Commit FS#12150 - Fully-functional audio mixer - and finally whip old limitations about playback of voice and other sounds when paused. Channels are independent in state and amplitude. Fade on stop/pause is handled by the channel's volume control rather than global volume which means it now works from anywhere. Opens up the possibility of plugin sounds during music playback by merely adding an additional channel enum. If any PCM drivers were not properly modified, see one of the last comments in the task for a description of the simple change that is expected. Some params are tunable in firmware/export/pcm-mixer.h as well.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30097 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 162 insertions, 117 deletions

diff --git a/apps/voice_thread.c b/apps/voice_thread.c
index 6683fcc067..3318bbecb3 100644
--- a/apps/voice_thread.c
+++ b/apps/voice_thread.c
@@ -27,6 +27,8 @@
 #include "audio.h"
 #include "playback.h"
 #include "pcmbuf.h"
+#include "pcm.h"
+#include "pcm_mixer.h"
 #include "codecs/libspeex/speex/speex.h"
 
 /* Define any of these as "1" and uncomment the LOGF_ENABLE line to log
@@ -53,24 +55,50 @@
 #define IBSS_ATTR_VOICE_STACK IBSS_ATTR
 #endif
 
+/* Minimum priority needs to be a bit elevated since voice has fairly low
+   latency */
+#define PRIORITY_VOICE (PRIORITY_PLAYBACK-4)
+
 #define VOICE_FRAME_SIZE    320 /* Samples / frame */
 #define VOICE_SAMPLE_RATE 16000 /* Sample rate in HZ */
 #define VOICE_SAMPLE_DEPTH   16 /* Sample depth in bits */
 
 /* Voice thread variables */
 static unsigned int voice_thread_id = 0;
-static long voice_stack[(DEFAULT_STACK_SIZE + 0x3C0)/sizeof(long)] IBSS_ATTR_VOICE_STACK;
+#ifdef CPU_COLDFIRE
+/* ISR uses any available stack - need a bit more room */
+#define VOICE_STACK_EXTRA   0x400
+#else
+#define VOICE_STACK_EXTRA   0x3c0
+#endif
+static long voice_stack[(DEFAULT_STACK_SIZE + VOICE_STACK_EXTRA)/sizeof(long)]
+    IBSS_ATTR_VOICE_STACK;
 static const char voice_thread_name[] = "voice";
 
 /* Voice thread synchronization objects */
 static struct event_queue voice_queue SHAREDBSS_ATTR;
-static struct mutex voice_mutex SHAREDBSS_ATTR;
 static struct queue_sender_list voice_queue_sender_list SHAREDBSS_ATTR;
 static bool voice_done SHAREDDATA_ATTR = true;
 
 /* Buffer for decoded samples */
 static spx_int16_t voice_output_buf[VOICE_FRAME_SIZE] CACHEALIGN_ATTR;
 
+#define VOICE_PCM_FRAME_COUNT   ((NATIVE_FREQUENCY*VOICE_FRAME_SIZE + \
+                                 VOICE_SAMPLE_RATE) / VOICE_SAMPLE_RATE)
+#define VOICE_PCM_FRAME_SIZE    (VOICE_PCM_FRAME_COUNT*4)
+
+/* Default number of native-frequency PCM frames to queue - adjust as
+   necessary per-target */
+#define VOICE_FRAMES            3
+
+/* Might have lookahead and be skipping samples, so size is needed */
+static size_t voicebuf_sizes[VOICE_FRAMES];
+static uint32_t (* voicebuf)[VOICE_PCM_FRAME_COUNT];
+static unsigned int cur_buf_in, cur_buf_out;
+
+/* A delay to not bring audio back to normal level too soon */
+#define QUIET_COUNT 3
+
 enum voice_thread_states
 {
     TSTATE_STOPPED = 0,   /* Voice thread is stopped and awaiting commands */
@@ -83,7 +111,6 @@ enum voice_thread_messages
     Q_VOICE_NULL = 0, /* A message for thread sync - no effect on state */
     Q_VOICE_PLAY,     /* Play a clip */
     Q_VOICE_STOP,     /* Stop current clip */
-    Q_VOICE_STATE,    /* Query playing state */
 };
 
 /* Structure to store clip data callback info */
@@ -98,7 +125,7 @@ struct voice_info
  * internal functions */
 struct voice_thread_data
 {
-    int state;              /* Thread state (TSTATE_*) */
+    volatile int state;     /* Thread state (TSTATE_*) */
     struct queue_event ev;  /* Last queue event pulled from queue */
     void *st;               /* Decoder instance */
     SpeexBits bits;         /* Bit cursor */
@@ -107,33 +134,79 @@ struct voice_thread_data
     const char *src[2];     /* Current output buffer pointers */
     int lookahead;          /* Number of samples to drop at start of clip */
     int count;              /* Count of samples remaining to send to PCM */
+    int quiet_counter;      /* Countdown until audio goes back to normal */
 };
 
