diff --git a/TOOLS/vivodump.c b/TOOLS/vivodump.c
index a35b4ddd58..568ff4e266 100644
--- a/TOOLS/vivodump.c
+++ b/TOOLS/vivodump.c
@@ -252,7 +252,7 @@ while((c=fgetc(f))>=0){
 	// end of frame:
 	printf("Frame size: %d\n",mux->buffer_len);
 	h263_decode_picture_header(mux->buffer);
-	muxer_write_chunk(mux,mux->buffer_len,0x10);
+	muxer_write_chunk(mux,mux->buffer_len,0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 	mux->buffer_len=0;
 	
 	if((v_id&0xF0)==0x10) fprintf(stderr,"hmm. last video packet %02X\n",v_id);
diff --git a/libmpcodecs/ve_divx4.c b/libmpcodecs/ve_divx4.c
index 79daf1e67e..565713bf99 100644
--- a/libmpcodecs/ve_divx4.c
+++ b/libmpcodecs/ve_divx4.c
@@ -396,9 +396,9 @@ static int put_image(struct vf_instance_s* vf, mp_image_t *mpi){
     vf->priv->enc_frame.produce_empty_frame = 0;
     encore(vf->priv->enc_handle, ENC_OPT_ENCODE, &vf->priv->enc_frame, &enc_result);
     if(enc_result.cType == 'I')
-        muxer_write_chunk(mux_v,vf->priv->enc_frame.length,0x10);
+        muxer_write_chunk(mux_v,vf->priv->enc_frame.length,0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     else
-        muxer_write_chunk(mux_v,vf->priv->enc_frame.length,0);
+        muxer_write_chunk(mux_v,vf->priv->enc_frame.length,0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 #else
     vf->priv->enc_frame.mvs=NULL;
 #ifdef HAVE_XVID_VBR
@@ -444,7 +444,7 @@ static int put_image(struct vf_instance_s* vf, mp_image_t *mpi){
 					       enc_result.quantizer);
 	}
     }
-    muxer_write_chunk(mux_v,vf->priv->enc_frame.length,enc_result.is_key_frame?0x10:0);
+    muxer_write_chunk(mux_v,vf->priv->enc_frame.length,enc_result.is_key_frame?0x10:0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 #endif
     return 1;
 }
diff --git a/libmpcodecs/ve_lavc.c b/libmpcodecs/ve_lavc.c
index 61d458e45c..2ef0065767 100644
--- a/libmpcodecs/ve_lavc.c
+++ b/libmpcodecs/ve_lavc.c
@@ -859,7 +859,7 @@ static int encode_frame(struct vf_instance_s* vf, AVFrame *pic){
     if(out_size == 0)
         return 0;
            
-    muxer_write_chunk(mux_v,out_size,lavc_venc_context->coded_frame->key_frame?0x10:0);
+    muxer_write_chunk(mux_v,out_size,lavc_venc_context->coded_frame->key_frame?0x10:0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
         
 #if LIBAVCODEC_BUILD >= 4643
     /* store psnr / pict size / type / qscale */
diff --git a/libmpcodecs/ve_libdv.c b/libmpcodecs/ve_libdv.c
index ab7b2ec727..0f9430f295 100644
--- a/libmpcodecs/ve_libdv.c
+++ b/libmpcodecs/ve_libdv.c
@@ -77,7 +77,7 @@ static int put_image(struct vf_instance_s* vf, mp_image_t *mpi){
 	(mpi->flags&MP_IMGFLAG_YUV) ? e_dv_color_yuv : e_dv_color_rgb,
 	mux_v->buffer);
 
-    muxer_write_chunk(mux_v, 480 * (vf->priv->enc->isPAL ? 300 : 250) , 0x10);
+    muxer_write_chunk(mux_v, 480 * (vf->priv->enc->isPAL ? 300 : 250) , 0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     return 1;
 }
 
diff --git a/libmpcodecs/ve_nuv.c b/libmpcodecs/ve_nuv.c
index 2cc96cbc54..e61ac326ad 100644
--- a/libmpcodecs/ve_nuv.c
+++ b/libmpcodecs/ve_nuv.c
@@ -118,7 +118,7 @@ static int put_image(struct vf_instance_s* vf, mp_image_t *mpi){
   
