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author | wm4 <wm4@nowhere> | 2020-08-20 20:37:17 +0200 |
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committer | wm4 <wm4@nowhere> | 2020-08-20 20:37:17 +0200 |
commit | b16a6cb6c62657d3efbe69bd854287da149b59a1 (patch) | |
tree | fdc6b6d6d55900ad91ef2798150cb1f8a1e8e3d2 /libmpv | |
parent | 30dcfbc9cb3f77dbb729fb6f95ffde7dbdddc4cb (diff) | |
download | mpv-b16a6cb6c62657d3efbe69bd854287da149b59a1.tar.bz2 mpv-b16a6cb6c62657d3efbe69bd854287da149b59a1.tar.xz |
client API: note about libswscale corrupting memory
The software rendering API makes libswscale directly write into supplied
user memory. As such, weird memory corruption bugs on non-optimal buffer
configurations are exposed to the user.
Diffstat (limited to 'libmpv')
-rw-r--r-- | libmpv/render.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/libmpv/render.h b/libmpv/render.h index c9a6cec65e..ead462cbb6 100644 --- a/libmpv/render.h +++ b/libmpv/render.h @@ -390,7 +390,13 @@ typedef enum mpv_render_param_type { * target surface. It must be a multiple of the pixel size, and have space * for the surface width as specified by MPV_RENDER_PARAM_SW_SIZE. * - * It should be a multiple of 64 to facilitate fast SIMD operation. + * It should be a multiple of 64 to facilitate fast SIMD operation. Lower + * alignment might trigger slower code paths. In addition, it appears that + * if libswscale is used, stride must be at least a multiple of 16, or + * libswscale may randomly corrupt memory. The API still accepts unaligned + * values, because libswscale is not supposed to corrupt memory, and whether + * it does depends on its implementation details and bugs. If mpv is built + * with zimg (and zimg is not disabled), no problems should occur. */ MPV_RENDER_PARAM_SW_STRIDE = 19, /* @@ -407,6 +413,9 @@ typedef enum mpv_render_param_type { * will do it anyway). It is assumed that even the padding after the last * line (starting at bytepos(w, h) until (pointer + stride * h)) is * writable. + * + * It should be a aligned to 64 to facilitate fast SIMD operation. Lower + * alignment might trigger slower code paths. */ MPV_RENDER_PARAM_SW_POINTER = 20, } mpv_render_param_type; |