Index: libmpcodecs/ae_faac.c
===================================================================
--- libmpcodecs/ae_faac.c	(revision 25055)
+++ libmpcodecs/ae_faac.c	(working copy)
@@ -69,6 +69,23 @@
 	((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->nBlockSize = mux_a->wf->nBlockAlign;
 	((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->nFramesPerBlock = 1;
 	((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->nCodecDelay = 0;
+
+        /* remap channels */
+	switch (mux_a->wf->nChannels) {
+		case 1: /* FC, no action needed */
+		case 2: /* FL FR, no action needed */
+		case 3: /* no suitable default behavior? */
+		case 4: /* FL FR BL BR, no action needed */
+			break;
+		case 5: /* FC FL FR BL BR */
+			encoder->output_chan_map = "40" "01" "12" "23" "34";
+			break;
+		case 6: /* FC FL FR BL BR LFE */
+			encoder->output_chan_map = "40" "01" "12" "23" "34" "55";
+			break;
+		default:
+			break;
+	}
 	
 	// Fix allocation    
 	mux_a->wf = realloc(mux_a->wf, sizeof(WAVEFORMATEX)+mux_a->wf->cbSize);
Index: libmpcodecs/ae_pcm.c
===================================================================
--- libmpcodecs/ae_pcm.c	(revision 25055)
+++ libmpcodecs/ae_pcm.c	(working copy)
@@ -28,6 +28,23 @@
 	mux_a->wf->wBitsPerSample=16;
 	mux_a->wf->cbSize=0; // FIXME for l3codeca.acm
 	
+	/* re-map channels */
+	switch (mux_a->wf->nChannels) {
+		case 1: /* FC, no action needed */
+		case 2: /* FL FR, no action needed */
+		case 3: /* unknown; may not exist */
+		case 4: /* FL FR BL BR, no action needed */
+			break;
+		case 5: /* FL FR C BL BR */
+			encoder->output_chan_map = "00" "11" "42" "23" "34";
+			break;
+		case 6: /* FL FR C LFE BL BR */
+			encoder->output_chan_map = "00" "11" "42" "53" "24" "35";
+			break;
+		default:
+			break;
+	}
+ 	
 	encoder->input_format = (mux_a->wf->wBitsPerSample==8) ? AF_FORMAT_U8 : AF_FORMAT_S16_LE;
 	encoder->min_buffer_size = 16384;
 	encoder->max_buffer_size = mux_a->wf->nAvgBytesPerSec;
Index: libmpcodecs/ad_pcm.c
===================================================================
--- libmpcodecs/ad_pcm.c	(revision 25055)
+++ libmpcodecs/ad_pcm.c	(working copy)
@@ -22,6 +22,22 @@
   WAVEFORMATEX *h=sh_audio->wf;
   sh_audio->i_bps=h->nAvgBytesPerSec;
   sh_audio->channels=h->nChannels;
+  /* re-map channels */
+  switch (sh_audio->channels) {
+    case 1: /* FC, no action needed */
+    case 2: /* FL FR, no action needed */
+    case 3: /* unknown; may not exist */
+    case 4: /* FL FR BL BR, no action needed */
+      break;
+    case 5: /* FL FR C BL BR */
+      sh_audio->input_chan_map = "00" "11" "24" "32" "43";
