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.

• This crate provides both BC1(DXT1)/BC2(DXT3)/BC3(DXT5)/BC7 decoder (using texture2ddecoder crate) and LZ4 decompressor (using lz4_flex crate), but recommended NOT to use BC1/BC2/BC3/BC7 decoder because it's CPU processing (slow).
  • 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 BC decoded and LZ4 decompressed frame with read_frame(index) and read_frame_at(time) methods. (easy for BGRA texture checking and CPU processing)
• 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 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.