From 09ec5f18a0583c94286f1f1f1b462f675d93d94d Mon Sep 17 00:00:00 2001
From: San Jacobs
Date: Wed, 12 Nov 2025 05:21:32 +0100
Subject: Starting to read wav metadata directly

---
 src/wav/wav.odin | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100644 src/wav/wav.odin

(limited to 'src/wav/wav.odin')

diff --git a/src/wav/wav.odin b/src/wav/wav.odin
new file mode 100644
index 0000000..04cb0cf
--- /dev/null
+++ b/src/wav/wav.odin
@@ -0,0 +1,140 @@
+package wav
+
+import "core:fmt"
+import "core:math"
+import "core:strings"
+import "core:os"
+
+Wav :: struct {
+	path : string,
+	handle : os.Handle,
+	buf : []u8,
+	reported_size : u32,
+	bext : string,
+	ixml : string,
+	format : Audio_Format,
+	channels : int,
+	channel_names : []string,
+	sample_rate : int,
+	bit_depth :  int,
+}
+Audio_Format :: enum {
+	PCM = 1,
+	FLOAT = 3,
+}
+
+BUFFER_SIZE :: 1<<15
+
+main :: proc() {
+	sweden, sweden_ok := read_wav("test/sweden.wav", context.temp_allocator)
+	fmt.printf("\n\nsweden = %#v\n\n", sweden)
+	enok, enok_ok := read_wav("test/ENOKS-BIRHTDAYT02.WAV", context.temp_allocator)
+	fmt.printf("\n\nenok = %#v\n\n", enok)
+}
+
+
+read_wav :: proc(path : string, allocator:=context.allocator) -> (Wav, bool) {
+	file : Wav
+	
+	file_ok : os.Error
+	file.handle, file_ok = os.open(path)
+	defer os.close(file.handle)
+	assert(file_ok == os.General_Error.None)
+	
+	file.buf = new([BUFFER_SIZE]u8)[:]
+	defer delete(file.buf)
+	
+	os.read(file.handle, file.buf)
+	
+	
+	head : int = 0
+	
+	// RIFF header
+	fmt.println(string(file.buf[0:4]))
+	if string(file.buf[0:4]) != "RIFF" do return {}, false
+	head += 4
+	
+	// Size
+	file.reported_size = read_little_endian_u32(file.buf[head:head+4])
+	fmt.println("Reported size:", file.reported_size)
+	head += 4
+
+	// Confirming again that this is a wave file	
+	fmt.println(string(file.buf[head:head+4]))
+	if string(file.buf[head:head+4]) != "WAVE" do return {}, false
+	head += 4
+	
+	fmt.println("\nChunks:\n")
+	
+	// Looping through chunks
+	for _ in 0..<BUFFER_SIZE {
+		chunk_id := string(file.buf[head:head+4])
+		head += 4
+		chunk_size := int(read_little_endian_u32(file.buf[head:head+4]))
+		head += 4
+		fmt.println(chunk_id,"\n-------------------------------------")
+		
+		if head+chunk_size < BUFFER_SIZE {
+			print_data : string
+			data_end := head+chunk_size
+			read_end := min(head+15000, data_end)
+			switch chunk_id {
+				case "iXML":
+					print_data = string(file.buf[head:read_end])
+					file.ixml = strings.clone(string(file.buf[head:data_end]), allocator=allocator)
+				case "bext":
+					print_data = string(file.buf[head:read_end])
+					file.bext = strings.clone(string(file.buf[head:data_end]), allocator=allocator)
+				case "fmt ":
+					file.format = Audio_Format(read_little_endian_u16(file.buf[head:]))
+					head += 2
+					file.channels = int(read_little_endian_u16(file.buf[head:]))
+					head += 2
+					file.sample_rate = int(read_little_endian_u32(file.buf[head:]))
+					head += 4
+					
+					// Skipping byte rate and block align.
+					// These two legacy fields are only ever redundant or wrong,
+					// and are implied by the other fields.
+					head += 4 + 2
+					
+					file.bit_depth = int(read_little_endian_u16(file.buf[head:]))
+					head += 2
+			}
+			fmt.println(print_data, "\n")
+		} else {
+			break
+		}
+		
+		
+		head += chunk_size
+	}
+	
+	file.channel_names = make([]string, file.channels)
+	
+	naming_channel := 0
+	for line in strings.split_lines(file.bext) {
+		if strings.starts_with(line, "sTRK") {
+			eq_index := strings.index(line, "=")
+			file.channel_names[naming_channel] = strings.clone(line[eq_index+1:], allocator=allocator)
+			naming_channel += 1
+		}
+	}
+	
+	delete(file.buf)
+	file.buf = nil
+	return file, true
+}
+
+
+read_little_endian_u32 :: proc(x : []u8) -> u32 {
+	return u32(x[0])       |
+	       u32(x[1]) <<  8 |
+	       u32(x[2]) << 16 |
+	       u32(x[3]) << 24
+}
+
+read_little_endian_u16 :: proc(x : []u8) -> u16 {
+	return u16(x[0])       |
+	       u16(x[1]) <<  8
+}
\ No newline at end of file
-- 
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