From 61e05286e204d3bf7ce3d40bfe61ca814074bca8 Mon Sep 17 00:00:00 2001
From: dagargo <dagargo@gmail.com>
Date: Fri, 6 Mar 2026 14:24:06 +0100
Subject: [PATCH 01/20] elektron: Add support for Syntakt samples

---
 res/elektron/devices.json |   3 +-
 src/connectors/elektron.c | 256 +++++++++++++++++++++++++++++++++++++-
 src/connectors/elektron.h |   7 +-
 test/tests_elektron.c     |  82 +++++++++++-
 4 files changed, 338 insertions(+), 10 deletions(-)

diff --git a/res/elektron/devices.json b/res/elektron/devices.json
index 731468a9..7122ccef 100644
--- a/res/elektron/devices.json
+++ b/res/elektron/devices.json
@@ -193,7 +193,8 @@
       ],
       "sound": [
         "stsnd"
-      ]
+      ],
+      "data-sample": null
     },
     "storage": []
   },
diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 1e17ede2..356d41f4 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -49,6 +49,7 @@ static const gchar *FS_DATA_ANY_EXTS[] = { "data", NULL };
 #define FS_DATA_PRJ_PREFIX "/projects"
 #define FS_DATA_SND_PREFIX "/soundbanks"
 #define FS_DATA_PST_PREFIX "/presets"
+#define FS_DATA_SAMPLES_PREFIX "/samples"
 #define FS_SMPLRW_START_POS 5
 #define FS_DATA_START_POS 18
 #define FS_RAM_SLOTS_START_POS 5
@@ -57,6 +58,7 @@ static const gchar *FS_DATA_ANY_EXTS[] = { "data", NULL };
 #define FS_SAMPLES_PAD_RES 22
 
 #define ELEKTRON_NAME_MAX_LEN 32
+#define ELEKTRON_DATA_SAMPLE_MAX_LEN 16
 
 #define ELEKTRON_SAMPLE_INFO_PAD_I32_LEN 10
 #define ELEKTRON_LOOP_TYPE_FWD 0
@@ -64,6 +66,7 @@ static const gchar *FS_DATA_ANY_EXTS[] = { "data", NULL };
 
 #define PROJECT_SLOTS 128
 #define SOUND_SLOTS 256
+#define SAMPLE_SLOTS 64
 
 #define AH_FX_SLOTS 512
 #define AH_SLOTS 128
@@ -108,6 +111,43 @@ struct elektron_iterator_data
   gboolean load_metadata;
 };
 
+// These belong to the header but have been removed to avoid alignment issues.
+struct elektron_data_header_preamble
+{
+  guint32 magic_head;		// 0xac11d303
+  guint8 header_version;
+};
+
+struct elektron_data_header
+{
+  guint16 family_id;		// 8 for Syntakt
+  guint16 device_id;		// 13 for Syntakt
+  guint32 os_version;		// OS release number
+  guint32 file_type;		// 8 for Syntakt samples
+  gint32 file_version;
+  gint32 file_index;
+  guint32 payload_size;		// uncompressed
+  guint8 is_compressed;
+  guint8 footer_size;		// Size of footer
+};
+
+struct elektron_data_sample_slot_header
+{
+  guint32 magic_head;		// 0x53414d50
+  guint8 version;		// Should be 0
+  guint8 pad[3];		// ignore
+  guint32 length;
+  gchar name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
+  guint32 rsvd32[9];		// ignore
+};
+
+struct elektron_data_footer
+{
+  guint32 hash;
+  guint32 content_size;
+  guint32 magic_tail;		// 0xaaa1daaa
+};
+
 typedef GByteArray *(*elektron_msg_id_func) (guint);
 
 typedef GByteArray *(*elektron_msg_id_len_func) (guint, guint);
@@ -2054,6 +2094,17 @@ elektron_read_data_dir_pst (struct backend *backend,
 					slots);
 }
 
+static gint
+elektron_read_data_dir_sample (struct backend *backend,
+			       struct item_iterator *iter, const gchar *dir,
+			       const gchar **extensions)
+{
+  return elektron_read_data_dir_prefix (backend, iter, dir,
+					FS_DATA_SAMPLES_PREFIX,
+					ITER_MODE_DATA, FS_DATA_START_POS,
+					SAMPLE_SLOTS);
+}
+
 static gint
 elektron_dst_src_data_prefix_common (struct backend *backend,
 				     const gchar *src, const gchar *dst,
@@ -2112,6 +2163,13 @@ elektron_move_data_item_pst (struct backend *backend, const gchar *src,
 					 FS_DATA_PST_PREFIX);
 }
 
+static gint
+elektron_move_data_item_sample (struct backend *backend, const gchar *src,
+				const gchar *dst)
+{
+  return elektron_move_data_item_prefix (backend, src, dst,
+					 FS_DATA_SAMPLES_PREFIX);
+}
 
 static gint
 elektron_copy_data_item_prefix (struct backend *backend, const gchar *src,
@@ -2153,6 +2211,14 @@ elektron_copy_data_item_pst (struct backend *backend, const gchar *src,
 					 FS_DATA_PST_PREFIX);
 }
 
+static gint
+elektron_copy_data_item_sample (struct backend *backend, const gchar *src,
+				const gchar *dst)
+{
+  return elektron_copy_data_item_prefix (backend, src, dst,
+					 FS_DATA_SAMPLES_PREFIX);
+}
+
 static gint
 elektron_path_data_prefix_common (struct backend *backend,
 				  const gchar *path, const char *prefix,
@@ -2200,6 +2266,13 @@ elektron_clear_data_item_pst (struct backend *backend, const gchar *path)
   return elektron_clear_data_item_prefix (backend, path, FS_DATA_PST_PREFIX);
 }
 
+static gint
+elektron_clear_data_item_sample (struct backend *backend, const gchar *path)
+{
+  return elektron_clear_data_item_prefix (backend, path,
+					  FS_DATA_SAMPLES_PREFIX);
+}
+
 static gint
 elektron_swap_data_item_prefix (struct backend *backend, const gchar *src,
 				const gchar *dst, const gchar *prefix)
@@ -2240,6 +2313,14 @@ elektron_swap_data_item_pst (struct backend *backend, const gchar *src,
 					 FS_DATA_PST_PREFIX);
 }
 
+static gint
+elektron_swap_data_item_sample (struct backend *backend, const gchar *src,
+				const gchar *dst)
+{
+  return elektron_swap_data_item_prefix (backend, src, dst,
+					 FS_DATA_SAMPLES_PREFIX);
+}
+
 static gint
 elektron_open_datum (struct backend *backend, const gchar *path,
 		     guint32 *jid, gint mode, guint32 size)
@@ -2274,13 +2355,15 @@ elektron_open_datum (struct backend *backend, const gchar *path,
 
   path_cp1252 = elektron_get_cp1252 (path);
 
+  // Samples are the only payload type we want to actually work with.
+  compression = g_str_has_prefix (path, FS_DATA_SAMPLES_PREFIX) ? 0 : 1;
+
   if (mode == O_RDONLY)
     {
       g_byte_array_append (tx_msg, (guint8 *) path_cp1252,
 			   strlen (path_cp1252) + 1);
       chunk_size = g_htonl (DATA_TRANSF_BLOCK_BYTES);
       g_byte_array_append (tx_msg, (guint8 *) & chunk_size, sizeof (guint32));
-      compression = 1;
       g_byte_array_append (tx_msg, &compression, sizeof (guint8));
     }
 
@@ -2577,6 +2660,114 @@ elektron_download_data_pst (struct backend *backend, const gchar *path,
 					FS_DATA_PST_PREFIX);
 }
 
