mfaudioenc: Handle empty IMFMediaBuffer

IMFMediaBuffer may not hold encoded data, which seems to happen
while draining.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1679>

diff --git a/subprojects/gst-plugins-bad/sys/mediafoundation/gstmfaudioenc.cpp b/subprojects/gst-plugins-bad/sys/mediafoundation/gstmfaudioenc.cpp
index 57a8332..1ad4433 100644 (file)
--- a/subprojects/gst-plugins-bad/sys/mediafoundation/gstmfaudioenc.cpp
+++ b/subprojects/gst-plugins-bad/sys/mediafoundation/gstmfaudioenc.cpp
@@ -244,12 +244,12 @@ gst_mf_audio_enc_process_output (GstMFAudioEnc * self)
 {
   GstMFAudioEncClass *klass = GST_MF_AUDIO_ENC_GET_CLASS (self);
   HRESULT hr;
-  BYTE *data;
+  BYTE *data = nullptr;
   ComPtr < IMFMediaBuffer > media_buffer;
   ComPtr < IMFSample > sample;
   GstBuffer *buffer;
   GstFlowReturn res = GST_FLOW_ERROR;
-  DWORD buffer_len;
+  DWORD buffer_len = 0;
 
   res = gst_mf_transform_get_output (self->transform, sample.GetAddressOf ());
 
@@ -264,6 +264,13 @@ gst_mf_audio_enc_process_output (GstMFAudioEnc * self)
   if (!gst_mf_result (hr))
     return GST_FLOW_ERROR;
 
+  /* Can happen while draining */
+  if (buffer_len == 0 || !data) {
+    GST_DEBUG_OBJECT (self, "Empty media buffer");
+    media_buffer->Unlock ();
+    return GST_FLOW_OK;
+  }
+
   buffer = gst_audio_encoder_allocate_output_buffer (GST_AUDIO_ENCODER (self),
       buffer_len);
   gst_buffer_fill (buffer, 0, data, buffer_len);