fix building & UTF8 output with MSVC + SDL2

[foldl]

This PR could also solve the issue mentioned in #2804, in which, TDM64 (gcc compiler) is used because MSVC failed to build.

Note: example lsp talks to vim script through std IO, so not updated.

[rabidcopy]

#2804 is 99.99% just SDL2.dll not being with the binaries. So I'm a little confused by this PR's naming.

[foldl]

#2804 is 99.99% just SDL2.dll not being with the binaries. So I'm a little confused by this PR's naming.

With this PR, MSVC can be used to build with SDL2. This is an issue mentioned in #2804, in which, since MSVC failed to build, TDM64 (gcc compiler) is used.

[ggerganov]

The CI errors are unrelated to this change. If the errors persist, we can apply the same fix that we did in llama.cpp: ggml-org/llama.cpp#11895

[tokyovigilante]

Thanks, this fixes the whisper-stream build for me on Win10 with MSVC, but the app is exiting immediately after launch with no indication of why:

C:\Users\ryan\Speech\whisper.cpp>.\build\bin\Release\whisper-stream.exe -m .\ggml-large-v3.bin
init: found 2 capture devices:
init:    - Capture device #0: 'Headset Microphone (Logitech Mono H650e)'
init:    - Capture device #1: 'Headset (Ryan’s AirPods Pro - Find My Hands-Free AG Audio)'
init: attempt to open default capture device ...
init: obtained spec for input device (SDL Id = 2):
init:     - sample rate:       16000
init:     - format:            33056 (required: 33056)
init:     - channels:          1 (required: 1)
init:     - samples per frame: 1024
whisper_init_from_file_with_params ...
whisper_init_from_file_with_params_no_state: loading model from '.\ggml-large-v3.bin'
whisper_init_with_params_no_state: use gpu    = 1
whisper_init_with_params_no_state: flash attn = 0
whisper_init_with_params_no_state: gpu_device = 0
whisper_init_with_params_no_state: dtw        = 0
ggml_vulkan: Found 1 Vulkan devices:
ggml_vulkan: 0 = AMD Radeon RX 7900 XT (AMD proprietary driver) | uma: 0 | fp16: 1 | warp size: 64 | matrix cores: KHR_coopmat
whisper_init_with_params_no_state: devices    = 2
whisper_init_with_params_no_state: backends   = 2
whisper_model_load: loading model
whisper_model_load: n_vocab       = 51866
whisper_model_load: n_audio_ctx   = 1500
whisper_model_load: n_audio_state = 1280
whisper_model_load: n_audio_head  = 20
whisper_model_load: n_audio_layer = 32
whisper_model_load: n_text_ctx    = 448
whisper_model_load: n_text_state  = 1280
whisper_model_load: n_text_head   = 20
whisper_model_load: n_text_layer  = 32
whisper_model_load: n_mels        = 128
whisper_model_load: ftype         = 1
whisper_model_load: qntvr         = 0
whisper_model_load: type          = 5 (large v3)
whisper_model_load: adding 1609 extra tokens
whisper_model_load: n_langs       = 100

C:\Users\ryan\Speech\whisper.cpp>

[foldl]

@tokyovigilante You need to copy SDL2.dll to C:\Users\ryan\Speech\whisper.cpp\build\bin\Release, or add it to PATH.

[tokyovigilante]

Thanks for looking, I think this should be ok?

Directory of C:\Users\ryan\Speech\whisper.cpp\build\bin\Release

20/02/2025  10:05 pm    <DIR>          .
20/02/2025  10:05 pm    <DIR>          ..
20/02/2025  09:40 pm            27,136 bench.exe
20/02/2025  09:40 pm            27,136 command.exe
20/02/2025  09:40 pm           487,936 ggml-base.dll
20/02/2025  09:40 pm           322,048 ggml-cpu.dll
20/02/2025  09:40 pm        20,034,048 ggml-vulkan.dll
20/02/2025  09:40 pm            75,264 ggml.dll
20/02/2025  10:05 pm           184,832 lsp.exe
20/02/2025  09:40 pm            27,136 main.exe
20/02/2025  09:40 pm           107,520 quantize.exe
20/02/2025  09:11 pm         1,664,000 SDL2.dll
20/02/2025  09:40 pm            27,136 stream.exe
20/02/2025  10:05 pm           165,888 wchess.exe
20/02/2025  09:40 pm            20,480 whisper-bench.exe
20/02/2025  09:40 pm           183,808 whisper-cli.exe
20/02/2025  10:05 pm           167,936 whisper-command.exe
20/02/2025  10:05 pm           407,040 whisper-server.exe
20/02/2025  10:05 pm            81,920 whisper-stream.exe
20/02/2025  10:05 pm         1,200,128 whisper-talk-llama.exe
20/02/2025  09:40 pm           438,272 whisper.dll
              19 File(s)     25,649,664 bytes
               2 Dir(s)  33,750,409,216 bytes free

[EDIT]
Hmm, seems to run on Windows for me with the -ng flag, despite having the Vulkan SDK installed (7900 XT). Have just tried on Linux with the mainline code whiich works fine with my GPU. I really need to use this with a Windows app unfortunately, but this is clearly not the issue. Sorry for the noise.