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Digital-Subband-Video-2

DSV2 is a lossy video codec using wavelets and block-based motion compensation. It is designed for medium-low to medium-high bitrates. Comparable to MPEG-4 Part 2 and Part 10 (H.264) (P frames only) in terms of efficiency and quality.

Example comparison (More can be found at the bottom of the README):

minih264:

minih264_tt.mp4

DSV2:

dsv2_212315.mp4

Note PDFs are likely to be out of date. They reflect the codec as it was when it was first uploaded here.

DSV2 Features (refer to PDF in repo for more detail)

  • compression using multiresolution subband analysis instead of DCT
    • also known as a wavelet transform
  • up to quarter-pixel motion compensation
  • 4:1:1, 4:2:0, 4:2:2 (+ UYVY) and 4:4:4 chroma subsampling formats
  • adaptive quantization
  • in-loop filtering
  • intra and inter frames with variable length closed GOP
    • no bidirectional prediction (also known as B-frames). Only forward prediction with previous picture as reference
  • only form of entropy coding is interleaved exponential-golomb coding for simplicity

Improvements and New Features since DSV1

  • in-loop filtering after motion compensation
  • more adaptive quantization potential
  • skip blocks for temporal stability
  • new subband filters + support for adaptive subband filtering
  • better motion compensation through Expanded Prediction Range Mode (EPRM)
  • quarter pixel compensation
  • psychovisual optimizations in the codec and encoder design

--- for more detailed information please refer to the informal specification document (DSV2_spec.pdf) in the repository.

Encoder Features (specific to this implementation of the DSV2 spec)

  • single pass average bitrate (ABR) or constant rate factor (CRF) rate control
  • more advanced Human Visual System (HVS) based intra block mode determination
  • new Human Visual System (HVS) based intra frame adaptive quantization
  • more complex scene change detection
  • hierarchical motion estimation
  • better temporal adaptive quantization
  • written to be compatible with C89

--- for more detailed information please refer to the encoder information document (DSV2_encoder.pdf) in the repository.

Limitations

  • no built-in interlacing support
  • only 8 bits of depth per component supported
  • frame sizes must be divisible by two

This code follows my self-imposed restrictions:

  1. Everything must be done in software, no explicit usage of hardware acceleration.
  2. No floating point types or literals, everything must be integer only.
  3. No 3rd party libraries, only C standard library and OS libraries for window, input, etc.
  4. No languages used besides C.
  5. No compiler specific features and no SIMD.
  6. Single threaded.

Compiling

C Compiler

All you need is a C compiler.

In the root directory of the project (with all the .h and .c files):

cc -O3 -o dsv2 *.c

Zig build system

If you have Zig installed, you can use the build.zig file to compile the project. Building requires Zig version ≥0.13.0.

  1. Ensure you have Zig & git installed

  2. Clone this repo & enter the cloned directory:

git clone https://github.com/LMP88959/Digital-Subband-Video-2
cd Digital-Subband-Video-2
  1. Build the binary with Zig:
zig build

Note: If you'd like to specify a different build target from your host OS/architecture, simply supply the target flag. Example: zig build -Dtarget=x86_64-linux-gnu

  1. Find the build binary in zig-out/bin. You can install it like so:
sudo cp zig-out/bin/dsv2 /usr/local/bin

Now, you should be all set to use the compiled dsv2 binary.

Running Encoder

Sample output:

