New recording feature: Prerecord up to 30 seconds before you press the Play key. Especially useful for FM radio recording. Also fixed a bug which didn't apply the recording settings correctly in the Radio screen.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4183 a1c6a512-1295-4272-9138-f99709370657

8 files changed, 526 insertions, 245 deletions

diff --git a/apps/lang/english.lang b/apps/lang/english.lang
index ffdc12b306..5cad562a7f 100644
--- a/apps/lang/english.lang
+++ b/apps/lang/english.lang
@@ -1847,3 +1847,13 @@ id: LANG_FLIP_DISPLAY
 desc: in settings_menu, option to turn display+buttos by 180 degreed
 eng: "Upside Down"
 new:
+
+id: LANG_RECORD_PRERECORD
+desc: in recording and radio screen
+eng: "Prerecording"
+new:
+
+id: LANG_RECORD_PRERECORD_TIME
+desc: in recording settings_menu
+eng: "Prerecord time"
+new:
diff --git a/apps/recorder/radio.c b/apps/recorder/radio.c
index ab0c1eb004..519e919964 100644
--- a/apps/recorder/radio.c
+++ b/apps/recorder/radio.c
@@ -172,9 +172,10 @@ bool radio_screen(void)
 
     mpeg_set_recording_options(global_settings.rec_frequency,
                                global_settings.rec_quality,
-                               1 /* Line In */,
+                               1, /* Line In */
                                global_settings.rec_channels,
-                               global_settings.rec_editable);
+                               global_settings.rec_editable,
+                               global_settings.rec_prerecord_time);
 
     
     mpeg_set_recording_gain(mpeg_sound_default(SOUND_LEFT_GAIN),
@@ -230,7 +231,7 @@ bool radio_screen(void)
         switch(button)
         {
             case BUTTON_OFF:
-                if(mpeg_status())
+                if(mpeg_status() == MPEG_STATUS_RECORD)
                 {
                     mpeg_stop();
                     status_set_playmode(STATUS_STOP);
@@ -244,17 +245,16 @@ bool radio_screen(void)
                 break;
 
             case BUTTON_F3:
-                /* Only act if the mpeg is stopped */
-                if(!mpeg_status())
+                if(mpeg_status() == MPEG_STATUS_RECORD)
                 {
-                    have_recorded = true;
-                    mpeg_record(rec_create_filename());
-                    status_set_playmode(STATUS_RECORD);
+                    mpeg_new_file(rec_create_filename());
                     update_screen = true;
                 }
                 else
                 {
-                    mpeg_new_file(rec_create_filename());
+                    have_recorded = true;
+                    mpeg_record(rec_create_filename());
+                    status_set_playmode(STATUS_RECORD);
                     update_screen = true;
                 }
                 last_seconds = 0;
@@ -353,11 +353,12 @@ bool radio_screen(void)
                 
             case SYS_USB_CONNECTED:
                 /* Only accept USB connection when not recording */
-                if(!mpeg_status())
+                if(mpeg_status() != MPEG_STATUS_RECORD)
                 {
                     usb_screen();
                     fmradio_set_status(0);
-                    have_recorded = true; /* Refreshes the browser later on */
+                    screen_freeze = true; /* Cosmetic: makes sure the
+                                             radio screen doesn't redraw */
                     done = true;
                 }
                 break;
@@ -368,6 +369,8 @@ bool radio_screen(void)
         if(!screen_freeze)
         {
             lcd_setmargins(0, 8);
+            
+            /* Only display the peak meter when not recording */
             if(!mpeg_status())
             {
                 lcd_clearrect(0, 8 + fh*(top_of_screen + 3), LCD_WIDTH, fh);
@@ -415,7 +418,7 @@ bool radio_screen(void)
                          str(LANG_CHANNEL_MONO));
                 lcd_puts(0, top_of_screen + 2, buf);
 
-                if(mpeg_status())
+                if(mpeg_status() == MPEG_STATUS_RECORD)
                 {
                     hours = seconds / 3600;
                     minutes = (seconds - (hours * 3600)) / 60;
@@ -424,6 +427,12 @@ bool radio_screen(void)
                              hours, minutes, seconds%60);
                     lcd_puts(0, top_of_screen + 3, buf);
                 }
+                else
+                {
+                    snprintf(buf, 32, "%s %02d",
+                             str(LANG_RECORD_PRERECORD), seconds%60);
+                    lcd_puts(0, top_of_screen + 3, buf);
+                }
                 
                 /* Only force the redraw if update_screen is true */
                 status_draw(update_screen);
@@ -687,7 +696,19 @@ bool radio_delete_preset(void)
 
 static bool fm_recording_settings(void)
 {
-    return recording_menu(true);
+    bool ret;
+    
+    ret = recording_menu(true);
+    if(!ret)
+    {
+        mpeg_set_recording_options(global_settings.rec_frequency,
+                                   global_settings.rec_quality,
+                                   1, /* Line In */
+                                   global_settings.rec_channels,
+                                   global_settings.rec_editable,
+                                   global_settings.rec_prerecord_time);
+    }
+    return ret;
 }
 
 bool radio_menu(void)
diff --git a/apps/recorder/recording.c b/apps/recorder/recording.c
index d94508e547..bc26ff8495 100644
--- a/apps/recorder/recording.c
+++ b/apps/recorder/recording.c
@@ -160,7 +160,8 @@ bool recording_screen(void)
                                global_settings.rec_quality,
                                global_settings.rec_source,
                                global_settings.rec_channels,
-                               global_settings.rec_editable);
+                               global_settings.rec_editable,
+                               global_settings.rec_prerecord_time);
 
     set_gain();
 
