mpegplayer: Make playback engine fully seekable and frame-accurate and split into logical parts. Be sure to have all current features work. Actual UI for seeking will be added soon. Recommended GOP size is about 15-30 frames depending on target or seeking can be slow with really long GOPs (nature of MPEG video). More refined encoding recommendations for a particular player should be posted soon.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15977 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 743 insertions, 0 deletions

diff --git a/apps/plugins/mpegplayer/audio_thread.c b/apps/plugins/mpegplayer/audio_thread.c
new file mode 100644
index 0000000000..ee6ff05d2d
--- /dev/null
+++ b/apps/plugins/mpegplayer/audio_thread.c
@@ -0,0 +1,743 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * mpegplayer audio thread implementation
+ *
+ * Copyright (c) 2007 Michael Sevakis
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "plugin.h"
+#include "mpegplayer.h"
+#include "../../codecs/libmad/bit.h"
+#include "../../codecs/libmad/mad.h"
+
+/** Audio stream and thread **/
+struct pts_queue_slot;
+struct audio_thread_data
+{
+    struct queue_event ev; /* Our event queue to receive commands */
+    int state;             /* Thread state */
+    int status;            /* Media status (STREAM_PLAYING, etc.) */
+    int mad_errors;        /* A count of the errors in each frame */
+};
+
+/* The audio stack is stolen from the core codec thread (but not in uisim) */
+/* Used for stealing codec thread's stack */
+static uint32_t* audio_stack;
+static size_t audio_stack_size; /* Keep gcc happy and init */
+#define AUDIO_STACKSIZE (9*1024)
+#ifndef SIMULATOR
+static uint32_t codec_stack_copy[AUDIO_STACKSIZE / sizeof(uint32_t)];
+#endif
+static struct event_queue audio_str_queue NOCACHEBSS_ATTR;
+static struct queue_sender_list audio_str_queue_send NOCACHEBSS_ATTR;
+struct stream audio_str IBSS_ATTR;
+
+/* libmad related definitions */
+static struct mad_stream stream IBSS_ATTR;
+static struct mad_frame  frame IBSS_ATTR;
+static struct mad_synth  synth IBSS_ATTR;
+
+/* 2567 bytes */
+static unsigned char mad_main_data[MAD_BUFFER_MDLEN];
+
+/* There isn't enough room for this in IRAM on PortalPlayer, but there
+   is for Coldfire. */
+
+/* 4608 bytes */
+#ifdef CPU_COLDFIRE
+static mad_fixed_t mad_frame_overlap[2][32][18] IBSS_ATTR;
+#else
+static mad_fixed_t mad_frame_overlap[2][32][18];
+#endif
+
+/** A queue for saving needed information about MPEG audio packets **/
+#define AUDIODESC_QUEUE_LEN  (1 << 5) /* 32 should be way more than sufficient -
+                                         if not, the case is handled */
+#define AUDIODESC_QUEUE_MASK (AUDIODESC_QUEUE_LEN-1)
+struct audio_frame_desc
+{
+    uint32_t time;  /* Time stamp for packet in audio ticks       */
+    ssize_t  size;  /* Number of unprocessed bytes left in packet */
+};
+
+ /* This starts out wr == rd but will never be emptied to zero during
+    streaming again in order to support initializing the first packet's
+    timestamp without a special case */
+struct
+{
+    /* Compressed audio data */
+    uint8_t *start;  /* Start of encoded audio buffer */
+    uint8_t *ptr;    /* Pointer to next encoded audio data */
+    ssize_t used;    /* Number of bytes in MPEG audio buffer */
+    /* Compressed audio data descriptors */
+    unsigned read, write;
+    struct audio_frame_desc *curr; /* Current slot */
+    struct audio_frame_desc descs[AUDIODESC_QUEUE_LEN];
+} audio_queue;
+
+static inline int audiodesc_queue_count(void)
+{
+    return audio_queue.write - audio_queue.read;
+}
+
+static inline bool audiodesc_queue_full(void)
+{
+    return audio_queue.used >= MPA_MAX_FRAME_SIZE + MAD_BUFFER_GUARD ||
+            audiodesc_queue_count() >= AUDIODESC_QUEUE_LEN;
+}
+
+/* Increments the queue tail postion - should be used to preincrement */
+static inline void audiodesc_queue_add_tail(void)
+{
