Live captions and study notes for class

Real-time transcription of Chinese and English lectures, with key points analyzed as the class goes and recordings filed by course unit.

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v0.1.4 · Windows 10 / 11

Live transcription and translation

Real-time bilingual translation, with the key points of the current lesson summarized automatically.

kk
CIS 2168/Oct 26 · BST deletion
When the node has two children, we can't just remove it.
如果该节点有两个子节点，就不能直接删除。
Instead, we replace it with its inorder predecessor, the largest value in the left subtree.
而应当用它的中序前驱替换，即左子树中的最大值。
This one will be on the exam, so write out every step.
这部分考试会考，每一步都要写出来。
Key pointsQ&AFiles
Traversal questions are sure to appear
Showing intermediate steps earns partial credit.
00:05:12
On the exam
Deleting a node with two children: replace it with its inorder predecessor; write out every step on the exam
00:41:08
Which node is the predecessor?
The largest node in the left subtree: go to the left child, then keep moving right to the end.
Source: Week8_Trees.pdf, p. 14
Word-by-word transcriptionThe English original appears as it is spoken; words still being recognized are shown in a lighter tone.
Bilingual displayThe Chinese translation appears once each sentence is finished, with specialized terms translated consistently according to the course glossary.
Key points and Q&AExam-related content is flagged as a key point automatically. Ask a question at any time; the answer cites its source.

Covering the whole semester

From importing the syllabus at the start of term to reviewing for the final exam.

Before class

One-step Canvas import

Import your course content from Canvas in one step, then create units and a course glossary from the syllabus.

kk
Library/CIS 2168/Syllabus
6 units and 2 exams detected from the syllabus
CIS2168_Syllabus_Fall.pdf · Units are created automatically once confirmed
01Recursion9/02–9/11
02Binary Trees / BST10/23–10/30
03Heaps & Priority Queues11/04–11/13
Test 4 · Trees, Heaps, Hashing12/08
04Hash Tables11/18–11/25
Drop slides here, or click to choose
Added to the glossary for more accurate recognition in class
inorder predecessorAVL rotationmin-heapload factorKoffmanamortized
In class

Instant answers to the instructor’s questions

When the instructor asks a question in class, a suggested answer appears within seconds with its source. You can also ask follow-up questions, answered from this lecture’s slides and what has been covered so far.

kk
CIS 2168/Oct 26 · BST deletion
Here that's forty, so forty moves up to the root.
这里就是 40，所以 40 上移到根节点的位置。
Then we delete the original forty, which is now a leaf.
然后删除原来的 40，它现在是叶节点。
Instructor’s question
So what happens if we delete the root itself?
那如果删除的是根节点本身呢？
Key pointsQ&AFiles
Suggested answer00:42:30
Same as any node with two children: copy the predecessor, 40, into the root, then delete the original 40.
Source: Week8_Trees.pdf, p. 15
Why not use the inorder successor?
Both work. This course uses the inorder predecessor, so follow that on the exam.
Source: Oct 26 recording, 00:41:08
Ask about this lecture…
After class

Unit notes

Multiple lectures and slides from the same unit are merged into one note with exam hints, question types, a glossary and practice problems. Every item can be traced to the time in the recording.

kk
Library/CIS 2168/02 Binary Trees / BST

02Binary Trees / BST

3 recordings · 1 slide deck · updated 11/6
Question types on the exam: terms and properties → four traversals → rebuilding a tree from traversals → BST insertion → BST deletion
Instructor’s exam hints
  • Traversal questions will appear; showing intermediate steps earns partial credit (10-26, about 5 min)
  • BST deletion is tested only with the “replace with inorder predecessor” method (10-26, about 41 min)
The idea in one sentence
A binary search tree additionally requires that everything on the left is smaller and everything on the right is larger.
TermMeaningExample
rootThe topmost node50
leafA node with no children20, 35
ContentsFilesTerms
Instructor’s exam hintsType A: terms and propertiesType B: four traversalsType E: BST deletionPractice problem 210-minute pre-exam recap
Sources for this note
10/23 Binary tree traversals74 min
10/26 BST deletion74 min
Week8_Trees.pdf32 pages
Exam prep

