From 15ca7152281225cb2b0684721a51e75984a91c61 Mon Sep 17 00:00:00 2001
From: kub <derkub@gmail.com>
Date: Thu, 4 Mar 2021 20:48:02 +0100
Subject: [PATCH] core, groundwork for chd support

still needs some scrutiny, and build integration is missing
---
 Makefile                      |   5 +
 Makefile.libretro             |   2 +
 pico/cart.c                   | 200 ++++++++++++++++++++++++++++++++++
 pico/cd/cd_image.c            |  20 ++--
 pico/cd/{cue.c => cd_parse.c} | 124 +++++++++++++++++++--
 pico/cd/cd_parse.h            |   5 +
 pico/cd/cdd.c                 |  12 +-
 pico/cd/cdd.h                 |   1 +
 pico/cd/cue.h                 |  29 -----
 pico/media.c                  |  39 ++++---
 pico/pico.h                   |  35 +++++-
 pico/sound/sound.c            |   3 +-
 platform/common/common.mak    |   2 +-
 platform/common/emu.c         |   4 +-
 platform/common/menu_pico.c   |   2 +-
 platform/gizmondo/menu.c      |   4 +-
 platform/libretro/libretro.c  |   6 +-
 platform/psp/emu.c            |  18 +--
 18 files changed, 411 insertions(+), 100 deletions(-)
 rename pico/cd/{cue.c => cd_parse.c} (73%)
 create mode 100644 pico/cd/cd_parse.h
 delete mode 100644 pico/cd/cue.h

diff --git a/Makefile b/Makefile
index 7955305d..99bfc6ac 100644
--- a/Makefile
+++ b/Makefile
@@ -236,6 +236,11 @@ OBJS += platform/common/mp3_minimp3.o
 endif
 endif
 
+ifneq (,$(HAVE_LIBCHDR))
+CFLAGS += -DUSE_LIBCHDR -Iplatform/common/libchdr/include
+LDFLAGS += -Lplatform/common/libchdr -lchdr
+endif
+
 ifeq "$(PLATFORM_ZLIB)" "1"
 # zlib
 OBJS += zlib/gzio.o zlib/inffast.o zlib/inflate.o zlib/inftrees.o zlib/trees.o \
diff --git a/Makefile.libretro b/Makefile.libretro
index e1d4414d..a7ef0085 100644
--- a/Makefile.libretro
+++ b/Makefile.libretro
@@ -564,6 +564,8 @@ asm_32xdraw = 0
 asm_32xmemory = 0
 endif
 
+#HAVE_LIBCHDR = 1
+
 CFLAGS += $(fpic)
 
 ifeq ($(findstring Haiku,$(shell uname -a)),)
diff --git a/pico/cart.c b/pico/cart.c
index 9d35c04c..702947c5 100644
--- a/pico/cart.c
+++ b/pico/cart.c
@@ -16,6 +16,11 @@
 #include "file_stream_transforms.h"
 #endif
 
+#if defined(USE_LIBCHDR)
+#include "libchdr/chd.h"
+#include "libchdr/cdrom.h"
+#endif
+
 static int rom_alloc_size;
 static const char *rom_exts[] = { "bin", "gen", "smd", "iso", "sms", "gg", "sg" };
 
@@ -102,6 +107,19 @@ struct zip_file {
   unsigned int pos;
 };
 
+#if defined(USE_LIBCHDR)
+struct chd_struct {
+  pm_file file;
+  int fpos;
+  int sectorsize;
+  chd_file *chd;
+  int unitbytes;
+  int hunkunits;
+  u8 *hunk;
+  int hunknum;
+};
+#endif
+
 pm_file *pm_open(const char *path)
 {
   pm_file *file = NULL;
@@ -228,6 +246,50 @@ cso_failed:
     if (f != NULL) fclose(f);
     return NULL;
   }
+#if defined(USE_LIBCHDR)
+  else if (strcasecmp(ext, "chd") == 0)
+  {
+    struct chd_struct *chd = NULL;
+    chd_file *cf = NULL;
+    const chd_header *head;
+
+    if (chd_open(path, CHD_OPEN_READ, NULL, &cf) != CHDERR_NONE)
+      goto chd_failed;
+
+    // sanity check
+    head = chd_get_header(cf);
+    if ((head->hunkbytes == 0) || (head->hunkbytes % CD_FRAME_SIZE))
+      goto chd_failed;
+
+    chd = calloc(1, sizeof(*chd));
+    if (chd == NULL)
+      goto chd_failed;
+    chd->hunk = (u8 *)malloc(head->hunkbytes);
+    if (!chd->hunk)
+      goto chd_failed;
+
+    chd->chd = cf;
+    chd->unitbytes = head->unitbytes;
+    chd->hunkunits = head->hunkbytes / head->unitbytes;
+    chd->sectorsize = CD_MAX_SECTOR_DATA; // default to RAW mode
+
+    chd->fpos = 0;
+    chd->hunknum = -1;
+
+    chd->file.file = chd;
+    chd->file.type = PMT_CHD;
+    // subchannel data is skipped, remove it from total size
+    chd->file.size = chd_get_header(cf)->logicalbytes / CD_FRAME_SIZE * CD_MAX_SECTOR_DATA;
+    strncpy(chd->file.ext, ext, sizeof(chd->file.ext) - 1);
+    return &chd->file;
+
+chd_failed:
+    /* invalid CHD file */
+    if (chd != NULL) free(chd);
+    if (cf != NULL) chd_close(cf);
+    return NULL;
+  }
+#endif
 
