diff --git a/app/src/main/cpp/sox/CmakeLists.txt b/app/src/main/cpp/sox/CmakeLists.txt
index cd5975d..420c15e 100644
--- a/app/src/main/cpp/sox/CmakeLists.txt
+++ b/app/src/main/cpp/sox/CmakeLists.txt
@@ -87,8 +87,6 @@ set(formats_srcs
         adpcms.h
         adpcms.c
         al-fmt.c
-        avr.c
-        cdr.c
         cvsd.h
         cvsd.c
         cvsd-fmt.c
diff --git a/app/src/main/cpp/sox/cdr.c b/app/src/main/cpp/sox/cdr.c
deleted file mode 100644
index 0b6b061..0000000
--- a/app/src/main/cpp/sox/cdr.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/* libSoX file format: cdda   (c) 2006-8 SoX contributors
- * Based on an original idea by David Elliott
- *
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or (at
- * your option) any later version.
- *
- * This library is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
- * General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- */
-
-#include "sox_i.h"
-
-static int start(sox_format_t * ft)
-{
-  return lsx_check_read_params(ft, 2, 44100., SOX_ENCODING_SIGN2, 16, (uint64_t)0, sox_true);
-}
-
-static int stopwrite(sox_format_t * ft)
-{
-  unsigned const sector_num_samples = 588 * ft->signal.channels;
-  unsigned i = ft->olength % sector_num_samples;
-
-  if (i) while (i++ < sector_num_samples)    /* Pad with silence to multiple */
-    lsx_writew(ft, 0);                       /* of 1/75th of a second. */
-  return SOX_SUCCESS;
-}
-
-LSX_FORMAT_HANDLER(cdr)
-{
-  static char const * const names[] = {"cdda", "cdr", NULL};
-  static unsigned const write_encodings[] = {SOX_ENCODING_SIGN2, 16, 0, 0};
-  static sox_rate_t const write_rates[] = {44100, 0};
-  static sox_format_handler_t handler = {SOX_LIB_VERSION_CODE,
-    "Red Book Compact Disc Digital Audio",
-    names, SOX_FILE_BIG_END|SOX_FILE_STEREO,
-    start, lsx_rawread, NULL,
-    NULL, lsx_rawwrite, stopwrite,
-    lsx_rawseek, write_encodings, write_rates, 0
-  };
-  return &handler;
-}
diff --git a/app/src/main/cpp/sox/formats.h b/app/src/main/cpp/sox/formats.h
index f199af8..0e78ada 100644
--- a/app/src/main/cpp/sox/formats.h
+++ b/app/src/main/cpp/sox/formats.h
@@ -22,7 +22,7 @@
   FORMAT(al)
 //  FORMAT(au)
 //  FORMAT(avr)
-  FORMAT(cdr)
+//  FORMAT(cdr)
   FORMAT(cvsd)
   FORMAT(cvu)
   FORMAT(dat)