@@ -174,7 +175,7 @@ bool recording_screen(void)
         switch(button)
         {
             case BUTTON_OFF:
-                if(mpeg_status())
+                if(mpeg_status() & MPEG_STATUS_RECORD)
                 {
                     mpeg_stop();
                     status_set_playmode(STATUS_STOP);
@@ -190,7 +191,7 @@ bool recording_screen(void)
 
             case BUTTON_PLAY:
                 /* Only act if the mpeg is stopped */
-                if(!mpeg_status())
+                if(!(mpeg_status() & MPEG_STATUS_RECORD))
                 {
                     have_recorded = true;
                     mpeg_record(rec_create_filename());
@@ -305,13 +306,16 @@ bool recording_screen(void)
                 if (recording_menu(false))
                     return SYS_USB_CONNECTED;
                 settings_save();
+
                 mpeg_set_recording_options(global_settings.rec_frequency,
                                            global_settings.rec_quality,
                                            global_settings.rec_source,
                                            global_settings.rec_channels,
-                                           global_settings.rec_editable);
+                                           global_settings.rec_editable,
+                                           global_settings.rec_prerecord_time);
                 
                 set_gain();
+
                 update_countdown = 1; /* Update immediately */
 
                 lcd_setfont(FONT_SYSFIXED);
@@ -319,7 +323,7 @@ bool recording_screen(void)
                 break;
 
             case BUTTON_F2:
-                if(!mpeg_status())
+                if(mpeg_status() != MPEG_STATUS_RECORD)
                 {
                     if (f2_rec_screen())
                     {
@@ -332,7 +336,7 @@ bool recording_screen(void)
                 break;
 
             case BUTTON_F3:
-                if(!mpeg_status())
+                if(mpeg_status() != MPEG_STATUS_RECORD)
                 {
                     if (f3_rec_screen())
                     {
@@ -346,14 +350,12 @@ bool recording_screen(void)
 
             case SYS_USB_CONNECTED:
                 /* Only accept USB connection when not recording */
-                if(!mpeg_status())
+                if(mpeg_status() != MPEG_STATUS_RECORD)
                 {
                     usb_screen();
                     have_recorded = true; /* Refreshes the browser later on */
                     done = true;
                 }
-                lcd_setfont(FONT_SYSFIXED);
-                lcd_setmargins(global_settings.invert_cursor ? 0 : w, 8);
                 break;
         }
 
@@ -387,21 +389,28 @@ bool recording_screen(void)
 
                 dseconds = rec_timesplit_seconds(); 
 
-                /* Display the split interval if the record timesplit
-                   is active */
-                if (global_settings.rec_timesplit)
+                if(mpeg_status() & MPEG_STATUS_PRERECORD)
                 {
-                    /* Display the record timesplit interval rather than 
-                       the file size if the record timer is active */
-                    dhours = dseconds / 3600;
-                    dminutes = (dseconds - (dhours * 3600)) / 60;
-                    snprintf(buf, 32, "%s %02d:%02d",
-                             str(LANG_RECORD_TIMESPLIT_REC),
-                             dhours, dminutes);
+                    snprintf(buf, 32, "%s...", str(LANG_RECORD_PRERECORD));
                 }
                 else
-                    snprintf(buf, 32, "%s %s", str(LANG_RECORDING_SIZE),
-                             num2max5(mpeg_num_recorded_bytes(), buf2));
+                {
+                    /* Display the split interval if the record timesplit
+                       is active */
+                    if (global_settings.rec_timesplit)
+                    {
+                        /* Display the record timesplit interval rather than 
+                           the file size if the record timer is active */
+                        dhours = dseconds / 3600;
+                        dminutes = (dseconds - (dhours * 3600)) / 60;
+                        snprintf(buf, 32, "%s %02d:%02d",
+                                 str(LANG_RECORD_TIMESPLIT_REC),
+                                 dhours, dminutes);
+                    }
+                    else
+                        snprintf(buf, 32, "%s %s", str(LANG_RECORDING_SIZE),
+                                 num2max5(mpeg_num_recorded_bytes(), buf2));
+                }
                 lcd_puts(0, 1, buf);
 
                 /* We will do file splitting regardless, since the OFF
@@ -622,7 +631,8 @@ bool f2_rec_screen(void)
                                global_settings.rec_quality,
                                global_settings.rec_source,
                                global_settings.rec_channels,
-                               global_settings.rec_editable);
+                               global_settings.rec_editable,
+                               global_settings.rec_prerecord_time);
 
     set_gain();
     
@@ -671,22 +681,6 @@ bool f3_rec_screen(void)
                 used = true;
                 break;
 
-            case BUTTON_DOWN:
-            case BUTTON_F3 | BUTTON_DOWN:
-                global_settings.rec_frequency++;
-                if(global_settings.rec_frequency > 5)
-                    global_settings.rec_frequency = 0;
-                used = true;
-                break;
-
-            case BUTTON_RIGHT:
-            case BUTTON_F3 | BUTTON_RIGHT:
-                global_settings.rec_channels++;
-                if(global_settings.rec_channels > 1)
-                    global_settings.rec_channels = 0;
-                used = true;
-                break;
-
             case BUTTON_F3 | BUTTON_REL:
                 if ( used )
                     exit = true;
@@ -707,10 +701,11 @@ bool f3_rec_screen(void)
                                global_settings.rec_quality,
                                global_settings.rec_source,
                                global_settings.rec_channels,
-                               global_settings.rec_editable);
+                               global_settings.rec_editable,
+                               global_settings.rec_prerecord_time);
 
     set_gain();
-    
+
     settings_save();
     lcd_setfont(FONT_UI);
 
diff --git a/apps/settings.c b/apps/settings.c
index b2fa22170b..35e75d12ca 100644
--- a/apps/settings.c
+++ b/apps/settings.c
@@ -129,6 +129,9 @@ location used, and reset the setting in question with a factory default if
 needed. Memory locations not used by a given version should not be
 modified unless the header & checksum test fails.
 
