCII art? trac.ffmpeg.org/wiki/FilteringGuide#Visualizingfilters mentions a
-dumpgraph option, but haven't managed to use it yet.Bibliography:
- ffmpeg.org/ffmpeg-filters.html official documentation
- trac.ffmpeg.org/wiki/FilteringGuide some handy tips from the FFMpeg Wiki
ffplay Updated 2025-07-16
AWS Deep Learning Base GPU AMI (Ubuntu 20.04) Updated 2025-07-16
These come with pre-installed drivers, so e.g. nvidia-smi just works on them out of the box, tested on g5.xlarge which has an Nvidia A10G GPU. Good choice as a starting point for deep learning experiments.
Bitcoin developer Updated 2025-07-16
Craig Steven Wright meme Updated 2025-07-16
TODO find the Shroud of Turin one.
- twitter.com/digitalnaut/status/1757464079076098212 vampire killed by cross of cryptographic evidence
Brazilian cuisine Updated 2025-07-16
DeepFloyd IF Updated 2025-07-16
HTTP Updated 2025-07-16
Bitcoin inscription method Updated 2025-07-16
Bibliography:
- www.reddit.com/r/BitcoinBeginners/comments/9dlo3w/how_to_write_arbitrary_data_on_the_bitcoin/
- bitcoin.stackexchange.com/questions/73165/how-to-store-arbitrary-data-in-the-bitcoin-blockchain-and-how-can-i-differentiat
- bitcoin.stackexchange.com/questions/32575/what-methods-are-currently-used-to-embed-additional-data-into-the-bitcoin-blockc
Ciro Santilli's hardware Lenovo ThinkPad P14s gen4 amd Updated 2025-07-16
Bought: November 2023 during Black Friday sale for £1,323.00 to be Ciro Santilli's main personal laptop.
Six years after, and we are 2x on every key spec (except processor Hz ;-) at about 1/2 the price and 1/2 the weight (though smaller 14" screen for greater portability), so not bad! Customized to max out each hardware spec:
Specs:
- Processor: AMD Ryzen 7 PRO 7840U Processor (3.30 GHz up to 5.10 GHz)
- Graphic Card: Integrated GraphicsThe Ubuntu 23.10 "About system GUI describes its graphics as: Radeon 780M Graphics × 16, which e.g. www.techpowerup.com/gpu-specs/radeon-780m.c4020 documents as running the RDNA 3 microarchitecture.
- Operating System: No Operating System selected upgrade
- Operating System Language: No Operating System Languag eselected upgrade
- Microsoft Productivity Software: None
- Memory: 64 GB LPDDR5X-6400MHz (Soldered)selected upgrade. Specs at: www.lenovo.com/gb/en/p/accessories-and-software/memory-and-storage/memory-and-storage-hard-drives/4xb1d04758 quotes "64 Gbps", i.e. 8 GB/s.
dd count=1M if=/dev/zero of=tmpgives only 255 MB/s however. - Solid State Drive: 2 TB SSD M.2 2280 PCIe Gen4 Performance TLC Opalselected upgrade
- Display: 14" WUXGA (1920 x 1200), IPS, Anti-Glare, Touch, 45%NTSC, 300 nits, 60Hz
- Camera: 1080P FHD RGB/IR Hybrid with Microphone
- Color: Thunder Black
- Factory Color Calibration: No Factory Color Calibration
- Wireless: Qualcomm Wi-Fi 6E NFA725A 2x2 AX & Bluetooth® 5.1 or above
- Integrated Mobile Broadband: No Wireless WAN
- Ethernet: Wired Ethernet
- Near Field Communication: No NFC
- Fingerprint Reader: Fingerprint Reader
- Keyboard: Black - English (EU)selected upgrade
- Battery: 4 Cell Li-Polymer 52.5Whselected upgrade
- Power Cord: 65W USB-C Slim 90% PCC 3pin AC Adapter - UKselected upgrade
- Electronic Privacy Filter: No ePrivacy Filter
- Adobe Elements: None
- Adobe Acrobat: None
- Adobe Creative Cloud: None
- Security Software: None
- Cloud Security Software: No Cloud Security Software
- Warranty: 3 Year Courier or Carry-in
Identifiers:
- Ethernet MAC address: fc:5c:ee:24:fb:b4
- Wi-Fi MAC address: 04:7b:cb:cc:1b:10
Upon arrival:
Buy research:
- www.phoronix.com/review/thinkpad-p14s-gen4 says Ubuntu running fine
- Intel vs amd: the Intel ones could come with a discrete rtx A500 GPU. GPU likely makes laptop heavier and less power efficient. And both have basically the same benchmark which is crazy:So the only downside is not being able to run CUDA.
