whisper : add integer quantization support (#540)

* whisper : add integer quantization support

* examples : add common-ggml + prepare to add "quantize" tool

* whisper : quantization tool ready

* whisper : fix F32 support

* whisper : try to fix shared lib linkage

* wasm : update quantized models to Q5

* bench.wasm : remove "medium" button

* bench.wasm : fix custom model button

* ggml : add Q5_0 and Q5_1 WASM SIMD

* wasm : add quantized models to all WASM examples

* wasm : bump DB version number to 2

* talk-llama : update example to latest llama.cpp

* node : increase test timeout to 10s

* readme : add information for model quantization

* wasm : add links to other examples

README.md

@@ -15,6 +15,7 @@ High-performance inference of [OpenAI's Whisper](https://github.com/openai/whisp
 - AVX intrinsics support for x86 architectures
 - VSX intrinsics support for POWER architectures
 - Mixed F16 / F32 precision
+- [4-bit and 5-bit integer quantization support](https://github.com/ggerganov/whisper.cpp#quantization)
 - Low memory usage (Flash Attention)
 - Zero memory allocations at runtime
 - Runs on the CPU
@@ -228,6 +229,22 @@ make large
 | medium | 1.5 GB | ~1.7 GB | `fd9727b6e1217c2f614f9b698455c4ffd82463b4` |
 | large  | 2.9 GB | ~3.3 GB | `0f4c8e34f21cf1a914c59d8b3ce882345ad349d6` |
 
+## Quantization
+
+`whisper.cpp` supports integer quantization of the Whisper `ggml` models.
+Quantized models require less memory and disk space and depending on the hardware can be processed more efficiently.
+
+Here are the steps for creating and using a quantized model:
+
+```bash
+# quantize a model with Q5_0 method
+make quantize
+./quantize models/ggml-base.en.bin models/ggml-base.en-q5_0.bin q5_0
+
+# run the examples as usual, specifying the quantized model file
+./main -m models/ggml-base.en-q5_0.bin ./samples/gb0.wav
+```
+
 ## Core ML support
 
 On Apple Silicon devices, the Encoder inference can be executed on the Apple Neural Engine (ANE) via Core ML. This can result in significant