Question about memory leak with speex and nframes > 1

[Eric de Jong]

Question about memory leak with speex and nframes > 1

Who can help me with the following problem? When I use the speex decoder 
and decode a speex stream with nframes > 1, memory is leaked and the 
application will crash after a day.

My system: Windows 8.1 32bit, Dell optiplex 780, Core2Duo E7500, 4GB ram
  I installed gstreamer-1.0-x86-1.6.3.msi with the following:
   GStreamer 1.0 core
   GStreamer 1.0 system plugins
   GStreamer 1.0 plugins for playback
   GStreamer 1.0 codecs
   GStreamer 1.0 plugins for capture

Then I run the following batch file, mytest.bat:
  SET PATH=c:\gstreamer\1.0\x86\bin\;%PATH%
  gst-launch-1.0 autoaudiosrc ! audioconvert ! speexenc nframes=10 
mode=3 quality=5 ! speexdec ! autoaudiosink > NULL

The memory leak is visible in taskmgr.exe after about 23 minutes. As 
gstreamer does initially allocates 22MB I guess this hides the 
increasing memory usage in taskmgr earlier.
The amount of memory leaked is dependent on nframes.

In my application (not the command line above but similar) I have a 
separate speex encoder and decoder. In the decoder I can see the following:
With nframes=1, no memory is leaked.
With 'nframes=2' memory is leaked, and with 'nframes=10' more memory is 
leaked.
I do not have exact figures, but it looks like that for every 
'nframes-1' a memory leak of about 420 bytes occurs. (only for the first 
frame the memory is freed)
Note that in my test every frame generates a 320 bytes raw audio packet, 
as speex decodes the stream into 16bit 8kHz mono with 50 frames/second.

With nframes > 1 I receive the following warning for every decoded frame:

  WARNING: from element /GstPipeline:pipeline0/GstSpeexDec:speexdec0: 
received more decoded frames 1 than provided 0
  Additional debug info:
  gstaudiodecoder.c(1343): gst_audio_decoder_finish_frame (): 
/GstPipeline:pipeline0/GstSpeexDec:speexdec0

In the following test I can get more information:

mytest.bat:
  SET PATH=c:\gstreamer\1.0\x86\bin\;%PATH%
  SET GST_DEBUG_FILE=_debug.txt
  SET GST_DEBUG=GST_MEMORY:7,speexdec:7
  gst-launch-1.0 autoaudiosrc ! audioconvert ! speexenc nframes=10 
mode=3 quality=5 ! speexdec ! autoaudiosink

In the generated _debug.txt file, I can see that every allocated buffer 
I checked it has a matching 'free'. So no help here.

In gstspeexdec.c I see the following (very simplified!) loop:
   /* now decode each frame, catering for unknown number of them (e.g. 
rtp) */
   for (i = 0; i < fpp; i++) {

     GstBuffer *outbuf;
     outbuf =
         gst_buffer_new_allocate (NULL,
         dec->frame_size * dec->header->nb_channels * 2, NULL);

     gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
     ret = speex_decode_int (dec->state, bits, (spx_int16_t *) map.data);
     gst_buffer_unmap (outbuf, &map);

     res = gst_audio_decoder_finish_frame (GST_AUDIO_DECODER (dec), 
outbuf, 1);
   }
Here it seems to me 'gst_audio_decoder_finish_frame' accepts and plays 
every frame.

Who can help me or point me in the proper direction?

Best regards, Eric de Jong