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use all recorded samples for peak metering and clipping detection

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8837 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Peter D'Hoye 2006-02-24 22:28:57 +00:00
parent ac115693da
commit 9ace16f87f
1 changed files with 46 additions and 40 deletions
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86
firmware/pcm_record.c
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@ -365,42 +365,39 @@ void pcm_rec_get_peaks(int *left, int *right)
/* Functions that executes in the context of pcmrec_thread */
/***************************************************************************/
/* Skip PEAK_STRIDE sample-pairs for each compare */
/* Skip PEAK_STRIDE sample-pairs for each compare
#define PEAK_STRIDE 3
static void pcmrec_find_peaks(int chunk)
static void pcmrec_find_peaks(int chunk, int* peak_l, int* peak_r)
{
short *ptr, value;
int peak_l, peak_r;
int j;
if(!peak_l || ! peak_r) return;
ptr = GET_CHUNK(chunk);
peak_l = 0;
peak_r = 0;
*peak_l = 0;
*peak_r = 0;
for (j=0; j<CHUNK_SIZE/4; j+=PEAK_STRIDE+1)
{
if ((value = ptr[0]) > peak_l)
peak_l = value;
else if (-value > peak_l)
peak_l = -value;
if ((value = ptr[0]) > *peak_l)
*peak_l = value;
else if (-value > *peak_l)
*peak_l = -value;
ptr++;
if ((value = ptr[0]) > peak_r)
peak_r = value;
else if (-value > peak_r)
peak_r = -value;
if ((value = ptr[0]) > *peak_r)
*peak_r = value;
else if (-value > *peak_r)
*peak_r = -value;
ptr++;
ptr += PEAK_STRIDE * 2;
}
peak_left = peak_l;
peak_right = peak_r;
}
*/
/**
* Process the chunks using read_index and write_index.
@ -418,38 +415,40 @@ static void pcmrec_callback(bool flush)
int num_ready, num_free, num_new;
unsigned short *ptr;
int i, j, w;
short value;
w = write_index;
num_new = w - read2_index;
if (num_new < 0)
num_new += num_chunks;
if (num_new > 0)
{
/* Collect peak values for the last buffer only */
j = w - 1;
if (j < 0)
j += num_chunks;
pcmrec_find_peaks(j);
}
if ((!is_recording || is_paused) && !flush)
{
/* not recording = no saving to disk, fake buffer clearing */
read_index = write_index;
return;
}
peak_left = 0;
peak_right = 0;
for (i=0; i<num_new; i++)
{
/* Convert the samples to little-endian so we only have to write later
(Less hd-spinning time)
(Less hd-spinning time), also do peak detection while we're at it
*/
ptr = GET_CHUNK(read2_index);
for (j=0; j<CHUNK_SIZE/2; j++)
for (j=0; j<CHUNK_SIZE/4; j++)
{
*ptr = htole16(*ptr);
value = *ptr;
if(value > peak_left)
peak_left = value;
else if (-value > peak_left)
peak_left = -value;
*ptr = htole16(value);
ptr++;
value = *ptr;
if(value > peak_right)
peak_right = value;
else if (-value > peak_right)
peak_right = -value;
*ptr = htole16(value);
ptr++;
}
@ -460,6 +459,13 @@ static void pcmrec_callback(bool flush)
read2_index = 0;
}
if ((!is_recording || is_paused) && !flush)
{
/* not recording = no saving to disk, fake buffer clearing */
read_index = write_index;
return;
}
num_ready = w - read_index;
if (num_ready < 0)
num_ready += num_chunks;