     le2me_rtframeheader(ench);
     mux_v->buffer=vf->priv->buffer;
-    muxer_write_chunk(mux_v,FRAMEHEADERSIZE + 128*sizeof(long int), 0x10);
+    muxer_write_chunk(mux_v,FRAMEHEADERSIZE + 128*sizeof(long int), 0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     vf->priv->tbl_wrote = 1;
     memset(ench,0,FRAMEHEADERSIZE); // Reset the header
   }
@@ -175,7 +175,7 @@ static int put_image(struct vf_instance_s* vf, mp_image_t *mpi){
   ench->packetlength = len;
   le2me_rtframeheader(ench);
   mux_v->buffer=(void*)ench;
-  muxer_write_chunk(mux_v, len + FRAMEHEADERSIZE, 0x10);
+  muxer_write_chunk(mux_v, len + FRAMEHEADERSIZE, 0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
   return 1;
 }
 
diff --git a/libmpcodecs/ve_qtvideo.c b/libmpcodecs/ve_qtvideo.c
index d5a1f83692..0d6fe172f5 100644
--- a/libmpcodecs/ve_qtvideo.c
+++ b/libmpcodecs/ve_qtvideo.c
@@ -260,7 +260,7 @@ if(!codec_inited){
     printf("Size %i->%i   \n",stride*height,compressedsize);
     printf("Ratio: %i:1\n",(stride*height)/compressedsize);
 #endif
-    muxer_write_chunk(mux_v, compressedsize , similarity?0:0x10);
+    muxer_write_chunk(mux_v, compressedsize , similarity?0:0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 
     if(((*desc)->idSize)>MAX_IDSIZE){
 	mp_msg(MSGT_MENCODER,MSGL_ERR,"FATAL! idSize=%d too big, increase MAX_IDSIZE in ve_qtvideo.c!\n",((*desc)->idSize));
diff --git a/libmpcodecs/ve_raw.c b/libmpcodecs/ve_raw.c
index 206b5fdf40..8557eae1da 100644
--- a/libmpcodecs/ve_raw.c
+++ b/libmpcodecs/ve_raw.c
@@ -117,7 +117,7 @@ static int query_format(struct vf_instance_s *vf, unsigned int fmt) {
 
 static int put_image(struct vf_instance_s *vf, mp_image_t *mpi) {
     mux_v->buffer = mpi->planes[0];
-    muxer_write_chunk(mux_v, mpi->width*mpi->height*mux_v->bih->biBitCount/8, 0x10);
+    muxer_write_chunk(mux_v, mpi->width*mpi->height*mux_v->bih->biBitCount/8, 0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     return 1;
 }
 
diff --git a/libmpcodecs/ve_vfw.c b/libmpcodecs/ve_vfw.c
index 063aa12535..b362908a89 100644
--- a/libmpcodecs/ve_vfw.c
+++ b/libmpcodecs/ve_vfw.c
@@ -243,7 +243,7 @@ static int put_image(struct vf_instance_s* vf, mp_image_t *mpi){
     int ret;
 //    flip_upside_down(vo_image_ptr,vo_image_ptr,3*vo_w,vo_h); // dirty hack
     ret=vfw_encode_frame(mux_v->bih, mux_v->buffer, vfw_bih, mpi->planes[0], &flags, 10000);
-    muxer_write_chunk(mux_v,mux_v->bih->biSizeImage,flags);
+    muxer_write_chunk(mux_v,mux_v->bih->biSizeImage,flags, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     return 1;
 }
 
diff --git a/libmpcodecs/ve_x264.c b/libmpcodecs/ve_x264.c
index 08b236740a..8e51796bd8 100644
--- a/libmpcodecs/ve_x264.c
+++ b/libmpcodecs/ve_x264.c
@@ -511,7 +511,7 @@ static int encode_frame(struct vf_instance_s *vf, x264_picture_t *pic_in)
         int keyframe = (pic_out.i_type == X264_TYPE_IDR) ||
                        (pic_out.i_type == X264_TYPE_I
                         && frame_ref == 1 && !bframe);
-        muxer_write_chunk(mod->mux, i_size, keyframe?0x10:0);
+        muxer_write_chunk(mod->mux, i_size, keyframe?0x10:0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     }
 
     return i_size;
diff --git a/libmpcodecs/ve_xvid.c b/libmpcodecs/ve_xvid.c
index 45fcacf68f..bfb08b70fb 100644
--- a/libmpcodecs/ve_xvid.c
+++ b/libmpcodecs/ve_xvid.c
@@ -523,7 +523,7 @@ put_image(struct vf_instance_s* vf, mp_image_t *mpi)
 #endif
     