   /* not a zip, treat as uncompressed file */
   f = fopen(path, "rb");
@@ -255,6 +317,88 @@ cso_failed:
   return file;
 }
 
+void pm_sectorsize(int length, pm_file *stream)
+{
+  // CHD reading needs to know how much binary data is in one data sector(=unit)
+#if defined(USE_LIBCHDR)
+  if (stream->type == PMT_CHD) {
+    struct chd_struct *chd = stream->file;
+    chd->sectorsize = length;
+    if (chd->sectorsize > chd->unitbytes)
+      elprintf(EL_STATUS|EL_ANOMALY, "cd: sector size %d too large for unit %d", chd->sectorsize, chd->unitbytes);
+  }
+#endif
+}
+
+#if defined(USE_LIBCHDR)
+static size_t _pm_read_chd(void *ptr, size_t bytes, pm_file *stream, int is_audio)
+{
+  int ret = 0;
+
+  if (stream->type == PMT_CHD) {
+    struct chd_struct *chd = stream->file;
+    // calculate sector and offset in sector
+    int sectsz = is_audio ? CD_MAX_SECTOR_DATA : chd->sectorsize;
+    int sector = chd->fpos / sectsz;
+    int offset = chd->fpos - (sector * sectsz);
+    // calculate hunk and sector offset in hunk
+    int hunknum = sector / chd->hunkunits;
+    int hunksec = sector - (hunknum * chd->hunkunits);
+    int hunkofs = hunksec * chd->unitbytes;
+
+    while (bytes != 0) {
+      // data left in current sector
+      int len = sectsz - offset;
+
+      // update hunk cache if needed
+      if (hunknum != chd->hunknum) {
+        chd_read(chd->chd, hunknum, chd->hunk);
+        chd->hunknum = hunknum;
+      }
+      if (len > bytes)
+        len = bytes;
+
+#ifdef CPU_IS_LE
+      if (is_audio) {
+        // convert big endian audio samples
+        u16 *dst = ptr, v;
+        u8 *src = chd->hunk + hunkofs + offset;
+        int i;
+
+        for (i = 0; i < len; i += 4) {
+          v = *src++ << 8; *dst++ = v | *src++;
+          v = *src++ << 8; *dst++ = v | *src++;
+        }
+      } else
+#endif
+        memcpy(ptr, chd->hunk + hunkofs + offset, len);
+
+      // house keeping
+      ret += len;
+      chd->fpos += len;
+      bytes -= len;
+
+      // no need to advance internals if there's no more data to read
+      if (bytes) {
+        ptr += len;
+        offset = 0;
+
+        sector ++;
+        hunksec ++;
+        hunkofs += chd->unitbytes;
+        if (hunksec >= chd->hunkunits) {
+          hunksec = 0;
+          hunkofs = 0;
+          hunknum ++;
+        }
+      }
+    }
+  }
+
+  return ret;
+}
+#endif
+
 size_t pm_read(void *ptr, size_t bytes, pm_file *stream)
 {
   int ret;
@@ -355,12 +499,46 @@ size_t pm_read(void *ptr, size_t bytes, pm_file *stream)
       index_end = cso->index[block+1];
     }
   }
+#if defined(USE_LIBCHDR)
+  else if (stream->type == PMT_CHD)
+  {
+    ret = _pm_read_chd(ptr, bytes, stream, 0);
+  }
+#endif
   else
     ret = 0;
 
