From 7bc241beb0b6dd22f0b6e722174779221ceec5de Mon Sep 17 00:00:00 2001
From: Edgard Lima <edgard.lima@indt.org.br>
Date: Thu, 13 Dec 2007 17:19:54 +0000
Subject: Code documentation.

Original commit message from CVS:
Code documentation.
---
 ext/metadata/gstmetadataparse.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

(limited to 'ext/metadata/gstmetadataparse.c')

diff --git a/ext/metadata/gstmetadataparse.c b/ext/metadata/gstmetadataparse.c
index a8ded250..d95a9399 100644
--- a/ext/metadata/gstmetadataparse.c
+++ b/ext/metadata/gstmetadataparse.c
@@ -932,10 +932,11 @@ gst_metadata_parse_calculate_offsets (GstMetadataParse * filter)
 }
 
 /*
+ * Do parsing step-by-step and reconfigure caps if need
  * return:
- *   -1 -> error
- *    0 -> succeded
- *    1 -> need more data
+ *   META_PARSING_ERROR
+ *   META_PARSING_DONE
+ *   META_PARSING_NEED_MORE_DATA
  */
 
 static int
@@ -943,7 +944,7 @@ gst_metadata_parse_parse (GstMetadataParse * filter, const guint8 * buf,
     guint32 size)
 {
 
-  int ret = -1;
+  int ret = META_PARSING_ERROR;
 
   filter->next_offset = 0;
   filter->next_size = 0;
@@ -951,14 +952,14 @@ gst_metadata_parse_parse (GstMetadataParse * filter, const guint8 * buf,
   ret = metadata_parse (&filter->parse_data, buf, size,
       &filter->next_offset, &filter->next_size);
 
-  if (ret < 0) {
+  if (ret == META_PARSING_ERROR) {
     if (META_DATA_IMG_TYPE (filter->parse_data) == IMG_NONE) {
       /* image type not recognized */
       GST_ELEMENT_ERROR (filter, STREAM, TYPE_NOT_FOUND, (NULL),
           ("Only jpeg and png are supported"));
       goto done;
     }
-  } else if (ret > 0) {
+  } else if (ret == META_PARSING_NEED_MORE_DATA) {
     filter->need_more_data = TRUE;
   } else {
     gst_metadata_parse_calculate_offsets (filter);
@@ -968,13 +969,14 @@ gst_metadata_parse_parse (GstMetadataParse * filter, const guint8 * buf,
     filter->need_send_tag = TRUE;
   }
 
+  /* reconfigure caps if it is different from type detected by 'metadata_parse' function */
   if (filter->img_type != META_DATA_IMG_TYPE (filter->parse_data)) {
     filter->img_type = META_DATA_IMG_TYPE (filter->parse_data);
     if (!gst_metadata_parse_configure_caps (filter)) {
       GST_ELEMENT_ERROR (filter, STREAM, FORMAT, (NULL),
           ("Couldn't reconfigure caps for %s",
               gst_metadata_parse_get_type_name (filter->img_type)));
-      ret = -1;
+      ret = META_PARSING_ERROR;
       goto done;
     }
   }
@@ -1047,8 +1049,11 @@ gst_metadata_parse_chain (GstPad * pad, GstBuffer * buf)
       const guint8 *new_buf =
           gst_adapter_peek (filter->adapter_parsing, adpt_size);
 
-      if (gst_metadata_parse_parse (filter, new_buf, adpt_size) < 0)
+      if (gst_metadata_parse_parse (filter, new_buf,
+              adpt_size) == META_PARSING_ERROR) {
+        ret = GST_FLOW_ERROR;
         goto done;
+      }
     }
   }
 
@@ -1151,8 +1156,13 @@ gst_metadata_parse_pull_range_parse (GstMetadataParse * filter)
 
     offset += filter->next_offset;
 
+    /* 'filter->next_size' only says the minimum required number of bytes.
+       We try provided more bytes (4096) just to avoid a lot of calls to 'metadata_parse'
+       returning META_PARSING_NEED_MORE_DATA */
     if (filter->next_size < 4096) {
       if (duration - offset < 4096) {
+        /* In case there is no 4096 bytes available upstream.
+           It should be done upstream but we do here for safety */
         filter->next_size = duration - offset;
       } else {
         filter->next_size = 4096;
@@ -1169,14 +1179,14 @@ gst_metadata_parse_pull_range_parse (GstMetadataParse * filter)
     res =
         gst_metadata_parse_parse (filter, GST_BUFFER_DATA (buf),
         GST_BUFFER_SIZE (buf));
-    if (res < 0) {
+    if (res == META_PARSING_ERROR) {
       ret = FALSE;
       goto done;
     }
 
     gst_buffer_unref (buf);
 
-  } while (res > 0);
+  } while (res == META_PARSING_NEED_MORE_DATA);
 
 done:
 
-- 
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