diff --git a/configure b/configure
index 289a327291..2722a9d7da 100755
--- a/configure
+++ b/configure
@@ -323,7 +323,7 @@ esac
 # of AltiVec on PowerPC
 TARGET_OS=`( uname -s ) 2>&1`
   case "$TARGET_OS" in
-  Linux|FreeBSD|NetBSD|BSD/OS|OpenBSD|SunOS|QNX|Darwin|GNU)
+  Linux|FreeBSD|NetBSD|BSD/OS|OpenBSD|SunOS|QNX|Darwin|GNU|BeOS)
     ;;
   IRIX*)
     TARGET_OS=IRIX
@@ -1215,6 +1215,7 @@ fi
 if test "$pthreads" = "yes" ; then
   echo "HAVE_PTHREADS=yes" >> config.mak
   echo "#define HAVE_PTHREADS 1" >> $TMPH
+  echo "#define HAVE_THREADS 1" >> $TMPH
   if test $targetos != FreeBSD; then
      extralibs="$extralibs -lpthread"
   fi
@@ -1366,6 +1367,7 @@ if test "$mingw32" = "yes" ; then
   echo "CONFIG_WIN32=yes" >> config.mak
   echo "HAVE_W32THREADS=yes" >> config.mak
   echo "#define HAVE_W32THREADS 1" >> $TMPH
+  echo "#define HAVE_THREADS 1" >> $TMPH
   echo "#ifndef __MINGW32__" >> $TMPH
   echo "#define __MINGW32__ 1" >> $TMPH
   echo "#endif" >> $TMPH
@@ -1380,6 +1382,12 @@ if test "$TARGET_OS" = "SunOS" ; then
   echo "#define CONFIG_SUNOS 1" >> $TMPH
 fi
 
+if test "$TARGET_OS" = "BeOS" ; then
+  echo "HAVE_BEOSTHREADS=yes" >> config.mak
+  echo "#define HAVE_BEOSTHREADS 1" >> $TMPH
+  echo "#define HAVE_THREADS 1" >> $TMPH
+fi
+
 if test "$darwin" = "yes"; then
   echo "#define CONFIG_DARWIN 1"  >> $TMPH
   echo "CONFIG_DARWIN=yes" >> config.mak
diff --git a/ffmpeg.c b/ffmpeg.c
index 31efd0ce9f..1c7118e204 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -2555,7 +2555,7 @@ static void opt_me_range(const char *arg)
 static void opt_thread_count(const char *arg)
 {
     thread_count= atoi(arg);
-#if !defined(HAVE_PTHREADS) && !defined(HAVE_W32THREADS)
+#if !defined(HAVE_THREADS)
     if (verbose >= 0)
         fprintf(stderr, "Warning: not compiled with thread support, using thread emulation\n");
 #endif
@@ -2825,7 +2825,7 @@ static void opt_input_file(const char *filename)
     /* update the current parameters so that they match the one of the input stream */
     for(i=0;i<ic->nb_streams;i++) {
         AVCodecContext *enc = &ic->streams[i]->codec;
-#if defined(HAVE_PTHREADS) || defined(HAVE_W32THREADS)
+#if defined(HAVE_THREADS)
         if(thread_count>1)
             avcodec_thread_init(enc, thread_count);
 #endif
@@ -2992,7 +2992,7 @@ static void opt_output_file(const char *filename)
                 fprintf(stderr, "Could not alloc stream\n");
                 exit(1);
             }
-#if defined(HAVE_PTHREADS) || defined(HAVE_W32THREADS)
+#if defined(HAVE_THREADS)
             if(thread_count>1)
                 avcodec_thread_init(&st->codec, thread_count);
 #endif
@@ -3244,7 +3244,7 @@ static void opt_output_file(const char *filename)
                 fprintf(stderr, "Could not alloc stream\n");
                 exit(1);
             }
-#if defined(HAVE_PTHREADS) || defined(HAVE_W32THREADS)
+#if defined(HAVE_THREADS)
             if(thread_count>1)
                 avcodec_thread_init(&st->codec, thread_count);
 #endif
diff --git a/ffplay.c b/ffplay.c
index c8d91997f3..13fbd989a7 100644
--- a/ffplay.c
+++ b/ffplay.c
@@ -1174,7 +1174,7 @@ static int stream_component_open(VideoState *is, int stream_index)
     if (!codec ||
         avcodec_open(enc, codec) < 0)
         return -1;
-#if defined(HAVE_PTHREADS) || defined(HAVE_W32THREADS)
+#if defined(HAVE_THREADS)
     if(thread_count>1)
         avcodec_thread_init(enc, thread_count);
 #endif
@@ -1809,7 +1809,7 @@ static void opt_vismv(const char *arg)
 static void opt_thread_count(const char *arg)
 {
     thread_count= atoi(arg);
-#if !defined(HAVE_PTHREADS) && !defined(HAVE_W32THREADS)
+#if !defined(HAVE_THREADS)
     fprintf(stderr, "Warning: not compiled with thread support, using thread emulation\n");
 #endif
 }
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 7d5e780676..67e6a30ff6 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -43,6 +43,10 @@ ifeq ($(HAVE_W32THREADS),yes)
 OBJS+= w32thread.o
 endif
 