   return ret;
 }
 
+size_t pm_read_audio(void *ptr, size_t bytes, pm_file *stream)
+{
+#if !(CPU_IS_LE)
+  if (stream->type == PMT_UNCOMPRESSED)
+  {
+    // convert little endian audio samples from WAV file
+    int ret = pm_read(ptr, bytes, stream);
+    u16 *dst = ptr, v;
+    u8 *src = ptr;
+    int i;
+
+    for (i = 0; i < ret; i += 4) {
+      v = *src++; *dst++ = v | (*src++ << 8);
+      v = *src++; *dst++ = v | (*src++ << 8);
+    }
+    return ret;
+  }
+  else
+#endif
+#if defined(USE_LIBCHDR)
+  if (stream->type == PMT_CHD)
+  {
+    return _pm_read_chd(ptr, bytes, stream, 1);
+  }
+#endif
+  return pm_read(ptr, bytes, stream);
+}
+
 int pm_seek(pm_file *stream, long offset, int whence)
 {
   if (stream->type == PMT_UNCOMPRESSED)
@@ -421,6 +599,19 @@ int pm_seek(pm_file *stream, long offset, int whence)
     }
     return cso->fpos_out;
   }
+#if defined(USE_LIBCHDR)
+  else if (stream->type == PMT_CHD)
+  {
+    struct chd_struct *chd = stream->file;
+    switch (whence)
+    {
+      case SEEK_CUR: chd->fpos += offset; break;
+      case SEEK_SET: chd->fpos  = offset; break;
+      case SEEK_END: chd->fpos  = stream->size - offset; break;
+    }
+    return chd->fpos;
+  }
+#endif
   else
     return -1;
 }
@@ -446,6 +637,15 @@ int pm_close(pm_file *fp)
     free(fp->param);
     fclose(fp->file);
   }
+#if defined(USE_LIBCHDR)
+  else if (fp->type == PMT_CHD)
+  {
+    struct chd_struct *chd = fp->file;
+    chd_close(chd->chd);
+    if (chd->hunk)
+      free(chd->hunk);
+  }
+#endif
   else
     ret = EOF;
 
diff --git a/pico/cd/cd_image.c b/pico/cd/cd_image.c
index f328be03..530071a6 100644
--- a/pico/cd/cd_image.c
+++ b/pico/cd/cd_image.c
@@ -9,7 +9,7 @@
 #include "../pico_int.h"
 #include "genplus_macros.h"
 #include "cdd.h"
-#include "cue.h"
+#include "cd_parse.h"
 
 #ifdef USE_LIBRETRO_VFS
 #include "file_stream_transforms.h"
@@ -90,7 +90,7 @@ int load_cd_image(const char *cd_img_name, int *type)
   int iso_name_len, missed, cd_img_sectors;
   char tmp_name[256], tmp_ext[10], tmp_ext_u[10];
   track_t *tracks = cdd.toc.tracks;
-  cue_data_t *cue_data = NULL;
+  cd_data_t *cue_data = NULL;
   pm_file *pmf;
 
   if (PicoCDLoadProgressCB != NULL)
@@ -103,16 +103,21 @@ int load_cd_image(const char *cd_img_name, int *type)
   if (cue_data != NULL) {
     cd_img_name = cue_data->tracks[1].fname;
     *type = cue_data->tracks[1].type;
+  } else {
+    cue_data = chd_parse(cd_img_name);
+    if (cue_data != NULL)
+      *type = cue_data->tracks[1].type;
   }
 
   pmf = pm_open(cd_img_name);
   if (pmf == NULL)
   {
     if (cue_data != NULL)
-      cue_destroy(cue_data);
+      cdparse_destroy(cue_data);
     return -1;
   }
   tracks[0].fd = pmf;
+  tracks[0].fname = strdup(cd_img_name);
 
   if (*type == CT_ISO)
        cd_img_sectors = pmf->size >>= 11;  // size in sectors
@@ -131,7 +136,7 @@ int load_cd_image(const char *cd_img_name, int *type)
 
   if (cue_data != NULL)
   {
-    if (cue_data->tracks[2].fname == NULL) {
+    if (cue_data->track_count > 1 && cue_data->tracks[2].fname == NULL) {
       // NULL fname means track2 is in same file as track1
       lba = tracks[0].end = cue_data->tracks[2].sector_offset;
     }
@@ -157,6 +162,7 @@ int load_cd_image(const char *cd_img_name, int *type)
         {
           // assume raw, ignore header for wav..
           tracks[index].fd = f;
+          tracks[index].fname = strdup(cue_data->tracks[n].fname);
           tracks[index].offset = cue_data->tracks[n].sector_offset;
           length = f->size / 2352;
         }
@@ -189,8 +195,8 @@ int load_cd_image(const char *cd_img_name, int *type)
       tracks[index].end = lba;
 
       sprintf_lba(tmp_ext, sizeof(tmp_ext), tracks[index].start);
-      elprintf(EL_STATUS, "Track %2i: %s %9i AUDIO %s",
-        n, tmp_ext, length, cue_data->tracks[n].fname);
+      elprintf(EL_STATUS, "Track %2i: %s %9i AUDIO %s", n, tmp_ext, length,
+          cue_data->tracks[n].fname ? cue_data->tracks[n].fname : "");
     }
     goto finish;
   }
@@ -269,7 +275,7 @@ finish:
     PicoCDLoadProgressCB(cd_img_name, 100);
 
   if (cue_data != NULL)
-    cue_destroy(cue_data);
+    cdparse_destroy(cue_data);
 
   return 0;
 }
diff --git a/pico/cd/cue.c b/pico/cd/cd_parse.c
similarity index 73%
rename from pico/cd/cue.c
rename to pico/cd/cd_parse.c
index e8174ce1..6ed6335b 100644
--- a/pico/cd/cue.c
+++ b/pico/cd/cd_parse.c
@@ -8,15 +8,20 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "cue.h"
 