+gint
+elektron_set_sample_from_data_sample (struct idata *sample,
+				      struct idata *data_sample)
+{
+  guint size = data_sample->content->len -
+    sizeof (struct elektron_data_header_preamble) -
+    sizeof (struct elektron_data_header) -
+    sizeof (struct elektron_data_sample_slot_header) -
+    sizeof (struct elektron_data_footer);
+  guint sample_data_start = sizeof (struct elektron_data_header_preamble) +
+    sizeof (struct elektron_data_header) +
+    sizeof (struct elektron_data_sample_slot_header);
+  GByteArray *content = g_byte_array_sized_new (size);
+
+  content->len = size;
+  memcpy (content->data, &data_sample->content->data[sample_data_start],
+	  size);
+  idata_init (sample, content, elektron_name_to_utf8 (data_sample->name),
+	      NULL, NULL);
+
+  return 0;
+}
+
+gint
+elektron_set_data_sample_from_sample (struct idata *data_sample,
+				      struct idata *sample, guint slot)
+{
+  struct elektron_data_header_preamble preamble;
+  struct elektron_data_header header;
+  struct elektron_data_sample_slot_header slot_header;
+  struct elektron_data_footer footer;
+  guint size = sample->content->len +
+    sizeof (struct elektron_data_header_preamble) +
+    sizeof (struct elektron_data_header) +
+    sizeof (struct elektron_data_sample_slot_header) +
+    sizeof (struct elektron_data_footer);
+  GByteArray *content = g_byte_array_sized_new (size);
+
+  preamble.magic_head = GUINT32_TO_BE (0xac11d303);
+  preamble.header_version = 2;
+
+  // For now, this is only compatyble with Syntakt.
+  header.family_id = GUINT16_TO_BE (8);
+  header.device_id = GUINT16_TO_BE (13);
+  header.os_version = GUINT32_TO_BE (0x30303832);
+  header.file_type = GUINT32_TO_BE (8);
+  header.file_version = 0xffffffff;
+  header.file_index = GINT32_TO_BE (slot);
+  header.payload_size =
+    GUINT32_TO_BE (sample->content->len +
+		   sizeof (struct elektron_data_sample_slot_header));
+  header.is_compressed = 0;
+  header.footer_size = sizeof (struct elektron_data_footer);
+
+  slot_header.magic_head = GUINT32_TO_BE (0x53414d50);
+  slot_header.version = 0;
+  slot_header.length = sample->content->len / 2;
+  snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
+	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, data_sample->name);
+
+  footer.hash =
+    GUINT32_TO_BE (crc32
+		   (0xffffffff, sample->content->data, sample->content->len));
+  footer.content_size = GUINT32_TO_BE (sample->content->len);
+  footer.magic_tail = GUINT32_TO_BE (0xaaa1daaa);
+
+  g_byte_array_append (content, (guint8 *) & preamble,
+		       sizeof (struct elektron_data_header_preamble));
+  g_byte_array_append (content, (guint8 *) & header,
+		       sizeof (struct elektron_data_header));
+  g_byte_array_append (content, (guint8 *) & slot_header,
+		       sizeof (struct elektron_data_sample_slot_header));
+  g_byte_array_append (content, sample->content->data, sample->content->len);
+  g_byte_array_append (content, (guint8 *) & footer,
+		       sizeof (struct elektron_data_footer));
+
+  idata_init (data_sample, content, elektron_get_cp1252 (sample->name), NULL,
+	      NULL);
+  return 0;
+}
+
+static gint
+elektron_download_data_sample (struct backend *backend, const gchar *path,
+			       struct idata *sample,
+			       struct task_control *control)
+{
+  gint err;
+  struct idata data_sample;
+
+  control->parts = 2;
+  control->part = 0;
+
+  err = elektron_download_data_prefix (backend, path, &data_sample, control,
+				       FS_DATA_SAMPLES_PREFIX);
+  if (err)
+    {
+      return err;
+    }
+
+  err = elektron_set_sample_from_data_sample (sample, &data_sample);
+  idata_clear (&data_sample);
+
+  task_control_set_progress (control, 1.0);
+  control->part++;
+
+  return err;
+}
+
 static gchar *
 elektron_get_download_name (struct backend *backend,
 			    const struct fs_operations *ops,
@@ -2892,6 +3083,40 @@ elektron_upload_data_pst (struct backend *backend, const gchar *path,
 				      FS_DATA_PST_PREFIX);
 }
 
+static gint
+elektron_upload_data_sample (struct backend *backend, const gchar *path,
+			     struct idata *sample,
+			     struct task_control *control)
+{
+  gint err;
+  guint id;
+  struct idata data_sample;
+
+  err = common_slot_get_id_from_path (path, &id);
+  if (err)
+    {
+      return err;
+    }
+
+  control->parts = 2;
+  control->part = 0;
+
+  err = elektron_set_data_sample_from_sample (&data_sample, sample, id);
+  if (err)
+    {
+      return err;
+    }
+
+  task_control_set_progress (control, 1.0);
+  control->part++;
+
+  err = elektron_upload_data_prefix (backend, path, &data_sample, control,
+				     FS_DATA_SAMPLES_PREFIX);
+  idata_clear (&data_sample);
+
+  return err;
+}
+
 static gint
 elektron_upload_pkg (struct backend *backend, const gchar *path,
 		     struct idata *input, struct task_control *control,
@@ -3727,6 +3952,31 @@ static const struct fs_operations FS_DATA_TAKT_II_PST_OPERATIONS = {
   .get_download_path = elektron_get_download_path
 };
 
+static const struct fs_operations FS_DATA_SAMPLES_OPERATIONS = {
+  .id = FS_DATA_SAMPLES,
+  .options = FS_OPTION_SLOT_STORAGE | FS_OPTION_SHOW_SIZE_COLUMN |
+    FS_OPTION_SHOW_SLOT_COLUMN | FS_OPTION_SHOW_INFO_COLUMN |
+    FS_OPTION_ALLOW_SEARCH,
+  .name = "data-samples",
+  .gui_name = "Samples",
+  .gui_icon = FS_ICON_WAVE,
+  .file_icon = FS_ICON_WAVE,
+  .readdir = elektron_read_data_dir_sample,
+  .print_item = elektron_print_data,
+  .delete = elektron_clear_data_item_sample,
+  .move = elektron_move_data_item_sample,
+  .copy = elektron_copy_data_item_sample,
+  .swap = elektron_swap_data_item_sample,
+  .download = elektron_download_data_sample,
+  .upload = elektron_upload_data_sample,
+  .get_slot = elektron_get_id_as_slot,
+  .load = elektron_sample_load,
+  .save = elektron_sample_save,
+  .get_exts = sample_get_sample_extensions,
+  .get_upload_path = common_slot_get_upload_path,
+  .get_download_path = common_system_get_download_path
+};
+
 static const struct fs_operations FS_DIGITAKT_RAM_OPERATIONS = {
   .id = FS_DIGITAKT_RAM,
   .options = FS_OPTION_SAMPLE_EDITOR | FS_OPTION_MONO |
@@ -3786,8 +4036,8 @@ static const struct fs_operations *FS_OPERATIONS[] = {
   &FS_SAMPLES_OPERATIONS, &FS_RAW_ANY_OPERATIONS, &FS_RAW_PRESETS_OPERATIONS,
   &FS_DATA_ANY_OPERATIONS, &FS_DATA_PRJ_OPERATIONS, &FS_DATA_SND_OPERATIONS,
   &FS_DATA_PST_OPERATIONS, &FS_DATA_TAKT_II_PST_OPERATIONS,
-  &FS_DIGITAKT_RAM_OPERATIONS, &FS_DIGITAKT_TRACK_OPERATIONS,
-  &FS_DIGITAKT_TRACK_LOOP_OPERATIONS, NULL
+  &FS_DATA_SAMPLES_OPERATIONS, &FS_DIGITAKT_RAM_OPERATIONS,
+  &FS_DIGITAKT_TRACK_OPERATIONS, &FS_DIGITAKT_TRACK_LOOP_OPERATIONS, NULL
 };
 
 gint
diff --git a/src/connectors/elektron.h b/src/connectors/elektron.h
index 0e5417b7..9d7ea0a1 100644
--- a/src/connectors/elektron.h
+++ b/src/connectors/elektron.h
@@ -43,9 +43,10 @@ enum elektron_fs
   FS_DATA_SND = (1 << 5),
   FS_DATA_PST = (1 << 6),
   FS_DATA_TAKT_II_PST = (1 << 7),
-  FS_DIGITAKT_RAM = (1 << 8),
-  FS_DIGITAKT_TRACK = (1 << 9),
-  FS_DIGITAKT_TRACK_LOOP = (1 << 10)
+  FS_DATA_SAMPLES = (1 << 8),
+  FS_DIGITAKT_RAM = (1 << 9),
+  FS_DIGITAKT_TRACK = (1 << 10),
+  FS_DIGITAKT_TRACK_LOOP = (1 << 11)
 };
 
 extern const struct connector CONNECTOR_ELEKTRON;
diff --git a/test/tests_elektron.c b/test/tests_elektron.c
index a8a59570..1a7b1126 100644
--- a/test/tests_elektron.c
+++ b/test/tests_elektron.c
@@ -3,6 +3,7 @@
 #include <CUnit/CUnit.h>
 #include <CUnit/Basic.h>
 #include "../config.h"
+#include "../src/sample.h"
 #include "../src/utils.h"
 #include "../src/connectors/package.h"
 #include "../src/connectors/elektron.h"
@@ -18,7 +19,12 @@ gint elektron_configure_device_from_file (struct backend *backend, guint8 id,
 
 void elektron_destroy_data (struct backend *backend);
 
-void
+gint elektron_set_sample_from_data_sample (struct idata *sample,
+					   struct idata *data_sample);
+gint elektron_set_data_sample_from_sample (struct idata *data_sample,
+					   struct idata *sample, guint slot);
+
+static void
 test_elektron_get_dev_exts ()
 {
   const gchar **exts;
@@ -65,7 +71,7 @@ compare_exts (const gchar **a, const gchar **b)
   return *y != NULL;
 }
 
