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DSV

DSV or DSV1 (Digital Subband Video 1) is a compact, software-only video codec focusing on simplicity and wavelet-based compression, with features rivaling early MPEG standards. The reference implementation of the codec is designed for flexibility and ease of use in C environments. As of October 2024, DSV1 has been superseded by DSV2.

Features​

  • Wavelet-based compression: Uses multiresolution subband analysis (wavelet transform) instead of DCT. More information on wavelet transforms is available on the DSV2 page.
  • Motion Compensation: Supports half-pixel motion compensation.
  • Chroma Subsampling: 4:1:1, 4:2:0, 4:2:2, and 4:4:4 formats.
  • Adaptive Quantization: Dynamically adjusts quantization for better quality.
  • Frame Types: Supports intra and inter frames with variable-length closed GOPs (no bidirectional/B-frames, only forward prediction).
  • Entropy Coding: Uses interleaved exponential-Golomb coding for simplicity.
  • Compression Range: Supports a wider range of compression and lower bitrates than MPEG-1/2.

The reference DSV encoder features:

  • Rate Control: Single-pass average bitrate (ABR) or constant rate factor (CRF).
  • Human Visual System (HVS) Optimization: Simple intra block mode determination.
  • Scene Change Detection: Based on average luma changes.
  • Hierarchical Motion Estimation: For improved efficiency.
  • Adaptive Quantization Stability Tracking: Improves quality.
  • C89 Compatibility: Written for standard C89, no external libraries, integer-only arithmetic, single-threaded, and portable.

Limitations​

  • No built-in interlacing support.
  • Only 8 bits per component supported.
  • Frame dimensions must be divisible by 2.

Example Usage​

The only DSV encoder available is the reference encoder.

  • Encoding: 
    ./dsv1 e -y -v -inp_bus_cif.yuv -out_saved.dsv -gop12 -w352 -h288 -fps_num30 -qp85 -kbps1100
  • Decoding: 
    ./dsv1 d -inp_video.dsv -out_decompressed.yuv -out420p

Documentation & More​

Detailed information is available in the repository’s PDF documents (DSV1_spec.pdf, DSV1_encoder.pdf). More example videos and usage instructions are provided in the README and linked resources in the repo.