-/* Audio playback is in a playing state? */
-static inline bool playback_is_playing(void)
+/* Number of frames in queue */
+static inline int voice_unplayed_frames(void)
 {
-    return (audio_status() & AUDIO_STATUS_PLAY) != 0;
+    return cur_buf_in - cur_buf_out;
+}
+
+/* Mixer channel callback */
+static void voice_pcm_callback(unsigned char **start, size_t *size)
+{
+    if (voice_unplayed_frames() == 0)
+        return; /* Done! */
+
+    unsigned int i = ++cur_buf_out % VOICE_FRAMES;
+
+    *start = (unsigned char *)voicebuf[i];
+    *size = voicebuf_sizes[i];
+}
+
+/* Start playback of voice channel if not already playing */
+static void voice_start_playback(void)
+{
+    if (mixer_channel_status(PCM_MIXER_CHAN_VOICE) != CHANNEL_STOPPED)
+        return;
+
+    unsigned int i = cur_buf_out % VOICE_FRAMES;
+    mixer_channel_play_data(PCM_MIXER_CHAN_VOICE, voice_pcm_callback,
+                            (unsigned char *)voicebuf[i], voicebuf_sizes[i]);
+}
+
+/* Stop the voice channel */
+static void voice_stop_playback(void)
+{
+    mixer_channel_stop(PCM_MIXER_CHAN_VOICE);
+    cur_buf_in = cur_buf_out = 0;
+}
+
+/* Grab a free PCM frame */
+static uint32_t * voice_buf_get(void)
+{
+    if (voice_unplayed_frames() >= VOICE_FRAMES)
+    {
+        /* Full */
+        voice_start_playback();
+        return NULL;
+    }
+
+    return voicebuf[cur_buf_in % VOICE_FRAMES];
+}
+
+/* Commit a frame returned by voice_buf_get and set the actual size */
+static void voice_buf_commit(size_t size)
+{
+    voicebuf_sizes[cur_buf_in++ % VOICE_FRAMES] = size;
 }
 
 /* Stop any current clip and start playing a new one */
 void mp3_play_data(const unsigned char* start, int size,
                    pcm_play_callback_type get_more)
 {
-    /* Shared struct to get data to the thread - once it replies, it has
-     * safely cached it in its own private data */
-    static struct voice_info voice_clip SHAREDBSS_ATTR;
-
     if (get_more != NULL && start != NULL && (ssize_t)size > 0)
     {
-        mutex_lock(&voice_mutex);
+        struct voice_info voice_clip =
+        {
+            .get_more = get_more,
+            .start    = (unsigned char *)start,
+            .size     = size,
+        };
 
-        voice_clip.get_more = get_more;
-        voice_clip.start    = (unsigned char *)start;
-        voice_clip.size     = size;
         LOGFQUEUE("mp3 >| voice Q_VOICE_PLAY");
         queue_send(&voice_queue, Q_VOICE_PLAY, (intptr_t)&voice_clip);
-
-        mutex_unlock(&voice_mutex);
     }
 }
 
@@ -143,11 +216,8 @@ void mp3_play_stop(void)
     if(!audio_is_thread_ready())
        return;
 
-    mutex_lock(&voice_mutex); /* Sync against voice_stop */
-    LOGFQUEUE("mp3 >| voice Q_VOICE_STOP: 1");
-    queue_send(&voice_queue, Q_VOICE_STOP, 1);
-
-    mutex_unlock(&voice_mutex);
+    LOGFQUEUE("mp3 >| voice Q_VOICE_STOP");
+    queue_send(&voice_queue, Q_VOICE_STOP, 0);
 }
 
 void mp3_play_pause(bool play)
@@ -156,36 +226,19 @@ void mp3_play_pause(bool play)
     (void)play;
 }
 
-/* Tell is voice is still in a playing state */
+/* Tell if voice is still in a playing state */
 bool mp3_is_playing(void)
 {
-    /* TODO: Implement a timeout or state query function for event objects */
-    LOGFQUEUE("mp3 >| voice Q_VOICE_STATE");
-    int state = queue_send(&voice_queue, Q_VOICE_STATE, 0);
-    return state != TSTATE_STOPPED;
+    return !voice_done;
 }
 
