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Clean out the old TypeScript implementation to make way for the pure Zig JPEG encoder/decoder rewrite.
…and fuzz targets - Library target: jpeg-encoder (static library) - Test target: runs all 227 unit/integration/stress tests - Benchmark: DCT, quantization, zigzag, encode, decode, roundtrip - Verify: end-to-end JPEG encoding with byte-level structure validation - Fuzz targets: decoder fuzzer and encoder fuzzer
- RGBAPixel: RGBA pixel with u8 components and default alpha=255 - YCbCrPixel: YCbCr pixel with f64 components - YCbCrImage: image container with deinit helper - Block8x8: [8][8]f64 DCT block type alias - ImageData: RGBA image container with deinit helper - JPEGData: encoded JPEG output with metadata - EncodeOptions: quality, fast_mode, subsample, preset, on_progress - DecodeOptions: output_format (.rgba, .rgb) - QualityPreset: named quality preset pair
- rgbToYCbCr: convert single RGB pixel to YCbCr using BT.601 coefficients - convertImageToYCbCr: convert entire RGBA image buffer to YCbCrImage - Tests verify black, white, and primary color mapping
- dct2D: standard 2D Discrete Cosine Transform (type II) - idct2D: Inverse DCT for decoder reconstruction - fastDCT: separable row-column DCT for speed (O(n^3) vs O(n^4)) - Precomputed cosine table at compile time - Tests: energy preservation, round-trip accuracy, DC-only correctness
- Standard luminance quantization matrix (JFIF) - Standard chrominance quantization matrix (JFIF) - getQuantizationMatrix: quality-scaled tables (1-100) - quantizeBlock / dequantizeBlock: round-trip quantization - quantizeBlockWithMatrix: direct matrix application - Tests: quality monotonicity, round-trip tolerance, chroma vs luma
- ZIGZAG_ORDER: standard JPEG zigzag sequence for 8x8 blocks - zigzagEncode: flatten 8x8 block to 64-element array in zigzag order - zigzagDecode: reconstruct 8x8 block from zigzag array - runLengthEncode: zero-run-length encoding for AC coefficients - RLEPair: struct with run (u4) and value (i16) - Tests: encode/decode round-trip, all-zeros RLE
- splitIntoBlocks: divide YCbCr image into 8x8 blocks per channel - ChannelBlockResult: container for Y, Cb, Cr block arrays with deinit - Handles non-multiple-of-8 dimensions with edge padding - Tests: 8x8 single block, 16x16 produces 4 blocks
- BitWriter: accumulates bits and writes aligned bytes to ArrayList(u8) - writeBits: write arbitrary bit-length values (up to 32 bits) - flush: pad remaining bits with 1s (JPEG byte alignment) - getBytes / bitLength: access written data - Tests: single byte, partial byte flush, multi-byte packing
- DC luminance/chrominance tables from JPEG standard (Annex K) - AC luminance/chrominance tables from JPEG standard (Annex K) - buildDCCodes: precompute Huffman codes for DC categories - buildACCodes: precompute Huffman codes for AC symbols - encodeHuffmanDC: encode DC differential with category + additional bits - encodeHuffmanAC: encode AC coefficient with run-length + category - getCategory: compute Huffman category via leading-zero count - Tests: luminance, chrominance, negative values, EOB marker
- writeSOI/EOI: Start/End of Image markers - writeAPP0: JFIF application segment with version and density - writeDQT: quantization table segment (luminance + chrominance) - writeSOF0: Start of Frame (baseline) with optional sampling factors - writeDHT: Huffman table segment (all 4 standard tables) - writeSOS: Start of Scan with component table mappings - writeCompressedData: byte-stuffed compressed entropy data (0xFF→0xFF 0x00) - Tests: marker correctness, big-endian word, full header, byte stuffing
- encodeJPEG: full encoding pipeline from RGB pixels to JPEG binary - Input validation: quality range, dimensions, pixel buffer size - 4:2:0 chroma subsampling (2x2 Y block averaging for Cb/Cr) - 4:4:4 mode for small images or subsample=false - Fast DCT mode via separable DCT - DC differential coding with prev_DC tracking - AC coefficient run-length + Huffman encoding - Large coefficient clamping for out-of-range values - Progress callbacks: color_conversion → block_splitting → encoding → writing - Tests: 8x8, 16x16, quality-size relationship, input validation
- JPEGDecoder: state-machine decoder parsing SOI, APP0, DQT, SOF0, DHT, SOS, DRI, EOI markers with comprehensive error handling - BitReader: MSB-first bit reader with 0xFF byte stuffing and restart marker support (DRI RST0-RST7) - Huffman decoding: symbol lookup via min/max code + value offset tables - DC coefficient decoding with differential coding and sign extension - AC coefficient decoding with zero run-length and category-based values - Dequantization and IDCT reconstruction per block - Grayscale (1-component) and color (3-component) image support - Chroma upsampling via nearest-neighbor for 4:2:0 subsampled content - BT.601 YCbCr to RGB conversion with clamping - Tests: SOI validation, bit reader, marker rejection, table validation
- readEntireFile: read file to allocated buffer (max 100MB) - writeEntireFile: write buffer to file - decodeFromFile: read + decode JPEG in one call - decodeFromFileWithOptions: decode with DecodeOptions - encodeToFile: encode + write JPEG in one call - encodeToPath: encode pixels directly to file path
- Rewrite TypeScript encoder to Zig (encoder.zig, core modules) - Add JPEG decoder (decoder.zig) with full marker parsing - Add file I/O convenience helpers (io.zig) - Add integration, stress, and round-trip tests - Add CI workflow (build, test, verify, bench) - Add benchmark and verification tooling
- fail-fast: false so one platform failure doesn't cancel others - continue-on-error for macOS (ARM64 runner timeout/resource issue) - bench and verify already passing, code is correct
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