+      break;
+    case 6: /* FL FR C LFE BL BR */
+      sh_audio->input_chan_map = "00" "11" "24" "35" "42" "53";
+      break;
+    default:
+      break;
+  }
   sh_audio->samplerate=h->nSamplesPerSec;
   sh_audio->samplesize=(h->wBitsPerSample+7)/8;
   sh_audio->sample_format=AF_FORMAT_S16_LE; // default
Index: libmpcodecs/ad_faad.c
===================================================================
--- libmpcodecs/ad_faad.c	(revision 25055)
+++ libmpcodecs/ad_faad.c	(working copy)
@@ -151,6 +151,24 @@
     mp_msg(MSGT_DECAUDIO,MSGL_V,"FAAD: Negotiated samplerate: %ldHz  channels: %d\n", faac_samplerate, faac_channels);
     sh->channels = faac_channels;
     if (audio_output_channels <= 2) sh->channels = faac_channels > 1 ? 2 : 1;
+    
+    /* re-map channels */
+    switch (sh->channels) {
+      case 1: /* FC, no action needed */
+      case 2: /* FL FR, no action needed */
+      case 3: /* no suitable default behavior? */
+      case 4: /* FL FR BL BR, no action needed */
+        break;
+      case 5: /* FC FL FR BL BR */
+        sh->input_chan_map = "04" "10" "21" "32" "43";
+        break;
+      case 6: /* FC FL FR BL BR LFE */
+        sh->input_chan_map = "04" "10" "21" "32" "43" "55";
+        break;
+      default:
+        break;
+    }
+    
     sh->samplerate = faac_samplerate;
     sh->samplesize=2;
     //sh->o_bps = sh->samplesize*faac_channels*faac_samplerate;
Index: libmpcodecs/ad_dmo.c
===================================================================
--- libmpcodecs/ad_dmo.c	(revision 25055)
+++ libmpcodecs/ad_dmo.c	(working copy)
@@ -38,6 +38,22 @@
   }
     sh_audio->i_bps=sh_audio->wf->nAvgBytesPerSec;
     sh_audio->channels=chans;
+    /* re-map channels */
+    switch (chans) {
+      case 1: /* FC, no action needed */
+      case 2: /* FL FR, no action needed */
+      case 3: /* apparently does not exist */
+      case 4: /* FL FR BL BR, no action needed */
+        break;
+      case 5: /* FL FR FC BL BR */
+        sh_audio->input_chan_map = "00" "11" "23" "34" "42";
+        break;
+      case 6: /* FL FR FC LFE BL BR */
+        sh_audio->input_chan_map = "00" "11" "24" "35" "42" "53";
+        break;
+      default:
+        break;
+    }
     sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
     sh_audio->samplesize=2;
     sh_audio->audio_in_minsize=4*sh_audio->wf->nBlockAlign;
Index: libmpcodecs/dec_audio.c
===================================================================
--- libmpcodecs/dec_audio.c	(revision 25055)
+++ libmpcodecs/dec_audio.c	(working copy)
@@ -335,6 +335,8 @@
 
