The const police raid playback.c, should be no change to behaviour.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16860 a1c6a512-1295-4272-9138-f99709370657

17 files changed, 154 insertions, 135 deletions

diff --git a/apps/buffering.c b/apps/buffering.c
index d49669777b..d891382d81 100644
--- a/apps/buffering.c
+++ b/apps/buffering.c
@@ -225,7 +225,7 @@ buf_ridx == buf_widx means the buffer is empty.
            only potential side effect is to allocate space for the cur_handle
            if it returns NULL.
    */
-static struct memory_handle *add_handle(size_t data_size, const bool can_wrap,
+static struct memory_handle *add_handle(const size_t data_size, const bool can_wrap,
                                         const bool alloc_all)
 {
     /* gives each handle a unique id */
@@ -873,8 +873,10 @@ management functions for all the actual handle management work.
    return value: <0 if the file cannot be opened, or one file already
    queued to be opened, otherwise the handle for the file in the buffer
 */
-int bufopen(const char *file, size_t offset, const enum data_type type)
-{
+int bufopen(const char *file, const size_t offset, const enum data_type type)
+{

+    size_t adjusted_offset = offset;

+
     int fd = open(file, O_RDONLY);
     if (fd < 0)
         return ERR_FILE_ERROR;
@@ -882,10 +884,10 @@ int bufopen(const char *file, size_t offset, const enum data_type type)
     size_t size = filesize(fd);
     bool can_wrap = type==TYPE_PACKET_AUDIO || type==TYPE_CODEC;
 
-    if (offset > size)
-        offset = 0;
+    if (adjusted_offset > size)
+        adjusted_offset = 0;
 
-    struct memory_handle *h = add_handle(size-offset, can_wrap, false);
+    struct memory_handle *h = add_handle(size-adjusted_offset, can_wrap, false);
     if (!h)
     {
         DEBUGF("bufopen: failed to add handle\n");
@@ -894,7 +896,7 @@ int bufopen(const char *file, size_t offset, const enum data_type type)
     }
 
     strncpy(h->path, file, MAX_PATH);
-    h->offset = offset;
+    h->offset = adjusted_offset;
     h->ridx = buf_widx;
     h->data = buf_widx;
     h->type = type;
@@ -923,7 +925,7 @@ int bufopen(const char *file, size_t offset, const enum data_type type)
     else
 #endif
     {
-        h->filerem = size - offset;
+        h->filerem = size - adjusted_offset;
         h->filesize = size;
         h->available = 0;
         h->widx = buf_widx;
@@ -1094,27 +1096,28 @@ static struct memory_handle *prep_bufdata(const int handle_id, size_t *size,
    Return the number of bytes copied or < 0 for failure (handle not found).
    The caller is blocked until the requested amount of data is available.
 */
-ssize_t bufread(const int handle_id, size_t size, void *dest)
+ssize_t bufread(const int handle_id, const size_t size, void *dest)
 {
-    const struct memory_handle *h;
+    const struct memory_handle *h;

+    size_t adjusted_size = size;
 
-    h = prep_bufdata(handle_id, &size, false);
+    h = prep_bufdata(handle_id, &adjusted_size, false);
     if (!h)
         return ERR_HANDLE_NOT_FOUND;
 
-    if (h->ridx + size > buffer_len)
+    if (h->ridx + adjusted_size > buffer_len)
     {
         /* the data wraps around the end of the buffer */
         size_t read = buffer_len - h->ridx;
         memcpy(dest, &buffer[h->ridx], read);
-        memcpy(dest+read, buffer, size - read);
+        memcpy(dest+read, buffer, adjusted_size - read);
     }
     else
     {
-        memcpy(dest, &buffer[h->ridx], size);
+        memcpy(dest, &buffer[h->ridx], adjusted_size);
     }
 
-    return size;
+    return adjusted_size;
 }
 
 /* Update the "data" pointer to make the handle's data available to the caller.
@@ -1126,20 +1129,21 @@ ssize_t bufread(const int handle_id, size_t size, void *dest)
    The guard buffer may be used to provide the requested size. This means it's
    unsafe to request more than the size of the guard buffer.
 */
-ssize_t bufgetdata(const int handle_id, size_t size, void **data)
+ssize_t bufgetdata(const int handle_id, const size_t size, void **data)
 {
     const struct memory_handle *h;
+    size_t adjusted_size = size;

 
-    h = prep_bufdata(handle_id, &size, true);
+    h = prep_bufdata(handle_id, &adjusted_size, true);
     if (!h)
         return ERR_HANDLE_NOT_FOUND;
 
