From: Andre Noll <maan@tuebingen.mpg.de>
Date: Thu, 19 Aug 2021 17:06:10 +0000 (+0200)
Subject: mp4: Simplify parse_atoms().
X-Git-Tag: v0.7.1~7^2~47
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=df6826829971cc26ee52ab924789cdcc14db6c09

mp4: Simplify parse_atoms().

We are only interested in subatoms of the moov atom, so skip everything
else. Rename the function to parse_root_atoms() and remove the comment
which does not convey any information anymore.
---

diff --git a/mp4.c b/mp4.c
index c77cedd2..469ec7d7 100644
--- a/mp4.c
+++ b/mp4.c
@@ -903,8 +903,7 @@ static int parse_sub_atoms(struct mp4 *f, uint64_t total_size, int meta_only)
 	return 1;
 }
 
-/* parse root atoms */
-static int parse_atoms(struct mp4 *f, int meta_only)
+static int parse_root_atoms(struct mp4 *f, int meta_only)
 {
 	int ret;
 	uint64_t size;
@@ -916,23 +915,15 @@ static int parse_atoms(struct mp4 *f, int meta_only)
 	while ((ret = atom_read_header(f, &atom_type, &header_size, &size)) > 0) {
 		f->file_size += size;
 		f->last_atom = atom_type;
-
-		if (atom_type == ATOM_MOOV && size > header_size) {
-			f->moov_offset = get_position(f) - header_size;
-			f->moov_size = size;
-		}
-
-		/* parse subatoms */
-		if (meta_only && !need_parse_when_meta_only(atom_type)) {
-			set_position(f, get_position(f) + size - header_size);
-		} else if (atom_type < SUBATOMIC) {
-			ret = parse_sub_atoms(f, size - header_size, meta_only);
-			if (ret <= 0)
-				break;
-		} else {
-			/* skip this atom */
+		if (atom_type != ATOM_MOOV || size <= header_size) { /* skip */
 			set_position(f, get_position(f) + size - header_size);
+			continue;
 		}
+		f->moov_offset = get_position(f) - header_size;
+		f->moov_size = size;
+		ret = parse_sub_atoms(f, size - header_size, meta_only);
+		if (ret <= 0)
+			break;
 	}
 	if (ret < 0)
 		return ret;
@@ -947,7 +938,7 @@ struct mp4 *mp4_open_read(const struct mp4_callback *cb)
 	struct mp4 *f = para_calloc(sizeof(struct mp4));
 
 	f->cb = cb;
-	ret = parse_atoms(f, 0);
+	ret = parse_root_atoms(f, 0);
 	if (ret < 0) {
 		free(f);
 		return NULL;
@@ -1073,7 +1064,7 @@ struct mp4 *mp4_open_meta(const struct mp4_callback *cb)
 	struct mp4 *f = para_calloc(sizeof(struct mp4));
 
 	f->cb = cb;
-	ret = parse_atoms(f, 1);
+	ret = parse_root_atoms(f, 1);
 	if (ret < 0) {
 		free(f);
 		return NULL;