-void
+static void
 test_elektron_configure_device_from_file ()
 {
   const gchar **exts;
@@ -120,7 +126,7 @@ test_elektron_configure_device_from_file ()
   CU_ASSERT_EQUAL (backend.data, NULL);
 }
 
-void
+static void
 test_elektron_special_exts ()
 {
   const gchar **exts;
@@ -185,6 +191,65 @@ test_elektron_special_exts ()
   CU_ASSERT_EQUAL (backend.data, NULL);
 }
 
+static void
+test_elektron_data_sample ()
+{
+  gint err;
+  struct idata sample, data_sample;
+  struct task_control task_control;
+  struct sample_info sample_info_src;
+  struct sample_load_opts sample_load_opts;
+  GByteArray *content_before, *content_after;
+
+  controllable_init (&task_control.controllable);
+  task_control.callback = NULL;
+
+  printf ("\n");
+
+  sample_load_opts_init (&sample_load_opts, 1, 48000, SF_FORMAT_PCM_16,
+			 FALSE);
+  err = sample_load_from_file (TEST_DATA_DIR "/connectors/square.wav",
+			       &sample, &task_control, &sample_load_opts,
+			       &sample_info_src);
+
+  controllable_clear (&task_control.controllable);
+
+  CU_ASSERT_EQUAL (err, 0);
+  if (err)
+    {
+      return;
+    }
+
+  err = elektron_set_data_sample_from_sample (&data_sample, &sample, 3);
+  CU_ASSERT_EQUAL (err, 0);
+  if (err)
+    {
+      idata_clear (&sample);
+      return;
+    }
+
+  content_before = idata_steal (&sample);
+
+  err = elektron_set_sample_from_data_sample (&sample, &data_sample);
+  CU_ASSERT_EQUAL (err, 0);
+  if (err)
+    {
+      idata_clear (&data_sample);
+      return;
+    }
+
+  idata_clear (&data_sample);
+
+  content_after = idata_steal (&sample);
+
+  CU_ASSERT_EQUAL (content_after->len, content_before->len);
+  CU_ASSERT_EQUAL (memcmp (content_after->data, content_before->data,
+			   content_after->len), 0);
+
+  g_byte_array_free (content_before, TRUE);
+  g_byte_array_free (content_after, TRUE);
+}
+
 gint
 main (gint argc, gchar *argv[])
 {
@@ -202,6 +267,12 @@ main (gint argc, gchar *argv[])
       goto cleanup;
     }
 
+  if (!CU_add_test (suite, "elektron_get_dev_exts",
+		    test_elektron_get_dev_exts))
+    {
+      goto cleanup;
+    }
+
   if (!CU_add_test (suite, "elektron_configure_device_from_file",
 		    test_elektron_configure_device_from_file))
     {
@@ -214,6 +285,11 @@ main (gint argc, gchar *argv[])
       goto cleanup;
     }
 
+  if (!CU_add_test (suite, "elektron_data_sample", test_elektron_data_sample))
+    {
+      goto cleanup;
+    }
+
   CU_basic_set_mode (CU_BRM_VERBOSE);
 
   CU_basic_run_tests ();

From 242473b5ed5e0e689412b9e38b35a8a9bcd9978c Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Fri, 6 Mar 2026 17:51:56 +0100
Subject: [PATCH 02/20] fix: typo

---
 src/connectors/elektron.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 356d41f4..fb156422 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -3957,7 +3957,7 @@ static const struct fs_operations FS_DATA_SAMPLES_OPERATIONS = {
   .options = FS_OPTION_SLOT_STORAGE | FS_OPTION_SHOW_SIZE_COLUMN |
     FS_OPTION_SHOW_SLOT_COLUMN | FS_OPTION_SHOW_INFO_COLUMN |
     FS_OPTION_ALLOW_SEARCH,
-  .name = "data-samples",
+  .name = "data-sample",
   .gui_name = "Samples",
   .gui_icon = FS_ICON_WAVE,
   .file_icon = FS_ICON_WAVE,

From 2c6650500feafc8b2f51d4649b6d04ef3d48e13f Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Sun, 15 Mar 2026 16:06:43 +0100
Subject: [PATCH 03/20] elektron: data-samples use slot number as name for now

---
 src/connectors/elektron.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index fb156422..53ac6e2a 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2617,7 +2617,9 @@ elektron_download_data_prefix (struct backend *backend, const gchar *path,
   if (active)
     {
       task_control_set_progress (control, 1.0);
-      idata_init (data, content, NULL, NULL, NULL);
+      basename = g_path_get_basename (path);
+      idata_init (data, content, g_path_get_basename (path), NULL, NULL);
+      g_free (basename);
     }
   else
     {

From eb414032f6a5b46eb3b2d5cf4d5e457941d53af6 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Sun, 15 Mar 2026 16:08:31 +0100
Subject: [PATCH 04/20] elektron: fill sample_info to allow save sample to run

---
 src/connectors/elektron.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 53ac6e2a..e43404fb 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2679,8 +2679,16 @@ elektron_set_sample_from_data_sample (struct idata *sample,
   content->len = size;
   memcpy (content->data, &data_sample->content->data[sample_data_start],
 	  size);
+
+  struct sample_info *sample_info = NULL;
+  sample_info = sample_info_new (FALSE);
+  sample_info->frames = size / 2;
+  sample_info->rate = 48000;
+  sample_info->channels = 1;
+  sample_info->format = SF_FORMAT_PCM_16;
+
   idata_init (sample, content, elektron_name_to_utf8 (data_sample->name),
-	      NULL, NULL);
+	      sample_info, sample_info_free);
 
   return 0;
 }

From d2cad43a0d5842d404b341648a71a5f692445c61 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 22:16:54 +0100
Subject: [PATCH 05/20] Add packed attribute to structs

---
 src/connectors/elektron.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index e43404fb..d0e0cc14 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -112,13 +112,13 @@ struct elektron_iterator_data
 };
 
 // These belong to the header but have been removed to avoid alignment issues.
-struct elektron_data_header_preamble
+struct __attribute__((packed)) elektron_data_header_preamble
 {
   guint32 magic_head;		// 0xac11d303
   guint8 header_version;
 };
 
-struct elektron_data_header
+struct __attribute__((packed)) elektron_data_header
 {
   guint16 family_id;		// 8 for Syntakt
   guint16 device_id;		// 13 for Syntakt
@@ -131,7 +131,7 @@ struct elektron_data_header
   guint8 footer_size;		// Size of footer
 };
 
-struct elektron_data_sample_slot_header
+struct __attribute__((packed)) elektron_data_sample_slot_header
 {
   guint32 magic_head;		// 0x53414d50
   guint8 version;		// Should be 0
@@ -141,7 +141,7 @@ struct elektron_data_sample_slot_header
   guint32 rsvd32[9];		// ignore
 };
 
-struct elektron_data_footer
+struct __attribute__((packed)) elektron_data_footer
 {
   guint32 hash;
   guint32 content_size;

From 45dcf2109ce4b5075fca62c6c1348cf0a2d261ac Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 22:43:08 +0100
Subject: [PATCH 06/20] Read sample name in header

---
 src/connectors/elektron.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index d0e0cc14..d4e337c7 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2617,9 +2617,7 @@ elektron_download_data_prefix (struct backend *backend, const gchar *path,
   if (active)
     {
       task_control_set_progress (control, 1.0);
-      basename = g_path_get_basename (path);
-      idata_init (data, content, g_path_get_basename (path), NULL, NULL);
-      g_free (basename);
+      idata_init (data, content, NULL, NULL, NULL);
     }
   else
     {
@@ -2674,6 +2672,21 @@ elektron_set_sample_from_data_sample (struct idata *sample,
   guint sample_data_start = sizeof (struct elektron_data_header_preamble) +
     sizeof (struct elektron_data_header) +
     sizeof (struct elektron_data_sample_slot_header);
+  struct elektron_data_sample_slot_header *slot_header =
+    (struct elektron_data_sample_slot_header *) &data_sample->content->data
+    [sizeof (struct elektron_data_header_preamble) +
+     sizeof (struct elektron_data_header)];
+  gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
+  gint j = 0;
+  for (gint i = 0; i < ELEKTRON_DATA_SAMPLE_MAX_LEN - 1 && slot_header->name[i] != '\0'; i++)
+    {
+      if (g_ascii_isprint (slot_header->name[i]) && slot_header->name[i] != '/' &&
+	  slot_header->name[i] != '\\')
+	{
+	  safe_name[j++] = slot_header->name[i];
+	}
+    }
+  safe_name[j] = '\0';
   GByteArray *content = g_byte_array_sized_new (size);
 
   content->len = size;
@@ -2687,7 +2700,7 @@ elektron_set_sample_from_data_sample (struct idata *sample,
   sample_info->channels = 1;
   sample_info->format = SF_FORMAT_PCM_16;
 
-  idata_init (sample, content, elektron_name_to_utf8 (data_sample->name),
+  idata_init (sample, content, elektron_name_to_utf8 (safe_name),
 	      sample_info, sample_info_free);
 
   return 0;