-    if (h->ridx + size > buffer_len)
+    if (h->ridx + adjusted_size > buffer_len)
     {
         /* the data wraps around the end of the buffer :
            use the guard buffer to provide the requested amount of data. */
-        size_t copy_n = h->ridx + size - buffer_len;
-        /* prep_bufdata ensures size <= buffer_len - h->ridx + GUARD_BUFSIZE,
+        size_t copy_n = h->ridx + adjusted_size - buffer_len;
+        /* prep_bufdata ensures adjusted_size <= buffer_len - h->ridx + GUARD_BUFSIZE,
            so copy_n <= GUARD_BUFSIZE */
         memcpy(guard_buffer, (const unsigned char *)buffer, copy_n);
     }
@@ -1147,7 +1151,7 @@ ssize_t bufgetdata(const int handle_id, size_t size, void **data)
     if (data)
         *data = &buffer[h->ridx];
 
-    return size;
+    return adjusted_size;
 }
 
 ssize_t bufgettail(const int handle_id, const size_t size, void **data)
@@ -1180,9 +1184,10 @@ ssize_t bufgettail(const int handle_id, const size_t size, void **data)
     return size;
 }
 
-ssize_t bufcuttail(const int handle_id, size_t size)
+ssize_t bufcuttail(const int handle_id, const size_t size)
 {
-    struct memory_handle *h;
+    struct memory_handle *h;

+    size_t adjusted_size = size;
 
     h = find_handle(handle_id);
 
@@ -1192,16 +1197,16 @@ ssize_t bufcuttail(const int handle_id, size_t size)
     if (h->filerem)
         return ERR_HANDLE_NOT_DONE;
 
-    if (h->available < size)
-        size = h->available;
+    if (h->available < adjusted_size)
+        adjusted_size = h->available;
 
-    h->available -= size;
-    h->filesize -= size;
-    h->widx = RINGBUF_SUB(h->widx, size);
+    h->available -= adjusted_size;
+    h->filesize -= adjusted_size;
+    h->widx = RINGBUF_SUB(h->widx, adjusted_size);
     if (h == cur_handle)
         buf_widx = h->widx;
 
-    return size;
+    return adjusted_size;
 }
 
 
diff --git a/apps/codecs.h b/apps/codecs.h
index fb5675fd84..85b73a4953 100644
--- a/apps/codecs.h
+++ b/apps/codecs.h
@@ -126,28 +126,28 @@ struct codec_api {
     void* (*get_codec_memory)(size_t *size);
     /* Insert PCM data into audio buffer for playback. Playback will start
        automatically. */
-    bool (*pcmbuf_insert)(const void *ch1, const void *ch2, int count);
+    bool (*pcmbuf_insert)(const void *ch1, const void *ch2, const int count);
     /* Set song position in WPS (value in ms). */
-    void (*set_elapsed)(unsigned int value);
+    void (*set_elapsed)(const unsigned int value);
     
     /* Read next <size> amount bytes from file buffer to <ptr>.
        Will return number of bytes read or 0 if end of file. */
-    size_t (*read_filebuf)(void *ptr, size_t size);
+    size_t (*read_filebuf)(void *ptr, const size_t size);
     /* Request pointer to file buffer which can be used to read
        <realsize> amount of data. <reqsize> tells the buffer system
        how much data it should try to allocate. If <realsize> is 0,
        end of file is reached. */
-    void* (*request_buffer)(size_t *realsize, size_t reqsize);
+    void* (*request_buffer)(size_t *realsize, const size_t reqsize);
     /* Advance file buffer position by <amount> amount of bytes. */
-    void (*advance_buffer)(size_t amount);
+    void (*advance_buffer)(const size_t amount);
     /* Advance file buffer to a pointer location inside file buffer. */
     void (*advance_buffer_loc)(void *ptr);
     /* Seek file buffer to position <newpos> beginning of file. */
-    bool (*seek_buffer)(size_t newpos);
+    bool (*seek_buffer)(const size_t newpos);
     /* Codec should call this function when it has done the seeking. */
     void (*seek_complete)(void);
     /* Calculate mp3 seek position from given time data in ms. */
-    off_t (*mp3_get_filepos)(int newtime);
+    off_t (*mp3_get_filepos)(const int newtime);
     /* Request file change from file buffer. Returns true is next
        track is available and changed. If return value is false,
        codec should exit immediately with PLUGIN_OK status. */
@@ -155,12 +155,12 @@ struct codec_api {
     /* Free the buffer area of the current codec after its loaded */
     void (*discard_codec)(void);
     
-    void (*set_offset)(size_t value);
+    void (*set_offset)(const size_t value);
     /* Configure different codec buffer parameters. */
-    void (*configure)(int setting, intptr_t value);
+    void (*configure)(const int setting, const intptr_t value);
 
     /* kernel/ system */
-    void (*PREFIX(sleep))(int ticks);
+    void (*PREFIX(sleep))(const int ticks);
     void (*yield)(void);
 
