lxdream.org :: lxdream :: r1089:a3984d242909

changeset	1089:a3984d242909
parent	1088:cf3900ae8acc
child	1090:71e28626b358
author	nkeynes
date	Mon Dec 07 08:59:50 2009 +1000 (14 years ago)

Mask audio RAM accesses from the mixer to ensure they're in bounds. Uncertain if
this is correct (vs eg zero-fill), but it's at least consistent with the masking
of the channel start position.

	src/aica/audio.c		view \| annotate \| diff \| log
	src/aica/audio.h		view \| annotate \| diff \| log

     1.1 --- a/src/aica/audio.c	Fri Dec 04 18:06:12 2009 +1000
     1.2 +++ b/src/aica/audio.c	Mon Dec 07 08:59:50 2009 +1000
     1.3 @@ -328,7 +328,7 @@
     1.4              switch( channel->sample_format ) {
     1.5              case AUDIO_FMT_16BIT:
     1.6                  for( j=0; j<num_samples; j++ ) {
     1.7 -                    sample = ((int16_t *)(aica_main_ram + channel->start))[channel->posn];
     1.8 +                    sample = *(int16_t *)(aica_main_ram + ((channel->start + channel->posn*2)&AUDIO_MEM_MASK));
     1.9                      result_buf[j][0] += sample * vol_left;
    1.10                      result_buf[j][1] += sample * vol_right;
    1.11  
    1.12 @@ -352,7 +352,7 @@
    1.13                  break;
    1.14              case AUDIO_FMT_8BIT:
    1.15                  for( j=0; j<num_samples; j++ ) {
    1.16 -                    sample = ((int8_t *)(aica_main_ram + channel->start))[channel->posn] << 8;
    1.17 +                    sample = (*(int8_t *)(aica_main_ram + ((channel->start + channel->posn)&AUDIO_MEM_MASK))) << 8;
    1.18                      result_buf[j][0] += sample * vol_left;
    1.19                      result_buf[j][1] += sample * vol_right;
    1.20  
    1.21 @@ -395,7 +395,7 @@
    1.22                                  break;
    1.23                              }
    1.24                          }
    1.25 -                        uint8_t data = ((uint8_t *)(aica_main_ram + channel->start))[channel->posn>>1];
    1.26 +                        uint8_t data = *(uint8_t *)(aica_main_ram + ((channel->start + (channel->posn>>1))&AUDIO_MEM_MASK));
    1.27                          if( channel->posn&1 ) {
    1.28                              adpcm_yamaha_decode_nibble( channel, (data >> 4) & 0x0F );
    1.29                          } else {

     2.1 --- a/src/aica/audio.h	Fri Dec 04 18:06:12 2009 +1000
     2.2 +++ b/src/aica/audio.h	Mon Dec 07 08:59:50 2009 +1000
     2.3 @@ -43,6 +43,7 @@
     2.4  
     2.5  #define AUDIO_FMT_16ST (AUDIO_FMT_16BIT|AUDIO_FMT_STEREO)
     2.6  #define AUDIO_FMT_FLOATST (AUDIO_FMT_FLOAT|AUDIO_FMT_STEREO)
     2.7 +#define AUDIO_MEM_MASK 0x1FFFFF
     2.8  
     2.9  #define DEFAULT_SAMPLE_RATE 44100
    2.10  #define DEFAULT_SAMPLE_FORMAT AUDIO_FMT_16ST