diff --git a/audio.c b/audio.c
index a703d660..90ca8fac 100644
--- a/audio.c
+++ b/audio.c
@@ -458,7 +458,7 @@ uint32_t get_channel_settings(const char *stanza_name, const char *setting_name)
           for (i = 0; i < channel_counts_count; i++) {
             debug(3, "channel count setting %d: %d.", i, channel_counts[i]);
 
-            if ((channel_counts[i] >= 1) && (channel_counts[i] <= 8)) {
+            if ((channel_counts[i] >= 1) && (channel_counts[i] <= SPS_GREATEST_CHANNEL_COUNT)) {
 #ifdef CONFIG_FFMPEG
               channel_set |= (1 << channel_counts[i]);
 #else
@@ -492,7 +492,7 @@ uint32_t get_channel_settings(const char *stanza_name, const char *setting_name)
   char numbuf[32];
   unsigned int c;
   uint32_t t_channel_set = channel_set;
-  for (c = 0; c <= 8; c++) {
+  for (c = 0; c <= SPS_GREATEST_CHANNEL_COUNT; c++) {
     if ((t_channel_set & (1 << c)) != 0) {
       snprintf(numbuf, sizeof(numbuf) - 1, "%u", c);
       snprintf(p, sizeof(buf) - (p - buf) - 1, "%s", numbuf);
diff --git a/common.h b/common.h
index a7a0604d..e18af0f9 100644
--- a/common.h
+++ b/common.h
@@ -146,7 +146,13 @@ typedef enum {
 // these sets omit the _UNKNOWN, _AUTO and _ILLEGAL values
 #define SPS_FORMAT_SET (((1 << (SPS_FORMAT_HIGHEST_NATIVE + 1)) - 1) - (1 << SPS_FORMAT_UNKNOWN))
 #define SPS_RATE_SET (((1 << (SPS_RATE_HIGHEST + 1)) - 1) - (1 << SPS_RATE_UNKNOWN))
-#define SPS_CHANNEL_SET (((1 << (8 + 1)) - 1) - (1 << 0)) // channels 1 to 8, not 0-based!
+
+// in SPS_CHANNEL_SET, bit 0 set means a channel set of no channels, bit 1 set means a channel set of 1 channel
+// and so on to bit 31 meaning a channel set of 31 channels. We want to consider all possible channel sets
+// apart from channel set 0.
+#define SPS_GREATEST_CHANNEL_COUNT 31 // should be 32 to be fully in line with ALSA limits
+#define SPS_CHANNEL_SET 0xFFFFFFFE // channel sets 31 to 1, but no channel set 0
+// #define SPS_CHANNEL_SET (((1 << (SPS_GREATEST_CHANNEL_COUNT + 1)) - 1) - (1 << 0)) // channels 1 to 31, not 0-based!
 
 #ifndef CONFIG_AIRPLAY_2
 #define SPS_FORMAT_NON_FFMPEG_SET SPS_FORMAT_SET
diff --git a/player.c b/player.c
index 2d8b9081..3ccd33de 100644
--- a/player.c
+++ b/player.c
@@ -656,24 +656,43 @@ int setup_software_resampler(rtsp_conn_info *conn, ssrc_t ssrc) {
     // set the resampler's channel layout either automatically or use the
     // setting that has been given
 
+    // We impose the rule that, if the mixdown setting is "auto",
+    // we will not upmix if the number of output channels available
+    // is greater than the number of channels needed.
+
+    // To do an upmix, you will have to specify the upmix target, e.g. "7.1"
+    // in the mixdown setting.
+    
+    // NOTE: upmixing at present, by default, simply copies the input channels to their
+    // equivalents in the output channel set. All the other channels are
+    // left alone.
+
 #if LIBAVUTIL_VERSION_MAJOR >= 57
     {
       AVChannelLayout input_channel_layout;
       av_channel_layout_from_mask(&input_channel_layout, input_layout);
+      int input_channel_count = input_channel_layout.nb_channels;
       av_opt_set_chlayout(swr, "in_chlayout", &input_channel_layout, 0);
       av_channel_layout_uninit(&input_channel_layout);
 
       AVChannelLayout output_channel_layout;
       if (config.mixdown_enable != 0) {
         if (config.mixdown_channel_layout == 0) {
-          av_channel_layout_default(&output_channel_layout,
+          if (CHANNELS_FROM_ENCODED_FORMAT(output_configuration) > (unsigned) input_channel_count) {
+            av_channel_layout_from_mask(&output_channel_layout, input_layout);
+          } else {
+            av_channel_layout_default(&output_channel_layout,
                                     CHANNELS_FROM_ENCODED_FORMAT(output_configuration));
+          }
         } else {
           av_channel_layout_from_mask(&output_channel_layout, config.mixdown_channel_layout);
         }
       } else {
         av_channel_layout_from_mask(&output_channel_layout, output_layout);
       }
+      char layout_desc[2048];
+      av_channel_layout_describe(&output_channel_layout, layout_desc, sizeof(layout_desc));
+      debug(1,"output channel layout: \"%s\"", layout_desc);
       av_opt_set_chlayout(swr, "out_chlayout", &output_channel_layout, 0);
       av_channel_layout_uninit(&output_channel_layout);
     }
@@ -681,8 +700,10 @@ int setup_software_resampler(rtsp_conn_info *conn, ssrc_t ssrc) {
     av_opt_set_int(swr, "in_channel_layout", input_layout, 0);
     if (config.mixdown_enable != 0) {
       if (config.mixdown_channel_layout == 0) {
-        output_layout =
-            av_get_default_channel_layout(CHANNELS_FROM_ENCODED_FORMAT(output_configuration));
+        if (CHANNELS_FROM_ENCODED_FORMAT(output_configuration) < av_get_channel_layout_nb_channels(input_layout)) {
+          output_layout =
+              av_get_default_channel_layout(CHANNELS_FROM_ENCODED_FORMAT(output_configuration));
+        } // else leave output_layout as it was: the sames as the input_layout.
       } else {
         output_layout = config.mixdown_channel_layout;
       }
@@ -962,7 +983,7 @@ int setup_software_resampler(rtsp_conn_info *conn, ssrc_t ssrc) {
 
       if (output_configuration_changed != 0) {
         char channel_mapping_list[256] = "";
-        for (c = 0; c < 8; c++) {
+        for (c = 0; c < SPS_GREATEST_CHANNEL_COUNT; c++) {
           if ((output_channels[c].allocated != 0) &&
               (conn->output_channel_to_resampler_channel_map[c] != silent_channel_index)) {
             char channel_mapping[32] = "";