X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=opus_afh.c;fp=opus_afh.c;h=53419243657e4d0e219d362693de0c55c52a2d5d;hp=bdc4a96dce306638d64ce6838dc4e5139ac89934;hb=7b59c6078d59073e50be72f6eaee2100a26a2337;hpb=c8466194a4842e319abdedfb38ddc93630e25471

diff --git a/opus_afh.c b/opus_afh.c
index bdc4a96d..53419243 100644
--- a/opus_afh.c
+++ b/opus_afh.c
@@ -84,6 +84,14 @@ static int opus_get_comments(char *comments, int length,
 	return 1;
 }
 
+/*
+ * Ogg/Opus has two mandatory header packets:
+ *
+ * 1. ID header (identifies the stream as Opus). Dedicated "BOS" ogg page.
+ * 2. Comment header (metadata). May span multiple pages.
+ *
+ * See doc/draft-ietf-codec-oggopus.xml in the opus source tree for details.
+ */
 static int opus_packet_callback(ogg_packet *packet, int packet_num,
 		__a_unused int serial, struct afh_info *afhi,
 		void *private_data)
@@ -227,6 +235,65 @@ static int opus_rewrite_tags(const char *map, size_t mapsize,
 	return ret;
 }
 
+/*
+ * See doc/draft-ietf-codec-oggopus.xml in the opus source tree for details
+ * about the format of the comment header.
+ */
+static int opus_get_header_callback(ogg_packet *packet, int packet_num,
+		int serial, __a_unused struct afh_info *afhi, void *private_data)
+{
+	struct oac_custom_header *h = private_data;
+	int ret;
+	static unsigned char dummy_tags[] = { /* a minimal comment header */
+		'O', 'p', 'u', 's', 'T', 'a', 'g', 's',
+		0x06, 0x00, 0x00, 0x00, /* vendor string length */
+		'd', 'u', 'm', 'm', 'y', '\0', /* vendor string */
+		0x00, 0x00, 0x00, 0x00, /* user comment list length */
+	};
+	ogg_packet replacement;
+
+	if (packet_num == 0) {
+		oac_custom_header_init(serial, h);
+		ret = oac_custom_header_append(packet, h);
+		if (ret < 0)
+			return ret;
+		oac_custom_header_flush(h);
+		return 1;
+	}
+	assert(packet_num == 1);
+	PARA_INFO_LOG("replacing metadata packet\n");
+	replacement = *packet;
+	replacement.packet = dummy_tags;
+	replacement.bytes = sizeof(dummy_tags);
+	ret = oac_custom_header_append(&replacement, h);
+	if (ret < 0)
+		return ret;
+	oac_custom_header_flush(h);
+	return 0;
+}
+
+static void opus_get_header(void *map, size_t mapsize, char **buf,
+		size_t *len)
+{
+	int ret;
+	struct oac_custom_header *h = oac_custom_header_new();
+	struct oac_callback_info cb = {
+		.packet_callback = opus_get_header_callback,
+		.private_data = h,
+	};
+
+	ret = oac_get_file_info(map, mapsize, NULL, &cb);
+	*len = oac_custom_header_get(buf, h);
+	if (ret < 0) {
+		PARA_ERROR_LOG("could not create custom header: %s\n",
+			para_strerror(-ret));
+		free(*buf);
+		*buf = NULL;
+		*len = 0;
+	} else
+		PARA_INFO_LOG("created %zu byte ogg/opus header\n", *len);
+}
+
 /**
  * The init function of the ogg/opus audio format handler.
  *
@@ -235,6 +302,7 @@ static int opus_rewrite_tags(const char *map, size_t mapsize,
 void opus_afh_init(struct audio_format_handler *afh)
 {
 	afh->get_file_info = opus_get_file_info,
+	afh->get_header = opus_get_header;
 	afh->suffixes = opus_suffixes;
 	afh->rewrite_tags = opus_rewrite_tags;
 }