From 8d4541e28babf8558fa879e8010050378ddf5e4b Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 23:04:38 +0100
Subject: [PATCH 07/20] Convert sample data to/from BE

---
 src/connectors/elektron.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index d4e337c7..e11a7c04 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2676,6 +2676,9 @@ elektron_set_sample_from_data_sample (struct idata *sample,
     (struct elektron_data_sample_slot_header *) &data_sample->content->data
     [sizeof (struct elektron_data_header_preamble) +
      sizeof (struct elektron_data_header)];
+  struct elektron_data_footer *footer =
+    (struct elektron_data_footer *) &data_sample->content->data
+    [data_sample->content->len - sizeof (struct elektron_data_footer)];
   gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
   gint j = 0;
   for (gint i = 0; i < ELEKTRON_DATA_SAMPLE_MAX_LEN - 1 && slot_header->name[i] != '\0'; i++)
@@ -2688,10 +2691,16 @@ elektron_set_sample_from_data_sample (struct idata *sample,
     }
   safe_name[j] = '\0';
   GByteArray *content = g_byte_array_sized_new (size);
+  g_byte_array_set_size (content, size);
 
-  content->len = size;
-  memcpy (content->data, &data_sample->content->data[sample_data_start],
-	  size);
+  const gint16 *src = (const gint16 *) &data_sample->content->data[sample_data_start];
+  gint16 *dest = (gint16 *) content->data;
+  guint samples_count = size / 2;
+  for (guint i = 0; i < samples_count; i++)
+    {
+      dest[i] = GINT16_FROM_BE (src[i]);
+    }
+    }
 
   struct sample_info *sample_info = NULL;
   sample_info = sample_info_new (FALSE);
@@ -2755,7 +2764,14 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
 		       sizeof (struct elektron_data_header));
   g_byte_array_append (content, (guint8 *) & slot_header,
 		       sizeof (struct elektron_data_sample_slot_header));
-  g_byte_array_append (content, sample->content->data, sample->content->len);
+  g_byte_array_set_size (content, content->len + sample->content->len);
+  const gint16 *src = (const gint16 *) sample->content->data;
+  guint samples_count = sample->content->len / 2;
+  gint16 *dest = (gint16 *) &content->data[content->len - sample->content->len];
+  for (guint i = 0; i < samples_count; i++)
+    {
+      dest[i] = GINT16_TO_BE (src[i]);
+    }
   g_byte_array_append (content, (guint8 *) & footer,
 		       sizeof (struct elektron_data_footer));
 

From c44c592d666a8d3bfceb0cce969b1fb6c74741d4 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 23:05:28 +0100
Subject: [PATCH 08/20] Length must be BE

---
 src/connectors/elektron.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index e11a7c04..a07d56d5 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2748,7 +2748,7 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
 
   slot_header.magic_head = GUINT32_TO_BE (0x53414d50);
   slot_header.version = 0;
-  slot_header.length = sample->content->len / 2;
+  slot_header.length = GINT32_TO_BE (sample->content->len / 2);
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
 	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, data_sample->name);
 

From 95a47438fb98a4e89648f84ec2b413fa7e9614db Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 23:06:47 +0100
Subject: [PATCH 09/20] Check CRC of downloaded samples

---
 src/connectors/elektron.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index a07d56d5..910e9f74 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2700,6 +2700,21 @@ elektron_set_sample_from_data_sample (struct idata *sample,
     {
       dest[i] = GINT16_FROM_BE (src[i]);
     }
+
+  guint crc_start = sizeof (struct elektron_data_header_preamble) +
+    sizeof (struct elektron_data_header);
+  guint32 crc = crc32 (0xffffffff,
+		       &data_sample->content->data[crc_start],
+		       sizeof (struct elektron_data_sample_slot_header));
+  crc = crc32 (crc, &data_sample->content->data[sample_data_start], size);
+  debug_print (1, "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x\n",
+	   size, crc);
+
+  if (crc != GUINT32_FROM_BE (footer->hash))
+    {
+      error_print ("CRC mismatch: calculated 0x%08x, expected 0x%08x",
+		  crc, GUINT32_FROM_BE (footer->hash));
+      return -1;
     }
 
   struct sample_info *sample_info = NULL;

From 8a0539427e5caed2a7665232d72c42cc90118619 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 23:15:07 +0100
Subject: [PATCH 10/20] Calculate CRC after BE conversion, CRC includes
 slot-header

---
 src/connectors/elektron.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 910e9f74..118dacd7 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2767,11 +2767,6 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
 	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, data_sample->name);
 
-  footer.hash =
-    GUINT32_TO_BE (crc32
-		   (0xffffffff, sample->content->data, sample->content->len));
-  footer.content_size = GUINT32_TO_BE (sample->content->len);
-  footer.magic_tail = GUINT32_TO_BE (0xaaa1daaa);
 
   g_byte_array_append (content, (guint8 *) & preamble,
 		       sizeof (struct elektron_data_header_preamble));
@@ -2787,6 +2782,13 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
     {
       dest[i] = GINT16_TO_BE (src[i]);
     }
+  guint32 crc = crc32 (0xffffffff, (guint8 *) & slot_header,
+		       sizeof (struct elektron_data_sample_slot_header));
+  crc = crc32 (crc, (guint8 *) dest, sample->content->len);
+  footer.hash = GUINT32_TO_BE (crc);
+  footer.content_size = GUINT32_TO_BE (sample->content->len +
+				       sizeof (struct elektron_data_sample_slot_header));
+  footer.magic_tail = GUINT32_TO_BE (0xaaa1daaa);
   g_byte_array_append (content, (guint8 *) & footer,
 		       sizeof (struct elektron_data_footer));
 

From 1a611c6768545461bb1e79c3016753fd4e98b5fb Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Tue, 17 Mar 2026 23:17:31 +0100
Subject: [PATCH 11/20] Use basename as sample name

---
 src/connectors/elektron.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 118dacd7..d42ce6d0 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2764,9 +2764,11 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   slot_header.magic_head = GUINT32_TO_BE (0x53414d50);
   slot_header.version = 0;
   slot_header.length = GINT32_TO_BE (sample->content->len / 2);
+  
+  gchar * basename = elektron_get_cp1252 (g_path_get_basename (sample->name));
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
-	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, data_sample->name);
-
+	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, basename);
+  g_free (basename);  
 
   g_byte_array_append (content, (guint8 *) & preamble,
 		       sizeof (struct elektron_data_header_preamble));
@@ -2792,7 +2794,7 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   g_byte_array_append (content, (guint8 *) & footer,
 		       sizeof (struct elektron_data_footer));
 
-  idata_init (data_sample, content, elektron_get_cp1252 (sample->name), NULL,
+  idata_init (data_sample, content, basename, NULL,
 	      NULL);
   return 0;
 }

From f7ea2e8814cbb0e2dbc3fc607f63007d3b33a3a2 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Wed, 18 Mar 2026 18:31:25 +0100
Subject: [PATCH 12/20] Fix progress when downloading sample

---
 src/connectors/elektron.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index d42ce6d0..efe25bc1 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2820,8 +2820,8 @@ elektron_download_data_sample (struct backend *backend, const gchar *path,
   err = elektron_set_sample_from_data_sample (sample, &data_sample);
   idata_clear (&data_sample);
 
-  task_control_set_progress (control, 1.0);
   control->part++;
+  task_control_set_progress (control, 1.0);
 
   return err;
 }

From 79d149ad42040529d930335c3953656cfca1b18b Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Wed, 18 Mar 2026 18:35:55 +0100
Subject: [PATCH 13/20] Merge elektron_data_header_preamble into
 elektron_data_header

---
 src/connectors/elektron.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index efe25bc1..71a1d453 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -111,15 +111,10 @@ struct elektron_iterator_data
   gboolean load_metadata;
 };
 
-// These belong to the header but have been removed to avoid alignment issues.
-struct __attribute__((packed)) elektron_data_header_preamble
+struct __attribute__((packed)) elektron_data_header
 {
   guint32 magic_head;		// 0xac11d303
   guint8 header_version;
-};
-
-struct __attribute__((packed)) elektron_data_header
-{
   guint16 family_id;		// 8 for Syntakt
   guint16 device_id;		// 13 for Syntakt
   guint32 os_version;		// OS release number
@@ -2665,17 +2660,14 @@ elektron_set_sample_from_data_sample (struct idata *sample,
 				      struct idata *data_sample)
 {
   guint size = data_sample->content->len -
-    sizeof (struct elektron_data_header_preamble) -
     sizeof (struct elektron_data_header) -
     sizeof (struct elektron_data_sample_slot_header) -
     sizeof (struct elektron_data_footer);
-  guint sample_data_start = sizeof (struct elektron_data_header_preamble) +
-    sizeof (struct elektron_data_header) +
+  guint sample_data_start = sizeof (struct elektron_data_header) +
     sizeof (struct elektron_data_sample_slot_header);
   struct elektron_data_sample_slot_header *slot_header =
     (struct elektron_data_sample_slot_header *) &data_sample->content->data
-    [sizeof (struct elektron_data_header_preamble) +
-     sizeof (struct elektron_data_header)];
+    [sizeof (struct elektron_data_header)];
   struct elektron_data_footer *footer =
     (struct elektron_data_footer *) &data_sample->content->data
     [data_sample->content->len - sizeof (struct elektron_data_footer)];
@@ -2701,8 +2693,7 @@ elektron_set_sample_from_data_sample (struct idata *sample,
       dest[i] = GINT16_FROM_BE (src[i]);
     }
 
