mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-12-20 23:36:38 +00:00
Code Issues 1 Projects Releases Wiki Activity

baseparse: allow increasing min_size for current frame parsing only

Browse source 
Also check that subclass actually either directs to skip bytes or
increases expected frame size to avoid going nowhere in bogus
indefinite looping.
This commit is contained in:
Mark Nauwelaerts 2011-01-06 11:41:44 +01:00
parent 18b69e9320
commit 829507b650
1 changed files with 42 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

51
gst/audioparsers/gstbaseparse.c
View file

@ -82,7 +82,8 @@
* @framesize according to the detected frame size. If buffer didn't
* contain a valid frame, this call must return FALSE and optionally
* set the @skipsize value to inform base class that how many bytes
* it needs to skip in order to find a valid frame. The passed buffer
* it needs to skip in order to find a valid frame. @framesize can always
* indicate a new minimum for current frame parsing. The passed buffer
* is read-only. Note that @check_valid_frame might receive any small
* amount of input data when leftover data is being drained (e.g. at EOS).
* </para></listitem>
@ -1874,7 +1875,7 @@ gst_base_parse_chain (GstPad * pad, GstBuffer * buffer)
guint fsize = 0;
gint skip = -1;
const guint8 *data;
guint min_size, av;
guint old_min_size = 0, min_size, av;
GstClockTime timestamp;
parse = GST_BASE_PARSE (GST_OBJECT_PARENT (pad));
@ -1905,11 +1906,17 @@ gst_base_parse_chain (GstPad * pad, GstBuffer * buffer)
while (!parse->priv->flushing) {
tmpbuf = gst_buffer_new ();
old_min_size = 0;
/* Synchronization loop */
for (;;) {
min_size = parse->priv->min_frame_size;
min_size = MAX (parse->priv->min_frame_size, fsize);
av = gst_adapter_available (parse->adapter);
/* loop safety check */
if (G_UNLIKELY (old_min_size >= min_size))
goto invalid_min;
old_min_size = min_size;
if (G_UNLIKELY (parse->priv->drain)) {
min_size = av;
GST_DEBUG_OBJECT (parse, "draining, data left: %d", min_size);
@ -1975,10 +1982,11 @@ gst_base_parse_chain (GstPad * pad, GstBuffer * buffer)
if (!parse->priv->discont)
parse->priv->sync_offset = parse->priv->offset;
parse->priv->discont = TRUE;
/* something changed least; nullify loop check */
old_min_size = 0;
}
/* There is a possibility that subclass set the skip value to zero.
This means that it has probably found a frame but wants to ask
more data (by increasing the min_size) to be sure of this. */
/* skip == 0 should imply subclass set min_size to need more data;
* we check this shortly */
if ((ret = gst_base_parse_check_sync (parse)) != GST_FLOW_OK) {
gst_buffer_unref (tmpbuf);
goto done;
@ -2033,6 +2041,15 @@ gst_base_parse_chain (GstPad * pad, GstBuffer * buffer)
done:
GST_LOG_OBJECT (parse, "chain leaving");
return ret;
/* ERRORS */
invalid_min:
{
GST_ELEMENT_ERROR (parse, STREAM, FAILED, (NULL),
("min_size evolution %d -> %d; breaking to avoid looping",
old_min_size, min_size));
return GST_FLOW_ERROR;
}
}
/* pull @size bytes at current offset,
@ -2180,14 +2197,18 @@ gst_base_parse_scan_frame (GstBaseParse * parse, GstBaseParseClass * klass,
{
GstBuffer *buffer, *outbuf;
GstFlowReturn ret = GST_FLOW_OK;
guint fsize = 0, min_size;
guint fsize = 0, min_size, old_min_size = 0;
gint skip = 0;
g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
while (TRUE) {
min_size = parse->priv->min_frame_size;
min_size = MAX (parse->priv->min_frame_size, fsize);
/* loop safety check */
if (G_UNLIKELY (old_min_size >= min_size))
goto invalid_min;
old_min_size = min_size;
ret = gst_base_parse_pull_range (parse, min_size, &buffer);
if (ret != GST_FLOW_OK)
@ -2227,8 +2248,11 @@ gst_base_parse_scan_frame (GstBaseParse * parse, GstBaseParseClass * klass,
if (!parse->priv->discont)
parse->priv->sync_offset = parse->priv->offset;
parse->priv->discont = TRUE;
/* something changed least; nullify loop check */
old_min_size = 0;
}
/* skip == 0 should imply subclass set min_size to need more data ... */
/* skip == 0 should imply subclass set min_size to need more data;
* we check this shortly */
GST_DEBUG_OBJECT (parse, "finding sync...");
gst_buffer_unref (buffer);
if ((ret = gst_base_parse_check_sync (parse)) != GST_FLOW_OK) {
@ -2264,6 +2288,15 @@ gst_base_parse_scan_frame (GstBaseParse * parse, GstBaseParseClass * klass,
done:
return ret;
/* ERRORS */
invalid_min:
{
GST_ELEMENT_ERROR (parse, STREAM, FAILED, (NULL),
("min_size evolution %d -> %d; breaking to avoid looping",
old_min_size, min_size));
return GST_FLOW_ERROR;
}
}
/**