+    if (audiodesc_queue_full())
+    {
+        DEBUGF("audiodesc_queue_add_tail: audiodesc queue full!\n");
+        return;
+    }
+
+    audio_queue.write++;
+}
+
+/* Increments the queue tail position - leaves one slot as current */
+static inline bool audiodesc_queue_remove_head(void)
+{
+    if (audio_queue.write == audio_queue.read)
+        return false;
+
+    audio_queue.read++;
+    return true;
+}
+
+/* Returns the "tail" at the index just behind the write index */
+static inline struct audio_frame_desc * audiodesc_queue_tail(void)
+{
+    return &audio_queue.descs[(audio_queue.write - 1) & AUDIODESC_QUEUE_MASK];
+}
+
+/* Returns a pointer to the current head */
+static inline struct audio_frame_desc * audiodesc_queue_head(void)
+{
+    return &audio_queue.descs[audio_queue.read & AUDIODESC_QUEUE_MASK];
+}
+
+/* Resets the pts queue - call when starting and seeking */
+static void audio_queue_reset(void)
+{
+    audio_queue.ptr = audio_queue.start;
+    audio_queue.used = 0;
+    audio_queue.read = 0;
+    audio_queue.write = 0;
+    audio_queue.curr = audiodesc_queue_head();
+    audio_queue.curr->time = 0;
+    audio_queue.curr->size = 0;
+}
+
+static void audio_queue_advance_pos(ssize_t len)
+{
+    audio_queue.ptr        += len;
+    audio_queue.used       -= len;
+    audio_queue.curr->size -= len;
+}
+
+static int audio_buffer(struct stream *str, enum stream_parse_mode type)
+{
+    int ret = STREAM_OK;
+
+    /* Carry any overshoot to the next size since we're technically
+       -size bytes into it already. If size is negative an audio
+       frame was split across packets. Old has to be saved before
+       moving the head. */
+    if (audio_queue.curr->size <= 0 && audiodesc_queue_remove_head())
+    {
+        struct audio_frame_desc *old = audio_queue.curr;
+        audio_queue.curr = audiodesc_queue_head();
+        audio_queue.curr->size += old->size;
+        old->size = 0;
+    }
+
+    /* Add packets to compressed audio buffer until it's full or the
+     * timestamp queue is full - whichever happens first */
+    while (!audiodesc_queue_full())
+    {
+        ret = parser_get_next_data(str, type);
+        struct audio_frame_desc *curr;
+        ssize_t len;
+
+        if (ret != STREAM_OK)
+            break;
+
+        /* Get data from next audio packet */
+        len = str->curr_packet_end - str->curr_packet;
+
+        if (str->pkt_flags & PKT_HAS_TS)
+        {
+            audiodesc_queue_add_tail();
+            curr = audiodesc_queue_tail();
+            curr->time = TS_TO_TICKS(str->pts);
+            /* pts->size should have been zeroed when slot was
+               freed */
+        }
+        else
+        {
+            /* Add to the one just behind the tail - this may be
+             * the head or the previouly added tail - whether or
+             * not we'll ever reach this is quite in question
+             * since audio always seems to have every packet
+             * timestamped */
+            curr = audiodesc_queue_tail();
+        }
+
+        curr->size += len;
+
+        /* Slide any remainder over to beginning */
+        if (audio_queue.ptr > audio_queue.start && audio_queue.used > 0)
+        {
+            rb->memmove(audio_queue.start, audio_queue.ptr,
+                        audio_queue.used);
+        }
+
+        /* Splice this packet onto any remainder */
+        rb->memcpy(audio_queue.start + audio_queue.used,
+                   str->curr_packet, len);
+
+        audio_queue.used += len;
+        audio_queue.ptr = audio_queue.start;
+
+        rb->yield();
+    }
+
+    return ret;
+}
+
+/* Initialise libmad */
+static void init_mad(void)
+{
+    mad_stream_init(&stream);
+    mad_frame_init(&frame);
+    mad_synth_init(&synth);
+
+    /* We do this so libmad doesn't try to call codec_calloc() */
+    rb->memset(mad_frame_overlap, 0, sizeof(mad_frame_overlap));
+    frame.overlap = (void *)mad_frame_overlap;