Exam review

Related units are gathered by exam scope, with review points and a suggested time for each.

kk
Library/CIS 2168/Exam review
Days left
12
Test 4 · Dec 8
Covers units 02, 03, 04 · 5 recordings
Four traversals: write out inorder / postorder by hand10 min
BST deletion, three cases: one problem each15 min
Bottom-up heapify: how to compute array indices15 min
What happens when the load factor exceeds 0.755 min
Presentation

Presentation prompts and Q&A

During a presentation, kk follows where you are speaking and shows the matching script, detects audience questions in real time, and suggests answer points.

kk
Presentation earpiece/Cache design talk
We chose a write-back policy because it reduces disk traffic during bursts.
Dirty blocks are flushed to disk every five seconds, and we keep a small journal.
Why write-back instead of write-through?
为什么选回写而不是直写？
We chose write-back because our workload is bursty, and it cuts disk traffic during those bursts.
我们选回写，是因为负载有突发性。
Source: script, paragraph 2

Floating window and caption bar

Does not obscure your slides, and also works for online courses and foreign-language videos.

HighlightInorder predecessor: the largest node in the left subtree
Floating windowShows the latest captions and the newest highlight. Stays on top and can be moved and resized.
Caption barLarge captions along the bottom of the screen on a translucent background. Can be set to click-through so the slides and video underneath stay usable.

More features

Except for cloud sync, these features are available with both kk Pass and a custom API.

Use your notes in Obsidian

Choose an Obsidian vault as your save location. Notes use Obsidian properties and callouts, and kk never overwrites changes you make in Obsidian.

Cloud sync Coming soon

When a class ends, its captions, Q&A and notes are uploaded so you can view them in the web app. Audio is never uploaded. Off by default; included with kk Pass.

Script following

During a presentation, your script scrolls to where you are speaking, words light up as you read them, and a page-turn cue appears at the end of each page.

Video and audio to subtitles

Import a lecture recording to get time-stamped bilingual subtitles, exportable as SRT, VTT or ASS.

Two ways to use kk

The features are identical; the only difference is who provides the recognition and AI services.

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Custom API

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Enter keys you obtained from speech recognition and LLM providers and every feature is free to use. The providers charge their own prices directly; kk adds no markup.

SpeechDeepgramConnected
LLMDeepSeekConnected
Keysk-••••••••3f2aStored on this PC only

Your data stays on your computer

  • Captions, Q&A and notes are saved as Markdown files in a folder you choose, and open in any editor.
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  • Our servers do not store classroom audio.

Pricing

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$0
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16hours
$5.99 / 30 days
≈ ¥43
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FAQ

Which systems are supported?

Windows 10 and Windows 11 are supported. A web version is in development.

Where are captions and notes saved?

By default, in a folder you choose on your computer, in Markdown format. kk’s servers do not store audio.

How is the custom API charged?

kk charges nothing. You pay your chosen providers directly for recognition and LLM usage.

How can I improve recognition of specialized terms?

Import your syllabus and slides before class; kk adds the terms they contain to the recognition vocabulary.

Are refunds available?

You can request a refund within 14 days of purchase. The refund is the amount paid minus the cost of the hours used and the payment processing fee. See the Refund Policy.

Which recognition and translation services are supported?
  • Speech recognition providers for the custom API: Deepgram, AssemblyAI, ElevenLabs, Gladia, Groq, OpenAI, Speechmatics, Alibaba Cloud Bailian, Volcengine, Tencent Cloud, iFLYTEK
  • LLM providers: DeepSeek, Claude, Google Gemini, OpenAI, OpenRouter, SiliconFlow, Volcano Ark, Kimi, Qwen, Zhipu, and local models through Ollama

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