Scarfski/basis_universal
1
0
Fork 0
mirror of https://github.com/BinomialLLC/basis_universal.git synced 2026-09-30 14:15:30 +00:00
Code Issues Packages Projects Releases Wiki Activity

Update README.md

Browse Source
This commit is contained in:
Rich Geldreich
2019-09-19 13:36:07 -07:00
committed by GitHub
parent bf3a194b19
commit a195fb524f
1 changed files with 22 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
README.md
View File

@@ -21,6 +21,28 @@ The encoder uses [lodepng](https://lodev.org/lodepng/) for loading and saving PN
The encoder uses [tcuAstcUtil.cpp](https://chromium.googlesource.com/external/deqp/+/refs/heads/master/framework/common/tcuAstcUtil.cpp), from the [Android drawElements Quality Program (deqp) Testing Suite](https://source.android.com/devices/graphics/deqp-testing), for unpacking the transcoder's ASTC output for testing/validation purposes. This code is Copyright 2016 The Android Open Source Project, and uses the Apache 2.0 license.
### Release notes
Milestone 2 (9/19/16) release notes:
- This is a major transcoder update. The encoder hasn't been modified at all.
A minor update will be coming in a couple days which adds additional lower priority formats (notable PVRTC2 4bpp RGB) to the transcoder.
- Beware that the "transcoder_texture_format" enum names and their values are in flux as we add new texture formats.
This issue particularly affects Javascript code. Passing the old enum values to the transcoder will cause bugs.
We are adding a few more texture formats, renaming the enums and then stabilizing them on the next minor release (within a couple days or so).
- The "BASISD_SUPPORT_BC7" transcoder macro has been renamed to "BASISD_SUPPORT_BC7_MODE6_OPAQUE_ONLY".
For web use, be sure to update how you compile the transcoder to reduce its size.
The older BC7 mode-6 RGB function seriously bloats the transcoder's compiled size. (The mode-6 transcoder is of marginal value and might be disabled by default or just removed.) The new BC7 mode 5 RGB/RGBA transcoder uses substantially smaller lookup tables and provides basically the same quality as mode-6 for RGB (becaue we're starting with ETC1S texture data.)
Set BASISD_SUPPORT_BC7_MODE6_OPAQUE_ONLY to 0 when compiling on platforms which don't support BC7 well/at all, or if transcoder size is an issue.
- Added ATC RGB/RGBA, ASTC 4x4 L/LA/RGB/RGBA, BC7 mode 5 RGB/RGBA, and PVRTC1 4bpp RGBA support to the transcoder and KTX writer.
- Major perf. optimizations to all the transcoders. Transcoding to BC1 is approx. 2x faster when compiled native and executed on a Core i7.
- PVRTC1 4bpp RGB opaque is slightly higher quality
- Added various uncompressed raster pixel formats to the transcoder. When outputting raw pixels, the transcoder writes to regular raster images, not blocks.
No dithering or downsampling yet, but it's coming.
A couple of the parameters to basisu_transcoder::transcode_image_level() and basisu_transcoder::transcode_slice() have new meanings when these methods are used with uncompressed raster pixel formats:
"output_blocks_buf_size_in_blocks_or_pixels" and "output_row_pitch_in_blocks_or_pixels". When transcoding to uncompressed raster pixel formats, these parameters are in pixels, not blocks. The output buffer is also treated as a plain raster image, not a 2D collection of compressed blocks.
- basisu command line tool's "-level" command line option changed to "-comp_level", to avoid confusion vs. the "-q" option.
### Command Line Compression Tool
The command line tool used to create, validate, and transcode/unpack .basis files is named "basisu". Run basisu without any parameters for help. Note this tool uses the reference encoder.