[Bug 770683] New: Not start code and slice_data_offset for H.264(AVS) VASliceDataBufferType type data

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=770683

Bug ID: 770683
Summary: Not start code and slice_data_offset for H.264(AVS)
VASliceDataBufferType type data
Classification: Platform
Product: GStreamer
Version: git master
OS: Linux
Status: NEW
Severity: normal
Priority: Normal
Component: gstreamer-vaapi
Assignee: gstreamer-***@lists.freedesktop.org
Reporter: ***@soulik.info
QA Contact: gstreamer-***@lists.freedesktop.org
CC: ***@gmail.com, ***@igalia.com
GNOME version: ---

The Intel i915 VA-API doesn't require the start code for H.264(AVS) but the
HEVC does, it would use the slice_data_offset to omit the start code
prefix(0x000001). But some hardware video process do require the start code for
AVS. The known device are those ARM chips from rockchips.

It would be not strip the start code for AVS to work in all the devices.

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=770683

--- Comment #1 from sreerenj <***@gmail.com> ---
(In reply to ayaka from comment #0)

Post by "GStreamer" (GNOME Bugzilla)
The Intel i915 VA-API doesn't require the start code for H.264(AVS) but the
HEVC does, it would use the slice_data_offset to omit the start code
prefix(0x000001). But some hardware video process do require the start code
for AVS. The known device are those ARM chips from rockchips.
It would be not strip the start code for AVS to work in all the devices.

copy & pasting my reply from mailing list:
https://lists.freedesktop.org/archives/libva/2016-September/004340.html

It is right that VA spec requires start code prefix, but AFAIK
vaapi-intel-driver can work even if middleware doesn't insert start code..
From gstreamer-vaapi side, we are not sending SC for both avc and hevc,
and we use a single code path for both
stream-formats (avc and avc_bytestream , hevc and hevc_bytestream).

We can make it compliant with the spec , but more code change requires
for non-bytestream format.
I mean, we have to explicitly insert the SC prefix for non-bytestream
formats of AVC and HEVC.

BTW, H264 is AVC, not AVS :)

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=770683

ayaka <***@soulik.info> changed:

What |Removed |Added
----------------------------------------------------------------------------
Summary|Not start code and |Not start code and
|slice_data_offset for |slice_data_offset for
|H.264(AVS) |H.264(AVC)
|VASliceDataBufferType type |VASliceDataBufferType type
|data |data

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=770683

--- Comment #2 from ayaka <***@soulik.info> ---
OK, you could assign this issue to me, I would like to submit patches in the
future time.

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=770683

sreerenj <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|gstreamer-***@lists.freede |***@soulik.info
|sktop.org |

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=770683

GStreamer system administrator <***@gstreamer.net> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |OBSOLETE

--- Comment #3 from GStreamer system administrator <***@gstreamer.net> ---
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