Controllable volume boost

zeldin · Jan 27, 2020 · 7feca94 · 7feca94
1 parent 23d693b
commit 7feca94
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Showing 2 changed files with 20 additions and 4 deletions.
diff --git a/docs/m64conv.md b/docs/m64conv.md
@@ -7,7 +7,7 @@ NAME
 SYNOPSIS
 ========
 
-`mc64conv` [`-f` _fps_] [`-r` _rate_] [`-m`] [`-n`] [`-d` _size_] [`-p`] [`-j` _number_] _videofile_ [_audiofile_] `>` _destination_
+`mc64conv` [`-f` _fps_] [`-r` _rate_] [`-v` _volume_] [`-m`] [`-n`] [`-d` _size_] [`-p`] [`-j` _number_] _videofile_ [_audiofile_] `>` _destination_
 
 
 DESCRIPTION
@@ -41,6 +41,13 @@ Options
    all audio data fitting within the header block (file size is unaffected
    by audio).  The default target audio sample rate is 16000 Hz.
 
+`-v` _volume_
+
+   Volume gain
+
+   If specified, the input volume will be multiplied by this number.
+   Output values are clipped to the maximum value.
+
 `-m`
 
    Enable multicolor mode

diff --git a/tools/source/main.c b/tools/source/main.c
@@ -352,13 +352,14 @@ static void convert(FILE *vframes, FILE *aframes, FILE *player, int mc,
 
 static void usage(const char *pname)
 {
-  fprintf(stderr, "Usage: %s [-f fps] [-r rate] [-m] [-n] [-d size] [-p]"
+  fprintf(stderr, "Usage: %s [-f fps] [-r rate] [-v volume] [-m] [-n] [-d size] [-p]"
 #if USE_THREADS
 	  " [-j number]"
 #endif
 	  "\n"
 	  "  -f fps      Set video fps\n"
 	  "  -r rate     Set audio sample rate\n"
+	  "  -v volume   Multiply audio volume\n"
 	  "  -m          Enable multicolor\n"
 	  "  -n          Target NTSC (60 Hz) C64:s\n"
 	  "  -d size     Dither with size pixel large dots\n"
@@ -452,6 +453,7 @@ int main(int argc, char *argv[])
   int opt, mc = 0, ntsc = 0, dither = 0, preview = 0;
   double fps = 50;
   double srate = 16000;
+  double volume = 1.0;
   char *endp, *cmdline;
 #if USE_THREADS
   int parallel = 1;
@@ -462,7 +464,7 @@ int main(int argc, char *argv[])
   FILE *player = NULL;
 
   while ((opt = getopt(argc, argv,
-		       "f:r:mnd:p"
+		       "f:r:v:mnd:p"
 #if USE_THREADS
 		       "j:"
 #endif
@@ -482,6 +484,13 @@ int main(int argc, char *argv[])
 	return 1;
       }
       break;
+    case 'v':
+      volume = strtod(optarg, &endp);
+      if (!*optarg || *endp) {
+	fprintf(stderr, "Invalid number: %s\n", optarg);
+	return 1;
+      }
+      break;
     case 'm':
       mc = 1;
       break;
@@ -541,7 +550,7 @@ int main(int argc, char *argv[])
   cmdline_append("ffmpeg -nostats -hide_banner");
   cmdline_append("-i");
   cmdline_append_quoted(argv[optind+1 >= argc? optind : optind+1]);
-  cmdline_append("-f u8 -af volume=10dB,aformat=sample_fmts=u8:sample_rates=%.8g:channel_layouts=mono -", srate);
+  cmdline_append("-f u8 -af volume=%.8g,aformat=sample_fmts=u8:sample_rates=%.8g:channel_layouts=mono -", volume, srate);
   cmdline = cmdline_finish();
 
   aframes = popen(cmdline, "r");