 #if NUM_CORES > 1
diff --git a/apps/debug_menu.c b/apps/debug_menu.c
index d21dc032a8..5c8a7f965f 100644
--- a/apps/debug_menu.c
+++ b/apps/debug_menu.c
@@ -77,6 +77,7 @@
 #if CONFIG_CODEC == SWCODEC
 #include "pcmbuf.h"
 #include "buffering.h"
+#include "playback.h"
 #if defined(HAVE_SPDIF_OUT) || defined(HAVE_SPDIF_IN)
 #include "spdif.h"
 #endif
diff --git a/apps/gui/gwps-common.c b/apps/gui/gwps-common.c
index a6bb917a5a..234cd62a64 100644
--- a/apps/gui/gwps-common.c
+++ b/apps/gui/gwps-common.c
@@ -54,6 +54,9 @@
 #include "action.h"
 #include "cuesheet.h"
 #include "playlist.h"
+#if CONFIG_CODEC == SWCODEC
+#include "playback.h"
+#endif
 
 #if (LCD_DEPTH > 1) || (defined(HAVE_LCD_REMOTE) && (LCD_REMOTE_DEPTH > 1))
 #include "backdrop.h"
diff --git a/apps/menus/playback_menu.c b/apps/menus/playback_menu.c
index b7aa1ae47f..1e07ef3781 100644
--- a/apps/menus/playback_menu.c
+++ b/apps/menus/playback_menu.c
@@ -33,7 +33,11 @@
 #include "dsp.h"
 #include "scrobbler.h"
 #include "audio.h"
-#include "cuesheet.h"
+#include "cuesheet.h"

+#if CONFIG_CODEC == SWCODEC

+#include "playback.h"

+#endif

+
 
 #if CONFIG_CODEC == SWCODEC
 int setcrossfadeonexit_callback(int action,const struct menu_item_ex *this_item)
diff --git a/apps/menus/settings_menu.c b/apps/menus/settings_menu.c
index c55695333c..9d816c99b1 100644
--- a/apps/menus/settings_menu.c
+++ b/apps/menus/settings_menu.c
@@ -34,7 +34,10 @@
 #include "splash.h"
 #include "talk.h"
 #include "sprintf.h"
-#include "powermgmt.h"
+#include "powermgmt.h"

+#if CONFIG_CODEC == SWCODEC

+#include "playback.h"

+#endif

 #ifdef HAVE_RTC_ALARM
 #include "alarm_menu.h"
 #endif
diff --git a/apps/pcmbuf.c b/apps/pcmbuf.c
index 8f16c90523..b9587d08dd 100644
--- a/apps/pcmbuf.c
+++ b/apps/pcmbuf.c
@@ -82,7 +82,7 @@ static char *fadebuf IDATA_ATTR;
 static char *voicebuf IDATA_ATTR;
 
 static void (*pcmbuf_event_handler)(void) IDATA_ATTR;
-static void (*position_callback)(size_t size) IDATA_ATTR;
+static void (*position_callback)(const size_t size) IDATA_ATTR;
 
 /* Crossfade related state */
 static bool crossfade_enabled;
@@ -188,7 +188,7 @@ static void pcmbuf_callback(unsigned char** start, size_t* size)
     }
 }
 
-void pcmbuf_set_position_callback(void (*callback)(size_t size))
+void pcmbuf_set_position_callback(void (*callback)(const size_t size))
 {
     position_callback = callback;
 }
@@ -938,7 +938,7 @@ void pcmbuf_write_complete(int count)
 }
 
 #if 0
-bool pcmbuf_insert_buffer(char *buf, int count)
+bool pcmbuf_insert_buffer(char *buf, const int count)
 {
     size_t length = (size_t)(unsigned int)count << 2;
 
diff --git a/apps/pcmbuf.h b/apps/pcmbuf.h
index 06362452c0..9263285a6b 100644
--- a/apps/pcmbuf.h
+++ b/apps/pcmbuf.h
@@ -63,7 +63,7 @@ bool pcmbuf_is_lowdata(void);
 void pcmbuf_play_start(void);
 bool pcmbuf_crossfade_init(bool manual_skip);
 void pcmbuf_set_event_handler(void (*callback)(void));
-void pcmbuf_set_position_callback(void (*callback)(size_t size));
+void pcmbuf_set_position_callback(void (*callback)(const size_t size));
 size_t pcmbuf_free(void);
 unsigned int pcmbuf_get_latency(void);
 void pcmbuf_set_low_latency(bool state);
diff --git a/apps/playback.c b/apps/playback.c
index 421783e0f7..4fd27ce72e 100644
--- a/apps/playback.c
+++ b/apps/playback.c
@@ -249,7 +249,7 @@ static size_t buffer_margin  = 0; /* Buffer margin aka anti-skip buffer (A/C-) *
 