+
+    rb->memset(mad_main_data, 0, sizeof(mad_main_data));
+    stream.main_data = &mad_main_data;
+}
+
+/* Sync audio stream to a particular frame - see main decoder loop for
+ * detailed remarks */
+static int audio_sync(struct audio_thread_data *td,
+                      struct str_sync_data *sd)
+{
+    int retval = STREAM_MATCH;
+    uint32_t sdtime = TS_TO_TICKS(clip_time(&audio_str, sd->time));
+    uint32_t time;
+    uint32_t duration = 0;
+    struct stream *str;
+    struct stream tmp_str;
+    struct mad_header header;
+    struct mad_stream stream;
+
+    if (td->ev.id == STREAM_SYNC)
+    {
+        /* Actually syncing for playback - use real stream */
+        time = 0;
+        str = &audio_str;
+    }
+    else
+    {
+        /* Probing - use temp stream */
+        time = INVALID_TIMESTAMP;
+        str = &tmp_str;
+        str->id = audio_str.id;
+    }        
+
+    str->hdr.pos = sd->sk.pos;
+    str->hdr.limit = sd->sk.pos + sd->sk.len;
+
+    mad_stream_init(&stream);
+    mad_header_init(&header);
+
+    while (1)
+    {
+        if (audio_buffer(str, STREAM_PM_RANDOM_ACCESS) == STREAM_DATA_END)
+        {
+            DEBUGF("audio_sync:STR_DATA_END\n  aqu:%ld swl:%ld swr:%ld\n",
+                    audio_queue.used, str->hdr.win_left, str->hdr.win_right);
+            if (audio_queue.used <= MAD_BUFFER_GUARD)
+                goto sync_data_end;
+        }
+
+        stream.error = 0;
+        mad_stream_buffer(&stream, audio_queue.ptr, audio_queue.used);
+
+        if (stream.sync && mad_stream_sync(&stream) < 0)
+        {
+            DEBUGF(" audio: mad_stream_sync failed\n");
+            audio_queue_advance_pos(MAX(audio_queue.curr->size - 1, 1));
+            continue;
+        }
+
+        stream.sync = 0;
+
+        if (mad_header_decode(&header, &stream) < 0)
+        {
+            DEBUGF(" audio: mad_header_decode failed:%s\n",
+                   mad_stream_errorstr(&stream));
+            audio_queue_advance_pos(1);
+            continue;
+        }
+
+        duration = 32*MAD_NSBSAMPLES(&header);
+        time = audio_queue.curr->time;
+
+        DEBUGF(" audio: ft:%u t:%u fe:%u nsamp:%u sampr:%u\n",
+               (unsigned)TICKS_TO_TS(time), (unsigned)sd->time,
+               (unsigned)TICKS_TO_TS(time + duration),
+               (unsigned)duration, header.samplerate);
+
+        audio_queue_advance_pos(stream.this_frame - audio_queue.ptr);
+
+        if (time <= sdtime && sdtime < time + duration)
+        {
+            DEBUGF(" audio: ft<=t<fe\n");
+            retval = STREAM_PERFECT_MATCH;
+            break;
+        }
+        else if (time > sdtime)
+        {
+            DEBUGF(" audio: ft>t\n");
+            break;
+        }
+
+        audio_queue_advance_pos(stream.next_frame - audio_queue.ptr);
+        audio_queue.curr->time += duration;
+
+        rb->yield();
+    }
+
+sync_data_end:
+    if (td->ev.id == STREAM_FIND_END_TIME)
+    {
+        if (time != INVALID_TIMESTAMP)
+        {
+            time = TICKS_TO_TS(time);
+            duration = TICKS_TO_TS(duration);
+            sd->time = time + duration;
+            retval = STREAM_PERFECT_MATCH;
+        }
+        else
+        {
+            retval = STREAM_NOT_FOUND;
+        }
+    }
+
+    DEBUGF(" audio header: 0x%02X%02X%02X%02X\n",
+           (unsigned)audio_queue.ptr[0], (unsigned)audio_queue.ptr[1],
+           (unsigned)audio_queue.ptr[2], (unsigned)audio_queue.ptr[3]);
+
+    return retval;
+    (void)td;
+}
+
+static void audio_thread_msg(struct audio_thread_data *td)
+{
+    while (1)
+    {
+        intptr_t reply = 0;
+
+        switch (td->ev.id)
+        {
+        case STREAM_PLAY:
+            td->status = STREAM_PLAYING;
+
+            switch (td->state)
+            {
+            case TSTATE_INIT:
+                td->state = TSTATE_DECODE;
+            case TSTATE_DECODE:
