tools/ffmpeg-sg: Add show-graph wrapper script for Windows

Signed-off-by: softworkz <softworkz@hotmail.com>

Author: softworkz

tools/ffmpeg-sg.cmd

@@ -0,0 +1,73 @@
+@echo off
+setlocal EnableDelayedExpansion
+REM
+REM ffmpeg-sg - FFmpeg Show-Graph Wrapper (aka killer feature)
+REM             Show the FFmpeg execution graph in default browser 
+REM
+REM Copyright (c) 2025 softworkz
+REM
+REM This file is part of FFmpeg.
+REM
+REM FFmpeg is free software; you can redistribute it and/or
+REM modify it under the terms of the GNU Lesser General Public
+REM License as published by the Free Software Foundation; either
+REM version 2.1 of the License, or (at your option) any later version.
+REM
+REM FFmpeg is distributed in the hope that it will be useful,
+REM but WITHOUT ANY WARRANTY; without even the implied warranty of
+REM MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+REM Lesser General Public License for more details.
+REM
+REM You should have received a copy of the GNU Lesser General Public
+REM License along with FFmpeg; if not, write to the Free Software
+REM Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+REM
+
+REM Check for ffmpeg.exe in folder
+if not exist "ffmpeg.exe" (
+    echo Error: ffmpeg.exe not found in current directory.
+    exit /b 1
+)
+
+REM Check params
+set "conflict_found="
+for %%i in (%*) do (
+    if /i "%%i"=="-print_graphs_file" set "conflict_found=1"
+    if /i "%%i"=="-print_graphs_format" set "conflict_found=1"
+)
+
+if defined conflict_found (
+    echo Error: -print_graphs_file or -print_graphs_format parameter already provided.
+    echo This script manages graph file generation automatically.
+    exit /b 1
+)
+
+REM Validate temp dir
+if not exist "%TEMP%" (
+    echo Error: Temp directory not accessible
+    exit /b 1
+)
+
+REM Generate HTML filename
+set "date_part=%date:~-4,4%-%date:~-10,2%-%date:~-7,2%"
+set "time_part=%time:~0,2%-%time:~3,2%-%time:~6,2%"
+set "date_part=%date_part:/=-%"
+set "time_part=%time_part: =0%"
+
+set "html_file=%TEMP%\ffmpeg_graph_%date_part%_%time_part%_%RANDOM%.html"
+
+REM Execute ffmpeg
+REM Use start /wait /b to avoid "Terminate batch job" prompt on Ctrl-C
+start /wait /b ffmpeg.exe -print_graphs_file "%html_file%" -print_graphs_format mermaidhtml %*
+set "ffmpeg_exit_code=%ERRORLEVEL%"
+
+REM Open browser if HTML file was created
+if exist "%html_file%" (
+    echo "Execution graph opened in browser: %html_file%
+    start "FFmpeg Graph" "%html_file%"
+) else (
+    echo Warning: FFmpeg completed but no graph file was generated.
+)
+
+REM Exit with ffmpeg exit code
+exit /b %ffmpeg_exit_code%