 /* Multiple threads */
 /* Set the watermark to trigger buffer fill (A/C) FIXME */
-static void set_filebuf_watermark(int seconds, size_t max);
+static void set_filebuf_watermark(const int seconds, const size_t max);
 
 /* Audio thread */
 static struct event_queue       audio_queue NOCACHEBSS_ATTR;
@@ -277,7 +277,7 @@ static struct event_queue pcmbuf_queue NOCACHEBSS_ATTR;
 /* Function to be called by pcm buffer callbacks.
  * Permissible Context(s): Audio interrupt
  */
-static void pcmbuf_callback_queue_post(long id, intptr_t data)
+static void pcmbuf_callback_queue_post(const long id, intptr_t data)
 {
     /* No lock since we're already in audio interrupt context */
     queue_post(&pcmbuf_queue, id, data);
@@ -313,7 +313,7 @@ static void pcmbuf_queue_clear(void)
 
 /* --- Helper functions --- */
 
-static struct mp3entry *bufgetid3(int handle_id)
+static struct mp3entry *bufgetid3(const int handle_id)
 {
     if (handle_id < 0)
         return NULL;
@@ -384,7 +384,7 @@ void audio_hard_stop(void)
 #endif
 }
 
-bool audio_restore_playback(int type)
+bool audio_restore_playback(const int type)
 {
     switch (type)
     {
@@ -401,7 +401,7 @@ bool audio_restore_playback(int type)
     }
 }
 
-unsigned char *audio_get_buffer(bool talk_buf, size_t *buffer_size)
+unsigned char *audio_get_buffer(const bool talk_buf, size_t *buffer_size)
 {
     unsigned char *buf, *end;
 
@@ -621,7 +621,7 @@ bool audio_has_changed_track(void)
     return false;
 }
 
-void audio_play(long offset)
+void audio_play(const long offset)
 {
     logf("audio_play");
 
@@ -710,7 +710,7 @@ void audio_pre_ff_rewind(void)
     queue_post(&audio_queue, Q_AUDIO_PRE_FF_REWIND, 0);
 }
 
-void audio_ff_rewind(long newpos)
+void audio_ff_rewind(const long newpos)
 {
     LOGFQUEUE("audio > audio Q_AUDIO_FF_REWIND");
     queue_post(&audio_queue, Q_AUDIO_FF_REWIND, newpos);
@@ -753,7 +753,7 @@ int audio_get_file_pos(void)
 }
 
 #ifndef HAVE_FLASH_STORAGE
-void audio_set_buffer_margin(int setting)
+void audio_set_buffer_margin(const int setting)
 {
     static const int lookup[] = {5, 15, 30, 60, 120, 180, 300, 600};
     buffer_margin = lookup[setting];
@@ -762,8 +762,8 @@ void audio_set_buffer_margin(int setting)
 }
 #endif
 
-/* Take nescessary steps to enable or disable the crossfade setting */
-void audio_set_crossfade(int enable)
+/* Take necessary steps to enable or disable the crossfade setting */
+void audio_set_crossfade(const int enable)
 {
     size_t offset;
     bool was_playing;
@@ -805,7 +805,7 @@ void audio_set_crossfade(int enable)
 
 /* --- Routines called from multiple threads --- */
 
-static void set_filebuf_watermark(int seconds, size_t max)
+static void set_filebuf_watermark(const int seconds, const size_t max)
 {
     size_t bytes;
 
@@ -817,7 +817,7 @@ static void set_filebuf_watermark(int seconds, size_t max)
     buf_set_watermark(bytes);
 }
 
-const char * get_codec_filename(int cod_spec)
+const char *get_codec_filename(const int cod_spec)
 {
     const char *fname;
 
@@ -849,13 +849,14 @@ const char * get_codec_filename(int cod_spec)
 
 /* --- Codec thread --- */
 static bool codec_pcmbuf_insert_callback(
-        const void *ch1, const void *ch2, int count)
+        const void *ch1, const void *ch2, const int count)
 {
     const char *src[2] = { ch1, ch2 };
 
-    while (count > 0)
+    int remaining = count;
+    while (remaining > 0)
     {
-        int out_count = dsp_output_count(ci.dsp, count);
+        int out_count = dsp_output_count(ci.dsp, remaining);
         int inp_count;
         char *dest;
 
@@ -879,8 +880,8 @@ static bool codec_pcmbuf_insert_callback(
             return true;
 
         /* Input size has grown, no error, just don't write more than length */
-        if (inp_count > count)
-            inp_count = count;
+        if (inp_count > remaining)
+            inp_count = remaining;
 
         out_count = dsp_process(ci.dsp, dest, src, inp_count);
 