+Because 0xff mean that the byte is unused, care must be taken so that
+a used byte can't have the value 0xff. Either use only 7 bits, or make sure
+that the value will never be 0xff.
 
 Rest of config block, only saved to disk:
 0xA8  (char)jump scroll mode (only for player)
@@ -151,9 +154,8 @@ Rest of config block, only saved to disk:
 0xB8  (char[20]) WPS file
 0xCC  (char[20]) Lang file
 0xE0  (char[20]) Font file
-0xF4  <unused>
-0xF8  <unused>
-0xFC  <unused>
+0xF4  Prerecording time (bit 0-4)
+0xF5-0xFF  <unused>
 
 *************************************/
 
@@ -432,6 +434,8 @@ int settings_save( void )
     strncpy(&config_block[0xcc], global_settings.lang_file, MAX_FILENAME);
     strncpy(&config_block[0xe0], global_settings.font_file, MAX_FILENAME);
 
+    config_block[0xf4]=(unsigned char)global_settings.rec_prerecord_time;
+
     if(save_config_buffer())
     {
         lcd_clear_display();
@@ -756,6 +760,10 @@ void settings_load(void)
         strncpy(global_settings.wps_file, &config_block[0xb8], MAX_FILENAME);
         strncpy(global_settings.lang_file, &config_block[0xcc], MAX_FILENAME);
         strncpy(global_settings.font_file, &config_block[0xe0], MAX_FILENAME);
+
+        if (config_block[0xf4] != 0xff)
+            global_settings.rec_prerecord_time = config_block[0xf4];
+        
 #ifdef HAVE_LCD_CHARCELLS
         if (config_block[0xa8] != 0xff)
             global_settings.jump_scroll = config_block[0xa8];
@@ -1079,6 +1087,9 @@ bool settings_load_config(char* file)
         else if (!strcasecmp(name, "editable recordings")) {
             set_cfg_bool(&global_settings.rec_editable, value);
         }
+        else if (!strcasecmp(name, "prerecording time")) {
+            set_cfg_int(&global_settings.rec_prerecord_time, value, 0, 30);
+        }
 #endif
         else if (!strcasecmp(name, "idle poweroff")) {
             static char* options[] = {"off","1","2","3","4","5","6","7","8",
@@ -1379,6 +1390,10 @@ bool settings_save_config(void)
     fprintf(fd, "line in: %s\r\n", boolopt[global_settings.line_in]);
 #endif
 
+    fprintf(fd, "max files in dir: %d\r\n", global_settings.max_files_in_dir);
+    fprintf(fd, "max files in playlist: %d\r\n",
+            global_settings.max_files_in_playlist);
+    
 #ifdef HAVE_MAS3587F
     fprintf(fd, "#\r\n# Recording\r\n#\r\n");
     fprintf(fd, "rec quality: %d\r\n", global_settings.rec_quality);
@@ -1409,12 +1424,12 @@ bool settings_save_config(void)
     fprintf(fd, "editable recordings: %s\r\n",
             boolopt[global_settings.rec_editable]);
 
+    fprintf(fd, "prerecording time: %d\r\n",
+            global_settings.rec_prerecord_time);
+
 #endif
 
-    fprintf(fd, "max files in dir: %d\r\n", global_settings.max_files_in_dir);
-    fprintf(fd, "max files in playlist: %d\r\n",
-            global_settings.max_files_in_playlist);
-    
+    fprintf(fd, "#\r\n# Playlists\r\n#\r\n");
     {
         static char* options[] = {"off", "on", "ask"};
         fprintf(fd, "recursive directory insert: %s\r\n",
@@ -1454,6 +1469,7 @@ void settings_reset(void) {
     global_settings.rec_left_gain = 2; /* 0dB */
     global_settings.rec_right_gain = 2; /* 0dB */
     global_settings.rec_editable = false;
+    global_settings.rec_prerecord_time = 0;
     global_settings.resume      = RESUME_ASK;
     global_settings.contrast    = lcd_default_contrast();
     global_settings.invert      = DEFAULT_INVERT_SETTING;
diff --git a/apps/settings.h b/apps/settings.h
index 074be0690a..49327b2f80 100644
--- a/apps/settings.h
+++ b/apps/settings.h
@@ -85,6 +85,8 @@ struct user_settings
                           5 = 01:00, 6 = 02:00, 7 = 04:00, 8 = 06:00
                           9 = 08:00, 10= 10:00, 11= 12:00, 12= 18:00,
                           13= 24:00 */
+
+    int rec_prerecord_time; /* In seconds, 0-30, 0 means OFF */
     
     /* device settings */
 
diff --git a/apps/sound_menu.c b/apps/sound_menu.c
index c5e254794e..557013df8a 100644
--- a/apps/sound_menu.c
+++ b/apps/sound_menu.c
@@ -241,6 +241,20 @@ static bool rectimesplit(void)
                       names, 14, NULL );
 }
 
