Should h264parse limit the max PPS id to 31 or 255?

Loren Rogers at
Tue May 3 07:29:15 PDT 2011

Hi Karen,
The h.264 spec definitely specifies 8 bits (0-255).  I've had
experience with some devices/codecs populating the PPS ID to something
definitely greater than 31.  It does seem incorrect to me also.  Maybe
adjust the h264parse.h to reflect that specific device/codec?  But a
response from the gstreamer folks would be most helpful.

On Mon, May 2, 2011 at 3:12 PM, Karen Schoener <kschoener at> wrote:
> Hi,
> I notice that the h264parse element currently limits the max PPS id to 31.
> According to section in the H264 spec, the PPS id may range from
> 0-255.  However the SPS id can range from 0-31.
> Here's the info from in the H264 spec:
> pic_parameter_set_id identifies the picture parameter set that is referred
> to in the slice header. The value of pic_parameter_set_id shall be in the
> range of 0 to 255, inclusive.
> seq_parameter_set_id refers to the active sequence parameter set. The value
> of seq_parameter_set_id shall be in the range of 0 to 31, inclusive.
> I was just wondering if this PPS ID limit to 31 was intentional.
> Does anyone see an issue with changing the following #define in h264parse.h
> from 32 to 256?
> #define MAX_PPS_COUNT   32
> Thanks, Karen
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