-  guint crc_start = sizeof (struct elektron_data_header_preamble) +
-    sizeof (struct elektron_data_header);
+  guint crc_start = sizeof (struct elektron_data_header);
   guint32 crc = crc32 (0xffffffff,
 		       &data_sample->content->data[crc_start],
 		       sizeof (struct elektron_data_sample_slot_header));
@@ -2734,19 +2725,17 @@ gint
 elektron_set_data_sample_from_sample (struct idata *data_sample,
 				      struct idata *sample, guint slot)
 {
-  struct elektron_data_header_preamble preamble;
   struct elektron_data_header header;
   struct elektron_data_sample_slot_header slot_header;
   struct elektron_data_footer footer;
   guint size = sample->content->len +
-    sizeof (struct elektron_data_header_preamble) +
     sizeof (struct elektron_data_header) +
     sizeof (struct elektron_data_sample_slot_header) +
     sizeof (struct elektron_data_footer);
   GByteArray *content = g_byte_array_sized_new (size);
 
-  preamble.magic_head = GUINT32_TO_BE (0xac11d303);
-  preamble.header_version = 2;
+  header.magic_head = GUINT32_TO_BE (0xac11d303);
+  header.header_version = 2;
 
   // For now, this is only compatyble with Syntakt.
   header.family_id = GUINT16_TO_BE (8);

From dcfc158ccefddaea07719d4081c5440745e301f5 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Wed, 18 Mar 2026 18:36:32 +0100
Subject: [PATCH 14/20] Fix formatting

---
 src/connectors/elektron.c | 42 +++++++++++++++++++++++----------------
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 71a1d453..78e64a0c 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2673,10 +2673,12 @@ elektron_set_sample_from_data_sample (struct idata *sample,
     [data_sample->content->len - sizeof (struct elektron_data_footer)];
   gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
   gint j = 0;
-  for (gint i = 0; i < ELEKTRON_DATA_SAMPLE_MAX_LEN - 1 && slot_header->name[i] != '\0'; i++)
+  for (gint i = 0;
+       i < ELEKTRON_DATA_SAMPLE_MAX_LEN - 1 && slot_header->name[i] != '\0';
+       i++)
     {
-      if (g_ascii_isprint (slot_header->name[i]) && slot_header->name[i] != '/' &&
-	  slot_header->name[i] != '\\')
+      if (g_ascii_isprint (slot_header->name[i])
+	  && slot_header->name[i] != '/' && slot_header->name[i] != '\\')
 	{
 	  safe_name[j++] = slot_header->name[i];
 	}
@@ -2685,7 +2687,8 @@ elektron_set_sample_from_data_sample (struct idata *sample,
   GByteArray *content = g_byte_array_sized_new (size);
   g_byte_array_set_size (content, size);
 
-  const gint16 *src = (const gint16 *) &data_sample->content->data[sample_data_start];
+  const gint16 *src =
+    (const gint16 *) &data_sample->content->data[sample_data_start];
   gint16 *dest = (gint16 *) content->data;
   guint samples_count = size / 2;
   for (guint i = 0; i < samples_count; i++)
@@ -2698,13 +2701,14 @@ elektron_set_sample_from_data_sample (struct idata *sample,
 		       &data_sample->content->data[crc_start],
 		       sizeof (struct elektron_data_sample_slot_header));
   crc = crc32 (crc, &data_sample->content->data[sample_data_start], size);
-  debug_print (1, "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x\n",
-	   size, crc);
+  debug_print (1,
+	       "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x\n",
+	       size, crc);
 
   if (crc != GUINT32_FROM_BE (footer->hash))
     {
       error_print ("CRC mismatch: calculated 0x%08x, expected 0x%08x",
-		  crc, GUINT32_FROM_BE (footer->hash));
+		   crc, GUINT32_FROM_BE (footer->hash));
       return -1;
     }
 
@@ -2737,7 +2741,7 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   header.magic_head = GUINT32_TO_BE (0xac11d303);
   header.header_version = 2;
 
-  // For now, this is only compatyble with Syntakt.
+  // For now, this is only compatible with Syntakt.
   header.family_id = GUINT16_TO_BE (8);
   header.device_id = GUINT16_TO_BE (13);
   header.os_version = GUINT32_TO_BE (0x30303832);
@@ -2753,38 +2757,42 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   slot_header.magic_head = GUINT32_TO_BE (0x53414d50);
   slot_header.version = 0;
   slot_header.length = GINT32_TO_BE (sample->content->len / 2);
-  
-  gchar * basename = elektron_get_cp1252 (g_path_get_basename (sample->name));
+
+  gchar *basename = elektron_get_cp1252 (g_path_get_basename (sample->name));
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
 	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, basename);
-  g_free (basename);  
+  g_free (basename);
 
-  g_byte_array_append (content, (guint8 *) & preamble,
-		       sizeof (struct elektron_data_header_preamble));
   g_byte_array_append (content, (guint8 *) & header,
 		       sizeof (struct elektron_data_header));
   g_byte_array_append (content, (guint8 *) & slot_header,
 		       sizeof (struct elektron_data_sample_slot_header));
   g_byte_array_set_size (content, content->len + sample->content->len);
+
+  /* Convert sample data from host to big-endian byte order for CRC and storage */
   const gint16 *src = (const gint16 *) sample->content->data;
   guint samples_count = sample->content->len / 2;
-  gint16 *dest = (gint16 *) &content->data[content->len - sample->content->len];
+  gint16 *dest =
+    (gint16 *) & content->data[content->len - sample->content->len];
   for (guint i = 0; i < samples_count; i++)
     {
       dest[i] = GINT16_TO_BE (src[i]);
     }
+
+  /* CRC includes slot_header + big-endian sample data */
   guint32 crc = crc32 (0xffffffff, (guint8 *) & slot_header,
 		       sizeof (struct elektron_data_sample_slot_header));
   crc = crc32 (crc, (guint8 *) dest, sample->content->len);
   footer.hash = GUINT32_TO_BE (crc);
   footer.content_size = GUINT32_TO_BE (sample->content->len +
-				       sizeof (struct elektron_data_sample_slot_header));
+				       sizeof (struct
+					       elektron_data_sample_slot_header));
   footer.magic_tail = GUINT32_TO_BE (0xaaa1daaa);
+
   g_byte_array_append (content, (guint8 *) & footer,
 		       sizeof (struct elektron_data_footer));
 
-  idata_init (data_sample, content, basename, NULL,
-	      NULL);
+  idata_init (data_sample, content, basename, NULL, NULL);
   return 0;
 }
 

From aa1bdc1f6fde182cdbcd20cf461957e9032dc081 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Wed, 18 Mar 2026 20:46:43 +0100
Subject: [PATCH 15/20] Simplify sample name handling

---
 src/connectors/elektron.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 78e64a0c..ccc44f82 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2672,18 +2672,8 @@ elektron_set_sample_from_data_sample (struct idata *sample,
     (struct elektron_data_footer *) &data_sample->content->data
     [data_sample->content->len - sizeof (struct elektron_data_footer)];
   gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
-  gint j = 0;
-  for (gint i = 0;
-       i < ELEKTRON_DATA_SAMPLE_MAX_LEN - 1 && slot_header->name[i] != '\0';
-       i++)
-    {
-      if (g_ascii_isprint (slot_header->name[i])
-	  && slot_header->name[i] != '/' && slot_header->name[i] != '\\')
-	{
-	  safe_name[j++] = slot_header->name[i];
-	}
-    }
-  safe_name[j] = '\0';
+  snprintf (safe_name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
+	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, slot_header->name);
   GByteArray *content = g_byte_array_sized_new (size);
   g_byte_array_set_size (content, size);
 
@@ -2758,10 +2748,9 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   slot_header.version = 0;
   slot_header.length = GINT32_TO_BE (sample->content->len / 2);
 
-  gchar *basename = elektron_get_cp1252 (g_path_get_basename (sample->name));
+  gchar *name = elektron_get_cp1252 (sample->name);
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
-	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, basename);
-  g_free (basename);
+	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, name);
 
   g_byte_array_append (content, (guint8 *) & header,
 		       sizeof (struct elektron_data_header));
@@ -2792,7 +2781,7 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   g_byte_array_append (content, (guint8 *) & footer,
 		       sizeof (struct elektron_data_footer));
 
