diff --git a/cinelerra-5.1/cinelerra/ffmpeg.C b/cinelerra-5.1/cinelerra/ffmpeg.C
index df39763c..786ca723 100644
--- a/cinelerra-5.1/cinelerra/ffmpeg.C
+++ b/cinelerra-5.1/cinelerra/ffmpeg.C
@@ -404,7 +404,7 @@ int FFStream::decode_activate()
 		}
 		while( ret >= 0 && st != 0 && !reading ) {
 			AVCodecID codec_id = st->codecpar->codec_id;
-			AVCodec *decoder = 0;
+			const AVCodec *decoder = 0;
 			if( is_video() ) {
 				if( ffmpeg->opt_video_decoder )
 					decoder = avcodec_find_decoder_by_name(ffmpeg->opt_video_decoder);
@@ -1243,6 +1243,7 @@ int FFVideoStream::probe(int64_t pos)
 		ret = -1;
 
 	ret = ret > 0 ? 1 : ret < 0 ? -1 : 0;
+	av_frame_free(&frame);
 	return ret;
 }
 
@@ -2089,7 +2090,7 @@ void FFMPEG::scan_audio_options(Asset *asset, EDL *edl)
 		cin_fmt = (int)av_get_sample_fmt(cin_sample_fmt);
 	if( cin_fmt < 0 ) {
 		char audio_codec[BCSTRLEN]; audio_codec[0] = 0;
-		AVCodec *av_codec = !FFMPEG::get_codec(audio_codec, "audio", asset->acodec) ?
+		const AVCodec *av_codec = !FFMPEG::get_codec(audio_codec, "audio", asset->acodec) ?
 			avcodec_find_encoder_by_name(audio_codec) : 0;
 		if( av_codec && av_codec->sample_fmts )
 			cin_fmt = find_best_sample_fmt_of_list(av_codec->sample_fmts, AV_SAMPLE_FMT_FLT);
@@ -2125,7 +2126,7 @@ void FFMPEG::scan_video_options(Asset *asset, EDL *edl)
 			cin_fmt = (int)av_get_pix_fmt(cin_pix_fmt);
 	if( cin_fmt < 0 ) {
 		char video_codec[BCSTRLEN];  video_codec[0] = 0;
-		AVCodec *av_codec = !get_codec(video_codec, "video", asset->vcodec) ?
+		const AVCodec *av_codec = !get_codec(video_codec, "video", asset->vcodec) ?
 			avcodec_find_encoder_by_name(video_codec) : 0;
 		if( av_codec && av_codec->pix_fmts ) {
 			if( 0 && edl ) { // frequently picks a bad answer
@@ -2322,7 +2323,7 @@ int FFCodecRemaps::add(const char *val)
 
 int FFCodecRemaps::update(AVCodecID &codec_id, AVCodec *&decoder)
 {
-	AVCodec *codec = avcodec_find_decoder(codec_id);
+	const AVCodec *codec = avcodec_find_decoder(codec_id);
 	if( !codec ) return -1;
 	const char *name = codec->name;
 	FFCodecRemaps &map = *this;
@@ -2542,7 +2543,7 @@ int FFMPEG::init_decoder(const char *filename)
 	char *sp = strrchr(bp, '.');
 	if( !sp ) sp = bp + strlen(bp);
 	FILE *fp = 0;
-	AVInputFormat *ifmt = 0;
+	const AVInputFormat *ifmt = 0;
 	if( sp ) {
 		strcpy(sp, ".opts");
 		fp = fopen(file_opts, "r");
@@ -2759,7 +2760,7 @@ int FFMPEG::open_encoder(const char *type, const char *spec)
 	AVCodecContext *ctx = 0;
 