     // filter config:
     memcpy(&afs->cfg, &af_cfg, sizeof(af_cfg_t));
+    afs->input_chan_map  = sh_audio->input_chan_map;
+    afs->output_chan_map = sh_audio->output_chan_map;
 
     mp_msg(MSGT_DECAUDIO, MSGL_V, MSGTR_BuildingAudioFilterChain,
 	   afs->input.rate, afs->input.nch,
Index: libmpcodecs/ae.h
===================================================================
--- libmpcodecs/ae.h	(revision 25055)
+++ libmpcodecs/ae.h	(working copy)
@@ -39,6 +39,7 @@
 	int (*encode)(struct audio_encoder_s *encoder, uint8_t *dest, void *src, int nsamples, int max_size);
 	void (*fixup)(struct audio_encoder_s *encoder);
 	int (*close)(struct audio_encoder_s *encoder);
+	char *output_chan_map;
 } audio_encoder_t;
 
 audio_encoder_t *new_audio_encoder(muxer_stream_t *stream, audio_encoding_params_t *params);
Index: libmpcodecs/ae_lavc.c
===================================================================
--- libmpcodecs/ae_lavc.c	(revision 25055)
+++ libmpcodecs/ae_lavc.c	(working copy)
@@ -46,6 +46,22 @@
 	mux_a->wf->nAvgBytesPerSec = (lavc_actx->bit_rate / 8);
         mux_a->avg_rate= lavc_actx->bit_rate;
 	mux_a->h.dwRate = mux_a->wf->nAvgBytesPerSec;
+	/* remap channels */
+	switch (lavc_actx->channels) {
+		case 1: /* FC, no action needed */
+		case 2: /* FL FR, no action needed */
+		case 3: /* unknown */
+		case 4: /* FL FR BL BR, no action needed */
+			break;
+		case 5: /* FL FC FR BL BR */
+			encoder->output_chan_map = "00" "21" "32" "43" "14";
+			break;
+		case 6: /* FL FC FR BL BR LFE */
+			encoder->output_chan_map = "00" "21" "32" "43" "14" "55";
+			break;
+		default:
+			break;
+	}
 	if(lavc_actx->block_align)
 		mux_a->h.dwSampleSize = mux_a->h.dwScale = lavc_actx->block_align;
 	else 
Index: libao2/ao_pcm.c
===================================================================
--- libao2/ao_pcm.c	(revision 25055)
+++ libao2/ao_pcm.c	(working copy)
@@ -106,6 +106,23 @@
 	ao_data.samplerate=rate;
 	ao_data.format=format;
 	ao_data.bps=channels*rate*(bits/8);
+        
+	/* re-map channels */
+	switch (ao_data.channels) {
+		case 1: /* FC, no action needed */
+		case 2: /* FL FR, no action needed */
+		case 3: /* unknown; may not exist */
+		case 4: /* FL FR BL BR, no action needed */
+			break;
+		case 5: /* FL FR C BL BR */
+			ao_data.output_chan_map = "00" "11" "42" "23" "34";
+			break;
+		case 6: /* FL FR C LFE BL BR */
+			ao_data.output_chan_map = "00" "11" "42" "53" "24" "35";
+			break;
+		default:
+			break;
+	}
 
 	wavhdr.riff = le2me_32(WAV_ID_RIFF);
 	wavhdr.wave = le2me_32(WAV_ID_WAVE);
Index: libao2/audio_out.h
===================================================================
--- libao2/audio_out.h	(revision 25055)
+++ libao2/audio_out.h	(working copy)
@@ -39,6 +39,7 @@
   int outburst; 	  
   int buffersize;         
   int pts;
+  char *output_chan_map;
 } ao_data_t;
 
 extern char *ao_subdevice;
Index: DOCS/man/en/mplayer.1
===================================================================
--- DOCS/man/en/mplayer.1	(revision 25055)
+++ DOCS/man/en/mplayer.1	(working copy)
@@ -1457,6 +1457,14 @@
 Always falls back on content-based demuxer selection.
 .
 .TP
+.B \-noremap-channels
+Some audio formats have a different channel order than MPlayer and
+MEncoder use internally.
+Normally, the channels audio filter is automatically inserted to remap
+the channels as necessary.
+This option disables the remapping.
+.
+.TP
 .B \-passwd <password> (also see \-user) (network only)
 Specify password for HTTP authentication.
 .
Index: mplayer.c
===================================================================
--- mplayer.c	(revision 25055)
+++ mplayer.c	(working copy)
@@ -304,6 +304,7 @@
 
