[gst-cvs] gst-plugins-good: qtdemux: consider 3gpp style tag parsing in some more cases
Mark Nauwelaerts
mnauw at kemper.freedesktop.org
Mon Aug 31 07:54:17 PDT 2009
Module: gst-plugins-good
Branch: master
Commit: c469f6b38d289a5c2c2acaf4343223b5b7fa217d
URL: http://cgit.freedesktop.org/gstreamer/gst-plugins-good/commit/?id=c469f6b38d289a5c2c2acaf4343223b5b7fa217d
Author: Mark Nauwelaerts <mark.nauwelaerts at collabora.co.uk>
Date: Thu Aug 13 16:11:59 2009 +0200
qtdemux: consider 3gpp style tag parsing in some more cases
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.
---
gst/qtdemux/qtdemux.c | 122 +++++++++++++++++++++++++++++++++++++-----------
gst/qtdemux/qtdemux.h | 1 +
2 files changed, 95 insertions(+), 28 deletions(-)
diff --git a/gst/qtdemux/qtdemux.c b/gst/qtdemux/qtdemux.c
index c96769e..0c7689f 100644
--- a/gst/qtdemux/qtdemux.c
+++ b/gst/qtdemux/qtdemux.c
@@ -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];
@@ -1398,6 +1401,21 @@ gst_qtdemux_change_state (GstElement * element, GstStateChange transition)
}
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);
diff --git a/gst/qtdemux/qtdemux.h b/gst/qtdemux/qtdemux.h
index 7b7c135..cff66ce 100644
--- a/gst/qtdemux/qtdemux.h
+++ b/gst/qtdemux/qtdemux.h
@@ -65,6 +65,7 @@ struct _GstQTDemux {
gint n_subp_streams;
guint major_brand;
+ GstBuffer *comp_brands;
GNode *moov_node;
GNode *moov_node_compressed;
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