+            case TSTATE_RENDER_WAIT:
+            case TSTATE_RENDER_WAIT_END:
+                break;
+
+            case TSTATE_EOS:
+                /* At end of stream - no playback possible so fire the
+                 * completion event */
+                stream_generate_event(&audio_str, STREAM_EV_COMPLETE, 0);
+                break;
+            }
+
+            break;
+
+        case STREAM_PAUSE:
+            td->status = STREAM_PAUSED;
+            reply = td->state != TSTATE_EOS;
+            break;
+
+        case STREAM_STOP:
+            if (td->state == TSTATE_DATA)
+                stream_clear_notify(&audio_str, DISK_BUF_DATA_NOTIFY);
+
+            td->status = STREAM_STOPPED;
+            td->state = TSTATE_EOS;
+
+            reply = true;
+            break;            
+
+        case STREAM_RESET:
+            if (td->state == TSTATE_DATA)
+                stream_clear_notify(&audio_str, DISK_BUF_DATA_NOTIFY);
+
+            td->status = STREAM_STOPPED;
+            td->state = TSTATE_INIT;
+
+            init_mad();
+            td->mad_errors = 0;
+
+            audio_queue_reset();
+
+            reply = true;
+            break;
+
+        case STREAM_NEEDS_SYNC:
+            reply = true; /* Audio always needs to */
+            break;
+
+        case STREAM_SYNC:
+        case STREAM_FIND_END_TIME:
+            if (td->state != TSTATE_INIT)
+                break;
+
+            reply = audio_sync(td, (struct str_sync_data *)td->ev.data);
+            break;
+
+        case DISK_BUF_DATA_NOTIFY:
+            /* Our bun is done */
+            if (td->state != TSTATE_DATA)
+                break;
+
+            td->state = TSTATE_DECODE;
+            str_data_notify_received(&audio_str);
+            break;
+
+        case STREAM_QUIT:
+            /* Time to go - make thread exit */
+            td->state = TSTATE_EOS;
+            return;
+        }
+
+        str_reply_msg(&audio_str, reply);
+
+        if (td->status == STREAM_PLAYING)
+        {
+            switch (td->state)
+            {
+            case TSTATE_DECODE:
+            case TSTATE_RENDER_WAIT:
+            case TSTATE_RENDER_WAIT_END:
+                /* These return when in playing state */
+                return;
+            }
+        }
+
+        str_get_msg(&audio_str, &td->ev);
+    }
+}
+
+static void audio_thread(void)
+{
+    struct audio_thread_data td;
+
+    td.status = STREAM_STOPPED;
+    td.state = TSTATE_EOS;
+
+    /* We need this here to init the EMAC for Coldfire targets */
+    init_mad();
+
+    goto message_wait;
+
+    /* This is the decoding loop. */
+    while (1)
+    {
+        td.state = TSTATE_DECODE;
+
+        /* Check for any pending messages and process them */
+        if (str_have_msg(&audio_str))
+        {
+        message_wait:
+            /* Wait for a message to be queued */
+            str_get_msg(&audio_str, &td.ev);
+
+        message_process:
+            /* Process a message already dequeued */
+            audio_thread_msg(&td);
+
+            switch (td.state)
+            {
+            /* These states are the only ones that should return */
+            case TSTATE_DECODE:          goto audio_decode;
+            case TSTATE_RENDER_WAIT:     goto render_wait;
+            case TSTATE_RENDER_WAIT_END: goto render_wait_end;
+            /* Anything else is interpreted as an exit */
+            default:                     return;
+            }
+        }
+
+    audio_decode:
+
+        /** Buffering **/
+        switch (audio_buffer(&audio_str, STREAM_PM_STREAMING))
+        {
+        case STREAM_DATA_NOT_READY:
+        {
+            td.state = TSTATE_DATA;
+            goto message_wait;
+            } /* STREAM_DATA_NOT_READY: */
+
+        case STREAM_DATA_END:
+        {
+            if (audio_queue.used > MAD_BUFFER_GUARD)
+                break;
+
+            /* Used up remainder of compressed audio buffer.