-  idata_init (data_sample, content, basename, NULL, NULL);
+  idata_init (data_sample, content, NULL, NULL, NULL);
   return 0;
 }
 

From 7b77053de946a4a3ccf8be2c69d6469e397ecc5b Mon Sep 17 00:00:00 2001
From: dagargo <dagargo@gmail.com>
Date: Thu, 19 Mar 2026 12:55:58 +0100
Subject: [PATCH 16/20] elektron: Fix memory leak

---
 src/connectors/elektron.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index ccc44f82..fb98fc50 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2751,6 +2751,7 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   gchar *name = elektron_get_cp1252 (sample->name);
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
 	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, name);
+  g_free (name);
 
   g_byte_array_append (content, (guint8 *) & header,
 		       sizeof (struct elektron_data_header));

From b1c5af319d2179fe162f022bd1a72567734b63f1 Mon Sep 17 00:00:00 2001
From: dagargo <dagargo@gmail.com>
Date: Thu, 19 Mar 2026 13:28:04 +0100
Subject: [PATCH 17/20] elektron: Rename variable

---
 src/connectors/elektron.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index fb98fc50..f01e64ae 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2987,7 +2987,7 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
   GByteArray *rx_msg;
   GByteArray *tx_msg;
   gchar *path_w_prefix;
-  GByteArray *array = data->content;
+  GByteArray *content = data->content;
 
   err = common_slot_get_id_from_path (path, &id);
   if (err)
@@ -2997,7 +2997,7 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
 
   path_w_prefix = elektron_add_prefix_to_path (path, prefix);
   err = elektron_open_datum (backend, path_w_prefix, &jid, O_WRONLY,
-			     array->len);
+			     content->len);
   g_free (path_w_prefix);
   if (err)
     {
@@ -3013,7 +3013,7 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
 
   active = controllable_is_active (&control->controllable);
 
-  while (offset < array->len && active)
+  while (offset < content->len && active)
     {
       tx_msg = elektron_new_msg (DATA_WRITE_PARTIAL_REQUEST,
 				 sizeof (DATA_WRITE_PARTIAL_REQUEST));
@@ -3021,23 +3021,23 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
       aux32 = g_htonl (seq);
       g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 
-      if (offset + DATA_TRANSF_BLOCK_BYTES < array->len)
+      if (offset + DATA_TRANSF_BLOCK_BYTES < content->len)
 	{
 	  len = DATA_TRANSF_BLOCK_BYTES;
 	}
       else
 	{
-	  len = array->len - offset;
+	  len = content->len - offset;
 	}
 
-      crc = crc32 (0xffffffff, &array->data[offset], len);
+      crc = crc32 (0xffffffff, &content->data[offset], len);
       aux32 = g_htonl (crc);
       g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 
       aux32 = g_htonl (len);
       g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 
-      g_byte_array_append (tx_msg, &array->data[offset], len);
+      g_byte_array_append (tx_msg, &content->data[offset], len);
 
       rx_msg = elektron_tx_and_rx (backend, tx_msg, &control->controllable);
       if (!rx_msg)
@@ -3082,14 +3082,14 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
 	     total, offset);
 	}
 
-      task_control_set_progress (control, offset / (gdouble) array->len);
+      task_control_set_progress (control, offset / (gdouble) content->len);
 
       active = controllable_is_active (&control->controllable);
     }
 
   debug_print (2, "%d bytes sent", offset);
 
-  err = elektron_close_datum (backend, jid, O_WRONLY, array->len);
+  err = elektron_close_datum (backend, jid, O_WRONLY, content->len);
 
 end:
   return err;

From b83c80ff4da4899c52539ab66f28a4c923d300e0 Mon Sep 17 00:00:00 2001
From: dagargo <dagargo@gmail.com>
Date: Thu, 19 Mar 2026 21:07:01 +0100
Subject: [PATCH 18/20] elektron: Refactor code to allow multiple partial
 writing requests

---
 src/connectors/elektron.c | 299 ++++++++++++++++++++++----------------
 test/tests_elektron.c     |  10 +-
 2 files changed, 182 insertions(+), 127 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index f01e64ae..49b768f3 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2655,6 +2655,8 @@ elektron_download_data_pst (struct backend *backend, const gchar *path,
 					FS_DATA_PST_PREFIX);
 }
 
+// In this case, data_sample contains the footer too.
+
 gint
 elektron_set_sample_from_data_sample (struct idata *sample,
 				      struct idata *data_sample)
@@ -2671,29 +2673,15 @@ elektron_set_sample_from_data_sample (struct idata *sample,
   struct elektron_data_footer *footer =
     (struct elektron_data_footer *) &data_sample->content->data
     [data_sample->content->len - sizeof (struct elektron_data_footer)];
-  gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
-  snprintf (safe_name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
-	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, slot_header->name);
-  GByteArray *content = g_byte_array_sized_new (size);
-  g_byte_array_set_size (content, size);
-
-  const gint16 *src =
-    (const gint16 *) &data_sample->content->data[sample_data_start];
-  gint16 *dest = (gint16 *) content->data;
-  guint samples_count = size / 2;
-  for (guint i = 0; i < samples_count; i++)
-    {
-      dest[i] = GINT16_FROM_BE (src[i]);
-    }
 
   guint crc_start = sizeof (struct elektron_data_header);
+  guint crc_size = sizeof (struct elektron_data_sample_slot_header) + size;
   guint32 crc = crc32 (0xffffffff,
 		       &data_sample->content->data[crc_start],
-		       sizeof (struct elektron_data_sample_slot_header));
-  crc = crc32 (crc, &data_sample->content->data[sample_data_start], size);
+		       crc_size);
   debug_print (1,
-	       "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x\n",
-	       size, crc);
+	       "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x",
+	       crc_size, crc);
 
   if (crc != GUINT32_FROM_BE (footer->hash))
     {
@@ -2702,9 +2690,24 @@ elektron_set_sample_from_data_sample (struct idata *sample,
       return -1;
     }
 
-  struct sample_info *sample_info = NULL;
+  gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
+  snprintf (safe_name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
+	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, slot_header->name);
+  GByteArray *content = g_byte_array_sized_new (size);
+  content->len = size;
+
+  const gint16 *src =
+    (const gint16 *) &data_sample->content->data[sample_data_start];
+  gint16 *dest = (gint16 *) content->data;
+  guint frames = size / 2;
+  for (guint i = 0; i < frames; i++)
+    {
+      dest[i] = GINT16_FROM_BE (src[i]);
+    }
+
+  struct sample_info *sample_info;
   sample_info = sample_info_new (FALSE);
-  sample_info->frames = size / 2;
+  sample_info->frames = frames;
   sample_info->rate = 48000;
   sample_info->channels = 1;
   sample_info->format = SF_FORMAT_PCM_16;
@@ -2715,18 +2718,26 @@ elektron_set_sample_from_data_sample (struct idata *sample,
   return 0;
 }
 
+// Due to a firmware limitation when working with uncompressed data,
+// footer must be transferred in a different partial request.
+
 gint
 elektron_set_data_sample_from_sample (struct idata *data_sample,
+				      struct idata *data_footer,
 				      struct idata *sample, guint slot)
 {
+  guint size;
   struct elektron_data_header header;
   struct elektron_data_sample_slot_header slot_header;
   struct elektron_data_footer footer;
-  guint size = sample->content->len +
-    sizeof (struct elektron_data_header) +
-    sizeof (struct elektron_data_sample_slot_header) +
-    sizeof (struct elektron_data_footer);
-  GByteArray *content = g_byte_array_sized_new (size);
+  GByteArray *sample_content, *footer_content;
+
+  size = sizeof (struct elektron_data_header) +
+    sizeof (struct elektron_data_sample_slot_header) + sample->content->len;
+  sample_content = g_byte_array_sized_new (size);
+
+  size = sizeof (struct elektron_data_footer);
+  footer_content = g_byte_array_sized_new (size);
 
   header.magic_head = GUINT32_TO_BE (0xac11d303);
   header.header_version = 2;
@@ -2739,50 +2750,55 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   header.file_version = 0xffffffff;
   header.file_index = GINT32_TO_BE (slot);
   header.payload_size =
-    GUINT32_TO_BE (sample->content->len +
-		   sizeof (struct elektron_data_sample_slot_header));
+    GUINT32_TO_BE (sizeof (struct elektron_data_sample_slot_header)
+		   + sample->content->len);
   header.is_compressed = 0;
   header.footer_size = sizeof (struct elektron_data_footer);
 
+  guint frames = sample->content->len / 2;
   slot_header.magic_head = GUINT32_TO_BE (0x53414d50);
   slot_header.version = 0;
-  slot_header.length = GINT32_TO_BE (sample->content->len / 2);
+  slot_header.length = GINT32_TO_BE (frames);
 
   gchar *name = elektron_get_cp1252 (sample->name);
   snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
 	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, name);
   g_free (name);
 