@@ -889,7 +890,7 @@ static bool codec_pcmbuf_insert_callback(
 
         pcmbuf_write_complete(out_count);
 
-        count -= inp_count;
+        remaining -= inp_count;
     }
 
     return true;
@@ -905,8 +906,8 @@ static void* codec_get_memory_callback(size_t *size)
    "elapsed" value of the previous (to the codec, but current to the
    user/PCM/WPS) track, so that the progressbar reaches the end.
    During that transition, the WPS will display prevtrack_id3. */
-static void codec_pcmbuf_position_callback(size_t size) ICODE_ATTR;
-static void codec_pcmbuf_position_callback(size_t size)
+static void codec_pcmbuf_position_callback(const size_t size) ICODE_ATTR;
+static void codec_pcmbuf_position_callback(const size_t size)
 {
     /* This is called from an ISR, so be quick */
     unsigned int time = size * 1000 / 4 / NATIVE_FREQUENCY +
@@ -921,7 +922,7 @@ static void codec_pcmbuf_position_callback(size_t size)
         prevtrack_id3.elapsed = time;
 }
 
-static void codec_set_elapsed_callback(unsigned int value)
+static void codec_set_elapsed_callback(const unsigned int value)
 {
     unsigned int latency;
     if (ci.seek_time)
@@ -941,7 +942,7 @@ static void codec_set_elapsed_callback(unsigned int value)
     }
 }
 
-static void codec_set_offset_callback(size_t value)
+static void codec_set_offset_callback(const size_t value)
 {
     unsigned int latency;
 
@@ -955,14 +956,14 @@ static void codec_set_offset_callback(size_t value)
         curtrack_id3.offset = value - latency;
 }
 
-static void codec_advance_buffer_counters(size_t amount)
+static void codec_advance_buffer_counters(const size_t amount)
 {
     bufadvance(CUR_TI->audio_hid, amount);
     ci.curpos += amount;
 }
 
 /* copy up-to size bytes into ptr and return the actual size copied */
-static size_t codec_filebuf_callback(void *ptr, size_t size)
+static size_t codec_filebuf_callback(void *ptr, const size_t size)
 {
     ssize_t copy_n;
 
@@ -982,7 +983,7 @@ static size_t codec_filebuf_callback(void *ptr, size_t size)
     return copy_n;
 } /* codec_filebuf_callback */
 
-static void* codec_request_buffer_callback(size_t *realsize, size_t reqsize)
+static void* codec_request_buffer_callback(size_t *realsize, const size_t reqsize)
 {
     size_t copy_n = reqsize;
     ssize_t ret;
@@ -1021,7 +1022,7 @@ static int get_codec_base_type(int type)
     return type;
 }
 
-static void codec_advance_buffer_callback(size_t amount)
+static void codec_advance_buffer_callback(const size_t amount)
 {
     codec_advance_buffer_counters(amount);
     codec_set_offset_callback(ci.curpos);
@@ -1088,7 +1089,7 @@ static int codec_get_file_pos(void)
     return pos;
 }
 
-static off_t codec_mp3_get_filepos_callback(int newtime)
+static off_t codec_mp3_get_filepos_callback(const int newtime)
 {
     off_t newpos;
 
@@ -1114,7 +1115,7 @@ static void codec_seek_complete_callback(void)
     ci.seek_time = 0;
 }
 
-static bool codec_seek_buffer_callback(size_t newpos)
+static bool codec_seek_buffer_callback(const size_t newpos)
 {
     logf("codec_seek_buffer_callback");
 
@@ -1128,7 +1129,7 @@ static bool codec_seek_buffer_callback(size_t newpos)
     }
 }
 
-static void codec_configure_callback(int setting, intptr_t value)
+static void codec_configure_callback(const int setting, const intptr_t value)
 {
     switch (setting) {
     case CODEC_SET_FILEBUF_WATERMARK:
@@ -1178,7 +1179,7 @@ static inline void codec_crossfade_track_change(void)
     codec_track_changed();
 }
 
-static void codec_track_skip_done(bool was_manual)
+static void codec_track_skip_done(const bool was_manual)
 {
     /* Manual track change (always crossfade or flush audio). */
     if (was_manual)
@@ -1485,7 +1486,7 @@ static void audio_update_trackinfo(void)
     ci.taginfo_ready = &CUR_TI->taginfo_ready;
 }
 
-static void buffering_audio_callback(enum callback_event ev, int value)
+static void buffering_audio_callback(const enum callback_event ev, const int value)
 {
     (void)value;
     logf("buffering_audio_callback");
@@ -1549,7 +1550,7 @@ static bool audio_release_tracks(void)
     return true;
 }
 
-static bool audio_loadcodec(bool start_play)
+static bool audio_loadcodec(const bool start_play)
 {
     int prev_track;
     char codec_path[MAX_PATH]; /* Full path to codec */
@@ -1667,7 +1668,7 @@ static void audio_set_elapsed(struct mp3entry* id3)
 