- thought about Yoga or other Ultrabook options, but 2x price at same specs, so nah...
Log:
2024-01-17: firmware update:Actually fixed performance mode: askubuntu.com/questions/604720/setting-to-high-performance/1343879#1343879
Vendor: LENOVO
Version: R2FET36W (1.16 )
Release Date: 10/24/2023useEffect Updated 2025-07-16 Ganesh Sittampalam Updated 2025-07-16
Bitcoin implementation Updated 2025-07-16
Cool data embedded in the Bitcoin blockchain ASCII art TODO Updated 2025-07-16
Computer mouse Updated 2025-07-16
Cool data embedded in the Bitcoin blockchain Nelson-Mandela.jpg analysis Updated 2025-07-16
The toplevel transaction is 78f0e6de0ce007f4dd4a09085e649d7e354f70bc7da06d697b167f353f115b8e
The full concatenated payload contains the following ASCII characters:
8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba|396*8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba
575061146335bd57f2dc132112152d0eeea44cf187ea6a52ac02435a7e5bea44
674c7cc34ea44bb276c6caf76f2b28fa1597380ab6e6a6906076d8f7229ca5b3
8e2642416ad20924b43f51a633fa1c0a5ba8e4a7b631877db1c64540a42081c9
a3084018096b92af04df57b6116e01ff4b7c7e8bd228235ed49e23f4a2817029
39348722b841afa0c5b67e5af10839afe965ed1b24874e89336bea9fa4ef3091
tomSea & EMBIIOutput 2 is a change, so it contains no data and has been excluded. Change appear to be randomly placed in the list of output of the uploads, but they can be easily removed because they are the only output with a different value.
The newlines shown above are explicitly encoded as CR LF newlines with characters 0d 0a.
396 is the number of payload bytes between 396*8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba and the last txid 39348722b841afa0c5b67e5af10839afe965ed1b24874e89336bea9fa4ef3091, including newlines but exclusding the last line.Now let's inspect the transactions linked to from toplevel.
tx 8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba contains only payloads without any change. It starts with the following UTF-8 string with CR LF spaces;
"396\“There is nothing like returning to a place
that remains unchanged to find the ways in
which you yourself have altered.”
-Nelson Mandela
Nelson Rolihlahla Mandela was a South African anti-apartheid revolutionary, politician and philanthropist who served as President of South Afrd۽^2c'︨`ica from 1994 to 1999. -Wikipedia
Born: July 18, 1918, Mvezo, South Africa
Died: December 5, 2013This is immediately followed without any separator by a filename, and another size marker:then followed by all the
Nelson-Mandela.jpg?14400/14400 - len(Nelson-Mandela.jpg?) + len(/) JPEG bytes bytes, starting with the two JPEG file signature byte "FF D8".Further toplevel transaction payloads are then simply concatenated with the previous ones, until the last bytes of the image "FF D9" appears at the end of the payload.padded once again by an
00000430 d2 81 de 80 0c 52 f1 40 ea 29 68 03 ff d9 6f 6d |.....R.@.)h...om|
00000440 53 65 61 20 26 20 45 4d 42 49 49 00 |Sea & EMBII.|AtomSea & EMBII string fragment terminated by a NUL character. 3D rigid body dynamics benchmark Updated 2025-07-16
Web portal Updated 2025-07-16
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