darktable-org / darktable-org/rawspeed

HuffmanTable* stuff needs an overhaul

Open
#148 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
C++
Stars
456
Forks
147
PR merge metrics
No merged PRs in 30d

Description

It's still too tightly coupled.
There are two things there:

  1. Generating Codes/Symbols as specified by JPEG spec
  2. Using some symbol table* to perform decoding
    It isn't necessary that said symbol table actually contains Huffman Codes as per JPEG spec,
    it only needs to satisfy the rules*
  • strict total ordering, no two codes have the same prefix

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the HuffmanTable implementations and the code paths that generate JPEG codes or symbols and perform decoding. Trace how those responsibilities are coupled, then define a separation that preserves strict ordering and the no-shared-prefix rule for both JPEG-generated tables and other valid symbol tables; done means both uses work independently.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
backend
Issue type
Refactor
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.