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105 lines
3.1 KiB
C
105 lines
3.1 KiB
C
#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <string.h>
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#include <gst/gst.h>
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#include "gstdashdemux.h"
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#define XML_BUFFER_SIZE 16
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#define XML_INC_BUFFER { \
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pos++; \
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if (pos == XML_BUFFER_SIZE) { \
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pos = 0; \
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offset += XML_BUFFER_SIZE; \
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data = gst_type_find_peek (tf, offset, XML_BUFFER_SIZE); \
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if (data == NULL) return FALSE; \
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} else { \
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data++; \
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} \
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}
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static gboolean
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xml_check_first_element (GstTypeFind * tf, const gchar * element, guint elen,
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gboolean strict)
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{
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gboolean got_xmldec;
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const guint8 *data;
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guint offset = 0;
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guint pos = 0;
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data = gst_type_find_peek (tf, 0, XML_BUFFER_SIZE);
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if (!data)
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return FALSE;
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/* look for the XMLDec
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* see XML spec 2.8, Prolog and Document Type Declaration
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* http://www.w3.org/TR/2004/REC-xml-20040204/#sec-prolog-dtd */
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got_xmldec = (memcmp (data, "<?xml", 5) == 0);
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if (strict && !got_xmldec)
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return FALSE;
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/* skip XMLDec in any case if we've got one */
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if (got_xmldec) {
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pos += 5;
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data += 5;
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}
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/* look for the first element, it has to be the requested element. Bail
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* out if it is not within the first 4kB. */
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while (data && (offset + pos) < 4096) {
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while (*data != '<' && (offset + pos) < 4096) {
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XML_INC_BUFFER;
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}
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XML_INC_BUFFER;
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if (!g_ascii_isalpha (*data)) {
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/* if not alphabetic, it's a PI or an element / attribute declaration
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* like <?xxx or <!xxx */
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XML_INC_BUFFER;
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continue;
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}
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/* the first normal element, check if it's the one asked for */
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data = gst_type_find_peek (tf, offset + pos, elen + 1);
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return (data && element && strncmp ((char *) data, element, elen) == 0);
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}
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return FALSE;
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}
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/*** application/dash+xml typefind helper ***/
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static GstStaticCaps dash_caps = GST_STATIC_CAPS ("application/dash+xml");
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#define DASH_CAPS gst_static_caps_get (&dash_caps)
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static void
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dash_type_find (GstTypeFind * tf, gpointer unused)
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{
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if (xml_check_first_element (tf, "MPD", 3, FALSE) ||
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xml_check_first_element (tf, "mpd", 3, FALSE)) {
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gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, DASH_CAPS);
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}
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}
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static gboolean
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fragmented_init (GstPlugin * plugin)
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{
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if (!gst_element_register (plugin, "dashdemux", GST_RANK_PRIMARY,
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GST_TYPE_DASH_DEMUX) || FALSE)
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return FALSE;
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if (!gst_type_find_register (plugin, "application/dash+xml",
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GST_RANK_SECONDARY, dash_type_find, NULL, DASH_CAPS, NULL, NULL))
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return FALSE;
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return TRUE;
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}
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GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
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GST_VERSION_MINOR,
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dashdemux,
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"DASH demuxer plugin",
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fragmented_init, VERSION, "LGPL", PACKAGE_NAME, "http://www.gstreamer.org/")
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