 	const AVCodecDescriptor *codec_desc = 0;
-	AVCodec *codec = avcodec_find_encoder_by_name(codec_name);
+	const AVCodec *codec = avcodec_find_encoder_by_name(codec_name);
 	if( !codec ) {
 		eprintf(_("cant find codec %s:%s\n"), codec_name, filename);
 		ret = 1;
@@ -3651,7 +3652,7 @@ Preferences *FFMPEG::ff_prefs()
 double FFVideoStream::get_rotation_angle()
 {
 	int size = 0;
-	int *matrix = (int*)av_stream_get_side_data(st, AV_PKT_DATA_DISPLAYMATRIX, &size);
+	uint32_t  *matrix = (uint32_t*)av_stream_get_side_data(st, AV_PKT_DATA_DISPLAYMATRIX, &size);
 	int len = size/sizeof(*matrix);
 	if( !matrix || len < 5 ) return 0;
 	const double s = 1/65536.;
@@ -3875,7 +3876,7 @@ AVCodecContext *FFMPEG::activate_decoder(AVStream *st)
 	AVDictionary *copts = 0;
 	av_dict_copy(&copts, opts, 0);
 	AVCodecID codec_id = st->codecpar->codec_id;
-	AVCodec *decoder = 0;
+	const AVCodec *decoder = 0;
 	switch( st->codecpar->codec_type ) {
 	case AVMEDIA_TYPE_VIDEO:
 		if( opt_video_decoder )
diff --git a/cinelerra-5.1/cinelerra/fileffmpeg.C b/cinelerra-5.1/cinelerra/fileffmpeg.C
index a71d692a..853e5839 100644
--- a/cinelerra-5.1/cinelerra/fileffmpeg.C
+++ b/cinelerra-5.1/cinelerra/fileffmpeg.C
@@ -159,7 +159,7 @@ void FFMpegPixelFormat::update_formats()
 	pixfmts.remove_all_objects();
 	char video_codec[BCSTRLEN]; video_codec[0] = 0;
 	const char *vcodec = vid_config->asset->vcodec;
-	AVCodec *av_codec = !FFMPEG::get_codec(video_codec, "video", vcodec) ?
+	const AVCodec *av_codec = !FFMPEG::get_codec(video_codec, "video", vcodec) ?
 		avcodec_find_encoder_by_name(video_codec) : 0;
 	const AVPixelFormat *pix_fmts = av_codec ? av_codec->pix_fmts : 0;
 	if( pix_fmts ) {
@@ -190,7 +190,7 @@ void FFMpegSampleFormat::update_formats()
 	samplefmts.remove_all_objects();
 	char audio_codec[BCSTRLEN]; audio_codec[0] = 0;
 	const char *acodec = aud_config->asset->acodec;
-	AVCodec *av_codec = !FFMPEG::get_codec(audio_codec, "audio", acodec) ?
+	const AVCodec *av_codec = !FFMPEG::get_codec(audio_codec, "audio", acodec) ?
 		avcodec_find_encoder_by_name(audio_codec) : 0;
 	const AVSampleFormat *sample_fmts = av_codec ? av_codec->sample_fmts : 0;
 	if( sample_fmts ) {
@@ -345,7 +345,7 @@ int FileFFMPEG::open_file(int rd, int wr)
 				asset->aspect_ratio = ff->ff_aspect_ratio(0);
 				if (!asset->interlace_mode) asset->interlace_mode = ff->ff_interlace(0);
 				if ( ff->ff_video_frames(0) > 1 ) {
-//				ff->video_probe(1);
+				ff->video_probe(1);
 				 if (!asset->interlace_mode && (ff->interlace_from_codec) ) asset->interlace_mode = ff->video_probe(1); 
 				}
 				if( !asset->layers ) asset->layers = video_layers;
@@ -1844,7 +1844,7 @@ int FFOptionsViewAudio::handle_event()
 	const char *name = asset->acodec;
 	char audio_format[BCSTRLEN];  audio_format[0] = 0;
 	char audio_codec[BCSTRLEN];   audio_codec[0] = 0;
-	AVCodec *codec = !ret &&
+	const AVCodec *codec = !ret &&
 	    !FFMPEG::get_format(audio_format, "audio", name) &&
 	    !FFMPEG::get_codec(audio_codec, "audio", name) ?
 		avcodec_find_encoder_by_name(audio_codec) : 0;
@@ -1882,7 +1882,7 @@ int FFOptionsViewVideo::handle_event()
 	const char *name = asset->vcodec;
 	char video_format[BCSTRLEN];  video_format[0] = 0;
 	char video_codec[BCSTRLEN];   video_codec[0] = 0;
-	AVCodec *codec = !ret &&
+	const AVCodec *codec = !ret &&
 	    !FFMPEG::get_format(video_format, "video", name) &&
 	    !FFMPEG::get_codec(video_codec, "video", name) ?
 		avcodec_find_encoder_by_name(video_codec) : 0;
diff --git a/cinelerra-5.1/configure.ac b/cinelerra-5.1/configure.ac
index ceddac2a..9404d2fb 100644
--- a/cinelerra-5.1/configure.ac
+++ b/cinelerra-5.1/configure.ac
@@ -1,11 +1,11 @@
 
-AC_PREREQ([2.69])
-AC_INIT([cinelerra], [5.1], [mail@lists.cinelerra-gg.org])
+AC_PREREQ([2.71])
+AC_INIT([cinelerra],[5.1],[mail@lists.cinelerra-gg.org])
 AM_INIT_AUTOMAKE([foreign])
 
