From 6f203df2d2911b7e91d40beefe303d0dc7840c8c Mon Sep 17 00:00:00 2001
From: Lars Immisch <lars@ibp.de>
Date: Mon, 4 Sep 2023 19:51:53 +0200
Subject: [PATCH] Implement aufile_set_position

---
 include/rem_aufile.h |  1 +
 rem/aufile/aufile.c  | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/rem_aufile.h b/include/rem_aufile.h
index 98a3628fd..88114b173 100644
--- a/include/rem_aufile.h
+++ b/include/rem_aufile.h
@@ -26,3 +26,4 @@ int aufile_read(struct aufile *af, uint8_t *p, size_t *sz);
 int aufile_write(struct aufile *af, const uint8_t *p, size_t sz);
 size_t aufile_get_size(struct aufile *af);
 size_t aufile_get_length(struct aufile *af, struct aufile_prm *prm);
+size_t aufile_set_position(struct aufile *af, struct aufile_prm *prm, size_t pos_ms);
diff --git a/rem/aufile/aufile.c b/rem/aufile/aufile.c
index 8c9587b44..42bc7f304 100644
--- a/rem/aufile/aufile.c
+++ b/rem/aufile/aufile.c
@@ -278,3 +278,18 @@ size_t aufile_get_length(struct aufile *af, struct aufile_prm *prm)
 
 	return 0;
 }
+
+/**
+ * Set initial playing position of a WAV file in ms
+ *
+ * @param af  Audio-file
+ * @param prm Audio file parameters from aufile_open
+ *
+ * @return position in bytes or (size_t)-1 in case of an error.
+ */
+size_t aufile_set_position(struct aufile *af, struct aufile_prm *prm, size_t pos_ms)
+{
+	size_t pos = prm->srate * aufmt_sample_size(prm->fmt) * prm->channels * pos_ms / 1000;
+
+	return fseek(af->f, pos, SEEK_SET);
+}