     // write output
-    muxer_write_chunk(fp->mux, fp->enc_frame.length, fp->enc_frame.intra==1 ? 0x10 : 0);
+    muxer_write_chunk(fp->mux, fp->enc_frame.length, fp->enc_frame.intra==1 ? 0x10 : 0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 
     // update the VBR engine
     vbrUpdate(&fp->vbr_state, enc_stats.quant, fp->enc_frame.intra,
diff --git a/libmpcodecs/ve_xvid4.c b/libmpcodecs/ve_xvid4.c
index d0016b5cd2..3789b8dc67 100644
--- a/libmpcodecs/ve_xvid4.c
+++ b/libmpcodecs/ve_xvid4.c
@@ -629,7 +629,7 @@ put_image(struct vf_instance_s* vf, mp_image_t *mpi)
 	/* xvidcore outputed bitstream -- mux it */
 	muxer_write_chunk(mod->mux,
 			  size,
-			  (mod->frame.out_flags & XVID_KEYFRAME)?0x10:0);
+			  (mod->frame.out_flags & XVID_KEYFRAME)?0x10:0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 
 	return(FINE);
 }
@@ -1378,7 +1378,7 @@ flush_internal_buffers(xvid_mplayer_module_t *mod)
 
 			/* xvidcore outputed bitstream -- mux it */
 			muxer_write_chunk(mod->mux, size,
-					(mod->frame.out_flags & XVID_KEYFRAME)?0x10:0);
+					(mod->frame.out_flags & XVID_KEYFRAME)?0x10:0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 		}
 	} while (size>0);
 }
diff --git a/libmpdemux/muxer.c b/libmpdemux/muxer.c
index e2da4efa3b..0a075886e6 100644
--- a/libmpdemux/muxer.c
+++ b/libmpdemux/muxer.c
@@ -52,9 +52,12 @@ muxer_t *muxer_new_muxer(int type,FILE *f){
 /* buffer frames until we either:
  * (a) have at least one frame from each stream
  * (b) run out of memory */
-void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags) {
+void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags, double dts, double pts) {
+    if(dts == MP_NOPTS_VALUE) dts= s->timer;
+    if(pts == MP_NOPTS_VALUE) pts= s->timer; // this is wrong
+
     if (s->muxer->muxbuf_skip_buffer) {
-      s->muxer->cont_write_chunk(s, len, flags);
+      s->muxer->cont_write_chunk(s, len, flags, dts, pts);
     }
     else {
       int num = s->muxer->muxbuf_num++;
@@ -70,7 +73,8 @@ void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags) {
       
       /* buffer this frame */
       buf->stream = s;
-      buf->timer = s->timer;
+      buf->dts= dts;
+      buf->pts= pts;
       buf->len = len;
       buf->flags = flags;
       buf->buffer = malloc(len * sizeof (unsigned char));
@@ -89,11 +93,6 @@ void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags) {
       
       /* see if we can flush buffer now */
       if (s->muxer->muxbuf_skip_buffer) {
-        muxbuf_t *tmp_buf = malloc(sizeof(muxbuf_t));
-        if (!tmp_buf) {
-          mp_msg(MSGT_MUXER, MSGL_FATAL, MSGTR_MuxbufMallocErr);
-          return;
-        }
         mp_msg(MSGT_MUXER, MSGL_V, MSGTR_MuxbufSending, s->muxer->muxbuf_num);
         
         /* fix parameters for all streams */
@@ -109,23 +108,23 @@ void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags) {
         
         /* send all buffered frames to muxer */
         for (num = 0; num < s->muxer->muxbuf_num; ++num) {
+          muxbuf_t tmp_buf;
           buf = s->muxer->muxbuf + num;
           s = buf->stream;
           
           /* 1. save timer and buffer (might have changed by now) */
-          tmp_buf->timer = s->timer;
-          tmp_buf->buffer = s->buffer;
+          tmp_buf.dts = s->timer;
+          tmp_buf.buffer = s->buffer;
           