+             * Force any residue to play if audio ended before
+             * reaching the threshold */
+            td.state = TSTATE_RENDER_WAIT_END;
+            audio_queue_reset();
+
+        render_wait_end:
+            pcm_output_drain();
+
+            while (pcm_output_used() > (ssize_t)PCMOUT_LOW_WM)
+            {
+                str_get_msg_w_tmo(&audio_str, &td.ev, 1);
+                if (td.ev.id != SYS_TIMEOUT)
+                    goto message_process;
+            }
+
+            td.state = TSTATE_EOS;
+            if (td.status == STREAM_PLAYING)
+                stream_generate_event(&audio_str, STREAM_EV_COMPLETE, 0);
+
+            rb->yield();
+            goto message_wait;
+            } /* STREAM_DATA_END: */
+        }
+
+        /** Decoding **/
+        mad_stream_buffer(&stream, audio_queue.ptr, audio_queue.used);
+
+        int mad_stat = mad_frame_decode(&frame, &stream);
+
+        ssize_t len = stream.next_frame - audio_queue.ptr;
+
+        if (mad_stat != 0)
+        {
+            DEBUGF("audio: Stream error: %s\n",
+                   mad_stream_errorstr(&stream));
+
+            /* If something's goofed - try to perform resync by moving
+             * at least one byte at a time */
+            audio_queue_advance_pos(MAX(len, 1));
+
+            if (stream.error == MAD_FLAG_INCOMPLETE
+                || stream.error == MAD_ERROR_BUFLEN)
+            {
+                /* This makes the codec support partially corrupted files */
+                if (++td.mad_errors <= MPA_MAX_FRAME_SIZE)
+                {
+                    stream.error = 0;
+                    rb->yield();
+                    continue;
+                }
+                DEBUGF("audio: Too many errors\n");
+            }
+            else if (MAD_RECOVERABLE(stream.error))
+            {
+                /* libmad says it can recover - just keep on decoding */
+                rb->yield();
+                continue;
+            }
+            else
+            {
+                /* Some other unrecoverable error */
+                DEBUGF("audio: Unrecoverable error\n");
+            }
+
+            /* This is too hard - bail out */
+            td.state = TSTATE_EOS;
+
+            if (td.status == STREAM_PLAYING)
+                stream_generate_event(&audio_str, STREAM_EV_COMPLETE, 0);
+
+            td.status = STREAM_ERROR;
+            goto message_wait;
+        }
+
+        /* Adjust sizes by the frame size */
+        audio_queue_advance_pos(len);
+        td.mad_errors = 0; /* Clear errors */
+
+        /* Generate the pcm samples */
+        mad_synth_frame(&synth, &frame);
+
+        /** Output **/
+
+        /* TODO: Output through core dsp. We'll still use our own PCM buffer
+           since the core pcm buffer has no timestamping or clock facilities */
+
+        /* Add a frame of audio to the pcm buffer. Maximum is 1152 samples. */
+    render_wait:
+        if (synth.pcm.length > 0)
+        {
+            struct pcm_frame_header *pcm_insert = pcm_output_get_buffer();
+            int16_t *audio_data = (int16_t *)pcm_insert->data;
+            unsigned length = synth.pcm.length;
+            ssize_t size = sizeof(*pcm_insert) + length*4;
+
+            td.state = TSTATE_RENDER_WAIT;
+
+            /* Wait for required amount of free buffer space */
+            while (pcm_output_free() < size)
+            {
+                /* Wait one frame */
+                int timeout = synth.pcm.length*HZ / synth.pcm.samplerate;
+                str_get_msg_w_tmo(&audio_str, &td.ev, MAX(timeout, 1));
+                if (td.ev.id != SYS_TIMEOUT)
+                    goto message_process;
+            }
+
