Support for mp3 decoding using MPG123 instead of MAD

Author: erikronstrom

CMakeLists.txt

@@ -124,6 +124,7 @@ optional(HAVE_SNDIO sndio.h sndio sio_open sndio)
 optional(HAVE_AO ao/ao.h ao ao_play ao)
 optional(HAVE_FLAC FLAC/all.h FLAC FLAC__stream_encoder_new flac)
 optional(HAVE_MAD_H mad.h mad mad_stream_buffer mp3)
+optional(HAVE_MPG123_H mpg123.h mpg123 mpg123_init mp3)
 optional(HAVE_LAME_LAME_H lame/lame.h mp3lame lame_get_lametag_frame mp3)
 if (NOT HAVE_LAME_LAME_H)
   optional(HAVE_LAME_LAME_H lame.h mp3lame lame_get_lametag_frame mp3)
@@ -162,9 +163,9 @@ optional4(HAVE_OGG_VORBIS vorbis/codec.h ogg ogg_stream_flush vorbis vorbis_anal
 optional3(HAVE_OPUS opusfile.h ogg ogg_stream_flush opus opus_encoder_create opusfile op_open_callbacks opus)
 optional(HAVE_WAVPACK wavpack/wavpack.h wavpack WavpackGetSampleRate wavpack)
 
-if (HAVE_LAME_LAME_H OR HAVE_MAD_H)
+if (HAVE_LAME_LAME_H OR HAVE_MAD_H OR HAVE_MPG123_H)
   set(HAVE_MP3 1)
-endif (HAVE_LAME_LAME_H OR HAVE_MAD_H)
+endif (HAVE_LAME_LAME_H OR HAVE_MAD_H OR HAVE_MPG123_H)
 
 set(CMAKE_REQUIRED_LIBRARIES mp3lame m)
 check_function_exists("lame_set_VBR_quality" HAVE_LAME_SET_VBR_QUALITY)

configure.ac

@@ -394,6 +394,32 @@ AM_CONDITIONAL(HAVE_ID3TAG, test x$using_id3tag = xyes)
 
 
 
+dnl Check for mpg123 libraries
+AC_ARG_WITH(mpg123,
+    AS_HELP_STRING([--with-mpg123],
+        [Try to use mpg123 (LGPL MP3 Audio Decoder)]))
+using_mpg123=no
+if test "$with_mpg123" == "yes"; then
+    using_mpg123=yes
+    AC_CHECK_HEADERS(mpg123.h,, using_mpg123=no)
+    AC_MSG_CHECKING([whether to dlopen mpg123])
+    AC_ARG_ENABLE(dl_mpg123,
+      AS_HELP_STRING([--enable-dl-mpg123], [Dlopen mpg123 instead of linking in.]),
+      enable_dl_mpg123=$enableval, enable_dl_mpg123=no)
+    AC_MSG_RESULT($enable_dl_mpg123)
+    if test "x$using_libltdl" = "xyes" -a "x$enable_dl_mpg123" = "xyes"; then
+      AC_DEFINE(DL_MPG123, 1, [Define to dlopen() mpg123.])
+    else
+      enable_dl_mpg123="no"
+      AC_CHECK_LIB(mpg123, mpg123_new, MP3_LIBS="$MP3_LIBS -lmpg123",using_mpg123=no)
+      if test "$with_mpg123" = "yes" -a "$using_mpg123" = "no"; then
+        AC_MSG_FAILURE([cannot find libmpg123])
+      fi
+    fi
+fi
+
+
+
 dnl Check for LAME library.
 AC_ARG_WITH(lame,
     AS_HELP_STRING([--without-lame],
@@ -623,9 +649,9 @@ AC_OPTIONAL_FORMAT(sunaudio, SUN_AUDIO, [AC_CHECK_HEADERS(sys/audioio.h,,
 
 
 
-# MP2/MP3 format depends on libmad || LAME || twolame
+# MP2/MP3 format depends on libmad || libmpg123 || LAME || twolame
 AC_OPTIONAL_FORMAT(mp3, MP3, [
-  if test "$using_mad" != yes -a "$using_lame" != yes -a "$using_twolame" != yes; then
+  if test "$using_mad" != yes -a "$using_mpg123" != yes -a "$using_lame" != yes -a "$using_twolame" != yes; then
     using_mp3=no
   fi])
 
@@ -740,6 +766,10 @@ echo " mad.......................$using_mad"
 if test "x$using_mad" = "xyes"; then
 echo " dlopen mad................$enable_dl_mad"
 fi
+echo " mpg123....................$using_mpg123"
+if test "x$using_mpg123" = "xyes"; then
+echo " dlopen mpg123.............$enable_dl_mpg123"
+fi
 echo " twolame...................$using_twolame"
 if test "x$using_twolame" = "xyes"; then
 echo " dlopen twolame............$enable_dl_twolame"

src/mp3-util.h

@@ -348,3 +348,39 @@ static size_t mp3_duration_ms(sox_format_t * ft)
 }
 
 #endif /* HAVE_MAD_H */
+
+#ifdef HAVE_MPG123_H
+
+static size_t mp3_duration(sox_format_t * ft)
+{
+  priv_t * p = (priv_t *) ft->priv;
+  FILE * fp = ft->fp;
+  if (!fp || !ft->seekable) {
+    lsx_fail_errno(ft, SOX_EOF, "File pointer is undefined or not seekable in mp3_duration_ms");
+    return SOX_UNSPEC;
+  }
+  int error;
+  mpg123_handle * handle = p->mpg123_new(NULL, &error);
+  if (!handle) {
+    lsx_fail_errno(ft, SOX_EOF, "Could not get mpg123 handle: %s", mpg123_plain_strerror(error));
+    return SOX_UNSPEC;
+  }
+
+  p->mpg123_open_fd(handle, fileno(fp));
+  p->mpg123_scan(handle);
+  off_t samples = p->mpg123_length(handle);
+  int channels = 0;
+  int encoding = 0;
+  long sample_rate = 0;
+  mpg123_getformat(handle, &sample_rate, &channels, &encoding);
+  p->mpg123_close(handle);
+  p->mpg123_delete(handle);
+
+  lsx_rewind(ft);
+
+  // fprintf(stderr, "File length in samples, according to mpg123 (after scan): %zu / %zu\n", samples, samples * channels);
+
+  return (size_t) (samples * channels);
+}
+
+#endif /* HAVE_MPG123_H */