Search
lxdream.org :: lxdream/src/aica/audio.c :: diff
lxdream 0.9.1
released Jun 29
Download Now
filename src/aica/audio.c
changeset 82:81a4acf75f10
prev79:6d832137fdff
next106:9048bac046c3
author nkeynes
date Tue Jan 17 12:54:02 2006 +0000 (14 years ago)
permissions -rw-r--r--
last change Add basic attempt at panning + proper volume
file annotate diff log raw
1.1 --- a/src/aica/audio.c Mon Jan 16 11:23:05 2006 +0000
1.2 +++ b/src/aica/audio.c Tue Jan 17 12:54:02 2006 +0000
1.3 @@ -1,5 +1,5 @@
1.4 /**
1.5 - * $Id: audio.c,v 1.3 2006-01-16 11:23:05 nkeynes Exp $
1.6 + * $Id: audio.c,v 1.4 2006-01-17 12:54:02 nkeynes Exp $
1.7 *
1.8 * Audio mixer core. Combines all the active streams into a single sound
1.9 * buffer for output.
1.10 @@ -25,7 +25,7 @@
1.11 #include <string.h>
1.12
1.13 #define NUM_BUFFERS 3
1.14 -#define MS_PER_BUFFER 100
1.15 +#define MS_PER_BUFFER 1000
1.16
1.17 #define BUFFER_EMPTY 0
1.18 #define BUFFER_WRITING 1
1.19 @@ -186,12 +186,14 @@
1.20 audio_channel_t channel = &audio.channels[i];
1.21 if( channel->active ) {
1.22 int32_t sample;
1.23 + int vol_left = (channel->vol * (32 - channel->pan)) >> 5;
1.24 + int vol_right = (channel->vol * (channel->pan + 1)) >> 5;
1.25 switch( channel->sample_format ) {
1.26 case AUDIO_FMT_16BIT:
1.27 for( j=0; j<num_samples; j++ ) {
1.28 sample = *(int16_t *)(arm_mem + channel->posn + channel->start);
1.29 - result_buf[j][0] += sample * channel->vol_left;
1.30 - result_buf[j][1] += sample * channel->vol_right;
1.31 + result_buf[j][0] += sample * vol_left;
1.32 + result_buf[j][1] += sample * vol_right;
1.33
1.34 channel->posn_left += channel->sample_rate;
1.35 while( channel->posn_left > audio.output_rate ) {
1.36 @@ -213,8 +215,8 @@
1.37 case AUDIO_FMT_8BIT:
1.38 for( j=0; j<num_samples; j++ ) {
1.39 sample = (*(int8_t *)(arm_mem + channel->posn + channel->start)) << 8;
1.40 - result_buf[j][0] += sample * channel->vol_left;
1.41 - result_buf[j][1] += sample * channel->vol_right;
1.42 + result_buf[j][0] += sample * vol_left;
1.43 + result_buf[j][1] += sample * vol_right;
1.44
1.45 channel->posn_left += channel->sample_rate;
1.46 while( channel->posn_left > audio.output_rate ) {
1.47 @@ -236,8 +238,8 @@
1.48 case AUDIO_FMT_ADPCM:
1.49 for( j=0; j<num_samples; j++ ) {
1.50 sample = (int16_t)channel->adpcm_predict;
1.51 - result_buf[j][0] += sample * channel->vol_left;
1.52 - result_buf[j][1] += sample * channel->vol_right;
1.53 + result_buf[j][0] += sample * vol_left;
1.54 + result_buf[j][1] += sample * vol_right;
1.55 channel->posn_left += channel->sample_rate;
1.56 while( channel->posn_left > audio.output_rate ) {
1.57 channel->posn_left -= audio.output_rate;
1.58 @@ -273,8 +275,8 @@
1.59 audio_buffer_t buf = audio.output_buffers[audio.write_buffer];
1.60 uint16_t *data = (uint16_t *)&buf->data[buf->posn];
1.61 for( j=0; j < num_samples; j++ ) {
1.62 - *data++ = (int16_t)(result_buf[j][0] >> 8);
1.63 - *data++ = (int16_t)(result_buf[j][1] >> 8);
1.64 + *data++ = (int16_t)(result_buf[j][0] >> 6);
1.65 + *data++ = (int16_t)(result_buf[j][1] >> 6);
1.66 buf->posn += 4;
1.67 if( buf->posn == buf->length ) {
1.68 audio_next_write_buffer();
.