From: Andre Noll <maan@systemlinux.org>
Date: Thu, 10 Feb 2011 20:06:27 +0000 (+0100)
Subject: Create three ogg pages when skipping vorbis comments.
X-Git-Tag: v0.4.6~19^2~2
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=3569c4ac0d5b35318e741b0123bc707473261ad9;ds=inline

Create three ogg pages when skipping vorbis comments.

This works around a shortcoming in older versions of libogg. It
makes get_header() create a separate ogg page for each of the
three header packets in an ogg/vorbis stream instead of combining
packets #2 and #3.

The patch also adds a couple of debug log messages which print the
size of the individual ogg packets and ogg pages.
---

diff --git a/ogg_afh.c b/ogg_afh.c
index 2837db61..e2d8dbc8 100644
--- a/ogg_afh.c
+++ b/ogg_afh.c
@@ -85,6 +85,18 @@ static void add_ogg_page(ogg_page *og, struct vorbis_get_header_data *vghd)
 		og->header_len, og->body_len, old_len, new_len);
 }
 
+/*
+ * Process the first three ogg packets.
+ *
+ * This creates chunk zero (the audio file header) from the first three ogg
+ * packets of the input file with metadata (vorbis comments) stripped off. Page
+ * 0 of the input file always contains only ogg packet #0 while page 1 usually
+ * contains both packets 1 (comments) and 2 (setup).  However, we always create
+ * an separate ogg page for each packet to circumvent a bug in older libogg
+ * versions which causes too little data being copied to the second ogg page.
+ * This affects at least Ubuntu Hardy, and there is no real disadvantage in
+ * creating three pages instead of two.
+ */
 static int vorbis_get_header_callback(ogg_packet *packet, int packet_num,
 		int serial, __a_unused struct afh_info *afhi, void *private_data)
 {
@@ -100,7 +112,8 @@ static int vorbis_get_header_callback(ogg_packet *packet, int packet_num,
 		0xff /* framing bit */
 	};
 
-	PARA_DEBUG_LOG("processing ogg packet #%d\n", packet_num);
+	PARA_DEBUG_LOG("processing ogg packet #%d (%li bytes)\n",
+		packet_num, packet->bytes);
 	if (packet_num > 2)
 		return 0;
 	if (packet_num == 0) {
@@ -116,15 +129,19 @@ static int vorbis_get_header_callback(ogg_packet *packet, int packet_num,
 		return 1;
 	}
 	if (packet_num == 1) {
-		PARA_INFO_LOG("replacing metadata packet\n");
+		PARA_INFO_LOG("replacing metadata packet (saved %ld bytes)\n",
+			packet->bytes - sizeof(dummy_packet));
 		ogg_packet replacement = *packet;
 		replacement.packet = dummy_packet;
 		replacement.bytes = sizeof(dummy_packet);
-		ret = ogg_stream_packetin(&vghd->os, &replacement);
-		if (ret >= 0)
-			return 1;
 		ret = -E_OGG_PACKET_IN;
-		goto out;
+		if (ogg_stream_packetin(&vghd->os, &replacement) < 0)
+			goto out;
+		ret = -E_OGG_STREAM_FLUSH;
+		if (ogg_stream_flush(&vghd->os, &og) == 0)
+			goto out;
+		add_ogg_page(&og, vghd);
+		return 1;
 	}
 	ret = -E_OGG_PACKET_IN;
 	if (ogg_stream_packetin(&vghd->os, packet) < 0)
@@ -154,7 +171,7 @@ static void vorbis_get_header(void *map, size_t mapsize, char **buf,
 		goto fail;
 	*buf = vghd.buf;
 	*len = vghd.len;
-	PARA_INFO_LOG("created %zu byte ogg vorbis header\n", *len);
+	PARA_INFO_LOG("created %zu byte ogg/vorbis header chunk\n", *len);
 	return;
 fail:
 	PARA_ERROR_LOG("%s\n", para_strerror(-ret));
diff --git a/ogg_afh_common.c b/ogg_afh_common.c
index ad5963eb..777e2138 100644
--- a/ogg_afh_common.c
+++ b/ogg_afh_common.c
@@ -32,15 +32,19 @@ static int process_packets_2_and_3(ogg_sync_state *oss,
 				break; /* Need more data */
 			if (ret != 1)
 				continue;
+			PARA_DEBUG_LOG("next input page (header/body): %lu/%lu\n",
+				page.header_len, page.body_len);
 			/*
 			 * We can ignore any errors here as they'll also become
 			 * apparent at packetout.
 			 */
 			ogg_stream_pagein(stream, &page);
-			PARA_INFO_LOG("ogg page serial: %d\n",
+			PARA_DEBUG_LOG("ogg page serial: %d\n",
 				ogg_page_serialno(&page));
 			while (i < 2) {
 				ret = ogg_stream_packetout(stream, &packet);
+				PARA_DEBUG_LOG("packet #%d: %lu bytes\n", i + 1,
+					packet.bytes);
 				if (ret == 0)
 					break;
 				if (ret < 0)
@@ -69,6 +73,8 @@ static int process_ogg_packets(ogg_sync_state *oss, struct afh_info *afhi,
 
 	if (ogg_sync_pageout(oss, &page) != 1)
 		return -E_SYNC_PAGEOUT;
+	PARA_DEBUG_LOG("first input page (header/body): %lu/%lu\n",
+		page.header_len, page.body_len);
 
 	ret = ogg_page_serialno(&page);
 	ogg_stream_init(&stream, ret);
@@ -80,6 +86,7 @@ static int process_ogg_packets(ogg_sync_state *oss, struct afh_info *afhi,
 	ret = -E_STREAM_PACKETOUT;
 	if (ogg_stream_packetout(&stream, &packet) != 1)
 		goto out;
+	PARA_DEBUG_LOG("packet #0: %lu bytes\n", packet.bytes);
 	ret = ci->packet_callback(&packet, 0, ogg_page_serialno(&page),
 		afhi, ci->private_data);
 	if (ret < 0)