           /* 2. move stored timer and buffer into stream and mux it */
-          s->timer = buf->timer;
+          s->timer = buf->dts;
           s->buffer = buf->buffer;
-          s->muxer->cont_write_chunk(s, buf->len, buf->flags);
+          s->muxer->cont_write_chunk(s, buf->len, buf->flags, buf->dts, buf->pts);
           
           /* 3. restore saved timer and buffer */
-          s->timer = tmp_buf->timer;
-          s->buffer = tmp_buf->buffer;
+          s->timer = tmp_buf.dts;
+          s->buffer = tmp_buf.buffer;
         }
-        free(tmp_buf);
         
         free(s->muxer->muxbuf);
         s->muxer->muxbuf_num = 0;
diff --git a/libmpdemux/muxer.h b/libmpdemux/muxer.h
index 353da665e7..fedbad64f8 100644
--- a/libmpdemux/muxer.h
+++ b/libmpdemux/muxer.h
@@ -76,7 +76,7 @@ typedef struct muxer_t{
   int muxbuf_skip_buffer;
   // functions:
   void (*fix_stream_parameters)(muxer_stream_t *);
-  void (*cont_write_chunk)(muxer_stream_t *,size_t,unsigned int);
+  void (*cont_write_chunk)(muxer_stream_t *,size_t,unsigned int, double dts, double pts);
   void (*cont_write_header)(struct muxer_t *);
   void (*cont_write_index)(struct muxer_t *);
   muxer_stream_t* (*cont_new_stream)(struct muxer_t *,int);
@@ -87,17 +87,19 @@ typedef struct muxer_t{
 /* muxer frame buffer */
 typedef struct muxbuf_t {
   muxer_stream_t *stream; /* pointer back to corresponding stream */
-  double timer; /* snapshot of stream timer */
+  double dts; /* decode timestamp / time at which this packet should be feeded into the decoder */
+  double pts; /* presentation timestamp / time at which the data in this packet will be presented to the user */
   unsigned char *buffer;
   size_t len;
   unsigned int flags;
 } muxbuf_t;
 
+#define MP_NOPTS_VALUE (-1LL<<63) //both int64_t and double should be able to represent this exactly
 
 muxer_t *muxer_new_muxer(int type,FILE *);
 #define muxer_new_stream(muxer,a) muxer->cont_new_stream(muxer,a)
 #define muxer_stream_fix_parameters(muxer, a) muxer->fix_stream_parameters(a)
-void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags);
+void muxer_write_chunk(muxer_stream_t *s, size_t len, unsigned int flags, double dts, double pts);
 #define muxer_write_header(muxer) muxer->cont_write_header(muxer)
 #define muxer_write_index(muxer) muxer->cont_write_index(muxer)
 
diff --git a/libmpdemux/muxer_avi.c b/libmpdemux/muxer_avi.c
index 32d47bc947..7169a8a4b0 100644
--- a/libmpdemux/muxer_avi.c
+++ b/libmpdemux/muxer_avi.c
@@ -191,7 +191,7 @@ static void avifile_odml_new_riff(muxer_t *muxer)
 
 static void avifile_write_header(muxer_t *muxer);
 
-static void avifile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags){
+static void avifile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags, double dts, double pts){
     off_t rifflen;
     muxer_t *muxer=s->muxer;
     struct avi_stream_info *si = s->priv;
diff --git a/libmpdemux/muxer_lavf.c b/libmpdemux/muxer_lavf.c
index 5ae2ab4f19..88aa1dfc96 100644
--- a/libmpdemux/muxer_lavf.c
+++ b/libmpdemux/muxer_lavf.c
@@ -248,7 +248,7 @@ static void fix_parameters(muxer_stream_t *stream)
 	}
 }
 
-static void write_chunk(muxer_stream_t *stream, size_t len, unsigned int flags)
+static void write_chunk(muxer_stream_t *stream, size_t len, unsigned int flags, double dts, double pts)
 {
 	muxer_t *muxer = (muxer_t*) stream->muxer;
 	muxer_priv_t *priv = (muxer_priv_t *) muxer->priv;
diff --git a/libmpdemux/muxer_mpeg.c b/libmpdemux/muxer_mpeg.c
index 58c8646bb7..59751b17f8 100644
--- a/libmpdemux/muxer_mpeg.c
+++ b/libmpdemux/muxer_mpeg.c
@@ -2349,7 +2349,7 @@ static int parse_audio(muxer_stream_t *s, int finalize, int *nf, double *timer)
 
