qtdemux: also push buffers without encryption info instead of dropping them

Test "17. PlayReadyH264Video" in YouTube leanback EME conformance tests 2016
for H.264[1] uses a media file[2] with cenc encryption whose first two 'moof'
boxes have no encryption information (no 'saiz' and 'saio' boxes).

Those boxes are actually not encrypted and the current qtdemux implementation
was just dropping them, breaking the test use case.

This patch detects those kind of situations and just lets the unencrypted
buffers pass. Of course, this needs some collaboration by the decryptors,
which should also do the same and not to try to decrypt those clear buffers.

[1] http://yt-dash-mse-test.commondatastorage.googleapis.com/unit-tests/2016.html?test_type=encryptedmedia-test&webm=false
[2] http://yt-dash-mse-test.commondatastorage.googleapis.com/unit-tests/media/oops_cenc-20121114-142.mp4

https://bugzilla.gnome.org/show_bug.cgi?id=770107

diff --git a/gst/isomp4/qtdemux.c b/gst/isomp4/qtdemux.c
index 4a99ca5..1c323b3 100644 (file)
--- a/gst/isomp4/qtdemux.c
+++ b/gst/isomp4/qtdemux.c
@@ -5783,25 +5783,25 @@ gst_qtdemux_decorate_and_push_buffer (GstQTDemux * qtdemux,
     }
 
     if (info->crypto_info == NULL) {
-      GST_DEBUG_OBJECT (qtdemux, "cenc metadata hasn't been parsed yet");
-      gst_buffer_unref (buf);
-      goto exit;
-    }
-
-    /* The end of the crypto_info array matches our n_samples position,
-     * so count backward from there */
-    index = stream->sample_index - stream->n_samples + info->crypto_info->len;
-    if (G_LIKELY (index >= 0 && index < info->crypto_info->len)) {
-      /* steal structure from array */
-      crypto_info = g_ptr_array_index (info->crypto_info, index);
-      g_ptr_array_index (info->crypto_info, index) = NULL;
-      GST_LOG_OBJECT (qtdemux, "attaching cenc metadata [%u/%u]", index,
-          info->crypto_info->len);
-      if (!crypto_info || !gst_buffer_add_protection_meta (buf, crypto_info))
-        GST_ERROR_OBJECT (qtdemux, "failed to attach cenc metadata to buffer");
+      GST_DEBUG_OBJECT (qtdemux,
+          "cenc metadata hasn't been parsed yet, pushing buffer as if it wasn't encrypted");
     } else {
-      GST_INFO_OBJECT (qtdemux, "No crypto info with index %d and sample %d",
-          index, stream->sample_index);
+      /* The end of the crypto_info array matches our n_samples position,
+       * so count backward from there */
+      index = stream->sample_index - stream->n_samples + info->crypto_info->len;
+      if (G_LIKELY (index >= 0 && index < info->crypto_info->len)) {
+        /* steal structure from array */
+        crypto_info = g_ptr_array_index (info->crypto_info, index);
+        g_ptr_array_index (info->crypto_info, index) = NULL;
+        GST_LOG_OBJECT (qtdemux, "attaching cenc metadata [%u/%u]", index,
+            info->crypto_info->len);
+        if (!crypto_info || !gst_buffer_add_protection_meta (buf, crypto_info))
+          GST_ERROR_OBJECT (qtdemux,
+              "failed to attach cenc metadata to buffer");
+      } else {
+        GST_INFO_OBJECT (qtdemux, "No crypto info with index %d and sample %d",
+            index, stream->sample_index);
+      }
     }
   }