From b2ad7c68c3478c433a0ede4aed6afb2f0b32702c Mon Sep 17 00:00:00 2001
From: Rafostar <40623528+Rafostar@users.noreply.github.com>
Date: Sun, 10 Jan 2021 15:44:45 +0100
Subject: [PATCH] matroska: fix attachments detection in large data blocks

Due to max block size limit being set to 15MB, large
attachments (fonts of few MB in size) were undetected
as attachments consist of single data block. Raise max
data block limit to 30MB to fix that.
---
 gst/matroska/matroska-demux.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/gst/matroska/matroska-demux.c b/gst/matroska/matroska-demux.c
index 4d0234743..ce906e5a3 100644
--- a/gst/matroska/matroska-demux.c
+++ b/gst/matroska/matroska-demux.c
@@ -5115,30 +5115,28 @@ gst_matroska_demux_parse_contents (GstMatroskaDemux * demux, GstEbmlRead * ebml)
 }
 
 #define GST_FLOW_OVERFLOW   GST_FLOW_CUSTOM_ERROR
-
-#define MAX_BLOCK_SIZE (15 * 1024 * 1024)
+#define MAX_BLOCK_SIZE (60 * 1024 * 1024)
 
 static inline GstFlowReturn
 gst_matroska_demux_check_read_size (GstMatroskaDemux * demux, guint64 bytes)
 {
-  if (G_UNLIKELY (bytes > MAX_BLOCK_SIZE)) {
-    /* only a few blocks are expected/allowed to be large,
-     * and will be recursed into, whereas others will be read and must fit */
-    if (demux->streaming) {
-      /* fatal in streaming case, as we can't step over easily */
-      GST_ELEMENT_ERROR (demux, STREAM, DEMUX, (NULL),
-          ("reading large block of size %" G_GUINT64_FORMAT " not supported; "
-              "file might be corrupt.", bytes));
-      return GST_FLOW_ERROR;
-    } else {
-      /* indicate higher level to quietly give up */
-      GST_DEBUG_OBJECT (demux,
-          "too large block of size %" G_GUINT64_FORMAT, bytes);
-      return GST_FLOW_ERROR;
-    }
-  } else {
+  if (G_LIKELY (bytes <= MAX_BLOCK_SIZE))
     return GST_FLOW_OK;
+
+  /* only a few blocks are expected/allowed to be large,
+   * and will be recursed into, whereas others will be read and must fit */
+  if (demux->streaming) {
+    /* fatal in streaming case, as we can't step over easily */
+    GST_ELEMENT_ERROR (demux, STREAM, DEMUX, (NULL),
+        ("reading large block of size %" G_GUINT64_FORMAT " not supported; "
+            "file might be corrupt.", bytes));
+  } else {
+    /* indicate higher level to quietly give up */
+    GST_DEBUG_OBJECT (demux, "too large block of size %" G_GUINT64_FORMAT,
+        bytes);
   }
+
+  return GST_FLOW_ERROR;
 }
 
 /* returns TRUE if we truly are in error state, and should give up */
-- 
2.29.2