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, 36 insertions, 7 deletions

diff --git a/firmware/target/arm/pcm-pp.c b/firmware/target/arm/pcm-pp.c
index c446f98fcf..704296d407 100644
--- a/firmware/target/arm/pcm-pp.c
+++ b/firmware/target/arm/pcm-pp.c
@@ -26,6 +26,7 @@
 #include "sound.h"
 #include "pcm.h"
 #include "pcm_sampr.h"
+#include "pcm-internal.h"
 
 /** DMA **/
 
@@ -115,6 +116,7 @@ void pcm_dma_apply_settings(void)
 /* NOTE: direct stack use forbidden by GCC stack handling bug for FIQ */
 void ICODE_ATTR __attribute__((interrupt("FIQ"))) fiq_playback(void)
 {
+    bool new_buffer = false;
     register size_t size;
 
     DMA0_STATUS; /* Clear any pending interrupt */
@@ -136,9 +138,14 @@ void ICODE_ATTR __attribute__((interrupt("FIQ"))) fiq_playback(void)
             /* Set the new DMA values and activate channel */
             DMA0_RAM_ADDR = dma_play_data.addr;
             DMA0_CMD = DMA_PLAY_CONFIG | (size - 4) | DMA_CMD_START;
+
+            if (new_buffer)
+                pcm_play_dma_started_callback();
             return;
         }
 
+        new_buffer = true;
+
         /* Buffer empty.  Try to get more. */
         pcm_play_get_more_callback((void **)&dma_play_data.addr,
                                    &dma_play_data.size);
@@ -181,8 +188,9 @@ void fiq_playback(void)
      * r0-r3 and r12 is a working register.
      */
     asm volatile (
-        "stmfd   sp!, { r0-r3, lr }  \n" /* stack scratch regs and lr */
+        "stmfd   sp!, { r0-r4, lr }  \n" /* stack scratch regs and lr */
 
+        "mov     r4, #0              \n" /* Was the callback called? */
 #if CONFIG_CPU == PP5002
         "ldr     r12, =0xcf001040    \n" /* Some magic from iPodLinux */
         "ldr     r12, [r12]          \n"
@@ -212,16 +220,13 @@ void fiq_playback(void)
         "tst     r1, #1              \n" /* two samples (one word) left? */
         "ldrne   r12, [r8], #4       \n" /* load two samples */
         "strne   r12, [r10, %[wr]]   \n" /* write sample 0-1 to IISFIFO_WR */
-
-        "cmp     r9, #0              \n" /* either FIFO is full or source buffer is empty */
-        "bgt     .exit               \n" /* if source buffer is not empty, FIFO must be full */
 #elif SAMPLE_SIZE == 32
     ".check_fifo:                    \n"
         "ldr     r0, [r10, %[cfg]]   \n" /* read IISFIFO_CFG to check FIFO status */
         "and     r0, r0, %[mask]     \n" /* r0 = IIS_TX_FREE_COUNT << 23 (PP5002) */
 
         "movs    r1, r0, lsr #24     \n" /* number of free pairs of FIFO slots */
-        "beq     .exit               \n" /* no complete pair? -> exit */
+        "beq     .fifo_fill_complete \n" /* no complete pair? -> exit */
         "cmp     r1, r9, lsr #2      \n" /* number of words from source */
         "movgt   r1, r9, lsr #2      \n" /* r1 = amount of allowed loops */
         "sub     r9, r9, r1, lsl #2  \n" /* r1 words will be written in following loop */
@@ -234,11 +239,23 @@ void fiq_playback(void)
         "subs    r1, r1, #1          \n" /* one more loop? */
         "bgt     .fifo_loop          \n" /* yes, continue */
 
+    ".fifo_fill_complete:            \n"
+#endif
+        "cmp     r4, #0              \n" /* If fill came after get_more... */
+        "beq     .still_old_buffer   \n"
+        "mov     r4, #0              \n"
+        "ldr     r2, =pcm_play_dma_started \n"
+        "ldrne   r2, [r2]            \n"
+        "cmp     r2, #0              \n"
+        "movne   lr, pc              \n"
+        "bxne    r2                  \n"
+
+    ".still_old_buffer:              \n"
         "cmp     r9, #0              \n" /* either FIFO is full or source buffer is empty */
         "bgt     .exit               \n" /* if source buffer is not empty, FIFO must be full */
-#endif
 
     ".more_data:                     \n"
+        "mov     r4, #1              \n" /* Remember we did this */
         "ldr     r2, =pcm_play_get_more_callback \n"
         "mov     r0, r11             \n" /* r0 = &p */
         "add     r1, r11, #4         \n" /* r1 = &size */
@@ -250,7 +267,7 @@ void fiq_playback(void)
 
     ".exit:                          \n" /* (r9=0 if stopping, look above) */
         "stmia   r11, { r8-r9 }      \n" /* save p and size */
-        "ldmfd   sp!, { r0-r3, lr }  \n"
+        "ldmfd   sp!, { r0-r4, lr }  \n"
         "subs    pc, lr, #4          \n" /* FIQ specific return sequence */
         ".ltorg                      \n"
         : /* These must only be integers! No regs */
@@ -264,6 +281,8 @@ void fiq_playback(void) __attribute__((interrupt ("FIQ"))) ICODE_ATTR;
 /* NOTE: direct stack use forbidden by GCC stack handling bug for FIQ */
 void fiq_playback(void)
 {
+    bool new_buffer = false;
+
 #if CONFIG_CPU == PP5002
     inl(0xcf001040);
 #endif
@@ -271,6 +290,10 @@ void fiq_playback(void)
     do {
         while (dma_play_data.size > 0) {
             if (IIS_TX_FREE_COUNT < 2) {
+                if (new_buffer) {
+                    new_buffer = false;
+                    pcm_play_dma_started_callback();
+                }
                 return;
             }
 #if SAMPLE_SIZE == 16
@@ -282,9 +305,15 @@ void fiq_playback(void)
             dma_play_data.size -= 4;
         }
 
+        if (new_buffer) {
+            new_buffer = false;
+            pcm_play_dma_started_callback();
+        }
+
         /* p is empty, get some more data */
         pcm_play_get_more_callback((void **)&dma_play_data.addr,
                                    &dma_play_data.size);
+        new_buffer = true;
     } while (dma_play_data.size);
 
     /* No more data  */