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authorJörg Frings-Fürst <debian@jff.email>2023-06-28 21:35:52 +0200
committerJörg Frings-Fürst <debian@jff.email>2023-06-28 21:35:52 +0200
commitb86540b743f1a87a163ffb811c8fe22a01fefa38 (patch)
treeb47cb3bb83c2377234226fb3987ab3320a987dd9 /src/video-support/QuickTimeAtom.vala
parentac6e0b731b9f0b2efd392e3309a5c07e2a66adad (diff)
parente905d8e16eec152d19797937f13ba3cf4b8f8aca (diff)
Merge branch 'release/debian/0.32.1-1'debian/0.32.1-1
Diffstat (limited to 'src/video-support/QuickTimeAtom.vala')
-rw-r--r--src/video-support/QuickTimeAtom.vala118
1 files changed, 118 insertions, 0 deletions
diff --git a/src/video-support/QuickTimeAtom.vala b/src/video-support/QuickTimeAtom.vala
new file mode 100644
index 0000000..996046a
--- /dev/null
+++ b/src/video-support/QuickTimeAtom.vala
@@ -0,0 +1,118 @@
+private class QuickTimeAtom {
+ private GLib.File file = null;
+ private string section_name = "";
+ private uint64 section_size = 0;
+ private uint64 section_offset = 0;
+ private GLib.DataInputStream input = null;
+ private QuickTimeAtom? parent = null;
+
+ public QuickTimeAtom(GLib.File file) {
+ this.file = file;
+ }
+
+ private QuickTimeAtom.with_input_stream(GLib.DataInputStream input, QuickTimeAtom parent) {
+ this.input = input;
+ this.parent = parent;
+ }
+
+ public void open_file() throws GLib.Error {
+ close_file();
+ input = new GLib.DataInputStream(file.read());
+ input.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
+ section_size = 0;
+ section_offset = 0;
+ section_name = "";
+ }
+
+ public void close_file() throws GLib.Error {
+ if (null != input) {
+ input.close();
+ input = null;
+ }
+ }
+
+ private void advance_section_offset(uint64 amount) {
+ section_offset += amount;
+ if (null != parent) {
+ parent.advance_section_offset(amount);
+ }
+ }
+
+ public QuickTimeAtom get_first_child_atom() {
+ // Child will simply have the input stream
+ // but not the size/offset. This works because
+ // child atoms follow immediately after a header,
+ // so no skipping is required to access the child
+ // from the current position.
+ return new QuickTimeAtom.with_input_stream(input, this);
+ }
+
+ public uchar read_byte() throws GLib.Error {
+ advance_section_offset(1);
+ return input.read_byte();
+ }
+
+ public uint32 read_uint32() throws GLib.Error {
+ advance_section_offset(4);
+ return input.read_uint32();
+ }
+
+ public uint64 read_uint64() throws GLib.Error {
+ advance_section_offset(8);
+ return input.read_uint64();
+ }
+
+ public void read_atom() throws GLib.Error {
+ // Read atom size.
+ section_size = read_uint32();
+
+ // Read atom name.
+ GLib.StringBuilder sb = new GLib.StringBuilder();
+ sb.append_c((char) read_byte());
+ sb.append_c((char) read_byte());
+ sb.append_c((char) read_byte());
+ sb.append_c((char) read_byte());
+ section_name = sb.str;
+
+ // Check string.
+ if (section_name.length != 4) {
+ throw new IOError.NOT_SUPPORTED("QuickTime atom name length is invalid for %s",
+ file.get_path());
+ }
+ for (int i = 0; i < section_name.length; i++) {
+ if (!section_name[i].isprint()) {
+ throw new IOError.NOT_SUPPORTED("Bad QuickTime atom in file %s", file.get_path());
+ }
+ }
+
+ if (1 == section_size) {
+ // This indicates the section size is a 64-bit
+ // value, specified below the atom name.
+ section_size = read_uint64();
+ }
+ }
+
+ private void skip(uint64 skip_amount) throws GLib.Error {
+ skip_uint64(input, skip_amount);
+ }
+
+ public uint64 section_size_remaining() {
+ assert(section_size >= section_offset);
+ return section_size - section_offset;
+ }
+
+ public void next_atom() throws GLib.Error {
+ skip(section_size_remaining());
+ section_size = 0;
+ section_offset = 0;
+ }
+
+ public string get_current_atom_name() {
+ return section_name;
+ }
+
+ public bool is_last_atom() {
+ return 0 == section_size;
+ }
+
+}