Revert "mpegtspacketizer: memcmp potentially seen_before data"

This reverts commit fcad4cc646.

This was wrong is so many ways.

* The memcmp was badly used (it should use == 0 to check the data is identical,
  and not != 0)
* There was no boundary checks on the present stream section_data when passing
  it to memcmp.
* The return value should have been TRUE (i.e. we have done all checks, none of
  them failed, therefore the section has been seen before)
* stream->section_data would *always* be NULL if the section had already been
  processed

Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/1559

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3427>
This commit is contained in:
Edward Hervey 2022-11-16 09:42:08 +01:00 committed by GStreamer Marge Bot
parent d0ed03fe3b
commit 080818140d

View file

@ -157,7 +157,7 @@ find_subtable (GSList * subtables, guint8 table_id, guint16 subtable_extension)
static gboolean
seen_section_before (MpegTSPacketizerStream * stream, guint8 table_id,
guint16 subtable_extension, guint8 version_number, guint8 section_number,
guint8 last_section_number, guint8 * data_start, gsize to_read)
guint8 last_section_number)
{
MpegTSPacketizerStreamSubtable *subtable;
@ -178,17 +178,7 @@ seen_section_before (MpegTSPacketizerStream * stream, guint8 table_id,
return FALSE;
}
/* Finally return whether we saw that section or not */
if (!MPEGTS_BIT_IS_SET (subtable->seen_section, section_number)) {
GST_DEBUG ("Different section_number");
return FALSE;
}
if (stream->section_data) {
/* Everything else is the same, fall back to memcmp */
return (memcmp (stream->section_data, data_start, to_read) != 0);
}
return FALSE;
return MPEGTS_BIT_IS_SET (subtable->seen_section, section_number);
}
static MpegTSPacketizerStreamSubtable *
@ -1203,8 +1193,7 @@ section_start:
* * same section_number was seen
*/
if (seen_section_before (stream, table_id, subtable_extension,
version_number, section_number, last_section_number, data_start,
to_read)) {
version_number, section_number, last_section_number)) {
GST_DEBUG
("PID 0x%04x Already processed table_id:0x%02x subtable_extension:0x%04x, version_number:%d, section_number:%d",
packet->pid, table_id, subtable_extension, version_number,