Need help building on windows.

[WuChanGG]

I read the previous issues regarding building in windows, and read the wiki too, but I still got the = note: LINK : fatal error LNK1181: cannot open input file 'avutil.lib' error despite having the correct FFMPEG_DIR value. I was wondering if there was more input about this. Alternatively I could try to develop with WSL since I'm having a lot of problems finding a video decoder for windows.

[zmwangx]

Need a lot more detailed info to help you. OS version, how FFmpeg is installed, exact series of commands to set up your build directory and lead to the error, etc.

[WuChanGG]

Windows x64, version 2004, build 19041.685.
FFMPEG is installed by the instructions of the wiki for MSVC toolchain

Install FFmpeg (complete with headers) through any means, e.g. downloading a pre-built "full_build-shared" version from https://ffmpeg.org/download.html. See FFMPEG_DIR to the directory containing include and lib.

I'm cloning the repository, and running cargo build on the root directory seems to work, but trying to run any example e.g. cargo run --example dump-frames C:\Videos\1280.mp4 gives the following logs
example_output.txt
Please let me know if you need more info

[zmwangx]

You sure avutil.lib and other libs are present under $FFMPEG_DIR\lib?

Also, give me the output of

cargo build -vv --example dump-frames

It should show the full rustc invocation, and at the end or close to the end you should find a linker flag specifying the library lookup path, like

-L native=C:\Users\zmwang\Projects\rust-ffmpeg\ffmpeg\lib

where all the libs should be under that directory. If there's no such flag then some configuration is amiss. Which is why I asked for the exact series of commands, not natural language descriptions of them.

[WuChanGG]

This is the output of the command cargo build -vv --example dump-frames, thanks for your time, and sorry for posting not enough info, my bad. and yes the libraries are present in FFMPEG_DIR/lib

PS H:\RustProjects\ff\rust-ffmpeg> cargo build -vv --example dump-frames
       Fresh version_check v0.9.2
       Fresh glob v0.3.0
       Fresh cc v1.0.66
       Fresh unicode-xid v0.2.1  
       Fresh regex-syntax v0.6.21     
       Fresh shlex v0.1.1
       Fresh lazycell v1.3.0
       Fresh peeking_take_while v0.1.2
       Fresh rustc-hash v1.1.0        
       Fresh cfg-if v0.1.10
       Fresh lazy_static v1.4.0       
       Fresh pkg-config v0.3.19       
       Fresh vcpkg v0.2.11
       Fresh regex v1.4.2
       Fresh winapi v0.3.9
       Fresh memchr v2.3.4
       Fresh libc v0.2.81
       Fresh proc-macro2 v1.0.24
       Fresh bitflags v1.2.1  
       Fresh nom v5.1.2       
       Fresh libloading v0.5.2
       Fresh quote v1.0.8
       Fresh num_cpus v1.13.0
       Fresh cexpr v0.4.0
       Fresh clang-sys v0.29.3
       Fresh bindgen v0.54.0
   Compiling ffmpeg-sys-next v4.3.5
     Running `H:\RustProjects\ff\rust-ffmpeg\target\debug\build\ffmpeg-sys-next-aec6b64fe5535b58\build-script-build`
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-search=native=H:\ffmpeg-n4.3.1-26-gca55240b8c-win64-gpl-shared-4.3;\lib
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=avcodec
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=avdevice
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=avfilter
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=avformat
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=avutil
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=swresample
[ffmpeg-sys-next 4.3.5] cargo:rustc-link-lib=dylib=swscale
[ffmpeg-sys-next 4.3.5] OPT_LEVEL = Some("0")
[ffmpeg-sys-next 4.3.5] HOST = Some("x86_64-pc-windows-msvc")
[ffmpeg-sys-next 4.3.5] CC_x86_64-pc-windows-msvc = None
[ffmpeg-sys-next 4.3.5] CC_x86_64_pc_windows_msvc = None
[ffmpeg-sys-next 4.3.5] HOST_CC = None
[ffmpeg-sys-next 4.3.5] CC = None
[ffmpeg-sys-next 4.3.5] CFLAGS_x86_64-pc-windows-msvc = None
[ffmpeg-sys-next 4.3.5] CFLAGS_x86_64_pc_windows_msvc = None
[ffmpeg-sys-next 4.3.5] HOST_CFLAGS = None
[ffmpeg-sys-next 4.3.5] CFLAGS = None
[ffmpeg-sys-next 4.3.5] CRATE_CC_NO_DEFAULTS = None
[ffmpeg-sys-next 4.3.5] CARGO_CFG_TARGET_FEATURE = Some("fxsr,sse,sse2")
[ffmpeg-sys-next 4.3.5] DEBUG = Some("true")
[ffmpeg-sys-next 4.3.5] cl : Command line warning D9035 : option 'o' has been deprecated and will be removed in a future release
[ffmpeg-sys-next 4.3.5] check.c
[ffmpeg-sys-next 4.3.5] check.c(3): fatal error C1083: Cannot open include file: 'libavutil/avutil.h': No such file or directory
[ffmpeg-sys-next 4.3.5] thread 'main' panicked at 'Compile failed', C:\Users\Wu\.cargo\registry\src\github.com-1ecc6299db9ec823\ffmpeg-sys-next-4.3.5\build.rs:492:9
[ffmpeg-sys-next 4.3.5] stack backtrace:
[ffmpeg-sys-next 4.3.5]    0: std::panicking::begin_panic<str*>
[ffmpeg-sys-next 4.3.5]              at C:\Users\Wu\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panicking.rs:497
[ffmpeg-sys-next 4.3.5]    1: build_script_build::check_features
[ffmpeg-sys-next 4.3.5]              at .\build.rs:492
[ffmpeg-sys-next 4.3.5]    2: build_script_build::main
[ffmpeg-sys-next 4.3.5]              at .\build.rs:751
[ffmpeg-sys-next 4.3.5]    3: core::ops::function::FnOnce::call_once<fn(),tuple<>>
[ffmpeg-sys-next 4.3.5]              at C:\Users\Wu\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:227
[ffmpeg-sys-next 4.3.5] note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
error: failed to run custom build command for `ffmpeg-sys-next v4.3.5`