+            pcm_insert->time = audio_queue.curr->time;
+            pcm_insert->size = size;
+
+            /* As long as we're on this timestamp, the time is just incremented
+               by the number of samples */
+            audio_queue.curr->time += length;
+
+            if (MAD_NCHANNELS(&frame.header) == 2)
+            {
+                int32_t *left = &synth.pcm.samples[0][0];
+                int32_t *right = &synth.pcm.samples[1][0];
+
+                do
+                {
+                    /* libmad outputs s3.28 */
+                    *audio_data++ = clip_sample(*left++ >> 13);
+                    *audio_data++ = clip_sample(*right++ >> 13);
+                }
+                while (--length > 0);
+            }
+            else  /* mono */
+            {
+                int32_t *mono = &synth.pcm.samples[0][0];
+
+                do
+                {
+                    int32_t s = clip_sample(*mono++ >> 13);
+                    *audio_data++ = s;
+                    *audio_data++ = s;
+                }
+                while (--length > 0);
+            }
+            /**/
+
+            /* Make this data available to DMA */
+            pcm_output_add_data();
+        }
+
+        rb->yield();
+    } /* end decoding loop */
+}
+
+/* Initializes the audio thread resources and starts the thread */
+bool audio_thread_init(void)
+{
+    int i;
+#ifdef SIMULATOR
+    /* The simulator thread implementation doesn't have stack buffers, and
+       these parameters are ignored. */
+    (void)i;  /* Keep gcc happy */
+    audio_stack = NULL;
+    audio_stack_size = 0;
+#else
+    /* Borrow the codec thread's stack (in IRAM on most targets) */
+    audio_stack = NULL;
+    for (i = 0; i < MAXTHREADS; i++)
+    {
+        if (rb->strcmp(rb->threads[i].name, "codec") == 0)
+        {
+            /* Wait to ensure the codec thread has blocked */
+            while (rb->threads[i].state != STATE_BLOCKED)
+                rb->yield();
+
+            /* Now we can steal the stack */
+            audio_stack = rb->threads[i].stack;
+            audio_stack_size = rb->threads[i].stack_size;
+
+            /* Backup the codec thread's stack */
+            rb->memcpy(codec_stack_copy, audio_stack, audio_stack_size);
+            break;
+        }
+    }
+
+    if (audio_stack == NULL)
+    {
+        /* This shouldn't happen, but deal with it anyway by using
+           the copy instead */
+        audio_stack = codec_stack_copy;
+        audio_stack_size = AUDIO_STACKSIZE;
+    }
+#endif
+
+    /* Initialise the encoded audio buffer and its descriptors */
+    audio_queue.start = mpeg_malloc(AUDIOBUF_ALLOC_SIZE,
+                                    MPEG_ALLOC_AUDIOBUF);
+    if (audio_queue.start == NULL)
+        return false;
+
+    /* Start the audio thread */
+    audio_str.hdr.q = &audio_str_queue;
+    rb->queue_init(audio_str.hdr.q, false);
+    rb->queue_enable_queue_send(audio_str.hdr.q, &audio_str_queue_send);
+
+    audio_str.thread = rb->create_thread(
+        audio_thread, audio_stack, audio_stack_size, 0,
+        "mpgaudio" IF_PRIO(,PRIORITY_PLAYBACK) IF_COP(, CPU));
+
+    if (audio_str.thread == NULL)
+        return false;
+
+    /* Wait for thread to initialize */
+    str_send_msg(&audio_str, STREAM_NULL, 0);
+
+    return true;
+}
+
+/* Stops the audio thread */
+void audio_thread_exit(void)
+{
+    if (audio_str.thread != NULL)
+    {
+        str_post_msg(&audio_str, STREAM_QUIT, 0);
+        rb->thread_wait(audio_str.thread);
+        audio_str.thread = NULL;
+    }
+
+#ifndef SIMULATOR
+    /* Restore the codec thread's stack */
+    rb->memcpy(audio_stack, codec_stack_copy, audio_stack_size);    
+#endif
+}