 /* Load one track by making the appropriate bufopen calls. Return true if
    everything required was loaded correctly, false if not. */
-static bool audio_load_track(int offset, bool start_play)
+static bool audio_load_track(const int offset, const bool start_play)
 {
     const char *trackname;
     char msgbuf[80];
@@ -1714,8 +1715,9 @@ static bool audio_load_track(int offset, bool start_play)
 
     tracks[track_widx].filesize = filesize(fd);
 
-    if ((unsigned)offset > tracks[track_widx].filesize)
-        offset = 0;
+    int adjusted_offset = offset;
+    if ((unsigned)adjusted_offset > tracks[track_widx].filesize)
+        adjusted_offset = 0;
 
     /* Set default values */
     if (start_play)
@@ -1827,17 +1829,17 @@ static bool audio_load_track(int offset, bool start_play)
     case AFMT_MPA_L1:
     case AFMT_MPA_L2:
     case AFMT_MPA_L3:
-        if (offset > 0) {
-            file_offset = offset;
-            track_id3->offset = offset;
+        if (adjusted_offset > 0) {
+            file_offset = adjusted_offset;
+            track_id3->offset = adjusted_offset;
             audio_set_elapsed(track_id3);
         }
         break;
 
     case AFMT_WAVPACK:
         if (offset > 0) {
-            file_offset = offset;
-            track_id3->offset = offset;
+            file_offset = adjusted_offset;
+            track_id3->offset = adjusted_offset;
             track_id3->elapsed = track_id3->length / 2;
         }
         break;
@@ -1850,8 +1852,8 @@ static bool audio_load_track(int offset, bool start_play)
     case AFMT_AAC:
     case AFMT_MPC:
     case AFMT_APE:
-        if (offset > 0)
-            track_id3->offset = offset;
+        if (adjusted_offset > 0)
+            track_id3->offset = adjusted_offset;
         break;
 
     case AFMT_NSF:
@@ -1890,7 +1892,7 @@ static bool audio_load_track(int offset, bool start_play)
     return true;
 }
 
-static void audio_fill_file_buffer(bool start_play, size_t offset)
+static void audio_fill_file_buffer(const bool start_play, const size_t offset)
 {
     struct queue_event ev;
     bool had_next_track = audio_next_track() != NULL;
@@ -1914,10 +1916,8 @@ static void audio_fill_file_buffer(bool start_play, size_t offset)
     /* Save the current resume position once. */
     playlist_update_resume_info(audio_current_track());
 
+    continue_buffering = audio_load_track(offset, start_play);
     do {
-        continue_buffering = audio_load_track(offset, start_play);
-        start_play = false;
-        offset = 0;
         sleep(1);
         if (queue_peek(&audio_queue, &ev)) {
             if (ev.id != Q_AUDIO_FILL_BUFFER)
@@ -1929,6 +1929,7 @@ static void audio_fill_file_buffer(bool start_play, size_t offset)
             }
             break;
         }
+        continue_buffering = audio_load_track(0, false);
     } while (continue_buffering);
 
     if (!had_next_track && audio_next_track())
@@ -2193,7 +2194,7 @@ static void audio_stop_playback(void)
     memset(&curtrack_id3, 0, sizeof(struct mp3entry));
 }
 
-static void audio_play_start(size_t offset)
+static void audio_play_start(const size_t offset)
 {
     int i;
 
@@ -2286,7 +2287,7 @@ static void audio_new_playlist(void)
 }
 
 /* Called on manual track skip */
-static void audio_initiate_track_change(long direction)
+static void audio_initiate_track_change(const long direction)
 {
     logf("audio_initiate_track_change(%ld)", direction);
 
@@ -2298,7 +2299,7 @@ static void audio_initiate_track_change(long direction)
 }
 
 /* Called on manual dir skip */
-static void audio_initiate_dir_change(long direction)
+static void audio_initiate_dir_change(const long direction)
 {
     playlist_end = false;
     dir_skip = true;
diff --git a/apps/playback.h b/apps/playback.h
index 748a4fe871..b65c572145 100644
--- a/apps/playback.h
+++ b/apps/playback.h
@@ -38,14 +38,32 @@
 #define MAX_TRACK_MASK  (MAX_TRACK-1)
 
 /* Functions */
-const char * get_codec_filename(int cod_spec);
+const char *get_codec_filename(const int cod_spec);
 void voice_wait(void);
+void audio_wait_for_init(void);
+int audio_track_count(void);
+long audio_filebufused(void);
+void audio_pre_ff_rewind(void);
+void audio_set_crossfade(const int type);
+
+void audio_hard_stop(void); /* Stops audio from serving playback */
+
+enum
+{
+    AUDIO_WANT_PLAYBACK = 0,
+    AUDIO_WANT_VOICE,
+};
+bool audio_restore_playback(const int type); /* Restores the audio buffer to handle the requested playback */
+
+#ifdef HAVE_ALBUMART
+int audio_current_aa_hid(void);
+#endif
 
