h264parse: keyframes marked as delta unit

Submitted by Nicola `@drakkan`

Created attachment 342575
file that show the issue

Please try this pipeline and observe the output

gst-launch-1.0 -v filesrc location= test.gdp ! gdpdepay ! fakesink silent=false

you can see that all keyframes are correctly marked as such, for example:

42672 bytes, dts: none, pts: 0:00:01.667941354, duration: none, offset: -1, offset_end: -1, flags: 00000000

42667 bytes, dts: none, pts: 0:00:03.267941354, duration: none, offset: -1, offset_end: -1, flags: 00000000

now try to add h264parse:

gst-launch-1.0 -v filesrc location= test.gdp ! gdpdepay ! h264parse ! video/x-h264,stream-format=avc,alignment=au ! fakesink silent=false

42672 bytes, dts: 0:00:01.401274664, pts: 0:00:01.667941354, duration: 0:00:00.033333333, offset: 91068, offset_end: -1, flags: 00002000 delta-unit

42667 bytes, dts: 0:00:02.734607984, pts: 0:00:03.267941354, duration: 0:00:00.033333333, offset: 182136, offset_end: -1, flags: 00002000 delta-unit

keyframes are now marked as delta-unit!

Attachment 342575, "file that show the issue":
test.gdp

Version: 1.x