doc++

README.md

@@ -0,0 +1,41 @@
+Audioextract
+============
+
+Extract audio files that are embedded within other files.
+
+Usage
+-----
+
+	audioextract [options] <filename> [<filename> ...]
+
+### Options
+
+	-h, --help             Print this help message.
+	-f, --formats=FORMATS  Comma separated list of formats (file magics) to extract.
+	                       Supported formats:
+	                         all       all supported formats
+	                         default   the default set of formats (AIFF, ID3v2, Ogg, RIFF)
+	                         aiff      big-endian (Apple) wave files
+	                         id3v2     MPEG files with ID3v2 tags at the start
+	                         mpeg      any MPEG files (e.g. MP3)
+	                         ogg       Ogg files (Vorbis, FLAC, Opus, Theora, etc.)
+	                         riff      little-endian (Windows) wave files
+	                         wav       alias for riff
+	                         wave      both RIFF and AIFF wave files
+
+	                       WARNING: Because MPEG files do not have a nice file magic, using
+	                       the 'mpeg' format may cause *a lot* of false positives. Nowadays
+	                       MP3 files usually have an ID3v2 tag at the start, so using the
+	                       'id3v2' format is the better option anyway.
+
+	                       NOTE: When using only the 'mpeg' format but not 'id3v2' any ID3v2
+	                       tag will be stripped. ID3v1 tags will still be kept.
+
+	                       If '-' is written before a format name the format will be
+	                       removed from the set of formats to extract. E.g. extract
+	                       everything except wave files:
+
+	                         audioextract --formats=all,-wave data.bin
+
+	-o, --output=DIR       Directory where extracted files should be written. (default: ".")
+	-q, --quiet            Do not print status messages.

audioextract.c

@@ -32,8 +32,10 @@ int usage(int argc, char **argv)
 {
 	const char *progname = argc <= 0 ? "audioextract" : argv[0]; 
 	fprintf(stderr,
+		"audioextract - extracts audio files that are embedded within other files\n"
+		"\n"
 		"Usage:\n"
-		"  %s <filename> [<filename> ...]\n"
+		"  %s [options] <filename> [<filename> ...]\n"
 		"\n"
 		"Options:\n"
 		"  -h, --help             Print this help message.\n"