Implemented CD Audio de-emphasizing for pre-emphasized tracks, closes #1623.

src/cdrom/cdrom.c

@@ -238,6 +238,16 @@ cdrom_seek(cdrom_t *dev, uint32_t pos)
 }
 
 
+int
+cdrom_is_pre(cdrom_t *dev, uint32_t lba)
+{
+    if (dev->ops && dev->ops->is_track_pre)
+	return dev->ops->is_track_pre(dev, lba);
+
+    return 0;
+}
+
+
 int
 cdrom_audio_callback(cdrom_t *dev, int16_t *output, int len)
 {

src/cdrom/cdrom_image.c

@@ -155,12 +155,28 @@ image_is_track_audio(cdrom_t *dev, uint32_t pos, int ismsf)
     if (track == -1)
 	return 0;
     else {
-	cdi_get_audio_track_info(img, 0, cdi_get_track(img, pos), &number, &tmsf, &attr);
+	cdi_get_audio_track_info(img, 0, track, &number, &tmsf, &attr);
 	return attr == AUDIO_TRACK;
     }
 }
 
 
+static int
+image_is_track_pre(cdrom_t *dev, uint32_t lba)
+{
+    cd_img_t *img = (cd_img_t *)dev->image;
+    int track;
+
+    /* GetTrack requires LBA. */
+    track = cdi_get_track(img, lba);
+
+    if (track != -1)
+	return cdi_get_audio_track_pre(img, track);
+
+    return 0;
+}
+
+
 static int 
 image_sector_size(struct cdrom *dev, uint32_t lba)
 {
@@ -231,6 +247,7 @@ static const cdrom_ops_t cdrom_image_ops = {
     image_get_tracks,
     image_get_track_info,
     image_get_subchannel,
+    image_is_track_pre,
     image_sector_size,
     image_read_sector,
     image_track_type,

src/cdrom/cdrom_image_backend.c

@@ -272,6 +272,18 @@ cdi_get_audio_tracks_lba(cd_img_t *cdi, int *st_track, int *end, uint32_t *lead_
 }
 
 
+int
+cdi_get_audio_track_pre(cd_img_t *cdi, int track)
+{
+    track_t *trk = &cdi->tracks[track - 1];
+
+    if ((track < 1) || (track > cdi->tracks_num))
+	return 0;
+
+    return trk->pre;
+}
+
+
 /* This replaces both Info and EndInfo, they are specified by a variable. */
 int
 cdi_get_audio_track_info(cd_img_t *cdi, int end, int track, int *track_num, TMSF *start, uint8_t *attr)
@@ -709,6 +721,25 @@ cdi_cue_get_frame(uint64_t *frames, char **line)
 }
 
 
+static int
+cdi_cue_get_flags(track_t *cur, char **line)
+{
+    char temp[128], temp2[128];
+    int success;
+
+    success = cdi_cue_get_buffer(temp, line, 0);
+    if (! success) return 0;
+
+    memset(temp2, 0x00, sizeof(temp2));
+    success = sscanf(temp, "%s", temp2) == 1;
+    if (! success) return 0;
+
+    cur->pre = (strstr(temp2, "PRE") != NULL);
+
+    return 1;
+}
+
+
 static int
 cdi_add_track(cd_img_t *cdi, track_t *cur, uint64_t *shift, uint64_t prestart, uint64_t *total_pregap, uint64_t cur_pregap)
 {
@@ -850,6 +881,8 @@ cdi_load_cue(cd_img_t *cdi, const char *cuefile)
 		trk.form = 0;
 		trk.mode2 = 0;
 
+		trk.pre = 0;
+
 		if (!strcmp(type, "AUDIO")) {
 			trk.sector_size = RAW_SECTOR_SIZE;
 			trk.attr = AUDIO_TRACK;
@@ -964,7 +997,9 @@ cdi_load_cue(cd_img_t *cdi, const char *cuefile)
 		}
 	} else if (!strcmp(command, "PREGAP"))
 		success = cdi_cue_get_frame(&cur_pregap, &line);
-	else if (!strcmp(command, "CATALOG") || !strcmp(command, "CDTEXTFILE") || !strcmp(command, "FLAGS") || !strcmp(command, "ISRC") ||
+	else if (!strcmp(command, "FLAGS"))
+		success = cdi_cue_get_flags(&trk, &line);
+	else if (!strcmp(command, "CATALOG") || !strcmp(command, "CDTEXTFILE") || !strcmp(command, "ISRC") ||
 		 !strcmp(command, "PERFORMER") || !strcmp(command, "POSTGAP") || !strcmp(command, "REM") ||
 		 !strcmp(command, "SONGWRITER") || !strcmp(command, "TITLE") || !strcmp(command, "")) {
 		/* Ignored commands. */

