mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2025-02-02 20:42:30 +00:00
Code Issues 1 Projects Releases Wiki Activity

qtdemux: consider 3gpp style tag parsing in some more cases

Browse source 
3GPP specs define a number of tags along with precise layout. While these
are normally expected to be found in a container whose major brand is a
3GPP brand, this may also happen when a 3GPP brand is only mentioned as a
compatible brand.  Apply some checks, heuristic and fallbacks to extract
such tags as well.
This commit is contained in:
Mark Nauwelaerts 2009-08-13 16:11:59 +02:00
parent 0f900afe1f
commit c469f6b38d
2 changed files with 95 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

122
gst/qtdemux/qtdemux.c
View file

@ -1363,6 +1363,9 @@ gst_qtdemux_change_state (GstElement * element, GstStateChange transition)
if (qtdemux->mdatbuffer)
gst_buffer_unref (qtdemux->mdatbuffer);
qtdemux->mdatbuffer = NULL;
if (qtdemux->comp_brands)
gst_buffer_unref (qtdemux->comp_brands);
qtdemux->comp_brands = NULL;
gst_adapter_clear (qtdemux->adapter);
for (n = 0; n < qtdemux->n_streams; n++) {
QtDemuxStream *stream = qtdemux->streams[n];
@ -1397,6 +1400,21 @@ gst_qtdemux_change_state (GstElement * element, GstStateChange transition)
return result;
}
static void
qtdemux_parse_ftyp (GstQTDemux * qtdemux, const guint8 * buffer, gint length)
{
/* only consider at least a sufficiently complete ftyp atom */
if (length >= 20) {
GstBuffer *buf;
qtdemux->major_brand = QT_FOURCC (buffer + 8);
GST_DEBUG_OBJECT (qtdemux, "major brand: %" GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (qtdemux->major_brand));
buf = qtdemux->comp_brands = gst_buffer_new_and_alloc (length - 16);
memcpy (GST_BUFFER_DATA (buf), buffer + 16, GST_BUFFER_SIZE (buf));
}
}
static void
extract_initial_length_and_fourcc (const guint8 * data, guint64 * plength,
guint32 * pfourcc)
@ -1529,12 +1547,8 @@ gst_qtdemux_loop_state_header (GstQTDemux * qtdemux)
if (ret != GST_FLOW_OK)
goto beach;
qtdemux->offset += length;
/* only consider at least a sufficiently complete ftyp atom */
if (length >= 20) {
qtdemux->major_brand = QT_FOURCC (GST_BUFFER_DATA (ftyp) + 8);
GST_DEBUG_OBJECT (qtdemux, "major brand: %" GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (qtdemux->major_brand));
}
qtdemux_parse_ftyp (qtdemux, GST_BUFFER_DATA (ftyp),
GST_BUFFER_SIZE (ftyp));
gst_buffer_unref (ftyp);
break;
}
@ -4609,16 +4623,33 @@ unknown_stream:
}
}
/* check if major or compatible brand is 3GP */
static inline gboolean
qtdemux_is_string_3gp (GstQTDemux * qtdemux, guint32 fourcc)
qtdemux_is_brand_3gp (GstQTDemux * qtdemux, gboolean major)
{
/* Detect if the tag must be handled as 3gpp - i18n metadata. The first
* check is for catching all the possible brands, e.g. 3gp4,3gp5,3gg6,.. and
* handling properly the tags present in more than one brand.*/
return ((qtdemux->major_brand & GST_MAKE_FOURCC (255, 255, 0, 0)) ==
GST_MAKE_FOURCC ('3', 'g', 0, 0)
&& (fourcc == FOURCC_cprt || fourcc == FOURCC_gnre
|| fourcc == FOURCC_kywd)) || fourcc == FOURCC_titl
if (major) {
return ((qtdemux->major_brand & GST_MAKE_FOURCC (255, 255, 0, 0)) ==
GST_MAKE_FOURCC ('3', 'g', 0, 0));
} else {
guint8 *data = GST_BUFFER_DATA (qtdemux->comp_brands);
guint size = GST_BUFFER_SIZE (qtdemux->comp_brands);
gboolean res = FALSE;
while (size >= 4) {
res = res || ((QT_FOURCC (data) & GST_MAKE_FOURCC (255, 255, 0, 0)) ==
GST_MAKE_FOURCC ('3', 'g', 0, 0));
data += 4;
size -= 4;
}
return res;
}
}
/* check if tag is a spec'ed 3GP tag keyword storing a string */
static inline gboolean
qtdemux_is_string_tag_3gp (GstQTDemux * qtdemux, guint32 fourcc)
{
return fourcc == FOURCC_cprt || fourcc == FOURCC_gnre || fourcc == FOURCC_titl
|| fourcc == FOURCC_dscp || fourcc == FOURCC_perf || fourcc == FOURCC_auth
|| fourcc == FOURCC_albm;
}
@ -4728,9 +4759,9 @@ qtdemux_tag_add_classification (GstQTDemux * qtdemux, const char *tag,