-  g_byte_array_append (content, (guint8 *) & header,
+  g_byte_array_append (sample_content, (guint8 *) & header,
 		       sizeof (struct elektron_data_header));
-  g_byte_array_append (content, (guint8 *) & slot_header,
+  g_byte_array_append (sample_content, (guint8 *) & slot_header,
 		       sizeof (struct elektron_data_sample_slot_header));
-  g_byte_array_set_size (content, content->len + sample->content->len);
 
   /* Convert sample data from host to big-endian byte order for CRC and storage */
   const gint16 *src = (const gint16 *) sample->content->data;
-  guint samples_count = sample->content->len / 2;
-  gint16 *dest =
-    (gint16 *) & content->data[content->len - sample->content->len];
-  for (guint i = 0; i < samples_count; i++)
+  gint16 *dest = (gint16 *) & sample_content->data[sample_content->len];
+  for (guint i = 0; i < frames; i++)
     {
       dest[i] = GINT16_TO_BE (src[i]);
     }
+  sample_content->len += sample->content->len;
 
   /* CRC includes slot_header + big-endian sample data */
-  guint32 crc = crc32 (0xffffffff, (guint8 *) & slot_header,
-		       sizeof (struct elektron_data_sample_slot_header));
-  crc = crc32 (crc, (guint8 *) dest, sample->content->len);
+  guint crc_start = sizeof (struct elektron_data_header);
+  guint crc_size = sizeof (struct elektron_data_sample_slot_header) +
+    sample->content->len;
+  guint32 crc = crc32 (0xffffffff, (guint8 *) & sample_content->data[crc_start],
+		       crc_size);
+  debug_print (1,
+	       "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x",
+	       crc_size, crc);
+
   footer.hash = GUINT32_TO_BE (crc);
-  footer.content_size = GUINT32_TO_BE (sample->content->len +
-				       sizeof (struct
-					       elektron_data_sample_slot_header));
+  footer.content_size = GUINT32_TO_BE (size);
   footer.magic_tail = GUINT32_TO_BE (0xaaa1daaa);
 
-  g_byte_array_append (content, (guint8 *) & footer,
+  g_byte_array_append (footer_content, (guint8 *) & footer,
 		       sizeof (struct elektron_data_footer));
 
-  idata_init (data_sample, content, NULL, NULL, NULL);
+  idata_init (data_sample, sample_content, NULL, NULL, NULL);
+  idata_init (data_footer, footer_content, NULL, NULL, NULL);
+
   return 0;
 }
 
@@ -2965,29 +2981,19 @@ elektron_get_download_path (struct backend *backend,
 }
 
 static gint
-elektron_upload_data_prefix (struct backend *backend, const gchar *path,
-			     struct idata *data,
-			     struct task_control *control,
-			     const gchar *prefix)
+elektron_upload_data_list_prefix (struct backend *backend, const gchar *path,
+				  GSList *list, struct task_control *control,
+				  const gchar *prefix)
 {
   gint err;
   guint id;
-  guint32 seq;
-  guint32 jid;
-  guint32 crc;
-  guint32 len;
-  guint32 r_jid;
-  guint32 r_seq;
-  guint32 offset;
-  guint32 *data32;
-  guint32 jidbe;
-  guint32 aux32;
+  GSList *iter;
   gboolean active;
-  guint32 total;
-  GByteArray *rx_msg;
-  GByteArray *tx_msg;
+  struct idata *data;
   gchar *path_w_prefix;
-  GByteArray *content = data->content;
+  GByteArray *rx_msg, *tx_msg, *content;
+  guint32 seq, jid, jidbe, crc, len, r_jid, r_seq, offset, *data32,
+    aux32, total, full_content_size, full_content_sent;
 
   err = common_slot_get_id_from_path (path, &id);
   if (err)
@@ -2995,9 +3001,17 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
       return err;
     }
 
+  full_content_size = 0;
+  for (iter = list; iter != NULL; iter = iter->next)
+    {
+      data = iter->data;
+      content = data->content;
+      full_content_size += content->len;
+    }
+
   path_w_prefix = elektron_add_prefix_to_path (path, prefix);
   err = elektron_open_datum (backend, path_w_prefix, &jid, O_WRONLY,
-			     content->len);
+			     full_content_size);
   g_free (path_w_prefix);
   if (err)
     {
@@ -3009,92 +3023,123 @@ elektron_upload_data_prefix (struct backend *backend, const gchar *path,
   jidbe = g_htonl (jid);
 
   seq = 0;
-  offset = 0;
+  full_content_sent = 0;
+  for (iter = list; iter != NULL; iter = iter->next)
+    {
+      data = iter->data;
+      content = data->content;
 
-  active = controllable_is_active (&control->controllable);
+      offset = 0;
 
-  while (offset < content->len && active)
-    {
-      tx_msg = elektron_new_msg (DATA_WRITE_PARTIAL_REQUEST,
-				 sizeof (DATA_WRITE_PARTIAL_REQUEST));
-      g_byte_array_append (tx_msg, (guint8 *) & jidbe, sizeof (guint32));
-      aux32 = g_htonl (seq);
-      g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
+      active = controllable_is_active (&control->controllable);
 
-      if (offset + DATA_TRANSF_BLOCK_BYTES < content->len)
+      while (offset < content->len && active)
 	{
-	  len = DATA_TRANSF_BLOCK_BYTES;
-	}
-      else
-	{
-	  len = content->len - offset;
-	}
+	  tx_msg = elektron_new_msg (DATA_WRITE_PARTIAL_REQUEST,
+				     sizeof (DATA_WRITE_PARTIAL_REQUEST));
+	  g_byte_array_append (tx_msg, (guint8 *) & jidbe, sizeof (guint32));
+	  aux32 = g_htonl (seq);
+	  g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 
-      crc = crc32 (0xffffffff, &content->data[offset], len);
-      aux32 = g_htonl (crc);
-      g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
+	  if (offset + DATA_TRANSF_BLOCK_BYTES < content->len)
+	    {
+	      len = DATA_TRANSF_BLOCK_BYTES;
+	    }
+	  else
+	    {
+	      len = content->len - offset;
+	    }
 
-      aux32 = g_htonl (len);
-      g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
+	  crc = crc32 (0xffffffff, &content->data[offset], len);
+	  aux32 = g_htonl (crc);
+	  g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 
-      g_byte_array_append (tx_msg, &content->data[offset], len);
+	  aux32 = g_htonl (len);
+	  g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 
-      rx_msg = elektron_tx_and_rx (backend, tx_msg, &control->controllable);
-      if (!rx_msg)
-	{
-	  err = -EIO;
-	  goto end;
-	}
+	  g_byte_array_append (tx_msg, &content->data[offset], len);
 
-      usleep (BE_REST_TIME_US);
+	  rx_msg = elektron_tx_and_rx (backend, tx_msg,
+				       &control->controllable);
+	  if (!rx_msg)
+	    {
+	      err = -EIO;
+	      goto end;
+	    }
 
-      if (!elektron_get_msg_status (rx_msg))
-	{
-	  err = -EPERM;
-	  error_print ("%s (%s)", backend_strerror (backend, err),
-		       elektron_get_msg_string (rx_msg));
-	  free_msg (rx_msg);
-	  break;
-	}
+	  usleep (BE_REST_TIME_US);
 
-      data32 = (guint32 *) & rx_msg->data[6];
-      r_jid = g_ntohl (*data32);
+	  if (!elektron_get_msg_status (rx_msg))
+	    {
+	      err = -EPERM;
+	      error_print ("%s (%s)", backend_strerror (backend, err),
+			   elektron_get_msg_string (rx_msg));
+	      free_msg (rx_msg);
+	      break;
+	    }
 
-      data32 = (guint32 *) & rx_msg->data[10];
-      r_seq = g_ntohl (*data32);
+	  data32 = (guint32 *) & rx_msg->data[6];
+	  r_jid = g_ntohl (*data32);
 
-      data32 = (guint32 *) & rx_msg->data[14];
-      total = g_ntohl (*data32);
+	  data32 = (guint32 *) & rx_msg->data[10];
+	  r_seq = g_ntohl (*data32);
 
-      free_msg (rx_msg);
+	  data32 = (guint32 *) & rx_msg->data[14];
+	  total = g_ntohl (*data32);
 
-      debug_print (1,
-		   "Write datum info: job id: %d; seq: %d; total: %d",
-		   r_jid, r_seq, total);
+	  free_msg (rx_msg);
 
-      seq++;
-      offset += len;
+	  debug_print (1,
+		       "Write datum info: job id: %d; seq: %d; total: %d",
+		       r_jid, r_seq, total);
 
-      if (total != offset)
-	{
-	  error_print
-	    ("Actual upload bytes (%d) differs from expected ones (%d)",
-	     total, offset);
+	  seq++;
+	  offset += len;
+
+	  if (total != offset)
+	    {
+	      error_print
+		("Actual upload bytes (%d) differs from expected ones (%d)",
+		 total, offset);
+	    }
+
+	  gdouble progress = (full_content_sent + offset) /
+	    (gdouble) full_content_size;
+	  task_control_set_progress (control, progress);
+
+	  active = controllable_is_active (&control->controllable);
 	}
 
