From 5f2e84d8cf2d210d83fe76bcb89de908207421b6 Mon Sep 17 00:00:00 2001
From: mid <>
Date: Sat, 12 Jul 2025 23:27:33 +0300
Subject: [PATCH] Support LOOPPOINT metadata field for ogg files

---
 src/k3mix.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/k3mix.c b/src/k3mix.c
index a62f0b2..2c260bc 100644
--- a/src/k3mix.c
+++ b/src/k3mix.c
@@ -1,11 +1,13 @@
 #include"k3mix.h"
 
+#define _GNU_SOURCE
 #include<vorbis/vorbisfile.h>
 #include<string.h>
 #include<stdlib.h>
 #include<math.h>
 #include<pthread.h>
 #include<assert.h>
+#include"k3.h"
 
 static uint32_t FinalSampleRate;
 static uint8_t FinalChannels;
@@ -19,12 +21,22 @@ struct k3MixSource {
 	char *filepath;
 	OggVorbis_File vf;
 	int bitstream;
+	size_t looppoint;
 };
 struct k3MixSource *k3MixSourceFile(const char *path) {
 	struct k3MixSource *ret = calloc(1, sizeof(*ret));
 	ret->filepath = strdup(path);
 	ov_fopen(path, &ret->vf);
 	ret->bitstream = 0;
+	
+	ret->looppoint = 0;
+	for(size_t ci = 0; ci < ret->vf.vc->comments; ci++) {
+		if(strcasestr(ret->vf.vc->user_comments[ci], "looppoint=") == ret->vf.vc->user_comments[ci]) {
+			ret->looppoint = strtol(ret->vf.vc->user_comments[ci] + 10, NULL, 0);
+			k3Log(k3_DEBUG, "%s has loop point %lu", path, ret->looppoint);
+		}
+	}
+	
 	return ret;
 }
 void k3MixSourceClose(struct k3MixSource *src) {
@@ -42,7 +54,7 @@ __attribute__((optimize("Ofast"))) static intmax_t ogg_read(struct k3MixWave *th
 		long lastRead = ov_read_float(&od->vf, &ni, sampleCount, &od->bitstream);
 		
 		if(this->loop && lastRead == 0) {
-			ov_pcm_seek(&od->vf, 0);
+			ov_pcm_seek(&od->vf, od->looppoint);
 			continue;
 		} else if(lastRead <= 0) {
 			this->end = true;