 #include "../pico_int.h"
+#include "cd_parse.h"
 // #define elprintf(w,f,...) printf(f "\n",##__VA_ARGS__);
 
 #ifdef USE_LIBRETRO_VFS
 #include "file_stream_transforms.h"
 #endif
 
+#if defined(USE_LIBCHDR)
+#include "libchdr/chd.h"
+#include "libchdr/cdrom.h"
+#endif
+
 #ifdef _MSC_VER
 #define snprintf _snprintf
 #endif
@@ -75,7 +80,8 @@ static int get_ext(const char *fname, char ext[4],
 	if (len > 0)
 		pos = len;
 
-	strcpy(ext, fname + pos + 1);
+	strncpy(ext, fname + pos + 1, 4/*sizeof(ext)*/-1);
+	ext[4/*sizeof(ext)*/-1] = '\0';
 
 	if (base != NULL) {
 		if (pos + 1 < base_size)
@@ -111,15 +117,110 @@ static int file_openable(const char *fname)
 #define BEGINS(buff,str) (strncmp(buff,str,sizeof(str)-1) == 0)
 
 /* note: tracks[0] is not used */
-cue_data_t *cue_parse(const char *fname)
+cd_data_t *chd_parse(const char *fname)
+{
+	cd_data_t *data = NULL;
+#if defined(USE_LIBCHDR)
+	cd_data_t *tmp;
+	int count = 0, count_alloc = 2;
+	int sectors = 0;
+	char metadata[256];
+	chd_file *cf = NULL;
+
+	if (fname == NULL || *fname == '\0')
+		return NULL;
+
+	if (chd_open(fname, CHD_OPEN_READ, NULL, &cf) != CHDERR_NONE)
+		goto out;
+
+	data = calloc(1, sizeof(*data) + count_alloc * sizeof(cd_track_t));
+	if (data == NULL)
+		goto out;
+
+	// get track info
+	while (count < CD_MAX_TRACKS) {
+		int track = 0, frames = 0, pregap = 0, postgap = 0;
+		char type[16], subtype[16], pgtype[16], pgsub[16];
+		type[0] = subtype[0] = pgtype[0] = pgsub[0] = 0;
+
+		// get metadata for track
+		if (chd_get_metadata(cf, CDROM_TRACK_METADATA2_TAG, count,
+			metadata, sizeof(metadata), 0, 0, 0) == CHDERR_NONE) {
+			if (sscanf(metadata, CDROM_TRACK_METADATA2_FORMAT,
+				&track, &type[0], &subtype[0], &frames,
+				&pregap, &pgtype[0], &pgsub[0], &postgap) != 8)
+			break;
+		}
+		else if (chd_get_metadata(cf, CDROM_TRACK_METADATA_TAG, count,
+			metadata, sizeof(metadata), 0, 0, 0) == CHDERR_NONE) {
+			if (sscanf(metadata, CDROM_TRACK_METADATA_FORMAT,
+				&track, &type[0], &subtype[0], &frames) != 4)
+			break;
+		}
+		else break;	// all tracks completed
+
+		// metadata sanity check
+		if (track != count + 1 || frames < 0 || pregap < 0)
+			break;
+
+		// allocate track structure
+		count ++;
+		if (count >= count_alloc) {
+			count_alloc *= 2;
+			tmp = realloc(data, sizeof(*data) + count_alloc * sizeof(cd_track_t));
+			if (tmp == NULL) {
+				count--;
+				break;
+			}
+			data = tmp;
+		}
+		memset(&data->tracks[count], 0, sizeof(data->tracks[0]));
+
+		if (count == 1) {	// binary code
+			data->tracks[count].fname = strdup(fname);
+		        if (!strcmp(type, "MODE1_RAW") || !strcmp(type, "MODE2_RAW")) {
+			        data->tracks[count].type = CT_BIN;
+		        } else if (!strcmp(type, "MODE1") || !strcmp(type, "MODE2_FORM1")) {
+				data->tracks[count].type = CT_ISO;
+			} else
+				break;
+		} else {		// audio
+			if (strcmp(type, "AUDIO"))
+				break;
+			data->tracks[count].type = CT_CHD;
+		}
+
+		data->tracks[count].pregap = pregap;
+		if (pgtype[0] != 'V')	// VAUDIO includes pregap in file
+			pregap = 0;
+		data->tracks[count].sector_offset = sectors + pregap;
+		data->tracks[count].sector_xlength = frames - pregap;
+		sectors += (((frames + CD_TRACK_PADDING - 1) / CD_TRACK_PADDING) * CD_TRACK_PADDING);
+	}
+
+	// check if image id OK, i.e. there are tracks, and length <= 80 min
+	if (count && sectors < (80*60*75)) {
+		data->track_count = count;
+	}  else {
+		free(data);
+		data = NULL;
+	}
+
+out:
+	if (cf)
+		chd_close(cf);
+#endif
+	return data;
+}
+
+cd_data_t *cue_parse(const char *fname)
 {
 	char current_file[256], *current_filep, cue_base[256];
 	char buff[256], buff2[32], ext[4], *p;
 	int ret, count = 0, count_alloc = 2, pending_pregap = 0;
 	size_t current_filep_size, fname_len;
-	cue_data_t *data = NULL;
+	cd_data_t *data = NULL, *tmp;
 	FILE *f = NULL;
-	void *tmp;
 