Caused by:
  process didn't exit successfully: `H:\RustProjects\ff\rust-ffmpeg\target\debug\build\ffmpeg-sys-next-aec6b64fe5535b58\build-script-build` (exit code: 101)
  --- stdout
  cargo:rustc-link-search=native=H:\ffmpeg-n4.3.1-26-gca55240b8c-win64-gpl-shared-4.3;\lib
  cargo:rustc-link-lib=dylib=avcodec
  cargo:rustc-link-lib=dylib=avdevice
  cargo:rustc-link-lib=dylib=avfilter
  cargo:rustc-link-lib=dylib=avformat
  cargo:rustc-link-lib=dylib=avutil
  cargo:rustc-link-lib=dylib=swresample
  cargo:rustc-link-lib=dylib=swscale
  OPT_LEVEL = Some("0")
  HOST = Some("x86_64-pc-windows-msvc")
  CC_x86_64-pc-windows-msvc = None
  CC_x86_64_pc_windows_msvc = None
  HOST_CC = None
  CC = None
  CFLAGS_x86_64-pc-windows-msvc = None
  CFLAGS_x86_64_pc_windows_msvc = None
  HOST_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  CARGO_CFG_TARGET_FEATURE = Some("fxsr,sse,sse2")
  DEBUG = Some("true")
  check.c
  check.c(3): fatal error C1083: Cannot open include file: 'libavutil/avutil.h': No such file or directory

  --- stderr
  cl : Command line warning D9035 : option 'o' has been deprecated and will be removed in a future release
  thread 'main' panicked at 'Compile failed', C:\Users\Wu\.cargo\registry\src\github.com-1ecc6299db9ec823\ffmpeg-sys-next-4.3.5\build.rs:492:9
  stack backtrace:
     0: std::panicking::begin_panic<str*>
               at C:\Users\Wu\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panicking.rs:497
     1: build_script_build::check_features
               at .\build.rs:492
     2: build_script_build::main
               at .\build.rs:751
     3: core::ops::function::FnOnce::call_once<fn(),tuple<>>
               at C:\Users\Wu\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:227
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
PS H:\RustProjects\ff\rust-ffmpeg>

[zmwangx]

So I'm confused, you said cargo build would succeed and cargo run would fail at linker stage, but this time it doesn't even get past compile stage, not being able to find the header. I suspect FFMPEG_DIR isn't set correctly. What shell is this (cmd? PowerShell?) and how are you setting FFMPEG_DIR? Still I don't see your exact series of commands.

Let me be clear why I ask for the exact series of commands, not natural language descriptions of them: often times when someone say "I did X, then Y, and Y failed, here's the output of Y", implying fault somewhere in Y, what they actually mean is "I think I did X, then Y, ..." , and in fact they failed to do X properly, so the failure was in X which is apparent once the exact steps are provided.

Basically, any step could have gone wrong, so you need to tell me how you did each step exactly, not just the final step.

[WuChanGG]

OKAY thanks a lot for your time, I was setting the FFMPEG_DIR and the LIBCLANG_PATH environment variables by using the windows GUI for environment variables, it never occurred to me that they weren't working (I don't know why, I restart my pc every time I set new environment variables). So I opened the project in VSCODE and set the environment variables in the console of VSCODE
$ENV:LIBCLANG_PATH="H:\llvm\bin" and $ENV:FFMPEG_DIR="H:\ffmpeg-n4.3.1-26-gca55240b8c-win64-gpl-shared-4.3" in the local vscode console. And this is the output I got by using cargo build -vv --example dump-frames > output.txt
output.txt
and this is the console output I got that wasn't redirected to output.txt
output_from_run.txt
I guess this means everything works! sorry for the trouble.