SOUNDS: Fix sounds with stereo samples, add mono sound PR test

Author: MotoLegacy

.github/workflows/test-wav-conformity.yml

@@ -0,0 +1,20 @@
+name: Verify WAV Sounds Conform to Standard
+on: [pull_request]
+jobs:
+  PCX-Conformity:
+    name: Verify WAV Sounds Conform to Standard
+    runs-on: ubuntu-latest
+    container:
+      image: ubuntu:24.04
+    steps:
+      - name: Install file
+        run: apt update && apt install file -y
+        shell: bash
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Wait for GitHub to keep up..
+        run: sleep 2s
+        shell: bash
+      - name: Run Script
+        run: |
+          bash testing/wav_validator.sh

common/sounds/misc/talk2.wav

@@ -0,0 +1,46 @@
+#!/bin/bash
+#
+# Nazi Zombies: Portable
+# Validate .WAV files are mono.
+# ----
+# This is intended to be used via a Docker 
+# container running ubuntu:24.04.
+#
+set -o errexit
+
+ASSETS_ROOT=$(dirname "${BASH_SOURCE[0]}")/../
+cd "${ASSETS_ROOT}"
+
+source "${ASSETS_ROOT}/testing/utils.sh"
+
+#
+# main()
+# ----
+# Test entry point.
+#
+function main()
+{
+    local total_failures=0
+
+    # Iterate through every .wav in our assets..
+    while read -r wav_file; do
+        echo "[INFO]: Verifying WAV sound file [${wav_file}].."
+        local file_output=$(file "${wav_file}")
+
+        # Check for indexed keyword
+        if [[ "${file_output}" != *", mono "* ]]; then
+            echo "  - ERROR: WAV [${wav_file}] is not a mono sample!"
+            total_failures=$((total_failures + 1))
+        fi
+    done < <(find . -type f -name "*.wav")
+
+    if [[ "${total_failures}" -ne 0 ]]; then
+        echo "[ERROR]: FAILED to validate [${total_failures}] WAV sounds!"
+        exit 1
+    else
+        echo "[PASS]: No issues found :)"
+        exit 0
+    fi
+}
+
+main;