h264parse: nal.size of incoming frame is corrupted

[Makoto Harada]

Hello experts,

I'm now investigating the problem that h264parse does not work as expected in some cases.

My pipelines are as shown below.

(OK)
gst-launch-1.0 filesrc location=test.mp4 typefind=true '!' qtdemux name=demux '!' video/x-h264 '!' h264parse '!' video/x-h264,stream-format=byte-stream '!' filesink location=test.h264
gst-launch-1.0 filesrc location=test.mp4 typefind=true '!' qtdemux name=demux '!' video/x-h264 '!' h264parse '!' video/x-h264,stream-format=byte-stream '!' mpegtsmux ! filesink location=test.ts

(NG)
gst-launch-1.0 filesrc location=test.mp4 typefind=true '!' qtdemux name=demux '!' video/x-h264 '!' h264parse '!' video/x-h264,stream-format=byte-stream '!' mpegtsmux ! appsrc

In OK case, h264parse works as expected and the test.h264/test.ts has correct data. We can decode this data as expected.
In NG case, h264parse outputs corrupted h264 data.
I see lot's of the "not processing nal size 1" message, when GST_DEBUG="h264parse:5".

I made debugging and it turned out that nalu.size is corrupted in NG case as shown below.
Other fields are ok. 

(OK)
   gst_h264_parse_handle_frame_packetized:<h264parse0> processing packet buffer of size 32
   gst_h264_parse_handle_frame_packetized:<h264parse0>nal offset : 4, nal size 28           <= ok                                              
   gst_h264_parse_handle_frame_packetized:<h264parse0>AVC nal offset 32                     
   gst_h264_parse_process_nal:<h264parse0>processing nal of type 1 Slice, size 28           

(NG)
   gst_h264_parse_handle_frame_packetized:<h264parse0>processing packet buffer of size 32
   gst_h264_parse_handle_frame_packetized:<h264parse0>nal offset : 4, nal size 1               <= nal size is corrupted to 1 !!
   gst_h264_parse_handle_frame_packetized:<h264parse0>AVC nal offset 5
   gst_h264_parse_process_nal:<h264parse0>  not processing nal size 1

nalu.size is got by the first 32 bit data of buffer in incoming frame to h264pasre plugin.
I confirmed this first 32 bit is broken at gst_h264_parse_handle_frame () while data size is expected.

version of h264parse I'm using is 1.4.1.

Question:
1. Is this known issue ? I could not find out the commit in git.
2. Who writes to this nalu.size field (first 32 bit of incoming frame to h264parse ) ?
    parent class of h264parse or qtdemux ?
    I could not figure it out the source code which does this yet.

Any feedback is highly appreciated.

Kind Regards,
Makoto