 #if CONFIG_CODEC == SWCODEC /* This #ifdef is better here than gui/gwps.c */
 extern void audio_next_dir(void);
 extern void audio_prev_dir(void);
 #else
-# define audio_next_dir() 
+#define audio_next_dir() 
 #define audio_prev_dir()
 #endif
 
diff --git a/apps/plugin.h b/apps/plugin.h
index 27fcffb69c..d6aed5d4c7 100644
--- a/apps/plugin.h
+++ b/apps/plugin.h
@@ -521,13 +521,13 @@ struct plugin_api {
     int (*playlist_amount)(void);
     int (*playlist_resume)(void);
     int (*playlist_start)(int start_index, int offset);
-    void (*PREFIX(audio_play))(long offset);
+    void (*PREFIX(audio_play))(const long offset);
     void (*audio_stop)(void);
     void (*audio_pause)(void);
     void (*audio_resume)(void);
     void (*audio_next)(void);
     void (*audio_prev)(void);
-    void (*audio_ff_rewind)(long newtime);
+    void (*audio_ff_rewind)(const long newtime);
     struct mp3entry* (*audio_next_track)(void);
     int (*audio_status)(void);
     bool (*audio_has_changed_track)(void);
diff --git a/apps/plugins/test_codec.c b/apps/plugins/test_codec.c
index f33d83fb15..7390318152 100644
--- a/apps/plugins/test_codec.c
+++ b/apps/plugins/test_codec.c
@@ -197,7 +197,7 @@ static void* get_codec_memory(size_t *size)
 }
 
 /* Null output */
-static bool pcmbuf_insert_null(const void *ch1, const void *ch2, int count)
+static bool pcmbuf_insert_null(const void *ch1, const void *ch2, const int count)
 {
     /* Always successful - just discard data */
     (void)ch1;
@@ -310,7 +310,7 @@ static bool pcmbuf_insert_wav(const void *ch1, const void *ch2, int count)
 
 
 /* Set song position in WPS (value in ms). */
-static void set_elapsed(unsigned int value)
+static void set_elapsed(const unsigned int value)
 {
     elapsed = value;
 }
@@ -318,7 +318,7 @@ static void set_elapsed(unsigned int value)
 
 /* Read next <size> amount bytes from file buffer to <ptr>.
    Will return number of bytes read or 0 if end of file. */
-static size_t read_filebuf(void *ptr, size_t size)
+static size_t read_filebuf(void *ptr, const size_t size)
 {
    if (ci.curpos > (off_t)track.filesize)
    {
@@ -336,7 +336,7 @@ static size_t read_filebuf(void *ptr, size_t size)
    <realsize> amount of data. <reqsize> tells the buffer system
    how much data it should try to allocate. If <realsize> is 0,
    end of file is reached. */
-static void* request_buffer(size_t *realsize, size_t reqsize)
+static void* request_buffer(size_t *realsize, const size_t reqsize)
 {
     *realsize = MIN(track.filesize-ci.curpos,reqsize);
 
@@ -345,7 +345,7 @@ static void* request_buffer(size_t *realsize, size_t reqsize)
 
 
 /* Advance file buffer position by <amount> amount of bytes. */
-static void advance_buffer(size_t amount)
+static void advance_buffer(const size_t amount)
 {
     ci.curpos += amount;
 }
@@ -359,7 +359,7 @@ static void advance_buffer_loc(void *ptr)
 
 
 /* Seek file buffer to position <newpos> beginning of file. */
-static bool seek_buffer(size_t newpos)
+static bool seek_buffer(const size_t newpos)
 {
     ci.curpos = newpos;
     return true;
@@ -374,7 +374,7 @@ static void seek_complete(void)
 
 
 /* Calculate mp3 seek position from given time data in ms. */
-static off_t mp3_get_filepos(int newtime)
+static off_t mp3_get_filepos(const int newtime)
 {
     /* We don't ask the codec to seek, so no need to implement this. */
     (void)newtime;
@@ -399,7 +399,7 @@ static void discard_codec(void)
 }
 