+static bool recprerecord(void)
+{
+    char *names[] = {
+        str(LANG_OFF),"1s","2s", "3s", "4s", "5s", "6s", "7s", "8s", "9s",
+        "10s", "11s", "12s", "13s", "14s", "15s", "16s", "17s", "18s", "19s",
+        "20s", "21s", "22s", "23s", "24s", "25s", "26s", "27s", "28s", "29s",
+        "30s"
+    };
+
+    return set_option(str(LANG_RECORD_PRERECORD_TIME),
+                      &global_settings.rec_prerecord_time, INT,
+                      names, 31, NULL );
+}
+
 #endif /* HAVE_MAS3587F */
 
 static void set_chanconf(int val)
@@ -294,7 +308,7 @@ bool recording_menu(bool no_source)
 {
     int m;
     int i = 0;
-    struct menu_items menu[6];
+    struct menu_items menu[7];
     bool result;
 
     menu[i].desc = str(LANG_RECORDING_QUALITY);
@@ -311,6 +325,8 @@ bool recording_menu(bool no_source)
     menu[i++].function = receditable;
     menu[i].desc = str(LANG_RECORD_TIMESPLIT);
     menu[i++].function = rectimesplit;
+    menu[i].desc = str(LANG_RECORD_PRERECORD_TIME);
+    menu[i++].function = recprerecord;
         
     m=menu_init( menu, i );
     result = menu_run(m);
diff --git a/firmware/export/mpeg.h b/firmware/export/mpeg.h
index 63eecf51db..bbace28ecd 100644
--- a/firmware/export/mpeg.h
+++ b/firmware/export/mpeg.h
@@ -32,6 +32,8 @@
 #define MPEG_PLAY_PENDING_THRESHOLD 0x10000
 #define MPEG_PLAY_PENDING_SWAPSIZE 0x10000
 
+#define MPEG_MAX_PRERECORD_SECONDS 30
+
 /* For ID3 info and VBR header */
 #define MPEG_RESERVED_HEADER_SPACE (4096 + 1500)
 
@@ -89,7 +91,7 @@ void mpeg_record(char *filename);
 void mpeg_new_file(char *filename);
 void mpeg_set_recording_options(int frequency, int quality,
                                 int source, int channel_mode,
-                                bool editable);
+                                bool editable, int prerecord_time);
 void mpeg_set_recording_gain(int left, int right, bool use_mic);
 unsigned long mpeg_recorded_time(void);
 unsigned long mpeg_num_recorded_bytes(void);
@@ -123,7 +125,8 @@ void mpeg_error_clear(void);
 #define MPEG_STATUS_PLAY 1
 #define MPEG_STATUS_PAUSE 2
 #define MPEG_STATUS_RECORD 4
-#define MPEG_STATUS_ERROR 8
+#define MPEG_STATUS_PRERECORD 8
+#define MPEG_STATUS_ERROR 16
 
 #define MPEGERR_DISK_FULL 1
 
diff --git a/firmware/mpeg.c b/firmware/mpeg.c
index 80e871597e..43da221800 100644
--- a/firmware/mpeg.c
+++ b/firmware/mpeg.c
@@ -44,6 +44,7 @@ extern void bitswap(unsigned char *data, int length);
 #ifdef HAVE_MAS3587F
 static void init_recording(void);
 static void init_playback(void);
+static void start_prerecording(void);
 static void start_recording(void);
 static void stop_recording(void);
 static int get_unsaved_space(void);
@@ -497,6 +498,17 @@ static char recording_filename[MAX_PATH];
 static int rec_frequency_index; /* For create_xing_header() calls */
 static int rec_version_index;   /* For create_xing_header() calls */
 static bool disable_xing_header; /* When splitting files */
+
+static bool prerecording; /* True if prerecording is enabled */
+static bool is_prerecording; /* True if we are prerecording */
+static int prerecord_buffer[MPEG_MAX_PRERECORD_SECONDS]; /* Array of buffer
+                                                            indexes for each
+                                                            prerecorded
+                                                            second */
+static int prerecord_index; /* Current index in the prerecord buffer */
+static int prerecording_max_seconds;   /* Max number of seconds to store */
+static int prerecord_count; /* Number of seconds in the prerecord buffer */
+static int prerecord_timeout; /* The tick count of the next prerecord data store */
 #endif
 
 static int mpeg_file;
@@ -865,17 +877,38 @@ static void dma_tick(void)
 
             num_rec_bytes += i;
             
-            /* Signal to save the data if we are running out of buffer
-               space */
-            num_bytes = mp3buf_write - mp3buf_read;
-            if(num_bytes < 0)
-                num_bytes += mp3buflen;
+            if(is_prerecording)
+            {
+                if(TIME_AFTER(current_tick, prerecord_timeout))
+                {
+                    prerecord_timeout = current_tick + HZ;
+
+                    /* Store the write pointer every second */
+                    prerecord_buffer[prerecord_index++] = mp3buf_write;
+
+                    /* Wrap if necessary */
+                    if(prerecord_index == prerecording_max_seconds)
+                        prerecord_index = 0;
 
-            if(mp3buflen - num_bytes < MPEG_RECORDING_LOW_WATER && !saving)
+                    /* Update the number of seconds recorded */
+                    if(prerecord_count < prerecording_max_seconds)
+                        prerecord_count++;
+                }
+            }
+            else
             {
-                saving = true;
-                queue_post(&mpeg_queue, MPEG_SAVE_DATA, 0);
-                wake_up_thread();
+                /* Signal to save the data if we are running out of buffer
+                   space */
+                num_bytes = mp3buf_write - mp3buf_read;
+                if(num_bytes < 0)
+                    num_bytes += mp3buflen;
+                
+                if(mp3buflen - num_bytes < MPEG_RECORDING_LOW_WATER && !saving)
+                {
+                    saving = true;
+                    queue_post(&mpeg_queue, MPEG_SAVE_DATA, 0);
+                    wake_up_thread();
+                }
             }
         }
     }
@@ -1887,20 +1920,84 @@ static void mpeg_thread(void)
             switch(ev.id)
             {
                 case MPEG_RECORD:
-                    DEBUGF("Recording...\n");
-                    reset_mp3_buffer();
+                    if(is_prerecording)
+                    {
+                        int startpos, i;
+                        
+                        /* Go back prerecord_count seconds in the buffer */
+                        startpos = prerecord_index - prerecord_count;
+                        if(startpos < 0)
+                            startpos += prerecording_max_seconds;
+
+                        /* Read the mp3 buffer pointer from the prerecord buffer */
+                        startpos = prerecord_buffer[startpos];
+
+                        DEBUGF("Start looking at address %x (%x)\n",
+                               mp3buf+startpos, startpos);
+
+                        saved_header = get_last_recorded_header();
+                        
+                        mem_find_next_frame(startpos, &offset, 5000,
+                                            saved_header);
+
+                        mp3buf_read = startpos + offset;
+                        
+                        DEBUGF("New mp3buf_read address: %x (%x)\n",
+                               mp3buf+mp3buf_read, mp3buf_read);
 