 	if (fname == NULL || (fname_len = strlen(fname)) == 0)
 		return NULL;
@@ -156,14 +257,13 @@ cue_data_t *cue_parse(const char *fname)
 	p = strrchr(cue_base, '.');
 	if (p)	p[1] = '\0';
 
-	data = calloc(1, sizeof(*data) + count_alloc * sizeof(cue_track));
+	data = calloc(1, sizeof(*data) + count_alloc * sizeof(cd_track_t));
 	if (data == NULL)
 		goto out;
 
 	while (!feof(f))
 	{
-		tmp = fgets(buff, sizeof(buff), f);
-		if (tmp == NULL)
+		if (fgets(buff, sizeof(buff), f) == NULL)
 			break;
 
 		mystrip(buff);
@@ -180,7 +280,7 @@ cue_data_t *cue_parse(const char *fname)
 			count++;
 			if (count >= count_alloc) {
 				count_alloc *= 2;
-				tmp = realloc(data, sizeof(*data) + count_alloc * sizeof(cue_track));
+				tmp = realloc(data, sizeof(*data) + count_alloc * sizeof(cd_track_t));
 				if (tmp == NULL) {
 					count--;
 					break;
@@ -344,7 +444,7 @@ out:
 }
 
 
-void cue_destroy(cue_data_t *data)
+void cdparse_destroy(cd_data_t *data)
 {
 	int c;
 
@@ -360,7 +460,7 @@ void cue_destroy(cue_data_t *data)
 #if 0
 int main(int argc, char *argv[])
 {
-	cue_data_t *data = cue_parse(argv[1]);
+	cd_data_t *data = cue_parse(argv[1]);
 	int c;
 
 	if (data == NULL) return 1;
@@ -370,7 +470,7 @@ int main(int argc, char *argv[])
 			data->tracks[c].sector_offset / (75*60), data->tracks[c].sector_offset / 75 % 60,
 			data->tracks[c].sector_offset % 75, data->tracks[c].pregap, data->tracks[c].fname);
 
-	cue_destroy(data);
+	cdparse_destroy(data);
 
 	return 0;
 }
diff --git a/pico/cd/cd_parse.h b/pico/cd/cd_parse.h
new file mode 100644
index 00000000..0e1f59e7
--- /dev/null
+++ b/pico/cd/cd_parse.h
@@ -0,0 +1,5 @@
+
+cd_data_t *chd_parse(const char *fname);
+cd_data_t *cue_parse(const char *fname);
+void        cdparse_destroy(cd_data_t *data);
+
diff --git a/pico/cd/cdd.c b/pico/cd/cdd.c
index 81bc23b6..8fa16e18 100644
--- a/pico/cd/cdd.c
+++ b/pico/cd/cdd.c
@@ -38,7 +38,7 @@
 
 #include "../pico_int.h"
 #include "genplus_macros.h"
-#include "cue.h"
+#include "cd_parse.h"
 #include "cdd.h"
 
 #ifdef USE_LIBTREMOR
@@ -321,6 +321,7 @@ int cdd_load(const char *filename, int type)
   ret = (type == CT_BIN) ? 2352 : 2048;
   if (ret != cdd.sectorSize)
     elprintf(EL_STATUS|EL_ANOMALY, "cd: type detection mismatch");
+  pm_sectorsize(cdd.sectorSize, cdd.toc.tracks[0].fd);
 
   /* read CD image header + security code */
   pm_read(header + 0x10, 0x200, cdd.toc.tracks[0].fd);
@@ -448,6 +449,9 @@ int cdd_unload(void)
     {
       pm_close(cdd.toc.tracks[0].fd);
       cdd.toc.tracks[0].fd = NULL;
+      if (cdd.toc.tracks[0].fname)
+        free(cdd.toc.tracks[0].fd);
+      cdd.toc.tracks[0].fname = NULL;
     }
 
     for (i = 1; i < cdd.toc.last; i++)
@@ -466,7 +470,11 @@ int cdd_unload(void)
         if (Pico_mcd->cdda_type == CT_MP3)
           fclose(cdd.toc.tracks[i].fd);
         else
-          pm_close(cdd.toc.tracks[0].fd);
+          pm_close(cdd.toc.tracks[i].fd);
+        cdd.toc.tracks[i].fd = NULL;
+        if (cdd.toc.tracks[i].fname)
+          free(cdd.toc.tracks[i].fd);
+        cdd.toc.tracks[i].fname = NULL;
 