 /* This function is meant to be used by the buffer request functions to
    ensure the codec is no longer active */
 void voice_stop(void)
 {
-    mutex_lock(&voice_mutex);
-
-    /* Stop the output and current clip */
-    mp3_play_stop();
-
-    /* Careful if using sync objects in talk.c - make sure locking order is
-     * observed with one or the other always granted first */
-
     /* Unqueue all future clips */
     talk_force_shutup();
-
-    /* Wait for any final queue_post to be processed */
-    LOGFQUEUE("mp3 >| voice Q_VOICE_NULL");
-    queue_send(&voice_queue, Q_VOICE_NULL, 0);
-
-    mutex_unlock(&voice_mutex);
-} /* voice_stop */
+}
 
 /* Wait for voice to finish speaking. */
 void voice_wait(void)
@@ -194,8 +247,7 @@ void voice_wait(void)
      * new clip by the time we wait. This should be resolvable if conditions
      * ever require knowing the very clip you requested has finished. */
 
-    /* Wait for PCM buffer to be exhausted. Works only if not playing. */
-    while(!voice_done || (!playback_is_playing() && pcm_is_playing()))
+    while (!voice_done)
         sleep(1);
 }
 
@@ -211,6 +263,9 @@ static void voice_data_init(struct voice_thread_data *td)
     dsp_configure(td->dsp, DSP_SET_FREQUENCY, VOICE_SAMPLE_RATE);
     dsp_configure(td->dsp, DSP_SET_SAMPLE_DEPTH, VOICE_SAMPLE_DEPTH);
     dsp_configure(td->dsp, DSP_SET_STEREO_MODE, STEREO_MONO);
+
+    mixer_channel_set_amplitude(PCM_MIXER_CHAN_VOICE, MIX_AMP_UNITY);
+    td->quiet_counter = 0;
 }
 
 /* Voice thread message processing */
@@ -222,7 +277,6 @@ static void voice_message(struct voice_thread_data *td)
         {
         case Q_VOICE_PLAY:
             LOGFQUEUE("voice < Q_VOICE_PLAY");
-            /* Put up a block for completion signal */
             voice_done = false;
 
             /* Copy the clip info */
@@ -239,12 +293,17 @@ static void voice_message(struct voice_thread_data *td)
                 /* Boost CPU now */
                 trigger_cpu_boost();
             }
-            else if (!playback_is_playing())
+            else
             {
-                /* Just voice, stop any clip still playing */
-                pcmbuf_play_stop();
+                /* Stop any clip still playing */
+                voice_stop_playback();
             }
 
+            /* Make audio play more softly and set delay to return to normal
+               playback level */
+            pcmbuf_soft_mode(true);
+            td->quiet_counter = QUIET_COUNT;
+
             /* Clean-start the decoder */
             td->st = speex_decoder_init(&speex_wb_mode);
 
@@ -255,30 +314,32 @@ static void voice_message(struct voice_thread_data *td)
             td->state = TSTATE_DECODE;
             return;
 
-        case Q_VOICE_STOP:
-            LOGFQUEUE("voice < Q_VOICE_STOP: %ld", (long)td->ev.data);
+        case SYS_TIMEOUT:
+            if (voice_unplayed_frames())
+            {
+                /* Waiting for PCM to finish */
+                break;
+            }
 
-            if (td->ev.data != 0 && !playback_is_playing())
+            /* Drop through and stop the first time after clip runs out */
+            if (td->quiet_counter-- != QUIET_COUNT)
             {
-                /* If not playing, it's just voice so stop pcm playback */
-                pcmbuf_play_stop();
+                if (td->quiet_counter <= 0)
+                    pcmbuf_soft_mode(false);
+
+                break;
             }
 
-            /* Cancel boost */
-            cancel_cpu_boost();
+            /* Fall-through */
+        case Q_VOICE_STOP:
+            LOGFQUEUE("voice < Q_VOICE_STOP");
 
             td->state = TSTATE_STOPPED;
             voice_done = true;
-            break;
-
-        case Q_VOICE_STATE:
-            LOGFQUEUE("voice < Q_VOICE_STATE");
-            queue_reply(&voice_queue, td->state);
-
-            if (td->state == TSTATE_STOPPED)
-                break; /* Not in a playback state */
 
-            return;
+            cancel_cpu_boost();
+            voice_stop_playback();
+            break;
 
         default:
             /* Default messages get a reply and thread continues with no
@@ -286,20 +347,24 @@ static void voice_message(struct voice_thread_data *td)
             LOGFQUEUE("voice < default");
 
             if (td->state == TSTATE_STOPPED)
-                break;  /* Not in playback state */
+                break;  /* Not in (active) playback state */
 
             queue_reply(&voice_queue, 0);
             return;
         }
 
-        queue_wait(&voice_queue, &td->ev);
+        if (td->quiet_counter > 0)
+            queue_wait_w_tmo(&voice_queue, &td->ev, HZ/10);
+        else
+            queue_wait(&voice_queue, &td->ev);
     }
 }
 