-                    /* Advance the write pointer to make
-                       room for an ID3 tag plus a VBR header */
-                    mp3buf_write = MPEG_RESERVED_HEADER_SPACE;
-                    memset(mp3buf, 0, MPEG_RESERVED_HEADER_SPACE);
+                        /* Make room for headers */
+                        mp3buf_read -= MPEG_RESERVED_HEADER_SPACE;
+                        if(mp3buf_read < 0)
+                        {
+                            /* Clear the bottom half */
+                            memset(mp3buf, 0,
+                                   mp3buf_read + MPEG_RESERVED_HEADER_SPACE);
 
-                    /* Insert the ID3 header */
-                    memcpy(mp3buf, empty_id3_header, sizeof(empty_id3_header));
+                            /* And the top half */
+                            mp3buf_read += mp3buflen;
+                            memset(mp3buf + mp3buf_read, 0,
+                                   mp3buflen - mp3buf_read);
+                        }
+                        else
+                        {
+                            memset(mp3buf + mp3buf_read, 0,
+                                   MPEG_RESERVED_HEADER_SPACE);
+                        }
+
+                        /* Copy the empty ID3 header */
+                        startpos = mp3buf_read;
+                        for(i = 0;i < (int)sizeof(empty_id3_header);i++)
+                        {
+                            mp3buf[startpos++] = empty_id3_header[i];
+                            if(startpos == mp3buflen)
+                                startpos = 0;
+                        }
+                        
+                        DEBUGF("New mp3buf_read address (reservation): %x\n",
+                               mp3buf+mp3buf_read);
+                        
+                        DEBUGF("Prerecording...\n");
+                    }
+                    else
+                    {
+                        reset_mp3_buffer();
+
+                        num_rec_bytes = 0;
+                        
+                        /* Advance the write pointer to make
+                           room for an ID3 tag plus a VBR header */
+                        mp3buf_write = MPEG_RESERVED_HEADER_SPACE;
+                        memset(mp3buf, 0, MPEG_RESERVED_HEADER_SPACE);
+                        
+                        /* Insert the ID3 header */
+                        memcpy(mp3buf, empty_id3_header,
+                               sizeof(empty_id3_header));
+
+                        DEBUGF("Recording...\n");
+                    }
 
                     start_recording();
-                    demand_irq_enable(true);
-                    
+
                     mpeg_file = open(recording_filename, O_WRONLY|O_CREAT);
                     
                     if(mpeg_file < 0)
@@ -1910,14 +2007,13 @@ static void mpeg_thread(void)
 
                 case MPEG_STOP:
                     DEBUGF("MPEG_STOP\n");
-                    demand_irq_enable(false);
 
                     /* Store the last recorded header for later use by the
                        Xing header generation */
                     saved_header = get_last_recorded_header();
                     
                     stop_recording();
-                    
+
                     /* Save the remaining data in the buffer */
                     stop_pending = true;
                     queue_post(&mpeg_queue, MPEG_SAVE_DATA, 0);
@@ -1942,6 +2038,11 @@ static void mpeg_thread(void)
                         if(num_recorded_frames == 0x7ffff)
                             num_recorded_frames = 0;
 
+                        /* Also, if we have been prerecording, the frame count
+                           will be wrong */
+                        if(prerecording)
+                            num_recorded_frames = 0;
+                        
                         /* saved_header is saved right before stopping
                            the MAS */
                         framelen = create_xing_header(mpeg_file, 0,
@@ -1970,6 +2071,11 @@ static void mpeg_thread(void)
                         }
                     }
 #endif
+
+                    if(prerecording)
+                    {
+                        start_prerecording();
+                    }
                     mpeg_stop_done = true;
                     break;
 
@@ -2117,7 +2223,6 @@ static void mpeg_thread(void)
                                 if(errno == ENOSPC)
                                 {
                                     mpeg_errno = MPEGERR_DISK_FULL;
-                                    demand_irq_enable(false);
                                     stop_recording();
                                     queue_post(&mpeg_queue, MPEG_STOP_DONE, 0);
                                     break;
@@ -2161,18 +2266,22 @@ static void mpeg_thread(void)
                     break;
 
                 case SYS_USB_CONNECTED:
-                    is_playing = false;
-                    paused = false;
-                    stop_playing();
-#ifndef SIMULATOR
+                    /* We can safely go to USB mode if no recording
+                       is taking place */
+                    if((!is_recording || is_prerecording) && mpeg_stop_done)
+                    {
+                        /* Even if we aren't recording, we still call this
+                           function, to put the MAS in monitoring mode,
+                           to save power. */
+                        stop_recording();
                 
-                    /* Tell the USB thread that we are safe */
-                    DEBUGF("mpeg_thread got SYS_USB_CONNECTED\n");
-                    usb_acknowledge(SYS_USB_CONNECTED_ACK);
+                        /* Tell the USB thread that we are safe */
+                        DEBUGF("mpeg_thread got SYS_USB_CONNECTED\n");
+                        usb_acknowledge(SYS_USB_CONNECTED_ACK);
                     