-      task_control_set_progress (control, offset / (gdouble) content->len);
+      debug_print (2, "Partial request with %d bytes sent", offset);
 
-      active = controllable_is_active (&control->controllable);
+      full_content_sent += content->len;
     }
 
-  debug_print (2, "%d bytes sent", offset);
+  debug_print (2, "%d bytes sent", full_content_sent);
 
-  err = elektron_close_datum (backend, jid, O_WRONLY, content->len);
+  err = elektron_close_datum (backend, jid, O_WRONLY, full_content_size);
 
 end:
   return err;
 }
 
+static gint
+elektron_upload_data_prefix (struct backend *backend, const gchar *path,
+			     struct idata *data,
+			     struct task_control *control,
+			     const gchar *prefix)
+{
+  gint err;
+  GSList *list;
+
+  list = g_slist_append (NULL, data);
+  err = elektron_upload_data_list_prefix (backend, path, list, control,
+					  prefix);
+  g_slist_free (list);
+
+  return err;
+}
+
 static gint
 elektron_upload_data_any (struct backend *backend, const gchar *path,
 			  struct idata *any, struct task_control *control)
@@ -3135,7 +3180,8 @@ elektron_upload_data_sample (struct backend *backend, const gchar *path,
 {
   gint err;
   guint id;
-  struct idata data_sample;
+  GSList *list;
+  struct idata data_sample, data_footer;
 
   err = common_slot_get_id_from_path (path, &id);
   if (err)
@@ -3146,7 +3192,8 @@ elektron_upload_data_sample (struct backend *backend, const gchar *path,
   control->parts = 2;
   control->part = 0;
 
-  err = elektron_set_data_sample_from_sample (&data_sample, sample, id);
+  err = elektron_set_data_sample_from_sample (&data_sample, &data_footer,
+					      sample, id);
   if (err)
     {
       return err;
@@ -3155,9 +3202,13 @@ elektron_upload_data_sample (struct backend *backend, const gchar *path,
   task_control_set_progress (control, 1.0);
   control->part++;
 
-  err = elektron_upload_data_prefix (backend, path, &data_sample, control,
-				     FS_DATA_SAMPLES_PREFIX);
+  list = g_slist_append (NULL, &data_sample);
+  list = g_slist_append (list, &data_footer);
+  err = elektron_upload_data_list_prefix (backend, path, list, control,
+					  FS_DATA_SAMPLES_PREFIX);
+  g_slist_free (list);
   idata_clear (&data_sample);
+  idata_clear (&data_footer);
 
   return err;
 }
diff --git a/test/tests_elektron.c b/test/tests_elektron.c
index 1a7b1126..7fe99ba5 100644
--- a/test/tests_elektron.c
+++ b/test/tests_elektron.c
@@ -22,6 +22,7 @@ void elektron_destroy_data (struct backend *backend);
 gint elektron_set_sample_from_data_sample (struct idata *sample,
 					   struct idata *data_sample);
 gint elektron_set_data_sample_from_sample (struct idata *data_sample,
+					   struct idata *data_footer,
 					   struct idata *sample, guint slot);
 
 static void
@@ -195,7 +196,7 @@ static void
 test_elektron_data_sample ()
 {
   gint err;
-  struct idata sample, data_sample;
+  struct idata sample, data_sample, data_footer;
   struct task_control task_control;
   struct sample_info sample_info_src;
   struct sample_load_opts sample_load_opts;
@@ -220,7 +221,8 @@ test_elektron_data_sample ()
       return;
     }
 
-  err = elektron_set_data_sample_from_sample (&data_sample, &sample, 3);
+  err = elektron_set_data_sample_from_sample (&data_sample, &data_footer,
+					      &sample, 3);
   CU_ASSERT_EQUAL (err, 0);
   if (err)
     {
@@ -230,6 +232,8 @@ test_elektron_data_sample ()
 
   content_before = idata_steal (&sample);
 
+  g_byte_array_append (data_sample.content, data_footer.content->data,
+		       data_footer.content->len);
   err = elektron_set_sample_from_data_sample (&sample, &data_sample);
   CU_ASSERT_EQUAL (err, 0);
   if (err)
@@ -237,8 +241,8 @@ test_elektron_data_sample ()
       idata_clear (&data_sample);
       return;
     }
-
   idata_clear (&data_sample);
+  idata_clear (&data_footer);
 
   content_after = idata_steal (&sample);
 

From dc4277e4f7bf7d4c745b269845d6c3d7b7f41f62 Mon Sep 17 00:00:00 2001
From: dagargo <dagargo@gmail.com>
Date: Thu, 19 Mar 2026 21:18:19 +0100
Subject: [PATCH 19/20] elektron: Extract CRC function

---
 src/connectors/elektron.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 49b768f3..9bb1e58e 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -1696,6 +1696,12 @@ elektron_new_msg_upgrade_os_start (guint size)
   return msg;
 }
 
+static guint32
+elektron_crc (guint8 *data, guint32 len)
+{
+  return crc32 (0xffffffff, data, len);
+}
+
 static GByteArray *
 elektron_new_msg_upgrade_os_write (GByteArray *os_data, gint *offset)
 {
@@ -1714,7 +1720,7 @@ elektron_new_msg_upgrade_os_write (GByteArray *os_data, gint *offset)
       len = os_data->len - *offset;
     }
 
-  crc = crc32 (0xffffffff, &os_data->data[*offset], len);
+  crc = elektron_crc (&os_data->data[*offset], len);
 
   debug_print (2, "CRC: %0x", crc);
 
@@ -2676,9 +2682,8 @@ elektron_set_sample_from_data_sample (struct idata *sample,
 
   guint crc_start = sizeof (struct elektron_data_header);
   guint crc_size = sizeof (struct elektron_data_sample_slot_header) + size;
-  guint32 crc = crc32 (0xffffffff,
-		       &data_sample->content->data[crc_start],
-		       crc_size);
+  guint32 crc = elektron_crc (&data_sample->content->data[crc_start],
+			      crc_size);
   debug_print (1,
 	       "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x",
 	       crc_size, crc);
@@ -2783,8 +2788,8 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   guint crc_start = sizeof (struct elektron_data_header);
   guint crc_size = sizeof (struct elektron_data_sample_slot_header) +
     sample->content->len;
-  guint32 crc = crc32 (0xffffffff, (guint8 *) & sample_content->data[crc_start],
-		       crc_size);
+  guint32 crc = elektron_crc ((guint8 *) & sample_content->data[crc_start],
+			      crc_size);
   debug_print (1,
 	       "Sample data size: %u bytes, CRC (slot_header+data): 0x%08x",
 	       crc_size, crc);
@@ -3050,7 +3055,7 @@ elektron_upload_data_list_prefix (struct backend *backend, const gchar *path,
 	      len = content->len - offset;
 	    }
 
-	  crc = crc32 (0xffffffff, &content->data[offset], len);
+	  crc = elektron_crc (&content->data[offset], len);
 	  aux32 = g_htonl (crc);
 	  g_byte_array_append (tx_msg, (guint8 *) & aux32, sizeof (guint32));
 

From e2a95598480bcedc02b7f537fd5a6a87886cf204 Mon Sep 17 00:00:00 2001
From: Gautier <gautier@soundconverter.org>
Date: Sat, 21 Mar 2026 11:26:12 +0100
Subject: [PATCH 20/20] elektron: slot_header.name is not zero-terminated

---
 src/connectors/elektron.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/connectors/elektron.c b/src/connectors/elektron.c
index 9bb1e58e..4843ef32 100644
--- a/src/connectors/elektron.c
+++ b/src/connectors/elektron.c
@@ -2695,9 +2695,9 @@ elektron_set_sample_from_data_sample (struct idata *sample,
       return -1;
     }
 
-  gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN];
+  gchar safe_name[ELEKTRON_DATA_SAMPLE_MAX_LEN + 1];
   snprintf (safe_name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
-	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, slot_header->name);
+	    ELEKTRON_DATA_SAMPLE_MAX_LEN, slot_header->name);
   GByteArray *content = g_byte_array_sized_new (size);
   content->len = size;
 
@@ -2766,8 +2766,8 @@ elektron_set_data_sample_from_sample (struct idata *data_sample,
   slot_header.length = GINT32_TO_BE (frames);
 
   gchar *name = elektron_get_cp1252 (sample->name);
-  snprintf (slot_header.name, ELEKTRON_DATA_SAMPLE_MAX_LEN, "%.*s",
-	    ELEKTRON_DATA_SAMPLE_MAX_LEN - 1, name);
+  memcpy (slot_header.name, name,
+	  MIN (strlen (name), ELEKTRON_DATA_SAMPLE_MAX_LEN));
   g_free (name);
 
   g_byte_array_append (sample_content, (guint8 *) & header,