 
-static void set_offset(size_t value)
+static void set_offset(const size_t value)
 {
     /* ??? */
     (void)value;
diff --git a/apps/settings.c b/apps/settings.c
index d4f14079b1..6e1aa3eaec 100644
--- a/apps/settings.c
+++ b/apps/settings.c
@@ -81,6 +81,7 @@ struct system_status global_status;
 #if CONFIG_CODEC == SWCODEC
 #include "pcmbuf.h"
 #include "dsp.h"
+#include "playback.h"
 #ifdef HAVE_RECORDING
 #include "enc_config.h"
 #endif
diff --git a/apps/voice_thread.c b/apps/voice_thread.c
index 6e70f43cc5..98b9cafc83 100644
--- a/apps/voice_thread.c
+++ b/apps/voice_thread.c
@@ -22,7 +22,8 @@
 #include "voice_thread.h"
 #include "talk.h"
 #include "dsp.h"
-#include "audio.h"
+#include "audio.h"

+#include "playback.h"
 #include "pcmbuf.h"
 #include "codecs/libspeex/speex/speex.h"
 
diff --git a/firmware/export/audio.h b/firmware/export/audio.h
index c39fca428c..49ff4c168a 100644
--- a/firmware/export/audio.h
+++ b/firmware/export/audio.h
@@ -77,49 +77,31 @@ struct audio_debug
 };
 
 void audio_init(void);
-void audio_wait_for_init(void);
-void audio_play(long offset);
+void audio_play(const long offset);
 void audio_stop(void);
 void audio_pause(void);
 void audio_resume(void);
 void audio_next(void);
 void audio_prev(void);
 int audio_status(void);
-#if CONFIG_CODEC == SWCODEC
-int audio_track_count(void); /* SWCODEC only */
-long audio_filebufused(void); /* SWCODEC only */
-void audio_pre_ff_rewind(void); /* SWCODEC only */
-#endif /* CONFIG_CODEC == SWCODEC */
-void audio_ff_rewind(long newtime);
+void audio_ff_rewind(const long newtime);
 void audio_flush_and_reload_tracks(void);
-#ifdef HAVE_ALBUMART
-int audio_current_aa_hid(void);
-#endif
 struct mp3entry* audio_current_track(void);
 struct mp3entry* audio_next_track(void);
 bool audio_has_changed_track(void);
 void audio_get_debugdata(struct audio_debug *dbgdata);
-void audio_set_crossfade(int type);
 #ifndef HAVE_FLASH_STORAGE
-void audio_set_buffer_margin(int seconds);
+void audio_set_buffer_margin(const int seconds);
 #endif
 unsigned int audio_error(void);
 void audio_error_clear(void);
 int audio_get_file_pos(void);
 void audio_beep(int duration);
 void audio_init_playback(void);
-/* Required call when audio buffer is require for some other purpose */
-unsigned char *audio_get_buffer(bool talk_buf, size_t *buffer_size);
-/* Stops audio from serving playback */
-void audio_hard_stop(void);
-/* Retores the audio buffer to handle the requested playback */
-enum
-{
-    AUDIO_WANT_PLAYBACK = 0,
-    AUDIO_WANT_VOICE,
-};
 
-bool audio_restore_playback(int type);
+/* Required call when audio buffer is required for some other purpose */
+unsigned char *audio_get_buffer(const bool talk_buf, size_t *buffer_size); 
+/* only implemented in playback.c, but called from firmware */
 
 /* channel modes */
 enum rec_channel_modes
diff --git a/firmware/mpeg.c b/firmware/mpeg.c
index 11cbcdcb68..78824cfe36 100644
--- a/firmware/mpeg.c
+++ b/firmware/mpeg.c
@@ -533,7 +533,7 @@ static void recalculate_watermark(int bitrate)
 }
 
 #ifndef HAVE_FLASH_STORAGE
-void audio_set_buffer_margin(int seconds)
+void audio_set_buffer_margin(const int seconds)
 {
     low_watermark_margin = seconds;
 }
@@ -2627,7 +2627,7 @@ void audio_set_recording_options(struct audio_recording_options *options)
 #endif /* SIMULATOR */
 #endif /* CONFIG_CODEC == MAS3587F */
 
-void audio_play(long offset)
+void audio_play(const long offset)
 {
 #ifdef SIMULATOR
     char* trackname;
@@ -2768,7 +2768,7 @@ void audio_prev(void)
 #endif /* SIMULATOR */
 }
 
-void audio_ff_rewind(long newtime)
+void audio_ff_rewind(const long newtime)
 {
 #ifndef SIMULATOR
     queue_post(&mpeg_queue, MPEG_FF_REWIND, newtime);
diff --git a/uisimulator/common/stubs.c b/uisimulator/common/stubs.c
index c40d10082c..81f3697802 100644
--- a/uisimulator/common/stubs.c
+++ b/uisimulator/common/stubs.c
@@ -33,7 +33,7 @@
 extern char having_new_lcd;
 
 #if CONFIG_CODEC != SWCODEC
-void audio_set_buffer_margin(int seconds)
+void audio_set_buffer_margin(const int seconds)
 {
      (void)seconds;
 }