-                    /* Wait until the USB cable is extracted again */
-                    usb_wait_for_disconnect(&mpeg_queue);
-#endif
+                        /* Wait until the USB cable is extracted again */
+                        usb_wait_for_disconnect(&mpeg_queue);
+                    }
                     break;
             }
         }
@@ -2245,22 +2354,90 @@ bool mpeg_has_changed_track(void)
 }
 
 #ifdef HAVE_MAS3587F
-void mpeg_init_recording(void)
+void mpeg_init_playback(void)
 {
-    init_recording_done = false;
-    queue_post(&mpeg_queue, MPEG_INIT_RECORDING, NULL);
+    init_playback_done = false;
+    queue_post(&mpeg_queue, MPEG_INIT_PLAYBACK, NULL);
 
-    while(!init_recording_done)
+    while(!init_playback_done)
         sleep_thread();
     wake_up_thread();
 }
 
-void mpeg_init_playback(void)
+static void init_playback(void)
 {
-    init_playback_done = false;
-    queue_post(&mpeg_queue, MPEG_INIT_PLAYBACK, NULL);
+    unsigned long val;
+    int rc;
 
-    while(!init_playback_done)
+    if(mpeg_mode == MPEG_ENCODER)
+        stop_recording();
+    
+    stop_dma();
+    
+    mas_reset();
+    
+    /* Enable the audio CODEC and the DSP core, max analog voltage range */
+    rc = mas_direct_config_write(MAS_CONTROL, 0x8c00);
+    if(rc < 0)
+        panicf("mas_ctrl_w: %d", rc);
+
+    /* Stop the current application */
+    val = 0;
+    mas_writemem(MAS_BANK_D0,0x7f6,&val,1);    
+    do
+    {
+        mas_readmem(MAS_BANK_D0, 0x7f7, &val, 1);
+    } while(val);
+    
+    /* Enable the D/A Converter */
+    mas_codec_writereg(0x0, 0x0001);
+
+    /* ADC scale 0%, DSP scale 100% */
+    mas_codec_writereg(6, 0x0000);
+    mas_codec_writereg(7, 0x4000);
+
+    /* Disable SDO and SDI */
+    val = 0x0d;
+    mas_writemem(MAS_BANK_D0,0x7f2,&val,1);
+
+    /* Set Demand mode and validate all settings */
+    val = 0x25;
+    mas_writemem(MAS_BANK_D0,0x7f1,&val,1);
+
+    /* Start the Layer2/3 decoder applications */
+    val = 0x0c;
+    mas_writemem(MAS_BANK_D0,0x7f6,&val,1);
+    do
+    {
+        mas_readmem(MAS_BANK_D0, 0x7f7, &val, 1);
+    } while((val & 0x0c) != 0x0c);
+
+    mpeg_sound_channel_config(MPEG_SOUND_STEREO);
+
+    mpeg_mode = MPEG_DECODER;
+
+    /* set IRQ6 to edge detect */
+    ICR |= 0x02;
+
+    /* set IRQ6 prio 8 */
+    IPRB = ( IPRB & 0xff0f ) | 0x0080;
+
+    DEBUGF("MAS Decoding application started\n");
+}
+
+/****************************************************************************
+ **
+ **
+ ** Recording functions
+ **
+ **
+ ***************************************************************************/
+void mpeg_init_recording(void)
+{
+    init_recording_done = false;
+    queue_post(&mpeg_queue, MPEG_INIT_RECORDING, NULL);
+
+    while(!init_recording_done)
         sleep_thread();
     wake_up_thread();
 }
@@ -2270,6 +2447,9 @@ static void init_recording(void)
     unsigned long val;
     int rc;
 
+    /* Disable IRQ6 */
+    IPRB &= 0xff0f;
+
     stop_playing();
     is_playing = false;
     paused = false;
@@ -2283,6 +2463,9 @@ static void init_recording(void)
 
     /* Init the recording variables */
     is_recording = false;
+    is_prerecording = false;
+
+    mpeg_stop_done = true;
     
     mas_reset();
     
@@ -2324,7 +2507,7 @@ static void init_recording(void)
 
     /* No mute */
     val = 0;
-    mas_writemem(MAS_BANK_D0, 0x7f9, &val, 1);    
+    mas_writemem(MAS_BANK_D0, 0x7f9, &val, 1);
     
     /* Set Demand mode, no monitoring and validate all settings */
     val = 0x125;
@@ -2345,70 +2528,16 @@ static void init_recording(void)
        Now let's wait for some data to be encoded. */
     sleep(20);
     
-    /* Disable IRQ6 */
-    IPRB &= 0xff0f;
+    /* Now set it to Monitoring mode as default, saves power */
+    val = 0x525;
+    mas_writemem(MAS_BANK_D0, 0x7f1, &val, 1);
 
     mpeg_mode = MPEG_ENCODER;
 