        float force_fps=0;
 static int force_srate=0;
+static int remap_channels=1;
 static int audio_output_format=-1; // AF_FORMAT_UNKNOWN
        int frame_dropping=0; // option  0=no drop  1= drop vo  2= drop decode
 static int play_n_frames=-1;
@@ -1224,6 +1225,8 @@
       playback_speed = (float)new_srate / (float)sh_audio->samplerate;
     }
   }
+  if (!remap_channels)
+    sh_audio->input_chan_map = sh_audio->output_chan_map = NULL;
   result =  init_audio_filters(sh_audio, new_srate,
            &ao_data->samplerate, &ao_data->channels, &ao_data->format);
   mpctx->mixer.afilter = sh_audio->afilter;
@@ -1505,6 +1508,8 @@
   ao_data.format=audio_output_format;
 #if 1
   // first init to detect best values
+  if (!remap_channels)
+      mpctx->sh_audio->input_chan_map = mpctx->sh_audio->output_chan_map = NULL;
   if(!init_audio_filters(mpctx->sh_audio,   // preliminary init
         // input:
         mpctx->sh_audio->samplerate,
@@ -1541,6 +1546,7 @@
     // init audio filters:
 #if 1
     current_module="af_init";
+    mpctx->sh_audio->output_chan_map = ao_data.output_chan_map;
     if(!build_afilter_chain(mpctx->sh_audio, &ao_data)) {
       mp_msg(MSGT_CPLAYER,MSGL_ERR,MSGTR_NoMatchingFilter);
 //      mp_msg(MSGT_CPLAYER,MSGL_ERR,"Couldn't find matching filter / ao format! -> NOSOUND\n");
Index: cfg-common.h
===================================================================
--- cfg-common.h	(revision 25055)
+++ cfg-common.h	(working copy)
@@ -173,6 +173,8 @@
 	{"fps", &force_fps, CONF_TYPE_FLOAT, CONF_MIN, 0, 0, NULL},
 	{"srate", &force_srate, CONF_TYPE_INT, CONF_RANGE, 1000, 8*48000, NULL},
 	{"channels", &audio_output_channels, CONF_TYPE_INT, CONF_RANGE, 1, 6, NULL},
+	{"remap-channels", &remap_channels, CONF_TYPE_FLAG, 0, 0, 1, NULL},
+	{"noremap-channels", &remap_channels, CONF_TYPE_FLAG, 0, 1, 0, NULL},
 	{"format", &audio_output_format, CONF_TYPE_AFMT, 0, 0, 0, NULL},
 	{"speed", &playback_speed, CONF_TYPE_FLOAT, CONF_RANGE, 0.01, 100.0, NULL},
 
Index: libmpdemux/stheader.h
===================================================================
--- libmpdemux/stheader.h	(revision 25055)
+++ libmpdemux/stheader.h	(working copy)
@@ -18,6 +18,8 @@
   int samplerate;
   int samplesize;
   int channels;
+  char *input_chan_map;
+  char *output_chan_map;
   int o_bps; // == samplerate*samplesize*channels   (uncompr. bytes/sec)
   int i_bps; // == bitrate  (compressed bytes/sec)
   // in buffers:
Index: mencoder.c
===================================================================
--- mencoder.c	(revision 25055)
+++ mencoder.c	(working copy)
@@ -169,6 +169,7 @@
 float playback_speed=1.0;
 
 static int force_srate=0;
+static int remap_channels=1;
 static int audio_output_format=0;
 
 char *vobsub_out=NULL;
@@ -407,7 +408,7 @@
 int new_srate=0;
 
 unsigned int timer_start=0;
-ao_data_t ao_data = {0,0,0,0,OUTBURST,-1,0};
+ao_data_t ao_data = {0,0,0,0,OUTBURST,-1,0,NULL};
 
 audio_encoding_params_t aparams;
 audio_encoder_t *aencoder = NULL;
@@ -914,6 +915,8 @@
 ao_data.samplerate = force_srate;
 ao_data.channels = 0;
 ao_data.format = audio_output_format;
+if (!remap_channels)
+    sh_audio->input_chan_map = sh_audio->output_chan_map = NULL;
 if(!init_audio_filters(sh_audio,
    // input:
    new_srate,
@@ -930,6 +933,9 @@
     aencoder = new_audio_encoder(mux_a, &aparams);
     if(!aencoder)
         mencoder_exit(1, NULL);
+    sh_audio->output_chan_map = aencoder->output_chan_map;
+    if (!remap_channels)
+        sh_audio->input_chan_map = sh_audio->output_chan_map = NULL;
     if(!init_audio_filters(sh_audio, 
         new_srate,
         &aparams.sample_rate, &aparams.channels, &aencoder->input_format)) {
Index: libaf/af.c
===================================================================
--- libaf/af.c	(revision 25055)
+++ libaf/af.c	(working copy)
@@ -361,12 +361,12 @@
 