         /* detect single file images */
         if (cdd.toc.tracks[i+1].fd == cdd.toc.tracks[i].fd)
diff --git a/pico/cd/cdd.h b/pico/cd/cdd.h
index 4789cdb4..da5b5108 100644
--- a/pico/cd/cdd.h
+++ b/pico/cd/cdd.h
@@ -60,6 +60,7 @@
 /* CD track */
 typedef struct
 {
+  char *fname;
   void *fd;
 #ifdef USE_LIBTREMOR
   OggVorbis_File vf;
diff --git a/pico/cd/cue.h b/pico/cd/cue.h
deleted file mode 100644
index 70ade53d..00000000
--- a/pico/cd/cue.h
+++ /dev/null
@@ -1,29 +0,0 @@
-
-typedef enum
-{
-	CT_UNKNOWN = 0,
-	CT_ISO = 1,	/* 2048 B/sector */
-	CT_BIN = 2,	/* 2352 B/sector */
-	CT_MP3 = 3,
-	CT_WAV = 4
-} cue_track_type;
-
-typedef struct
-{
-	char *fname;
-	int pregap;		/* pregap for current track */
-	int sector_offset;	/* in current file */
-	int sector_xlength;
-	cue_track_type type;
-} cue_track;
-
-typedef struct
-{
-	int track_count;
-	cue_track tracks[0];
-} cue_data_t;
-
-
-cue_data_t *cue_parse(const char *fname);
-void        cue_destroy(cue_data_t *data);
-
diff --git a/pico/media.c b/pico/media.c
index f9b053bd..1294243a 100644
--- a/pico/media.c
+++ b/pico/media.c
@@ -8,7 +8,7 @@
 
 #include <string.h>
 #include "pico_int.h"
-#include "cd/cue.h"
+#include "cd/cd_parse.h"
 
 unsigned char media_id_header[0x100];
 
@@ -49,7 +49,7 @@ static int detect_media(const char *fname)
     return PM_BAD_DETECT;
 
   /* don't believe in extensions, except .cue */
-  if (strcasecmp(ext, ".cue") == 0)
+  if (strcasecmp(ext, ".cue") == 0 || strcasecmp(ext, ".chd") == 0)
     return PM_CD;
 
   pmf = pm_open(fname);
@@ -129,26 +129,31 @@ int PicoCdCheck(const char *fname_in, int *pregion)
   pm_file *cd_f;
   int region = 4; // 1: Japan, 4: US, 8: Europe
   char ext[5];
-  cue_track_type type = CT_UNKNOWN;
-  cue_data_t *cue_data = NULL;
+  enum cd_track_type type = CT_UNKNOWN;
+  cd_data_t *cd_data = NULL;
 
   // opens a cue, or searches for one
-  cue_data = cue_parse(fname_in);
-  if (cue_data != NULL) {
-    fname = cue_data->tracks[1].fname;
-    type  = cue_data->tracks[1].type;
-  }
-  else {
+  if (!cd_data && (cd_data = cue_parse(fname_in)) == NULL) {
     get_ext(fname_in, ext);
     if (strcasecmp(ext, ".cue") == 0)
       return -1;
   }
+  // opens a chd
+  if (!cd_data && (cd_data = chd_parse(fname_in)) == NULL) {
+    get_ext(fname_in, ext);
+    if (strcasecmp(ext, ".chd") == 0)
+      return -1;
+  }
 
-  cd_f = pm_open(fname);
-  if (cue_data != NULL)
-    cue_destroy(cue_data);
+  if (cd_data != NULL) {
+    // 1st track contains the code
+    fname = cd_data->tracks[1].fname;
+    type  = cd_data->tracks[1].type;
+  }
 
-  if (cd_f == NULL) return 0; // let the upper level handle this
+  cd_f = pm_open(fname);
+  cdparse_destroy(cd_data);
+  if (cd_f == NULL) return CT_UNKNOWN; // let the upper level handle this
 
   if (pm_read(buf, 32, cd_f) != 32) {
     pm_close(cd_f);
@@ -198,7 +203,7 @@ enum media_type_e PicoLoadMedia(const char *filename,
 {
   const char *rom_fname = filename;
   enum media_type_e media_type;
-  enum cd_img_type cd_img_type = CIT_NOT_CD;
+  enum cd_track_type cd_img_type = CT_UNKNOWN;
   unsigned char *rom_data = NULL;
   unsigned int rom_size = 0;
   pm_file *rom = NULL;
@@ -219,7 +224,7 @@ enum media_type_e PicoLoadMedia(const char *filename,
   {
     // check for MegaCD image
     cd_img_type = PicoCdCheck(filename, &cd_region);
-    if ((int)cd_img_type >= 0 && cd_img_type != CIT_NOT_CD)
+    if ((int)cd_img_type >= 0 && cd_img_type != CT_UNKNOWN)
     {
       // valid CD image, ask frontend for BIOS..
       rom_fname = NULL;
@@ -290,7 +295,7 @@ enum media_type_e PicoLoadMedia(const char *filename,
   Pico.m.ncart_in = 0;
 