     DEBUGF("MAS Recording application started\n");
-}
-
-static void init_playback(void)
-{
-    unsigned long val;
-    int rc;
-
-    stop_dma();
-    
-    mas_reset();
-    
-    /* Enable the audio CODEC and the DSP core, max analog voltage range */
-    rc = mas_direct_config_write(MAS_CONTROL, 0x8c00);
-    if(rc < 0)
-        panicf("mas_ctrl_w: %d", rc);
-
-    /* Stop the current application */
-    val = 0;
-    mas_writemem(MAS_BANK_D0,0x7f6,&val,1);    
-    do
-    {
-        mas_readmem(MAS_BANK_D0, 0x7f7, &val, 1);
-    } while(val);
-    
-    /* Enable the D/A Converter */
-    mas_codec_writereg(0x0, 0x0001);
-
-    /* ADC scale 0%, DSP scale 100% */
-    mas_codec_writereg(6, 0x0000);
-    mas_codec_writereg(7, 0x4000);
-
-    /* Disable SDO and SDI */
-    val = 0x0d;
-    mas_writemem(MAS_BANK_D0,0x7f2,&val,1);
-
-    /* Set Demand mode and validate all settings */
-    val = 0x25;
-    mas_writemem(MAS_BANK_D0,0x7f1,&val,1);
-
-    /* Start the Layer2/3 decoder applications */
-    val = 0x0c;
-    mas_writemem(MAS_BANK_D0,0x7f6,&val,1);
-    do
-    {
-        mas_readmem(MAS_BANK_D0, 0x7f7, &val, 1);
-    } while((val & 0x0c) != 0x0c);
-
-    mpeg_sound_channel_config(MPEG_SOUND_STEREO);
-
-    mpeg_mode = MPEG_DECODER;
-
-    /* set IRQ6 to edge detect */
-    ICR |= 0x02;
-
-    /* set IRQ6 prio 8 */
-    IPRB = ( IPRB & 0xff0f ) | 0x0080;
 
-    DEBUGF("MAS Decoding application started\n");
+    /* At this point, all settings are the reset MAS defaults, next thing is to
+       call mpeg_set_recording_options(). */
 }
 
 void mpeg_record(char *filename)
@@ -2418,53 +2547,109 @@ void mpeg_record(char *filename)
     strncpy(recording_filename, filename, MAX_PATH - 1);
     recording_filename[MAX_PATH - 1] = 0;
     
-    num_rec_bytes = 0;
     disable_xing_header = false;
     queue_post(&mpeg_queue, MPEG_RECORD, NULL);
 }
 
-static void start_recording(void)
+static void start_prerecording(void)
 {
     unsigned long val;
 
-    num_recorded_frames = 0;
+    DEBUGF("Starting prerecording\n");
     
-    /* Stop monitoring and record for real */
+    prerecord_index = 0;
+    prerecord_count = 0;
+    prerecord_timeout = current_tick + HZ;
+    memset(prerecord_buffer, 0, sizeof(prerecord_buffer));
+    reset_mp3_buffer();
+    
+    is_prerecording = true;
+
+    /* Stop monitoring and start the encoder */
     mas_readmem(MAS_BANK_D0, 0x7f1, &val, 1);
     val &= ~(1 << 10);
     val |= 1;
     mas_writemem(MAS_BANK_D0, 0x7f1, &val, 1);
+    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f1, %x)\n", val);
 
     /* Wait until the DSP has accepted the settings */
     do
     {
         mas_readmem(MAS_BANK_D0, 0x7f1, &val,1);
     } while(val & 1);
-
-    sleep(20);
     
-    /* Store the current time */
-    record_start_time = current_tick;
+    sleep(20);
 
     is_recording = true;
     stop_pending = false;
     saving = false;
+
+    demand_irq_enable(true);
+}
+
+static void start_recording(void)
+{
+    unsigned long val;
+
+    num_recorded_frames = 0;
+
+    if(is_prerecording)
+    {
+        /* This will make the IRQ handler start recording
+           for real, i.e send MPEG_SAVE_DATA messages when
+           the buffer is full */
+        is_prerecording = false;
+    }
+    else
+    {
+        /* If prerecording is off, we need to stop the monitoring
+           and start the encoder */
+        mas_readmem(MAS_BANK_D0, 0x7f1, &val, 1);
+        val &= ~(1 << 10);
+        val |= 1;
+        mas_writemem(MAS_BANK_D0, 0x7f1, &val, 1);
+        DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f1, %x)\n", val);
+        
+        /* Wait until the DSP has accepted the settings */
+        do
+        {
+            mas_readmem(MAS_BANK_D0, 0x7f1, &val,1);
+        } while(val & 1);
+        
+        sleep(20);
+    }
+    
+    is_recording = true;
+    stop_pending = false;
+    saving = false;
+
+    /* Store the current time */
+    if(prerecording)
+        record_start_time = current_tick - prerecord_count * HZ;
+    else
+        record_start_time = current_tick;
+        
+    demand_irq_enable(true);
 }
 
 static void stop_recording(void)
 {
     unsigned long val;
 
-    is_recording = false;
+    demand_irq_enable(false);
 
+    is_recording = false;
+    is_prerecording = false;
+        
     /* Read the number of frames recorded */
     mas_readmem(MAS_BANK_D0, 0xfd0, &num_recorded_frames, 1);
-    
+
     /* Start monitoring */
     mas_readmem(MAS_BANK_D0, 0x7f1, &val, 1);
     val |= (1 << 10) | 1;
     mas_writemem(MAS_BANK_D0, 0x7f1, &val, 1);
-
+    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f1, %x)\n", val);
+    
     /* Wait until the DSP has accepted the settings */
     do
     {
@@ -2474,6 +2659,82 @@ static void stop_recording(void)
     drain_dma_buffer();
 }
 
