libextractor

commit 3f542fba4232cd50d198a658e72ac46961ebd374
parent ddbe32198104530774a770fad4a271e9436f13ef
Author: LRN <lrn1986@gmail.com>
Date:   Thu, 16 Aug 2012 10:41:59 +0000

Fix buffer underrunning

Apparently, pull-mode requires us to satisfy appsrc's every whim,
i.e. if it asks more data than we can give it in one go (due to shm
size limit), then we have to buffer it up before giving it away.
Now discoverer works correctly in random mode, so reverting previous
commit as well.

Diffstat:
M
src/plugins/gstreamer_extractor.c
 | 
69
+++++++++++++++++++++++++++++++++++++++++++--------------------------

1 file changed, 43 insertions(+), 26 deletions(-)
diff --git a/src/plugins/gstreamer_extractor.c b/src/plugins/gstreamer_extractor.c
@@ -711,8 +711,10 @@ _source_setup (GstDiscoverer * dc, GstElement * source, PrivStruct * ps)
   if (ps->length > 0)
   {
     g_object_set (ps->source, "size", (gint64) ps->length, NULL);
+    gst_util_set_object_arg (G_OBJECT (ps->source), "stream-type", "random-access");
   }
-  gst_util_set_object_arg (G_OBJECT (ps->source), "stream-type", "seekable");
+  else
+    gst_util_set_object_arg (G_OBJECT (ps->source), "stream-type", "seekable");
 
   /* configure the appsrc, we will push a buffer to appsrc when it needs more
    * data */
@@ -726,6 +728,11 @@ feed_data (GstElement * appsrc, guint size, PrivStruct * ps)
   GstFlowReturn ret;
   long data_len;
   uint8_t *le_data;
+  guint accumulated;
+  GstMemory *mem;
+  GstMapInfo mi;
+
+  GST_DEBUG ("Request %u bytes", size);
 
   if (ps->length > 0 && ps->offset >= ps->length) {
     /* we are at the EOS, send end-of-stream */
@@ -736,37 +743,47 @@ feed_data (GstElement * appsrc, guint size, PrivStruct * ps)
   if (ps->length > 0 && ps->offset + size > ps->length)
     size = ps->length - ps->offset;
 
-  data_len = ps->ec->read (ps->ec->cls, (void **) &le_data, size);
-  if (data_len > 0)
+  mem = gst_allocator_alloc (NULL, size, NULL);
+  if (!gst_memory_map (mem, &mi, GST_MAP_WRITE))
   {
-    GstMemory *mem;
-    GstMapInfo mi;
-    mem = gst_allocator_alloc (NULL, data_len, NULL);
-    if (gst_memory_map (mem, &mi, GST_MAP_WRITE))
-    {
-      GstBuffer *buffer;
-      memcpy (mi.data, le_data, data_len);
-      gst_memory_unmap (mem, &mi);
-      buffer = gst_buffer_new ();
-      gst_buffer_append_memory (buffer, mem);
-
-      /* we need to set an offset for random access */
-      GST_BUFFER_OFFSET (buffer) = ps->offset;
-      GST_BUFFER_OFFSET_END (buffer) = ps->offset + data_len;
-
-      GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
-          ps->offset, data_len);
-      ret = gst_app_src_push_buffer (GST_APP_SRC (ps->source), buffer);
-      ps->offset += data_len;
-    }
-    else
+    gst_memory_unref (mem);
+    GST_DEBUG ("Failed to map the memory");
+    ret = gst_app_src_end_of_stream (GST_APP_SRC (ps->source));
+    return;
+  }
+
+  accumulated = 0;
+  data_len = 1;
+  while (accumulated < size && data_len > 0)
+  {
+    data_len = ps->ec->read (ps->ec->cls, (void **) &le_data, size - accumulated);
+    if (data_len > 0)
     {
-      gst_memory_unref (mem);
-      ret = gst_app_src_end_of_stream (GST_APP_SRC (ps->source));
+      memcpy (&mi.data[accumulated], le_data, data_len);
+      accumulated += data_len;
     }
   }
+  gst_memory_unmap (mem, &mi);
+  if (data_len > 0)
+  {
+    GstBuffer *buffer;
+    buffer = gst_buffer_new ();
+    gst_buffer_append_memory (buffer, mem);
+
+    /* we need to set an offset for random access */
+    GST_BUFFER_OFFSET (buffer) = ps->offset;
+    GST_BUFFER_OFFSET_END (buffer) = ps->offset + size;
+
+    GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
+        ps->offset, size);
+    ret = gst_app_src_push_buffer (GST_APP_SRC (ps->source), buffer);
+    ps->offset += size;
+  }
   else
+  {
+    gst_memory_unref (mem);
     ret = gst_app_src_end_of_stream (GST_APP_SRC (ps->source));
+  }
 
   return;
 }