   // insert CD if it was detected
-  if (cd_img_type != CIT_NOT_CD) {
+  if (cd_img_type != CT_UNKNOWN) {
     ret = cdd_load(filename, cd_img_type);
     if (ret != 0) {
       PicoCartUnload();
diff --git a/pico/pico.h b/pico/pico.h
index b75a0146..5ec67d40 100644
--- a/pico/pico.h
+++ b/pico/pico.h
@@ -161,7 +161,8 @@ typedef enum
 {
 	PMT_UNCOMPRESSED = 0,
 	PMT_ZIP,
-	PMT_CSO
+	PMT_CSO,
+	PMT_CHD
 } pm_type;
 typedef struct
 {
@@ -172,7 +173,9 @@ typedef struct
 	char ext[4];
 } pm_file;
 pm_file *pm_open(const char *path);
+void     pm_sectorsize(int length, pm_file *stream);
 size_t   pm_read(void *ptr, size_t bytes, pm_file *stream);
+size_t   pm_read_audio(void *ptr, size_t bytes, pm_file *stream);
 int      pm_seek(pm_file *stream, long offset, int whence);
 int      pm_close(pm_file *fp);
 int PicoCartLoad(pm_file *f,unsigned char **prom,unsigned int *psize,int is_sms);
@@ -255,14 +258,34 @@ enum media_type_e {
   PM_CD,
 };
 
-enum cd_img_type
+enum cd_track_type
 {
-  CIT_NOT_CD = 0,
-  CIT_ISO,
-  CIT_BIN,
-  CIT_CUE
+  CT_UNKNOWN = 0,
+  // data tracks
+  CT_ISO = 1,	/* 2048 B/sector */
+  CT_BIN = 2,	/* 2352 B/sector */
+  // audio tracks
+  CT_MP3 = 3,
+  CT_WAV = 4,
+  CT_CHD = 5,
 };
 
+typedef struct
+{
+	char *fname;
+	int pregap;		/* pregap for current track */
+	int sector_offset;	/* in current file */
+	int sector_xlength;
+	enum cd_track_type type;
+} cd_track_t;
+
+typedef struct
+{
+	int track_count;
+	cd_track_t tracks[0];
+} cd_data_t;
+
+
 enum media_type_e PicoLoadMedia(const char *filename,
   const char *carthw_cfg_fname,
   const char *(*get_bios_filename)(int *region, const char *cd_fname),
diff --git a/pico/sound/sound.c b/pico/sound/sound.c
index ad748688..0807c030 100644
--- a/pico/sound/sound.c
+++ b/pico/sound/sound.c
@@ -11,7 +11,6 @@
 #include "ym2612.h"
 #include "sn76496.h"
 #include "../pico_int.h"
-#include "../cd/cue.h"
 #include "mix.h"
 #include "emu2413/emu2413.h"
 
@@ -266,7 +265,7 @@ static void cdda_raw_update(int *buffer, int length)
   if (PicoIn.sndRate <  22050 - 100) mult = 4;
   cdda_bytes *= mult;
 
-  ret = pm_read(cdda_out_buffer, cdda_bytes, Pico_mcd->cdda_stream);
+  ret = pm_read_audio(cdda_out_buffer, cdda_bytes, Pico_mcd->cdda_stream);
   if (ret < cdda_bytes) {
     memset((char *)cdda_out_buffer + ret, 0, cdda_bytes - ret);
     Pico_mcd->cdda_stream = NULL;
diff --git a/platform/common/common.mak b/platform/common/common.mak
index de1c3d7c..0aabeab6 100644
--- a/platform/common/common.mak
+++ b/platform/common/common.mak
@@ -99,7 +99,7 @@ endif
 # CD
 SRCS_COMMON += $(R)pico/cd/mcd.c $(R)pico/cd/memory.c $(R)pico/cd/sek.c \
 	$(R)pico/cd/cdc.c $(R)pico/cd/cdd.c $(R)pico/cd/cd_image.c \
-	$(R)pico/cd/cue.c $(R)pico/cd/gfx.c $(R)pico/cd/gfx_dma.c \
+	$(R)pico/cd/cd_parse.c $(R)pico/cd/gfx.c $(R)pico/cd/gfx_dma.c \
 	$(R)pico/cd/misc.c $(R)pico/cd/pcm.c
 # 32X
 ifneq "$(no_32x)" "1"
diff --git a/platform/common/emu.c b/platform/common/emu.c
index 089189d5..151fb531 100644
--- a/platform/common/emu.c
+++ b/platform/common/emu.c
@@ -539,11 +539,11 @@ out:
 