 AM_PROG_AS
-AC_LANG_CPLUSPLUS
-AC_LANG_C
+AC_LANG([C++])
+AC_LANG([C])
 AC_PROG_CXX
 
 CFG_CFLAGS+=" -fno-omit-frame-pointer -fno-math-errno -fno-signed-zeros"
@@ -24,14 +24,15 @@ CFG_CFLAGS+=" -D__STDC_CONSTANT_MACROS"
 CFG_CFLAGS+=" -D__STDC_LIMIT_MACROS"
 CFG_CFLAGS+=" -DPNG_SKIP_SETJMP_CHECK=1"
 CFG_CFLAGS+=" -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64"
-CFG_CFLAGS+=" -I/usr/include -I/usr/local/include"
+# CFG_CFLAGS+=" -I/usr/include -I/usr/local/include"
+CFG_CFLAGS+=" -I/data/data/com.termux/files/usr/include/freetype2"
 CFG_CFLAGS+=" -I/usr/include/freetype2 -I/usr/local/include/freetype2"
 CFG_CFLAGS+=" -I/usr/include/uuid -I/usr/local/include/uuid"
 CFG_CFLAGS+=" -I/usr/include/mjpegtools -I/usr/local/include/mjpegtools"
 
 AC_DEFUN([CHECK_WITH], [
 AC_ARG_WITH([$1],
-  AC_HELP_STRING([--with-[$1]], [$2 ($4)]),
+  AS_HELP_STRING([--with-[$1]],[$2 ($4)]),
   [WANT_$3=$withval], [WANT_$3='$4'])
 AC_SUBST([WANT_$3])
 ])
@@ -64,6 +65,45 @@ CHECK_WITH([nv],[nvenc/nvdec ffnvcodec api],[NV],[yes])
 CHECK_WITH([cuda],[nv cuda plugins],[CUDA],[auto])
 CHECK_WITH([clang],[use clang instead of gcc/g++],[CLANG],[no])
 
+# Checks for header files.
+AC_PATH_X
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h fenv.h inttypes.h libintl.h malloc.h mntent.h netdb.h netinet/in.h stdint.h strings.h sys/file.h sys/ioctl.h sys/socket.h sys/statfs.h sys/time.h unistd.h utime.h])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_CHECK_HEADER_STDBOOL
+AC_C_INLINE
+AC_TYPE_INT16_T
+AC_TYPE_INT32_T
+AC_TYPE_INT64_T
+AC_TYPE_INT8_T
+AC_TYPE_OFF_T
+AC_TYPE_PID_T
+AC_TYPE_SIZE_T
+AC_TYPE_SSIZE_T
+AC_CHECK_MEMBERS([struct stat.st_blksize])
+AC_STRUCT_ST_BLOCKS
+AC_CHECK_MEMBERS([struct stat.st_rdev])
+AC_TYPE_UINT16_T
+AC_TYPE_UINT32_T
+AC_TYPE_UINT64_T
+AC_TYPE_UINT8_T
+
+# Checks for library functions.
+AC_FUNC_ALLOCA
+AC_FUNC_ERROR_AT_LINE
+AC_FUNC_FORK
+AC_FUNC_FSEEKO
+AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
+AC_FUNC_MALLOC
+AC_FUNC_MKTIME
+AC_FUNC_MMAP
+AC_FUNC_REALLOC
+AC_FUNC_STRERROR_R
+AC_FUNC_STRNLEN
+AC_FUNC_STRTOD
+AC_CHECK_FUNCS([atexit bzero dup2 endpwent floor ftruncate getcwd gethostbyname gettimeofday inet_ntoa localtime_r memmove memset mkdir mkfifo modf munmap nl_langinfo pow putenv realpath rint rmdir select setenv setlocale socket sqrt strcasecmp strchr strdup strerror strncasecmp strrchr strstr strtol strtoul tzset uname utime])
+
+
 if test "x$WANT_LV2" != "xno"; then
   GTK2_LIBS=`pkg-config --libs gtk+-2.0`
   AC_CHECK_LIB([m], [gtk_init], [HAVE_gtk=yes], [HAVE_gtk=no], [$GTK2_LIBS])
@@ -153,7 +193,7 @@ inc_$1="$4"
 
 AC_DEFUN([PKG_3RD],[
 AC_ARG_ENABLE([$1],
-  AC_HELP_STRING([--enable-$1],[build $1 ($2)]),
+  AS_HELP_STRING([--enable-$1],[build $1 ($2)]),
   [PKG_$1=$enableval], [PKG_$1=$2])
 PKG_DEF([$1],[$3],[$4],[$5])
 ])
@@ -432,7 +472,7 @@ AC_SUBST(STATIC_PKGS)
 
 AC_DEFUN([CHECK_ENABLE], [
 AC_ARG_ENABLE([$1],
-  AC_HELP_STRING([--enable-[$1]], [$3 ([$4])]),
+  AS_HELP_STRING([--enable-[$1]],[$3 ([$4])]),
   [WANT_$2=$enableval], [WANT_$2=[$4]])
 ])
 