g_free (tag_str);
}
static void
qtdemux_tag_add_str (GstQTDemux * qtdemux, const char *tag, const char *dummy,
GNode * node)
static gboolean
qtdemux_tag_add_str_full (GstQTDemux * qtdemux, const char *tag,
const char *dummy, GNode * node)
{
const gchar *env_vars[] = { "GST_QT_TAG_ENCODING", "GST_TAG_ENCODING", NULL };
GNode *data;
@ -4738,6 +4769,7 @@ qtdemux_tag_add_str (GstQTDemux * qtdemux, const char *tag, const char *dummy,
int len;
guint32 type;
int offset;
gboolean ret = TRUE;
data = qtdemux_tree_get_child_by_type (node, FOURCC_data);
if (data) {
@ -4763,14 +4795,26 @@ qtdemux_tag_add_str (GstQTDemux * qtdemux, const char *tag, const char *dummy,
* the language code, which we ignore */
offset = 12;
GST_DEBUG_OBJECT (qtdemux, "found international text tag");
} else if (qtdemux_is_string_3gp (qtdemux,
} else if (len > 14 && qtdemux_is_string_tag_3gp (qtdemux,
QT_FOURCC ((guint8 *) node->data + 4))) {
offset = 14;
/* 16-bit Language code is ignored here as well */
GST_DEBUG_OBJECT (qtdemux, "found 3gpp text tag");
guint32 type = QT_UINT32 ((guint8 *) node->data + 8);
/* we go for 3GP style encoding if major brands claims so,
* or if no hope for data be ok UTF-8, and compatible 3GP brand present */
if (qtdemux_is_brand_3gp (qtdemux, TRUE) ||
(qtdemux_is_brand_3gp (qtdemux, FALSE) &&
((type & 0x00FFFFFF) == 0x0) && (type >> 24 <= 0xF))) {
offset = 14;
/* 16-bit Language code is ignored here as well */
GST_DEBUG_OBJECT (qtdemux, "found 3gpp text tag");
} else {
goto normal;
}
} else {
normal:
offset = 8;
GST_DEBUG_OBJECT (qtdemux, "found normal text tag");
ret = FALSE; /* may have to fallback */
}
s = gst_tag_freeform_string_to_utf8 ((char *) node->data + offset,
len - offset, env_vars);
@ -4778,10 +4822,19 @@ qtdemux_tag_add_str (GstQTDemux * qtdemux, const char *tag, const char *dummy,
GST_DEBUG_OBJECT (qtdemux, "adding tag %s", GST_STR_NULL (s));
gst_tag_list_add (qtdemux->tag_list, GST_TAG_MERGE_REPLACE, tag, s, NULL);
g_free (s);
ret = TRUE;
} else {
GST_DEBUG_OBJECT (qtdemux, "failed to convert %s tag to UTF-8", tag);
}
}
return ret;
}
static void
qtdemux_tag_add_str (GstQTDemux * qtdemux, const char *tag,
const char *dummy, GNode * node)
{
qtdemux_tag_add_str_full (qtdemux, tag, dummy, node);
}
static void
@ -4795,9 +4848,17 @@ qtdemux_tag_add_keywords (GstQTDemux * qtdemux, const char *tag,
int offset;
int count;
/* re-route to normal string tag if not 3GP */
if (!qtdemux_is_string_3gp (qtdemux, FOURCC_kywd))
return qtdemux_tag_add_str (qtdemux, tag, dummy, node);
/* first try normal string tag if major brand not 3GP */
if (!qtdemux_is_brand_3gp (qtdemux, TRUE)) {
if (!qtdemux_tag_add_str_full (qtdemux, tag, dummy, node)) {
/* hm, that did not work, maybe 3gpp storage in non-3gpp major brand;
* let's try it 3gpp way after minor safety check */
data = node->data;
if (QT_UINT32 (data) < 15 || !qtdemux_is_brand_3gp (qtdemux, FALSE))
return;
} else
return;
}
GST_DEBUG_OBJECT (qtdemux, "found 3gpp keyword tag");
@ -5011,11 +5072,16 @@ qtdemux_tag_add_gnre (GstQTDemux * qtdemux, const char *tag, const char *dummy,
int type;
int n;
/* re-route to normal string tag if 3GP */
if (qtdemux_is_string_3gp (qtdemux, FOURCC_gnre))
return qtdemux_tag_add_str (qtdemux, tag, dummy, node);
data = qtdemux_tree_get_child_by_type (node, FOURCC_data);
/* re-route to normal string tag if major brand says so
* or no data atom and compatible brand suggests so */
if (qtdemux_is_brand_3gp (qtdemux, TRUE) ||
(qtdemux_is_brand_3gp (qtdemux, FALSE) && !data)) {
qtdemux_tag_add_str (qtdemux, tag, dummy, node);
return;
}
if (data) {
len = QT_UINT32 (data->data);
type = QT_UINT32 ((guint8 *) data->data + 8);

1
gst/qtdemux/qtdemux.h
View file

@ -65,6 +65,7 @@ struct _GstQTDemux {
gint n_subp_streams;
guint major_brand;
GstBuffer *comp_brands;
GNode *moov_node;
GNode *moov_node_compressed;