devs/foxbox
1
0
Fork 0
forked from len0rd/rockbox
Code Pull requests Activity

use all recorded samples for peak metering and clipping detection

Browse source 
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
Download patch file Download diff file Expand all files Collapse all files

80
firmware/pcm_record.c
View file

@ -365,42 +365,39 @@ void pcm_rec_get_peaks(int *left, int *right)
/* Functions that executes in the context of pcmrec_thread */ /* 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 #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; short *ptr, value;
int peak_l, peak_r;
int j; int j;
if(!peak_l || ! peak_r) return;
ptr = GET_CHUNK(chunk); ptr = GET_CHUNK(chunk);
peak_l = 0; *peak_l = 0;
peak_r = 0; *peak_r = 0;
for (j=0; j<CHUNK_SIZE/4; j+=PEAK_STRIDE+1) for (j=0; j<CHUNK_SIZE/4; j+=PEAK_STRIDE+1)
{ {
if ((value = ptr[0]) > peak_l) if ((value = ptr[0]) > *peak_l)
peak_l = value; *peak_l = value;
else if (-value > peak_l) else if (-value > *peak_l)
peak_l = -value; *peak_l = -value;
ptr++; ptr++;
if ((value = ptr[0]) > peak_r) if ((value = ptr[0]) > *peak_r)
peak_r = value; *peak_r = value;
else if (-value > peak_r) else if (-value > *peak_r)
peak_r = -value; *peak_r = -value;
ptr++; ptr++;
ptr += PEAK_STRIDE * 2; ptr += PEAK_STRIDE * 2;
} }
peak_left = peak_l;
peak_right = peak_r;
} }
*/
/** /**
* Process the chunks using read_index and write_index. * Process the chunks using read_index and write_index.
@ -418,6 +415,7 @@ static void pcmrec_callback(bool flush)
int num_ready, num_free, num_new; int num_ready, num_free, num_new;
unsigned short *ptr; unsigned short *ptr;
int i, j, w; int i, j, w;
short value;
w = write_index; w = write_index;
@ -425,31 +423,32 @@ static void pcmrec_callback(bool flush)
if (num_new < 0) if (num_new < 0)
num_new += num_chunks; num_new += num_chunks;
if (num_new > 0) peak_left = 0;
{ peak_right = 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;
}
for (i=0; i<num_new; i++) for (i=0; i<num_new; i++)
{ {
/* Convert the samples to little-endian so we only have to write later /* 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); 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++; ptr++;
} }
@ -460,6 +459,13 @@ static void pcmrec_callback(bool flush)
read2_index = 0; 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; num_ready = w - read_index;
if (num_ready < 0) if (num_ready < 0)
num_ready += num_chunks; num_ready += num_chunks;