Seems to be utilized by Handbrake for track titling and is
actually defined as "title for the media" as per the
specification.
Definition from 3GPP TS 26.244 follows:
Field Type Details
Value
BoxHeader.Size Unsigned int(32)
BOX_SIZE
BoxHeader.Type Unsigned int(32)
'titl'
BoxHeader.Version Unsigned int(8) 0
BoxHeader.Flags Bit(24) 0
Pad Bit(1) 0
Language Unsigned int(5)[3] Packed ISO-639-2/T language code
Title String Text of title
Semantics:
Language: declares the language code for the following text. See
ISO 639-2/T for the set of three character codes. Each character
is packed as the difference between its ASCII value and 0x60.
The code is confined to being three lower-case letters, so these
values are strictly positive.
Title: null-terminated string in either UTF-8 or UTF-16 characters,
giving a title information. If UTF-16 is used, the string shall
start with the BYTE ORDER MARK (0xFEFF).
---
libavformat/mov.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 040babed95..9edb3d6596 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -291,6 +291,111 @@ static int mov_metadata_hmmt(MOVContext *c, AVIOContext
*pb, unsigned len)
return 0;
}
+// 3GPP TS 26.244, 8.2 3GPP asset meta data
+static int mov_metadata_titl(MOVContext *c, AVIOContext *pb, unsigned len)
+{
+ AVFormatContext *s = c->fc;
+ int version = -1, ret = AVERROR_BUG;
+ unsigned left_bytes = len, langcode = 0, flags = 100, bom = 0, buf_size =
0;
+ char language[4] = { 0 };
+ AVStream *st = NULL;
+ char *title_buf = NULL;
+ const char key[] = "title";
+
+ // 4 byte FullBox header, 2 byte lang. code, at least 1 byte for string
+ if (len < 4 + 2 + 1) {
+ av_log(s, AV_LOG_ERROR, "3GPP titl box too short!\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (s->nb_streams >= 1)
+ st = s->streams[s->nb_streams-1];
+
+ // FullBox header
+ version = avio_r8(pb);
+ flags = avio_rb24(pb);
+ left_bytes -= 4;
+
+ if (version != 0 || flags != 0) {
+ av_log(s, AV_LOG_ERROR,
+ "Invalid nonzero version (%d) or flags (%x) for 3GPP titl!\n",
+ version, flags);
+ return AVERROR_INVALIDDATA;
+ }
+
+ langcode = avio_rb16(pb) & ~(1 << 15);
+ if ((ret = ff_mov_lang_to_iso639(langcode, language)) < 0) {
+ av_log(s, AV_LOG_ERROR,
+ "Failed to parse 3GPP titl language code %x: %s!\n",
+ langcode, av_err2str(ret));
+ return ret;
+ }
+
+ left_bytes -= 2;
+
+ if (left_bytes <= 1)
+ // no contents (just null)
+ return 0;
+
+ buf_size = left_bytes + 1;
+ if (!(title_buf = av_mallocz(buf_size))) {
+ av_log(s, AV_LOG_ERROR,
+ "Could not allocate buffer of length %u for parsed 3GPP titl "
+ "title string!\n",
+ left_bytes);
+ return AVERROR(ENOMEM);
+ }
+
+ bom = avio_rb16(pb);
+ left_bytes -= 2;
+
+ if (bom == 0xfeff)
+ avio_get_str16be(pb, left_bytes, title_buf, buf_size);
+ else if (bom == 0xfffe)
+ avio_get_str16le(pb, left_bytes, title_buf, buf_size);
+ else {
+ AV_WB16(title_buf, bom);
+ if (!left_bytes)
+ title_buf[2] = 0;
+ else
+ avio_get_str(pb, left_bytes, title_buf + 2, buf_size - 2);
+ }
+
+ av_log(s, AV_LOG_TRACE, "%s TitlBox(lang: %s, title: %s)\n",
+ st ? "track" : "media",
+ language, title_buf);
+
+ s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
+
+ if (*language && strcmp(language, "und")) {
+ char lang_key[sizeof(key) + 1 + sizeof(language)] = { 0 };
+ snprintf(lang_key, sizeof(lang_key), "%s-%s", key, language);
+
+ if ((ret = av_dict_set(st ? &st->metadata : &s->metadata,
+ lang_key, title_buf, 0)) < 0) {
+ av_log(s, AV_LOG_ERROR,
+ "Failed to set %s metadata key %s to value %s: %s!\n",
+ st ? "track" : "media",
+ lang_key, title_buf,
+ av_err2str(ret));
+ goto cleanup;
+ }
+ }
+
+ ret = av_dict_set(st ? &st->metadata : &s->metadata, key, title_buf, 0);
+ if (ret < 0)
+ av_log(s, AV_LOG_ERROR,
+ "Failed to set %s metadata key %s to value %s: %s!\n",
+ st ? "track" : "media",
+ key, title_buf,
+ av_err2str(ret));
+
+cleanup:
+ av_freep(&title_buf);
+
+ return ret;
+}
+
static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
char tmp_key[AV_FOURCC_MAX_STRING_SIZE] = {0};
@@ -349,6 +454,8 @@ static int mov_read_udta_string(MOVContext *c, AVIOContext
*pb, MOVAtom atom)
case MKTAG( 's','o','s','n'): key = "sort_show"; break;
case MKTAG( 's','t','i','k'): key = "media_type";
parse = mov_metadata_int8_no_padding; break;
+ case MKTAG( 't','i','t','l'):
+ return mov_metadata_titl(c, pb, atom.size);
case MKTAG( 't','r','k','n'): key = "track";
parse = mov_metadata_track_or_disc_number; break;
case MKTAG( 't','v','e','n'): key = "episode_id"; break;
--
2.31.1
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