+ifeq ($(HAVE_BEOSTHREADS),yes)
+OBJS+= beosthread.o
+endif
+
 ifeq ($(AMR_WB),yes)
 OBJS+= amr.o amrwb_float/dec_acelp.o amrwb_float/dec_dtx.o amrwb_float/dec_gain.o \
 		amrwb_float/dec_if.o amrwb_float/dec_lpc.o amrwb_float/dec_main.o \
diff --git a/libavcodec/beosthread.c b/libavcodec/beosthread.c
new file mode 100644
index 0000000000..90ff1f452d
--- /dev/null
+++ b/libavcodec/beosthread.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2004 François Revol <revol@free.fr>
+ *
+ * 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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+//#define DEBUG
+
+#include "avcodec.h"
+#include "common.h"
+
+#include <OS.h>
+
+typedef struct ThreadContext{
+    AVCodecContext *avctx;
+    thread_id thread;
+    sem_id work_sem;
+    sem_id done_sem;
+    int (*func)(AVCodecContext *c, void *arg);
+    void *arg;
+    int ret;
+}ThreadContext;
+
+
+static int32 ff_thread_func(void *v){
+    ThreadContext *c= v;
+
+    for(;;){
+//printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
+        acquire_sem(c->work_sem);
+//printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
+        if(c->func)
+            c->ret= c->func(c->avctx, c->arg);
+        else
+            return 0;
+//printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
+        release_sem(c->done_sem);
+    }
+    
+    return B_OK;
+}
+
+/**
+ * free what has been allocated by avcodec_thread_init().
+ * must be called after decoding has finished, especially dont call while avcodec_thread_execute() is running
+ */
+void avcodec_thread_free(AVCodecContext *s){
+    ThreadContext *c= s->thread_opaque;
+    int i;
+    int32 ret;
+
+    for(i=0; i<s->thread_count; i++){
+        
+        c[i].func= NULL;
+        release_sem(c[i].work_sem);
+        wait_for_thread(c[i].thread, &ret);
+        if(c[i].work_sem > B_OK) delete_sem(c[i].work_sem);
+        if(c[i].done_sem > B_OK) delete_sem(c[i].done_sem);
+    }
+
+    av_freep(&s->thread_opaque);
+}
+
+int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void **arg, int *ret, int count){
+    ThreadContext *c= s->thread_opaque;
+    int i;
+    
+    assert(s == c->avctx);
+    assert(count <= s->thread_count);
+    
+    /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
+
+    for(i=0; i<count; i++){
+        c[i].arg= arg[i];
+        c[i].func= func;
+        c[i].ret= 12345;
+
+        release_sem(c[i].work_sem);
+    }
+    for(i=0; i<count; i++){
+        acquire_sem(c[i].done_sem);
+        
+        c[i].func= NULL;
+        if(ret) ret[i]= c[i].ret;
+    }
+    return 0;
+}
+
+int avcodec_thread_init(AVCodecContext *s, int thread_count){
+    int i;
+    ThreadContext *c;
+
+    s->thread_count= thread_count;
+
+    assert(!s->thread_opaque);
+    c= av_mallocz(sizeof(ThreadContext)*thread_count);
+    s->thread_opaque= c;
+    
+    for(i=0; i<thread_count; i++){
+//printf("init semaphors %d\n", i); fflush(stdout);
+        c[i].avctx= s;
+
+        if((c[i].work_sem = create_sem(0, "ff work sem")) < B_OK)
+            goto fail;
+        if((c[i].done_sem = create_sem(0, "ff done sem")) < B_OK)
+            goto fail;
+
+//printf("create thread %d\n", i); fflush(stdout);
+        c[i].thread = spawn_thread(ff_thread_func, "libavcodec thread", B_LOW_PRIORITY, &c[i] );
+        if( c[i].thread < B_OK ) goto fail;
+        resume_thread(c[i].thread );
+    }
+//printf("init done\n"); fflush(stdout);
+    
+    s->execute= avcodec_thread_execute;
+
+    return 0;
+fail:
+    avcodec_thread_free(s);
+    return -1;
+}
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 6702cd1ae8..c1f88d0cb4 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -912,7 +912,7 @@ void av_log_set_callback(void (*callback)(void*, int, const char*, va_list))
     av_log_callback = callback;
 }
 
-#if !defined(HAVE_PTHREADS) && !defined(HAVE_W32THREADS)
+#if !defined(HAVE_THREADS)
 int avcodec_thread_init(AVCodecContext *s, int thread_count){
     return -1;
 }