GV Video Decoder for Rust

Port of GV video (Extreme Gpu Friendly Video Format) https://github.com/Ushio/ofxExtremeGpuVideo#binary-file-format-gv decoder for Rust.

GV video format is nutshell LZ4 compressed GPU textures with stored address tables.

This crate provides both:

• LZ4 decompressor (using lz4_flex crate)
• BC1(DXT1)/BC2(DXT3)/BC3(DXT5)/BC7 decoder (using texture2ddecoder crate)

But recommended NOT to use BC1/BC2/BC3/BC7 decoder because it's CPU processing (slow). Instead, you should pass (LZ4 decompressed) GPU texture directly to game engine or rendering engine.

• You can get LZ4 decompressed (not BC decoded) frame with read_frame_compressed(index) and read_frame_compressed_at(time) methods. (fastest way for GPU texture upload)
• You can get both LZ4 decompressed and BC decoded frame with read_frame(index) and read_frame_at(time) methods. (easy for BGRA texture checking and CPU processing)

This crate is ...

• This crate NOT provides movie player function. Please use like bevy_movie_player crate for it (as an alternative of ofxExtremeGpuVideo for openFrameworks).
• This crate NOT provides encoder for now (but planning to provide it in the future.) Currently, you can use ofxExtremeGpuVideo tools (or my new encoder) for encoding.

binary file format (gv)

0: uint32_t width
4: uint32_t height
8: uint32_t frame count
12: float fps
16: uint32_t format (DXT1 = 1, DXT3 = 3, DXT5 = 5, BC7 = 7)
20: uint32_t frame bytes
24: raw frame storage (lz4 compressed)
eof - (frame count) * 16: [(uint64_t, uint64_t)..<frame count] (address, size) of lz4, address is zero based from file head

Credits

• decode_bc2_alpha, decode_bc2_block functions in bc2_decoder included from https://github.com/autergame/texture2ddecoder/commit/6a5e8eaa8a146a0ed117fc245ebfbefa06abe8a5, dual licensed under MIT and Apache-2.0.