 int emu_swap_cd(const char *fname)
 {
-	enum cd_img_type cd_type;
+	enum cd_track_type cd_type;
 	int ret = -1;
 
 	cd_type = PicoCdCheck(fname, NULL);
-	if (cd_type != CIT_NOT_CD)
+	if (cd_type != CT_UNKNOWN)
 		ret = cdd_load(fname, cd_type);
 	if (ret != 0) {
 		menu_update_msg("Load failed, invalid CD image?");
diff --git a/platform/common/menu_pico.c b/platform/common/menu_pico.c
index 38adcc27..fc238c30 100644
--- a/platform/common/menu_pico.c
+++ b/platform/common/menu_pico.c
@@ -40,7 +40,7 @@
 static const char *rom_exts[] = {
 	"zip",
 	"bin", "smd", "gen", "md",
-	"iso", "cso", "cue",
+	"iso", "cso", "cue", "chd",
 	"32x",
 	"sms",
 	NULL
diff --git a/platform/gizmondo/menu.c b/platform/gizmondo/menu.c
index 07a2ce7b..cf1f5b48 100644
--- a/platform/gizmondo/menu.c
+++ b/platform/gizmondo/menu.c
@@ -1577,9 +1577,9 @@ int menu_loop_tray(void)
 					selfname = romsel_loop(curr_path);
 					if (selfname) {
 						int ret = -1;
-						cd_img_type cd_type;
+						cd_track_type cd_type;
 						cd_type = emu_cdCheck(NULL, romFileName);
-						if (cd_type != CIT_NOT_CD)
+						if (cd_type >= 0 && cd_type != CT_UNKNOWN)
 							ret = Insert_CD(romFileName, cd_type);
 						if (ret != 0) {
 							sprintf(menuErrorMsg, "Load failed, invalid CD image?");
diff --git a/platform/libretro/libretro.c b/platform/libretro/libretro.c
index d889fb20..a6fce3e5 100644
--- a/platform/libretro/libretro.c
+++ b/platform/libretro/libretro.c
@@ -749,7 +749,7 @@ void retro_get_system_info(struct retro_system_info *info)
 #define _GIT_VERSION "-" GIT_VERSION
 #endif
    info->library_version = VERSION _GIT_VERSION;
-   info->valid_extensions = "bin|gen|smd|md|32x|cue|iso|sms";
+   info->valid_extensions = "bin|gen|smd|md|32x|cue|iso|chd|sms";
    info->need_fullpath = true;
 }
 
@@ -1002,7 +1002,7 @@ static unsigned int disk_get_image_index(void)
 
 static bool disk_set_image_index(unsigned int index)
 {
-   enum cd_img_type cd_type;
+   enum cd_track_type cd_type;
    int ret;
 
    if (index >= sizeof(disks) / sizeof(disks[0]))
@@ -1024,7 +1024,7 @@ static bool disk_set_image_index(unsigned int index)
 
    ret = -1;
    cd_type = PicoCdCheck(disks[index].fname, NULL);
-   if (cd_type != CIT_NOT_CD)
+   if (cd_type >= 0 && cd_type != CT_UNKNOWN)
       ret = cdd_load(disks[index].fname, cd_type);
    if (ret != 0) {
       if (log_cb)
diff --git a/platform/psp/emu.c b/platform/psp/emu.c
index 080784db..016c44d9 100644
--- a/platform/psp/emu.c
+++ b/platform/psp/emu.c
@@ -30,7 +30,6 @@
 #include <pico/pico_int.h>
 #include <pico/cd/genplus_macros.h>
 #include <pico/cd/cdd.h>
-#include <pico/cd/cue.h>
 
 #define OSD_FPS_X 432
 
@@ -744,23 +743,10 @@ void emu_handle_resume(void)
 	// reopen first CD track
 	if (cdd.toc.tracks[0].fd != NULL)
 	{
-		const char *fname = rom_fname_reload;
-		int len = strlen(rom_fname_reload);
-		cue_data_t *cue_data = NULL;
-
-		if (len > 4 && strcasecmp(fname + len - 4,  ".cue") == 0)
-		{
-			cue_data = cue_parse(rom_fname_reload);
-			if (cue_data != NULL)
-				fname = cue_data->tracks[1].fname;
-		}
-
-		lprintf("emu_HandleResume: reopen %s\n", fname);
+		lprintf("emu_HandleResume: reopen %s\n", cdd.toc.tracks[0].fname);
 		pm_close(cdd.toc.tracks[0].fd);
-		cdd.toc.tracks[0].fd = pm_open(fname);
+		cdd.toc.tracks[0].fd = pm_open(cdd.toc.tracks[0].fname);
 		lprintf("reopen %s\n", cdd.toc.tracks[0].fd != NULL ? "ok" : "failed");
-
-		if (cue_data != NULL) cue_destroy(cue_data);
 	}
 
 	mp3_reopen_file();
-- 
2.39.5