30b2c593c9
Reasoning: The struct `VP8LBitWriter` in `src/utils/bit_writer_utils.h` uses `buf`, `cur`, and `end` pointers to manage a dynamic buffer. Pointer arithmetic on `buf` and `cur` caused bounds safety errors. Initial attempts using `WEBP_ENDED_BY(end)` for both `buf` and `cur` failed due to compiler limitations (one field cannot be the upper bound for multiple other fields). Using `WEBP_INDEXABLE` for `buf` and `cur` resolved the arithmetic errors but caused ABI incompatibility issues, as `VP8LBitWriter` is used in multiple compilation units with different settings. The final approach annotates `buf` with `WEBP_ENDED_BY(end)` and `cur` with `WEBP_UNSAFE_INDEXABLE`. This resolves the arithmetic errors for both pointers without changing the ABI. `WEBP_UNSAFE_INDEXABLE` is used for `cur` as a workaround for the `WEBP_ENDED_BY` limitation and ABI constraints. Additionally, the `VP8LBitWriterResize` function in `src/utils/bit_writer_utils.c` was modified: - The assignments to `bw->buf`, `bw->end`, and `bw->cur` (lines 231-233) were reordered and updated to use the local `allocated_buf` variable on the right-hand side. This satisfies the consecutive assignment requirement imposed by `WEBP_ENDED_BY(end)` on `bw->buf`. - The local variable `allocated_buf` (line 207) was annotated with `WEBP_BIDI_INDEXABLE`. - The allocation for `allocated_buf` (line 222) now uses `WEBP_UNSAFE_FORGE_BIDI_INDEXABLE` to create a safe, bounded pointer from the result of `WebPSafeMalloc`, fixing potential type mismatches when `suppress_fbounds_errors=yes`. Bug: 432511821 Change-Id: I603a6a7d3ff3bf2a8edf9749a9898ea227c32982
WebP Codec
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WebP codec is a library to encode and decode images in WebP format. This package contains the library that can be used in other programs to add WebP support, as well as the command line tools 'cwebp' and 'dwebp' to compress and decompress images respectively.
See https://developers.google.com/speed/webp for details on the image format.
The latest source tree is available at https://chromium.googlesource.com/webm/libwebp
It is released under the same license as the WebM project. See https://www.webmproject.org/license/software/ or the "COPYING" file for details. An additional intellectual property rights grant can be found in the file PATENTS.
Building
See the building documentation.
Encoding and Decoding Tools
The examples/ directory contains tools to encode and decode images and animations, view information about WebP images, and more. See the tools documentation.
APIs
See the APIs documentation, and API usage examples in the
examples/ directory.
Bugs
Please report all bugs to the issue tracker. For security reports, select 'Security report' from the Template dropdown.
Patches welcome! See how to contribute.
Discuss
Email: webp-discuss@webmproject.org
Web: https://groups.google.com/a/webmproject.org/group/webp-discuss