 /* Voice thread entrypoint */
-static void voice_thread(void)
+static void NORETURN_ATTR voice_thread(void)
 {
     struct voice_thread_data td;
+    char *dest;
 
     voice_data_init(&td);
 
@@ -361,19 +426,10 @@ static void voice_thread(void)
             }
 
             /* If all clips are done and not playing, force pcm playback. */
-            if (!pcm_is_playing())
-                pcmbuf_play_start();
-
-            /* Synthesize a stop request */
-            /* NOTE: We have no way to know when the pcm data placed in the
-             * buffer is actually consumed and playback has reached the end
-             * so until the info is available or inferred somehow, this will
-             * not be accurate and the stopped signal will come too soon.
-             * ie. You may not hear the "Shutting Down" splash even though
-             * it waits for voice to stop. */
-            td.ev.id = Q_VOICE_STOP;
-            td.ev.data = 0; /* Let PCM drain by itself */
-            yield();
+            voice_start_playback();
+
+            td.state = TSTATE_STOPPED;
+            td.ev.id = SYS_TIMEOUT;
             goto message_process;
         }
 
@@ -385,62 +441,39 @@ static void voice_thread(void)
         td.src[1] = NULL;
         td.lookahead -= MIN(VOICE_FRAME_SIZE, td.lookahead);
 
+        if (td.count <= 0)
+            continue;
+
+        td.state = TSTATE_BUFFER_INSERT;
+
     buffer_insert:
         /* Process the PCM samples in the DSP and send out for mixing */
-        td.state = TSTATE_BUFFER_INSERT;
 
-        while (td.count > 0)
+        while (1)
         {
-            int out_count = dsp_output_count(td.dsp, td.count);
-            int inp_count;
-            char *dest;
+            if (!queue_empty(&voice_queue))
+                goto message_wait;
 
-            while (1)
-            {
-                if (!queue_empty(&voice_queue))
-                    goto message_wait;
-
-                if ((dest = pcmbuf_request_voice_buffer(&out_count)) != NULL)
-                    break;
-
-                yield();
-            }
-
-            /* Get the real input_size for output_size bytes, guarding
-             * against resampling buffer overflows. */
-            inp_count = dsp_input_count(td.dsp, out_count);
-
-            if (inp_count <= 0)
-                break;
-
-            /* Input size has grown, no error, just don't write more than
-             * length */
-            if (inp_count > td.count)
-                inp_count = td.count;
-
-            out_count = dsp_process(td.dsp, dest, td.src, inp_count);
-
-            if (out_count <= 0)
+            if ((dest = (char *)voice_buf_get()) != NULL)
                 break;
 
-            pcmbuf_write_voice_complete(out_count);
-            td.count -= inp_count;
+            yield();
         }
 
-        yield();
+        voice_buf_commit(dsp_process(td.dsp, dest, td.src, td.count)
+                         * sizeof (int32_t));
     } /* end while */
-} /* voice_thread */
+}
 
 /* Initialize all synchronization objects create the thread */
 void voice_thread_init(void)
 {
     logf("Starting voice thread");
     queue_init(&voice_queue, false);
-    mutex_init(&voice_mutex);
 
     voice_thread_id = create_thread(voice_thread, voice_stack,
             sizeof(voice_stack), CREATE_THREAD_FROZEN,
-            voice_thread_name IF_PRIO(, PRIORITY_PLAYBACK) IF_COP(, CPU));
+            voice_thread_name IF_PRIO(, PRIORITY_VOICE) IF_COP(, CPU));
 
     queue_enable_queue_send(&voice_queue, &voice_queue_sender_list,
                             voice_thread_id);
@@ -457,6 +490,18 @@ void voice_thread_resume(void)
 /* Set the voice thread priority */
 void voice_thread_set_priority(int priority)
 {
+    if (priority > PRIORITY_VOICE)
+        priority = PRIORITY_VOICE;
+
     thread_set_priority(voice_thread_id, priority);
 }
 #endif
+
+/* Initialize voice PCM buffer and return size, allocated from the end */
+size_t voicebuf_init(unsigned char *bufend)
+{
+    size_t size = VOICE_FRAMES * VOICE_PCM_FRAME_SIZE;
+    cur_buf_out = cur_buf_in = 0;
+    voicebuf = (uint32_t (*)[VOICE_PCM_FRAME_COUNT])(bufend - size);
+    return size;
+}