+void mpeg_set_recording_options(int frequency, int quality,
+                                int source, int channel_mode,
+                                bool editable, int prerecord_time)
+{
+    bool is_mpeg1;
+    unsigned long val;
+
+    is_mpeg1 = (frequency < 3)?true:false;
+
+    rec_version_index = is_mpeg1?3:2;
+    rec_frequency_index = frequency % 3;
+    
+    val = (quality << 17) |
+        (rec_frequency_index << 10) |
+        ((is_mpeg1?1:0) << 9) |
+        (1 << 8) | /* CRC on */
+        (((channel_mode * 2 + 1) & 3) << 6) |
+        (1 << 5) /* MS-stereo */ |
+        (1 << 2) /* Is an original */;
+    mas_writemem(MAS_BANK_D0, 0x7f0, &val,1);
+
+    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f0, %x)\n", val);
+
+    val = editable?4:0;
+    mas_writemem(MAS_BANK_D0, 0x7f9, &val,1);
+
+    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f9, %x)\n", val);
+
+    val = (((source < 2)?1:2) << 8) | /* Input select */
+        (1 << 5) | /* SDO strobe invert */
+        ((is_mpeg1?0:1) << 3) |
+        (1 << 2) | /* Inverted SIBC clock signal */
+        1; /* Validate */
+    mas_writemem(MAS_BANK_D0, 0x7f1, &val,1);
+
+    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f1, %x)\n", val);
+
+    drain_dma_buffer();
+    
+    if(source == 0) /* Mic */
+    {
+        /* Copy left channel to right (mono mode) */
+        mas_codec_writereg(8, 0x8000);
+    }
+    else
+    {
+        /* Stereo input mode */
+        mas_codec_writereg(8, 0);
+    }
+
+    prerecording_max_seconds = prerecord_time;
+    if(prerecording_max_seconds)
+    {
+        prerecording = true;
+        start_prerecording();
+    }
+    else
+    {
+        prerecording = false;
+        is_prerecording = false;
+        is_recording = false;
+    }
+}
+
+/* If use_mic is true, the left gain is used */
+void mpeg_set_recording_gain(int left, int right, bool use_mic)
+{
+    /* Enable both left and right A/D */
+    mas_codec_writereg(0x0,
+                       (left << 12) |
+                       (right << 8) |
+                       (left << 4) |
+                       (use_mic?0x0008:0) | /* Connect left A/D to mic */
+                       0x0007);
+}
+
 void mpeg_new_file(char *filename)
 {
     mpeg_errno = 0;
@@ -2492,16 +2753,37 @@ void mpeg_new_file(char *filename)
 
 unsigned long mpeg_recorded_time(void)
 {
+    if(is_prerecording)
+        return prerecord_count * HZ;
+    
     if(is_recording)
         return current_tick - record_start_time;
-    else
-        return 0;
+
+    return 0;
 }
 
 unsigned long mpeg_num_recorded_bytes(void)
 {
+    int num_bytes;
+    int index;
+    
     if(is_recording)
-        return num_rec_bytes;
+    {
+        if(is_prerecording)
+        {
+            index = prerecord_index - prerecord_count;
+            if(index < 0)
+                index += prerecording_max_seconds;
+            
+            num_bytes = mp3buf_write - prerecord_buffer[index];
+            if(num_bytes < 0)
+                num_bytes += mp3buflen;
+            
+            return num_bytes;;
+        }
+        else
+            return num_rec_bytes;
+    }
     else
         return 0;
 }
@@ -2660,8 +2942,11 @@ int mpeg_status(void)
         ret |= MPEG_STATUS_PAUSE;
     
 #ifdef HAVE_MAS3587F
-    if(is_recording)
+    if(is_recording && !is_prerecording)
         ret |= MPEG_STATUS_RECORD;
+
+    if(is_prerecording)
+        ret |= MPEG_STATUS_PRERECORD;
 #endif
 
     if(mpeg_errno)
@@ -3057,73 +3342,6 @@ void mpeg_set_pitch(int pitch)
 }
 #endif
 
-#ifdef HAVE_MAS3587F
-void mpeg_set_recording_options(int frequency, int quality,
-                                int source, int channel_mode,
-                                bool editable)
-{
-    bool is_mpeg1;
-    unsigned long val;
-
-    is_mpeg1 = (frequency < 3)?true:false;
-
-    rec_version_index = is_mpeg1?3:2;
-    rec_frequency_index = frequency % 3;
-    
-    val = (quality << 17) |
-        (rec_frequency_index << 10) |
-        ((is_mpeg1?1:0) << 9) |
-        (1 << 8) | /* CRC on */
-        (((channel_mode * 2 + 1) & 3) << 6) |
-        (1 << 5) /* MS-stereo */ |
-        (1 << 2) /* Is an original */;
-    mas_writemem(MAS_BANK_D0, 0x7f0, &val,1);
-
-    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f0, %x)\n", val);
-
-    val = editable?4:0;
-    mas_writemem(MAS_BANK_D0, 0x7f9, &val,1);
-
-    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f9, %x)\n", val);
-
-    val = ((!is_recording << 10) | /* Monitoring */
-        ((source < 2)?1:2) << 8) | /* Input select */
-        (1 << 5) | /* SDO strobe invert */
-        ((is_mpeg1?0:1) << 3) |
-        (1 << 2) | /* Inverted SIBC clock signal */
-        1; /* Validate */
-    mas_writemem(MAS_BANK_D0, 0x7f1, &val,1);
-
-    DEBUGF("mas_writemem(MAS_BANK_D0, 0x7f1, %x)\n", val);
-
-    drain_dma_buffer();
-    
-    if(source == 0) /* Mic */
-    {
-        /* Copy left channel to right (mono mode) */
-        mas_codec_writereg(8, 0x8000);
-    }
-    else
-    {
-        /* Stereo input mode */
-        mas_codec_writereg(8, 0);
-    }
-}
-
-/* If use_mic is true, the left gain is used */
-void mpeg_set_recording_gain(int left, int right, bool use_mic)
-{
-    /* Enable both left and right A/D */
-    mas_codec_writereg(0x0,
-                       (left << 12) |
-                       (right << 8) |
-                       (left << 4) |
-                       (use_mic?0x0008:0) | /* Connect left A/D to mic */
-                       0x0007);
-}
-
-#endif
-
 #ifdef SIMULATOR
 static char mpeg_stack[DEFAULT_STACK_SIZE];
 static char mpeg_thread_name[] = "mpeg";