timestamp issue

[Chuck Crisler]

I am using GStreamer 0.10.30 and good plugins 0.10.25 and have a strange
timestamp issue. My pipeline has h264parse feeding buffers to rtph264pay. I
have modified both elements to display the buffer timestamp. In h264parse
it is just before the buffer is pushed, in rtph264pay it is immediately
upon receiving the buffer. Here are 2 lines from the log file.

Jun  7 14:07:43 imsvcctl[3106]: 0:00:03.924666709  3106
0x82e96b0 DEBUG              h264parse
gsth264parse.c:2385:gst_h264_parse_chain_forward:<H264Parse> pushing
buffer 0xf6f031a0, size 2742, ts 0:00:00.600000000
Jun  7 14:07:43 imsvcctl[3106]: 0:00:03.924686125  3106
0x82e96b0 DEBUG             rtph264pay
gstrtph264pay.c:948:gst_rtp_h264_pay_handle_buffer:<RTPPayloader> got
2742 bytes, 0x00  0x00 0x0a 0xb2 TS: 600000000:00:4145690968.1293306562

The h264parse element generates a timestamp and sets it on the buffer. The
rtph264pay element reads the timestamp from the buffer immediately upon
receiving the buffer. So it seems that something in between is changing the
timestamp.

The good plugins 0.10.26 did have a RTP timestamp bug fix (#630256), but
that doesn't seem like the same issue. Also, the fix was in the depay
element, which this particular pipeline doesn't even use.

This pipeline is sending h264/RTP to an IPad, which is not decoding the
stream and I think that the invalid and unchanging timestamps may be the
problem. I have this same code running in other places and sending H264/RTP
to a script that sets up a GStreamer RTP Rx pipeline that works.

Does anyone have any comments or suggestions of where I should look next?

Thank you,
Chuck Crisler
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