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Messing with the peak calculation in pcm_playback.c for Coldfire ports.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11178 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Michael Sevakis 2006-10-10 19:12:05 +00:00
parent 2740914ee1
commit 02d756dfd4
1 changed files with 107 additions and 6 deletions
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113
firmware/pcm_playback.c
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@ -98,6 +98,8 @@ size_t pcm_get_bytes_waiting(void)
static int pcm_freq = 0x6; /* 44.1 is default */
int peak_left = 0, peak_right = 0;
/* Set up the DMA transfer that kicks in when the audio FIFO gets empty */
static void dma_start(const void *addr, size_t size)
{
@ -205,7 +207,6 @@ void DMA0(void)
SAR0 = (unsigned long)next_start; /* Source address */
BCR0 = next_size; /* Bytes to transfer */
DCR0 |= DMA_EEXT;
}
else
{
@ -846,6 +847,109 @@ bool pcm_is_paused(void) {
return pcm_paused;
}
#if defined(CPU_COLDFIRE)
/* Peaks ahead in the DMA buffer based upon the calling period to
attempt to compensate for the delay. Keeps a moving average of
length four. */
void pcm_calculate_peaks(int *left, int *right)
{
unsigned long samples;
unsigned long *addr, *end;
long peak_p, peak_n;
static unsigned long last_peak_tick = 0;
static unsigned long frame_period = 0;
/* Throttled peak ahead based on calling period */
unsigned long period = current_tick - last_peak_tick;
/* Keep reasonable limits on period */
if (period < 1)
period = 1;
else if (period > HZ/5)
period = HZ/5;
frame_period = (3*frame_period + period) >> 2;
last_peak_tick = current_tick;
if (!pcm_playing || pcm_paused)
{
peak_left = peak_right = 0;
goto peak_done;
}
samples = (BCR0 & 0xffffff) >> 2;
addr = (long *)(SAR0 & ~3);
samples = MIN(frame_period*44100/HZ, samples);
end = addr + samples;
peak_p = peak_n = 0;
if (left && right)
{
if (samples > 0)
{
long peak_rp = 0, peak_rn = 0;
do
{
long value = *addr;
long ch;
ch = value >> 16;
if (ch > peak_p) peak_p = ch;
else if (ch < peak_n) peak_n = ch;
ch = (short)value;
if (ch > peak_rp) peak_rp = ch;
else if (ch < peak_rn) peak_rn = ch;
addr += 4;
}
while (addr < end);
peak_left = MAX(peak_p, -peak_n);
peak_right = MAX(peak_rp, -peak_rn);
}
}
else if (left || right)
{
if (samples > 0)
{
if (left)
{
/* Put left channel in low word */
addr = (long *)((short *)addr - 1);
end = (long *)((short *)end - 1);
}
do
{
long value = *(short *)addr;
if (value > peak_p) peak_p = value;
else if (value < peak_n) peak_n = value;
addr += 4;
}
while (addr < end);
if (left)
peak_left = MAX(peak_p, -peak_n);
else
peak_right = MAX(peak_p, -peak_n);
}
}
peak_done:
if (left)
*left = peak_left;
if (right)
*right = peak_right;
}
#else
/*
* This function goes directly into the DMA buffer to calculate the left and
* right peak values. To avoid missing peaks it tries to look forward two full
@ -860,7 +964,6 @@ bool pcm_is_paused(void) {
/* Up to 1/50th of a second of audio for peak calculation */
/* This should use NATIVE_FREQUENCY, or eventually an adjustable freq. value */
#define PEAK_SAMPLES (44100/50)
void pcm_calculate_peaks(int *left, int *right)
{
#if (CONFIG_CPU == S3C2440)
@ -870,10 +973,7 @@ void pcm_calculate_peaks(int *left, int *right)
short *addr;
short *end;
{
#ifdef CPU_COLDFIRE
size_t samples = (BCR0 & 0xffffff) / 4;
addr = (short *) (SAR0 & ~3);
#elif defined(HAVE_WM8975) || defined(HAVE_WM8758) \
#if defined(HAVE_WM8975) || defined(HAVE_WM8758) \
|| defined(HAVE_WM8731) || defined(HAVE_WM8721) \
|| (CONFIG_CPU == PNX0101)
size_t samples = p_size / 4;
@ -931,3 +1031,4 @@ void pcm_calculate_peaks(int *left, int *right)
}
#endif
}
#endif /* CPU_COLDFIRE */