Ondřej Hošek RavuAlHemio

JPEG marker types

Taken from ISO/IEC 10918-1:1994.

Most hexadecimal digits are written in uppercase; b is written in lowercase to reduce confusion of B with 8.

sequence	length	abbr	description	reference to standard
FF00	0		not a marker; actual 0xFF value in entropy-coded data segment	§§ D.1.6, F.1.2.3
FF01	0	TEM	temporary value used during arithmetic coding	§ D.1.6

Splitting and Reassembling HLS/DASH Audio and Video

You might have experienced the following: you are watching a video in your browser and audio and video both work fine, but when you pass the .m3u8 URL that you found in the page's source to a download tool, the download tool makes a veritable pig's breakfast out of it -- perhaps the video works but the audio doesn't, perhaps the audio is completely desynchronized from the video, perhaps the audio appears to interrupt the video.

The likely culprit is the encoding of each video fragment. .m3u8 is actually a playlist -- a list of individual files named fragments that should be played in sequence as if they were one big video. Normally, a fragment would start with some metadata (M) and then carry video (V) and audio (A) intermingled:

MMVVVAAVVVAAVVVAA...

board	product ID	chip	usable as controller?
BLE 2 Click	MIKROE-1715	RN4020	no
BLE 3 Click	MIKROE-2471	NINA-B1	yes?
BLE 4 Click	MIKROE-3773	NINA-B312	yes?
BLE 5 Click	MIKROE-4120	PAN1760A	NRND?
BLE 6 Click	MIKROE-4170	BlueNRG-M2	yes
BLE 7 Click	MIKROE-3872	BGX13S22GA-V31	yes?
BLE 8 Click	MIKROE-3674	ANNA-B112	yes?
BLE 9 Click	MIKROE-4487	BGM220P	yes?

	(kicad_sch
	(version 20250114)
	(generator "eeschema")
	(generator_version "9.0")
	(uuid "18d66037-9dd9-450e-b3ca-189463bf472c")
	(paper "A4")
	(lib_symbols
	(symbol "Connector:DE15_Socket_HighDensity_MountingHoles"
	(pin_names
	(offset 1.016)

	<!DOCTYPE html>
	<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
	<head>

	<meta charset="utf-8" />
	<title>Alphabet Converter</title>
	<meta name="viewport" content="width=device-width, initial-scale=1" />

	<script type="text/javascript">
	// <![CDATA[

	#!/usr/bin/env python3
	import binascii
	import io
	import struct
	import sys
	from typing import NamedTuple


	class MidiEvent(NamedTuple):
	time: int

	#!/usr/bin/env python3
	#
	# Provides an HTTP server for nginx's http_auth_request_module that performs basic authentication
	# and sets a cookie that offers longer-lived sessions than regular basic authentication.
	#
	# Requires argon2-cffi and werkzeug.
	#
	# Example of configuration (default filename: "http_basic_cookie_auth.json"):
	#
	# {

	& "C:\Program Files\qemu\qemu-system-i386.exe" `
	-cpu pentium3 `
	-m 1024 `
	-vga cirrus `
	-drive "if=ide,bus=0,unit=0,media=disk,file=w2k_de.qcow2" `
	-drive "if=ide,bus=1,unit=0,media=cdrom" `
	-device sb16 `
	-device "usb-ehci" `
	-device "usb-tablet" `
	-qmp "tcp:127.0.0.1:6969,server,wait=off" `