gsth265parser does it already. Although corresponding API of h265parser is
gst_h265_sei_free, _clear suffix is more consistent naming for h264parser
since there are gst_h264_{sps,pps}_clear().
That's the value of NumDeltaPocs[RefRpsIdx] and we might be able to derive
the value from given sps and slice header.
Because well known hardware implementations refer to the value, however,
storing the value makes things easier.
Following is the list of hardware implementations
* DXVA2: ucNumDeltaPocsOfRefRpsIdx
* NVDEC/VDPAU: NumDeltaPocsOfRefRpsIdx
Some hardware decoders, for example Hantro G1, have to be told the
size of the pic_order_cnt related syntax elements pic_order_cnt_lsb,
delta_pic_order_cnt_bottom, delta_pic_order_cnt[0], and
delta_pic_order_cnt[1] in bits.
Some hardware decoders, for example Hantro G1, have to be told the size
of the dec_ref_pic_marking() syntax element in bits. Record the size so
it can be passed on to the hardware.
The calculated size of short_term_ref_pic_set is not a part of
HEVC syntax but the value is used by some stateless decoders
(e.g., vaapi, dxva, vdpau and nvdec) for the purpose of skipping
parsing the syntax by the accelerator.
Add num_ref_idx_active_override_flag and sp_for_switch_flag to
member of GstH264SliceHdr. No reason to hiding them and
some decoder implementations (e.g., DXVA) rely on externally parsed header
data which can be provided by h264parser.
Add a separate epb_cache variable to the codecparser NalReader to
detect Emulation Prevention Bytes separately from the main bit cache.
This fixes problems where the existing logic can mistakenly detect
multiple EPB with a sequence like: 0x00 0x00 0x03 0x00 0x03. In that
case, the 5th byte should not be regarded as an EPB.
3-byte emulation bytes can confuse the current code that skips
bits at the end of an SEI. Use a simpler method that's also
quicker because it skips all remaining bits in one go instead
of 1 bit at a time.
The SPS parsing functions take a parse_vui_param flag
to skip VUI parsing, but there's no indication in the output
SPS struct that the VUI was skipped.
The only caller that ever passed FALSE seems to be the
important gst_h264_parser_parse_nal() function, meaning - so the
cached SPS were always silently invalid. That needs changing
anyway, meaning noone ever passes FALSE.
I don't see any use for saving a few microseconds in
order to silently produce garbage, and since this is still
unstable API, let's remove the parse_vui_param.
The spec calls for pic_timing SEI to be absent unless
there's either a CpbDpbDelaysPresentFlag or
pic_struct_present_flag in the SPS VUI data. If
both those flags are missing, warn.
If parsing an SEI errors out, it might not consume
all bits, leaving extra unparsed data in the reader
that the outer loop then tries to parse as a new
appended SEI.
Skip all the bits if any are left over to avoid
'finding' extra garbage SEI in the parsing.
When parsing SEI that require an SPS, return
GST_H264_PARSER_BROKEN_LINK instead of a generic
parsing error to let callers distinguish
bitstream errors from (expected) missing packets
when resuming decode.
"High Throughput", "Multiview", "Scalable", "3D", "Screen Content Coding",
and "Scalable format range extensions" profiles can be supported
via h265parser APIs now.
The same timing_info will be present at vps or vui.
When the timeing_info is present in the VPS, vui_timing_info
, when present, shall be equal to vps_timing_info, and when
not present, is inferred to be equal to vps_timing_info.
Expose SEI data in the H.264 bitstream parser API and
extract closed captions and other things that are not
specified in the H.264 spec itself in the videoparser.
Based on patch by: Mathieu Duponchelle <mathieu@centricular.com>
https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/issues/940
