Currently, both bsfs used the same CodedBitstreamContext for reading and
writing; as a consequence, the state of the writer's context at the
beginning of writing a fragment is exactly the state of the reader after
having read the fragment; in particular, the writer might not have
encountered one of its active parameter sets yet.
This is not nice and may lead to invalid output even when the input
is completely spec-compliant: Think of an access unit containing
a primary coded picture referencing a PPS with id id (that is known from
an earlier access unit/from extradata), then a new version of the PPS
with id id and then a redundant coded picture that is also referencing
the PPS with id id. This is spec-compliant, as the standard allows to
overwrite a PPS with a different PPS in between coded pictures and not
only at the beginning of an access unit. In this scenario, the reader
would read the primary coded picture with the old PPS and the redundant
coded picture with the new PPS (as it should); yet the writer would
write both with the new PPS as extradata which might lead to errors or
to invalid data being output without any error (e.g. if the two PPS
differed in redundant_pic_cnt_present_flag).
The above scenario does not directly translate to HEVC as long as one
restricts oneself to input with nuh_layer_id == 0 only (as cbs_h265
does: it currently strips away any NAL unit with nuh_layer_id > 0 when
decomposing); if one doesn't the same issue as above can happen.
If one also allowed input packets to contain more than one access unit,
issues like the above can happen even without redundant coded
pictures/multiple layers.
Therefore this commit uses separate contexts for reader and writer.
Reviewed-by: Mark Thompson <sw@jkqxz.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Several cbs-functions had an unused CodedBitstreamContext parameter.
This commit removes these.
Reviewed-by: Mark Thompson <sw@jkqxz.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
If the relevant elements (the color description elements for AV1 and the
VUI elements in general for H.264 (since 1156b507)) are absent, then their
correct values (usually meaning unknown) have already been inferred by
the reading process, so that it is unnecessary to initialize them again
in the av1/h264_metadata filters even when they were initially absent.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Given the recent changes to ff_cbs_delete_unit, it is no longer sensible
to use a return value for ff_cbs_h264_delete_sei_message; instead, use
asserts to ensure that the required conditions are met and remove the
callers' checks for the return value. Also, document said conditions.
An assert that is essentially equivalent to the one used in
ff_cbs_delete_unit has been removed, too.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
ff_cbs_delete_unit never fails if the index of the unit to delete is
valid, as it is with all current callers of the function. So just assert
in ff_cbs_delete_unit that the index is valid and change the return
value to void in order to remove the callers' checks for whether
ff_cbs_delete_unit failed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The recent changes to h264_metadata (enabled by the recent changes to
ff_cbs_write_packet) made it possible to add side_data to the output
packet at any place, not only after the output packet has been written
and the properties of the input packet copied. This means that one can
now localize the code to add display orientation side-data to the packet
to the place dealing with said display-orientation.
Furthermore, the documentation of av_display_rotation_set states that
the matrix will be fully overwritten by it, so there is no need to
allocate it with av_mallocz.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit changes h264_metadata to (a) use ff_bsf_get_packet_ref
instead of ff_bsf_get_packet (thereby avoiding one malloc and free per
filtered packet) and (b) to use only one packet structure at all,
thereby avoiding a call to av_packet_copy_props.
(b) has been made possible by the recent changes to ff_cbs_write_packet.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
When testing whether a particular unit should be kept or discarded, it
is best to start at the very last unit of a fragment and count down,
because that way a unit that will eventually be deleted won't be
memmoved during earlier deletions; and frag/au->nb_units need only be
evaluated once in this case and the counter is automatically correct
when a unit got deleted.
It also works for double loops, i.e. when looping over all SEI messages
in all SEI units of an access unit.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Currently, a fragment's unit array is constantly reallocated during
splitting of a packet. This commit changes this: One can keep the units
array by distinguishing between the number of allocated and the number
of valid units in the units array.
The more units a packet is split into, the bigger the benefit.
So MPEG-2 benefits the most; for a video coming from an NTSC-DVD
(usually 32 units per frame) the average cost of cbs_insert_unit (for a
single unit) went down from 6717 decicycles to 450 decicycles (based
upon 10 runs with 4194304 runs each); if each packet consists of only
one unit, it went down from 2425 to 448; for a H.264 video where most
packets contain nine units, it went from 4431 to 450.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@googlemail.com>
Using the value of buffering frames inferred from the old level is
not a sensible approach when one wants to guess the level.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@googlemail.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>
profile_idc for level 1b should be 11, not 10.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@googlemail.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>
* commit '6d5a6dde5301c81e221a37b3f39bb03149492b98':
h264_metadata: Add option to delete filler data
Fixes#6899.
Merged-by: Mark Thompson <sw@jkqxz.net>
* commit '78fa0b9033c0834c049e2aedf71a8c613fed87ab':
h264_metadata: Always add the SEI user data to the first access unit
Mostly already present from a308872b04,
one cosmetic change applied.
Merged-by: Mark Thompson <sw@jkqxz.net>
* commit '69062d0f9b6aef5d9d9b8c9c9b5cfb23037caddb':
h264_metadata: Use common SEI addition function
Minor changes because the following patch is already present.
Merged-by: Mark Thompson <sw@jkqxz.net>
* commit 'ce5870a3a8f2b10668ee4f04c2ae0287f66f31b2':
cbs: Refcount all the things!
Some changes for bitstream API.
Merged-by: Mark Thompson <sw@jkqxz.net>
This makes it easier for users of the CBS API to get alloc/free right -
all subelements use the buffer API so that it's clear how to free them.
It also allows eliding some redundant copies: the packet -> fragment copy
disappears after this change if the input packet is refcounted, and more
codec-specific cases are now possible (but not included in this patch).