Envel Graphics DSV v2.0 compliant codec by EMMIR 2024
usage: ./dsv2 e [options]
sample usage: ./dsv2 e -inp=video.yuv -out=compressed.dsv -w=352 -h=288 -fps_num=24 -fps_den=1 -qp=85 -gop=15
------------------------------------------------------------
	-qp : quality percent. If -1 and ABR mode, estimate good qp for desired bitrate. If -1 and CRF mode, default to 85. -1 = default
	      [min = -1, max = 100]
	-effort : encoder effort. 0 = least effort, 10 = most effort. higher value -> better video, slower encoding. default = 10
	      [min = 0, max = 10]
	-w : width of input video. 352 = default
	      [min = 16, max = 16777216]
	-h : height of input video. 288 = default
	      [min = 16, max = 16777216]
	-gop : Group Of Pictures length. 0 = intra frames only, 12 = default
	      [min = 0, max = 2147483647]
	-fmt : chroma subsampling format of input video. 0 = 4:4:4, 1 = 4:2:2, 2 = 4:2:0, 3 = 4:1:1, 4 = 4:2:2 UYVY, 2 = default
	      [min = 0, max = 4]
	-nfr : number of frames to compress. -1 means as many as possible. -1 = default
	      [min = -1, max = 2147483647]
	-sfr : frame number to start compressing at. 0 = default
	      [min = 0, max = 2147483647]
	-fps_num : fps numerator of input video. 30 = default
	      [min = 1, max = 16777216]
	-fps_den : fps denominator of input video. 1 = default
	      [min = 1, max = 16777216]
	-aspect_num : aspect ratio numerator of input video. 1 = default
	      [min = 1, max = 16777216]
	-aspect_den : aspect ratio denominator of input video. 1 = default
	      [min = 1, max = 16777216]
	-ipct : percentage threshold of intra blocks in an inter frame after which it is simply made into an intra frame. 50 = default
	      [min = 0, max = 100]
	-pyrlevels : number of pyramid levels to use in hierarchical motion estimation. 0 means auto-determine. 0 = default
	      [min = 0, max = 5]
	-rc_mode : rate control mode. 0 = single pass average bitrate (ABR), 1 = constant rate factor (CRF). 0 = default
	      [min = 1, max = 0]
	-kbps : ONLY FOR ABR RATE CONTROL: bitrate in kilobits per second. 0 = auto-estimate needed bitrate for desired qp. 0 = default
	      [min = 0, max = 2147483647]
	-maxqstep : max quality step for ABR, absolute quant amount in range [1, 400]. 1 = default (0.25%)
	      [min = 1, max = 400]
	-minqp : minimum quality. 0 = default
	      [min = 0, max = 100]
	-maxqp : maximum quality. 100 = default
	      [min = 0, max = 100]
	-iminqp : minimum quality for intra frames. 20 = default
	      [min = 0, max = 100]
	-stabref : period (in # of frames) to refresh the stability block tracking. 0 = auto-determine. 0 = default
	      [min = 0, max = 2147483647]
	-scd : do scene change detection. 1 = default
	      [min = 0, max = 1]
	-tempaq : do temporal adaptive quantization. If disabled, spatial methods will be used instead. 1 = default
	      [min = 0, max = 1]
	-bszx : override block sizes in the x (horizontal) direction. -1 = auto-determine. -1 = default. 0 = 16, 1 = 32
	      [min = -1, max = 1]
	-bszy : override block sizes in the y (vertical) direction. -1 = auto-determine. -1 = default. 0 = 16, 1 = 32
	      [min = -1, max = 1]
	-scpct : scene change percentage. 55 = default
	      [min = 0, max = 100]
	-skipthresh : skip block threshold. -1 = disable. 0 = default, larger value means more likely to mark a block as skipped.
	      [min = -1, max = 2147483647]
	-varint : intra frames that are created outside of the normal GOP cycle reset the GOP cycle if 1. 1 = default
	      [min = 0, max = 1]
	-psy : enable/disable psychovisual optimizations. 1 = default
	      [min = 0, max = 1]
	-y4m : set to 1 if input is in Y4M format, 0 if raw YUV. 0 = default
	      [min = 0, max = 1]
	-inp= : input file. NOTE: if not specified, defaults to stdin
	-out= : output file. NOTE: if not specified, defaults to stdout
	-y : do not prompt for confirmation when potentially overwriting an existing file
	-l<n> : set logging level to n (0 = none, 1 = error, 2 = warning, 3 = info, 4 = debug/all)
	-v : set verbose

Running Decoder

Sample output:

Envel Graphics DSV v2.0 compliant codec by EMMIR 2024
usage: ./dsv2 d [options]
sample usage: ./dsv2 d -inp=video.dsv -out=decompressed.yuv -out420p=1
------------------------------------------------------------
	-out420p : convert video to 4:2:0 chroma subsampling before saving output. 0 = default
	      [min = 0, max = 1]
	-drawinfo : draw debugging information on the decoded frames (bit OR together to get multiple at the same time):
		1 = draw stability info
		2 = draw motion vectors
		4 = draw intra subblocks. 0 = default
	      [min = 0, max = 7]
	-inp= : input file. NOTE: if not specified, defaults to stdin
	-out= : output file. NOTE: if not specified, defaults to stdout
	-y : do not prompt for confirmation when potentially overwriting an existing file
	-l<n> : set logging level to n (0 = none, 1 = error, 2 = warning, 3 = info, 4 = debug/all)
	-v : set verbose

NOTE: if -inp= and -out= are not specified, it will default to standard in / out (stdin/stdout). Only .yuv (one file containing all the frames) and .y4m files are supported as inputs to the encoder.

Notes

This codec is by no means fully optimized, so there is a lot of room for performance gains. It performs quite well for what it is though.

If you have any questions feel free to leave a comment on YouTube OR join the King's Crook Discord server :)

YouTube: https://www.youtube.com/@EMMIR_KC/videos

Discord: https://discord.gg/hdYctSmyQJ

itch.io: https://kingscrook.itch.io/kings-crook

Example videos:

All videos are encoded at 30fps with a GOP length of 12. The H.264 file sizes were within a few kilobytes of their respective DSV2 file size. H.264 examples were encoded using https://github.com/lieff/minih264 using -speed0 (best quality) DSV2 examples were encoded with -effort=10 (best quality)

minih264:

minih264_mob.mp4

DSV2:

dsv2_944306.mp4

minih264:

minih264_bus.mp4

DSV2:

dsv2_385627.mp4