@@ -615,7 +655,7 @@ AC_DEFUN([CHECK_WANT], [
 RESULT=yes
 # WANT_$1
 AC_ARG_WITH(m4_tolower([$1]),
- AC_HELP_STRING([m4_join([-],[--with],m4_tolower([$1]))], [$3] (auto)),
+ AS_HELP_STRING([m4_join([-],[--with],m4_tolower([$1]))],[$3 (auto)]),
   [WANT_$1=$withval],[WANT_$1=$2])
  m4_quote($4)
  if test "x$WANT_$1" = "xauto" ; then
@@ -821,14 +861,14 @@ HAVE_ilmbase=no \
 OBJDIR=`uname -m`
 AC_SUBST(OBJDIR)
 
-echo "AC_HELP_STRING([Reason],[Package])"
-echo "AC_HELP_STRING([------],[-------])"
+echo "AS_HELP_STRING([Reason],[Package])"
+echo "AS_HELP_STRING([------],[-------])"
 
 AC_DEFUN([PKG_DISABLED],[
  PKG_$1="no"
  BUILD_$1=0
  AC_SUBST(BUILD_$1)
- echo "AC_HELP_STRING([disabled],[$1])"
+ echo "AS_HELP_STRING([disabled],[$1])"
 ])
 AC_DEFUN([PKG_SHARED],[
  PKG_$1="shared"
@@ -843,7 +883,7 @@ AC_DEFUN([PKG_STATIC],[
   BUILD_$1=1
   AC_SUBST(BUILD_$1)
   STATIC_BLDS+=" [$1]"
-  echo "AC_HELP_STRING([$2],[$1])"
+  echo "AS_HELP_STRING([$2],[$1])"
  fi
 ])
 
@@ -937,11 +977,11 @@ fi
 
 AC_SUBST(STATIC_BLDS)
 for f in $SHARED_LIBS; do
-  echo "AC_HELP_STRING([shared],[$f])"
+  echo "AS_HELP_STRING([shared],[$f])"
 done
 AC_SUBST(SHARED_LIBS)
 for f in $SYSTEM_LIBS; do
-  echo "AC_HELP_STRING([system],[$f])"
+  echo "AS_HELP_STRING([system],[$f])"
 done
 AC_SUBST(SYSTEM_LIBS)
 
@@ -955,7 +995,7 @@ for v in GL XFT XXF86VM OSS ALSA FIREWIRE OGG DV DVB LADSPA \
 	 VAAPI VDPAU CUDA NV WINTV X10TV; do
   eval vv="\$WANT_$v"
   if test "x$vv" != "xno"; then
-    CFG_CFLAGS+=" -DHAVE_$v"
+    echo "CFG_CFLAGS+="-DHAVE_$v""
     vv=with
   else
     vv=without
diff --git a/cinelerra-5.1/guicast/bcresources.h b/cinelerra-5.1/guicast/bcresources.h
index 2b305f80..c3f85a35 100644
--- a/cinelerra-5.1/guicast/bcresources.h
+++ b/cinelerra-5.1/guicast/bcresources.h
@@ -39,6 +39,8 @@
 #include "vframe.inc"
 
 #include <X11/Xlib.h>
+#include <freetype/freetype.h>
+#include <fontconfig/fontconfig.h>
 
 typedef struct
 {
diff --git a/cinelerra-5.1/guicast/bcwindowbase.h b/cinelerra-5.1/guicast/bcwindowbase.h
index e4eb8ba4..8a034acd 100644
--- a/cinelerra-5.1/guicast/bcwindowbase.h
+++ b/cinelerra-5.1/guicast/bcwindowbase.h
@@ -97,6 +97,10 @@
 #include <GL/glx.h>
 #endif
 
+#include <freetype/freetype.h>
+#include <fontconfig/fontconfig.h>
+#include <X11/Xft/Xft.h>
+
 // scaled x,y unit
 #define xS(v) (BC_WindowBase::get_resources()->x_scale*(v))
 #define yS(v) (BC_WindowBase::get_resources()->y_scale*(v))
diff --git a/cinelerra-5.1/guicast/thread.h b/cinelerra-5.1/guicast/thread.h
index 79f3e713..bec2509d 100644
--- a/cinelerra-5.1/guicast/thread.h
+++ b/cinelerra-5.1/guicast/thread.h
@@ -29,13 +29,15 @@
 #ifndef NO_TID
 #include <sys/syscall.h>
 
+#if defined(__GLIBC__)
 // glibc >= 2.30 provides gettid() in unistd
 #if !defined(__GLIBC_PREREQ) || !__GLIBC_PREREQ(2, 30)
 static inline int gettid() { return syscall(SYS_gettid, 0, 0, 0); }
 #endif
 #else
-static inline long gettid() { return (long)pthread_self(); }
+//static inline long gettid() { return (long)pthread_self(); }
 #endif
+#endif // GLIBC
 
 // The thread does not autodelete by default.
 // If autodelete is 1 the thread autodeletes.