 
 
-static void mpegfile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags){
+static void mpegfile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags, double dts_arg, double pts_arg){
   size_t ptr=0, sz = 0;
   uint64_t pts, tmp;
   muxer_t *muxer = s->muxer;
diff --git a/libmpdemux/muxer_rawaudio.c b/libmpdemux/muxer_rawaudio.c
index 71bf56628e..a7132d227b 100644
--- a/libmpdemux/muxer_rawaudio.c
+++ b/libmpdemux/muxer_rawaudio.c
@@ -45,7 +45,7 @@ static muxer_stream_t* rawaudiofile_new_stream(muxer_t *muxer,int type){
     return s;
 }
 
-static void rawaudiofile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags){
+static void rawaudiofile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags, double dts, double pts){
     muxer_t *muxer=s->muxer;
 
     // write out the chunk:
diff --git a/libmpdemux/muxer_rawvideo.c b/libmpdemux/muxer_rawvideo.c
index 00c4436562..fda4eb8bac 100644
--- a/libmpdemux/muxer_rawvideo.c
+++ b/libmpdemux/muxer_rawvideo.c
@@ -50,7 +50,7 @@ static void write_rawvideo_chunk(FILE *f,int len,void* data){
     }
 }
 
-static void rawvideofile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags){
+static void rawvideofile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags, double dts, double pts){
     muxer_t *muxer=s->muxer;
 
     // write out the chunk:
diff --git a/mencoder.c b/mencoder.c
index 177116d30e..faff346eb0 100644
--- a/mencoder.c
+++ b/mencoder.c
@@ -1219,7 +1219,7 @@ if(sh_audio){
 	    }
 	}
 	if(len<=0) break; // EOF?
-	muxer_write_chunk(mux_a,len,0x10);
+	muxer_write_chunk(mux_a,len,0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 	if(!mux_a->h.dwSampleSize && mux_a->timer>0)
 	    mux_a->wf->nAvgBytesPerSec=0.5f+(double)mux_a->size/mux_a->timer; // avg bps (VBR)
 	if(mux_a->buffer_len>=len){
@@ -1304,11 +1304,11 @@ ptimer_start = GetTimerMS();
 switch(mux_v->codec){
 case VCODEC_COPY:
     mux_v->buffer=frame_data.start;
-    if(skip_flag<=0) muxer_write_chunk(mux_v,frame_data.in_size,(sh_video->ds->flags&1)?0x10:0);
+    if(skip_flag<=0) muxer_write_chunk(mux_v,frame_data.in_size,(sh_video->ds->flags&1)?0x10:0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     break;
 case VCODEC_FRAMENO:
     mux_v->buffer=(unsigned char *)&decoded_frameno; // tricky
-    if(skip_flag<=0) muxer_write_chunk(mux_v,sizeof(int),0x10);
+    if(skip_flag<=0) muxer_write_chunk(mux_v,sizeof(int),0x10, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
     break;
 default:
     // decode_video will callback down to ve_*.c encoders, through the video filters
@@ -1333,7 +1333,7 @@ default:
 	if(skip_limit==0){
 	    // skipping not allowed -> write empty frame:
 	    if (!encode_duplicates || !sh_video->vfilter || ((vf_instance_t *)sh_video->vfilter)->control(sh_video->vfilter, VFCTRL_DUPLICATE_FRAME, 0) != CONTROL_TRUE)
-	      muxer_write_chunk(mux_v,0,0);
+	      muxer_write_chunk(mux_v,0,0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 	} else {
 	    // skipping allowed -> skip it and distriubute timer error:
 	    v_timer_corr-=(float)mux_v->h.dwScale/mux_v->h.dwRate;
@@ -1352,7 +1352,7 @@ if(skip_flag<0){
     while(skip_flag<0){
 	duplicatedframes++;
 	if (!encode_duplicates || !sh_video->vfilter || ((vf_instance_t *)sh_video->vfilter)->control(sh_video->vfilter, VFCTRL_DUPLICATE_FRAME, 0) != CONTROL_TRUE)
-	    muxer_write_chunk(mux_v,0,0);
+	    muxer_write_chunk(mux_v,0,0, MP_NOPTS_VALUE, MP_NOPTS_VALUE);
 	++skip_flag;
     }
 } else