3 files changed, 31 insertions, 8 deletions

diff --git a/apps/debug_menu.c b/apps/debug_menu.c
index 9f71d14156..af8853d93c 100644
--- a/apps/debug_menu.c
+++ b/apps/debug_menu.c
@@ -38,6 +38,7 @@
 #include "font.h"
 #include "disk.h"
 #include "mpeg.h"
+#include "widgets.h"
 
 /*---------------------------------------------------*/
 /*    SPECIAL DEBUG STUFF                            */
@@ -137,8 +138,11 @@ bool dbg_mpeg_thread(void)
 {
     char buf[32];
     int button;
+    int percent;
     struct mpeg_debug d;
 
+    lcd_setmargins(0, 0);
+    
     while(1)
     {
         button = button_get_w_tmo(HZ/5);
@@ -164,6 +168,15 @@ bool dbg_mpeg_thread(void)
         lcd_puts(0, 4, buf);
         snprintf(buf, sizeof(buf), "unswapped: %x", d.unswapped_space);
         lcd_puts(0, 5, buf);
+
+        percent = d.unplayed_space * 100 / d.mp3buflen;
+        progressbar(0, 6*8, 112, 4, percent, Grow_Right);
+
+        percent = MPEG_LOW_WATER * 100 / d.mp3buflen;
+        progressbar(0, 6*8+4, 112, 4, percent, Grow_Right);
+
+        snprintf(buf, sizeof(buf), "lowest: %x", d.lowest_watermark_level);
+        lcd_puts(0, 7, buf);
         
         lcd_update();
     }
diff --git a/firmware/mpeg.c b/firmware/mpeg.c
index d7e7acbf92..9937c3be47 100644
--- a/firmware/mpeg.c
+++ b/firmware/mpeg.c
@@ -40,13 +40,6 @@ extern void bitswap(unsigned char *data, int length);
 static int get_unplayed_space(void);
 static int get_unswapped_space(void);
 
-#define MPEG_SWAP_CHUNKSIZE  0x2000
-#define MPEG_HIGH_WATER  2 /* We leave 2 bytes empty because otherwise we
-                              wouldn't be able to see the difference between
-                              an empty buffer and a full one. */
-#define MPEG_LOW_WATER  0x40000
-#define MPEG_LOW_WATER_CHUNKSIZE  0x40000
-
 #define MPEG_PLAY         1
 #define MPEG_STOP         2
 #define MPEG_PAUSE        3
@@ -439,7 +432,8 @@ static bool is_playing; /* We are (attempting to) playing MP3 files */
 static bool filling; /* We are filling the buffer with data from disk */
 static bool dma_underrun; /* True when the DMA has stopped because of
                              slow disk reading (read error, shaking) */
-
+static int lowest_watermark_level; /* Debug value to observe the buffer
+                                      usage */
 static int mpeg_file;
 
 void mpeg_get_debugdata(struct mpeg_debug *dbgdata)
@@ -460,6 +454,8 @@ void mpeg_get_debugdata(struct mpeg_debug *dbgdata)
 
     dbgdata->unplayed_space = get_unplayed_space();
     dbgdata->unswapped_space = get_unswapped_space();
+
+    dbgdata->lowest_watermark_level = lowest_watermark_level;
 }
 
 static void mas_poll_start(int interval_in_ms)
@@ -598,6 +594,7 @@ static void reset_mp3_buffer(void)
     mp3buf_read = 0;
     mp3buf_write = 0;
     mp3buf_swapwrite = 0;
+    lowest_watermark_level = mp3buflen;
 }
 
 #pragma interrupt
@@ -662,6 +659,10 @@ void DEI3(void)
             DTCR3 = last_dma_chunk_size & 0xffff;
             SAR3 = (unsigned int)mp3buf + mp3buf_read;
             id3tags[tag_read_idx]->id3.offset += last_dma_chunk_size;
+
+            /* Update the watermark debug level */
+            if(unplayed_space_left < lowest_watermark_level)
+                lowest_watermark_level = unplayed_space_left;
         }
         else
         {
diff --git a/firmware/mpeg.h b/firmware/mpeg.h
index 97a1b36c1a..02c5e814a2 100644
--- a/firmware/mpeg.h
+++ b/firmware/mpeg.h
@@ -21,6 +21,13 @@
 
 #include <stdbool.h>
 
+#define MPEG_SWAP_CHUNKSIZE  0x2000
+#define MPEG_HIGH_WATER  2 /* We leave 2 bytes empty because otherwise we
+                              wouldn't be able to see the difference between
+                              an empty buffer and a full one. */
+#define MPEG_LOW_WATER  0x40000
+#define MPEG_LOW_WATER_CHUNKSIZE  0x40000
+
 struct mpeg_debug
 {
         int mp3buflen;
@@ -39,6 +46,8 @@ struct mpeg_debug
 
         int unplayed_space;
         int unswapped_space;
+
+        int lowest_watermark_level;
 };
 
 void mpeg_init(int volume, int bass, int treble, int balance,