src/include/86box/cdrom.h

@@ -83,6 +83,7 @@ typedef struct {
     void	(*get_tracks)(struct cdrom *dev, int *first, int *last);
     void	(*get_track_info)(struct cdrom *dev, uint32_t track, int end, track_info_t *ti);
     void	(*get_subchannel)(struct cdrom *dev, uint32_t lba, subchannel_t *subc);
+    int		(*is_track_pre)(struct cdrom *dev, uint32_t lba);
     int		(*sector_size)(struct cdrom *dev, uint32_t lba);
     int		(*read_sector)(struct cdrom *dev, int type, uint8_t *b, uint32_t lba);
     int		(*track_type)(struct cdrom *dev, uint32_t lba);
@@ -136,6 +137,7 @@ extern cdrom_t	cdrom[CDROM_NUM];
 extern int	cdrom_lba_to_msf_accurate(int lba);
 extern double	cdrom_seek_time(cdrom_t *dev);
 extern void	cdrom_stop(cdrom_t *dev);
+extern int	cdrom_is_pre(cdrom_t *dev, uint32_t lba);
 extern int	cdrom_audio_callback(cdrom_t *dev, int16_t *output, int len);
 extern uint8_t	cdrom_audio_play(cdrom_t *dev, uint32_t pos, uint32_t len, int ismsf);
 extern uint8_t	cdrom_audio_track_search(cdrom_t *dev, uint32_t pos, int type, uint8_t playbit);

src/include/86box/cdrom_image_backend.h

@@ -58,7 +58,7 @@ typedef struct {
 
 typedef struct {
     int			number, track_number, attr, sector_size,
-			mode2, form;
+			mode2, form, pre, pad;
     uint64_t		start, length,
 			skip;
     track_file_t	*file;
@@ -75,6 +75,7 @@ extern void	cdi_close(cd_img_t *cdi);
 extern int	cdi_set_device(cd_img_t *cdi, const char *path);
 extern int	cdi_get_audio_tracks(cd_img_t *cdi, int *st_track, int *end, TMSF *lead_out);
 extern int	cdi_get_audio_tracks_lba(cd_img_t *cdi, int *st_track, int *end, uint32_t *lead_out);
+extern int	cdi_get_audio_track_pre(cd_img_t *cdi, int track);
 extern int	cdi_get_audio_track_info(cd_img_t *cdi, int end, int track, int *track_num, TMSF *start, uint8_t *attr);
 extern int	cdi_get_audio_track_info_lba(cd_img_t *cdi, int end, int track, int *track_num, uint32_t *start, uint8_t *attr);
 extern int	cdi_get_track(cd_img_t *cdi, uint32_t sector);

src/sound/sound.c

@@ -212,7 +212,8 @@ sound_cd_clean_buffers(void)
 static void
 sound_cd_thread(void *param)
 {
-    int c, r, i, channel_select[2];
+    uint32_t lba;
+    int c, r, i, pre, channel_select[2];
     double audio_vol_l, audio_vol_r;
     double cd_buffer_temp[2] = {0.0, 0.0};
 
@@ -231,9 +232,11 @@ sound_cd_thread(void *param)
 		if ((cdrom[i].bus_type == CDROM_BUS_DISABLED) ||
 		    (cdrom[i].cd_status == CD_STATUS_EMPTY))
 			continue;
+		lba = cdrom[i].seek_pos;
 		r = cdrom_audio_callback(&(cdrom[i]), cd_buffer[i], CD_BUFLEN * 2);
 		if (!cdrom[i].bus_type || !cdrom[i].sound_on || !r)
 				continue;
+		pre = cdrom_is_pre(&(cdrom[i]), lba);
 
 		if (cdrom[i].get_volume) {
 			audio_vol_l = (float) (cdrom[i].get_volume(cdrom[i].priv, 0));
@@ -277,6 +280,9 @@ sound_cd_thread(void *param)
 					cd_buffer_temp[0] += ((double) cd_buffer[i][c + 1]);	/* Channel 1 => Port 0 */
 
 				cd_buffer_temp[0] *= audio_vol_l;				/* Multiply Port 0 by Port 0 volume */
+
+				if (pre)
+					cd_buffer_temp[0] = deemph_iir(0, cd_buffer_temp[0]);	/* De-emphasize if necessary */
 			}
 
 			if ((audio_vol_r != 0.0) && (channel_select[1] != 0)) {
@@ -286,6 +292,9 @@ sound_cd_thread(void *param)
 					cd_buffer_temp[1] += ((double) cd_buffer[i][c + 1]);	/* Channel 1 => Port 1 */
 
 				cd_buffer_temp[1] *= audio_vol_r;				/* Multiply Port 1 by Port 1 volume */
+
+				if (pre)
+					cd_buffer_temp[1] = deemph_iir(1, cd_buffer_temp[1]);	/* De-emphasize if necessary */
 			}
 
 			/* Apply sound card CD volume and filters */