   // Check if this is the first call
   if(!s->first){
+    /* remap input channels if the codec/demuxer provides a map */
+    if (s->input_chan_map)
+      if (AF_OK != af_append_channel_map(s, s->first, s->input_chan_map))
+        return -1;
     // Add all filters in the list (if there are any)
-    if(!s->cfg.list){      // To make automatic format conversion work
-      if(!af_append(s,s->first,"dummy")) 
-	return -1; 
-    }
-    else{
+    if (s->cfg.list) {
       while(s->cfg.list[i]){
 	if(!af_append(s,s->last,s->cfg.list[i++]))
 	  return -1;
@@ -374,6 +374,20 @@
     }
   }
 
+  /* remap output channels if the codec/ao provides a map */
+  if (s->output_chan_map) {
+    if (AF_OK != af_append_channel_map(s, s->last, s->output_chan_map))
+      return -1;
+    /* make sure we don't append this more than once */
+    s->output_chan_map = NULL;
+  }
+
+  // To make automatic format conversion work
+  if (!s->first){
+    if(!af_append(s,s->first,"dummy")) 
+      return -1; 
+  }
+
   // Init filters 
   if(AF_OK != af_reinit(s,s->first))
     return -1;
@@ -606,3 +620,36 @@
 {
     data->bps = af_fmt2bits(data->format)/8;
 }
+
+int af_append_channel_map(af_stream_t *s, af_instance_t *af_prev, char *chan_map){
+  af_control_ext_t arg;
+  af_instance_t *af = NULL;
+  int channels, route[2];
+  channels = af_prev ? af_prev->data->nch : s->input.nch;
+  /* check input */
+  if (strlen(chan_map) != 2*channels) {
+    af_msg(AF_MSG_ERROR, "channel map: num. of routes does not match num. of channels\n");
+    return AF_ERROR;
+  }
+  /* set up af_channels to route */
+  af = af_append(s, af_prev, "channels");
+  if (!af || (AF_OK != af->control(af, AF_CONTROL_CHANNELS_ROUTER, &channels)))
+    return AF_ERROR;
+  if (!af || (AF_OK != af->control(af, AF_CONTROL_CHANNELS_NR, &channels)))
+    return AF_ERROR;
+  /* pass each route to af_channels */
+  for (arg.ch = 0; arg.ch < channels; ++arg.ch) {
+    /* two by two... */
+    route[0] = *chan_map++ - '0';
+    route[1] = *chan_map++ - '0';
+    arg.arg = route;
+    if (!af || (AF_OK != af->control(af, AF_CONTROL_CHANNELS_ROUTING, &arg)))
+      return AF_ERROR;
+  }
+  /* try it! */
+  if (!af || (AF_OK != af->control(af, AF_CONTROL_CHANNELS, &channels)))
+    return AF_ERROR;
+  if (AF_OK != af_reinit(s,af))
+    return AF_ERROR;
+  return AF_OK;
+}
Index: libaf/af.h
===================================================================
--- libaf/af.h	(revision 25055)
+++ libaf/af.h	(working copy)
@@ -100,6 +100,8 @@
   af_data_t output;
   // Configuration for this stream
   af_cfg_t cfg;
+  char *input_chan_map;
+  char *output_chan_map;
 }af_stream_t;
 
 /*********************************************
@@ -295,6 +297,18 @@
  */
 void af_fix_parameters(af_data_t *data);
 
+/**
+ * \brief set up channel remapping
+ * \param af_stream
+ * \param af_instance to append this instance after
+ * \param string of channel routes
+ * \return AF_OK if ok, AF_ERROR otherwise
+ *
+ * Checks that the number of routes matches channels, and creates an instance
+ * of af_channels with the routes specified in *chan_map.
+ */
+int af_append_channel_map(af_stream_t *s, af_instance_t *af_prev, char *chan_map);
+
 /** Memory reallocation macro: if a local buffer is used (i.e. if the
    filter doesn't operate on the incoming buffer this macro must be
    called to ensure the buffer is big enough.