Calling ff_h264_field_end() when the per-field state is not properly
initialized leads to all kinds of undefined behaviour.
CC: libav-stable@libav.org
Bug-Id: 977 978 992
For field picture, the first_field is set based on its previous value.
Before this commit, first_field is set when reading the picture
coding extension. However, in corrupted files there may be multiple
picture coding extension headers, so the final value of first_field that
is actually used during decoding can be wrong. That can lead to various
undefined behaviour, like predicting from a non-existing field.
Fix this problem, by setting first_field in mpeg_field_start(), which
should be called exactly once per field.
CC: libav-stable@libav.org
Bug-ID: 999
When the input string is too large, so the second condition in if ()
fails, the code will erroneously execute the else branch, indexing the
mac_to_unicode table with a negative index.
CC: libav-stable@libav.org
Bug-Id: 1000
Found-By: Kamil Frankowicz
Certain hardware decoding APIs are not guaranteed to be thread-safe, so
having the user access decoded hardware surfaces while the decoder is
running in another thread can cause failures (this is mainly known to
happen with DXVA2).
For such hwaccels, only allow the decoding thread to run while the user
is inside a lavc decode call (avcodec_send_packet/receive_frame).
It should only be set after the decoder state has been fully initialized
for using that SPS.
Fixes possible invalid reads on get_format() failure.
CC: libav-stable@libav.org
It is more natural for this codec and allows to avoid awkward constructs
like "consuming 0 bytes from input". Also, keep a reference to the input
packet to avoid unnecessary copying.
Currently, the new decoding API is pretty much just a wrapper around the
old deprecated one. This is problematic, since it interferes with making
full use of the flexibility added by the new API. The old API should
also be removed at some future point.
Reorganize the code so that the new send_packet/receive_frame functions
call the actual decoding directly and change the old deprecated
avcodec_decode_* functions into wrappers around the new API.
The new internal API for decoders is now changing as well. Before this
commit, it mirrors the public API, so the decoders need to implement
send_packet() and receive_frame() callbacks. This turns out to require
awkward constructs in both the decoders and the generic code. After this
commit, the decoders only implement the receive_frame() callback and
call a new internal function, ff_decode_get_packet() to obtain input
data, in the same manner to how the bitstream filters now work.
avcodec will now always make a reference to the input packet, which means
that non-refcounted input packets will be copied. Keeping the previous
behaviour, where this copy could sometimes be avoided, would make the
code significantly more complex and fragile for only dubious gains,
since packets are typically small and everyone who cares about
performance should use refcounted packets anyway.
The current code stores a pointer to the packet passed to the decoder,
which is then used during get_buffer() for timestamps and side data
passthrough. However, since this is a pointer to user data which we do
not own, storing it is potentially dangerous. It is also ill defined for
the new decoding API with split input/output.
Fix this problem by making an explicit internally owned copy of the
packet properties.
It is useful for testing/debugging and will also be used as the default
filter in the following commit adding pre-decode filtering to avoid
having a separate non-filtered codepath.
Just the presence of a hw frames context is not enough to detect whether
the transfer is an upload or a download, because hw frames mapped to
system memory will have a hw frames context attached.
D3DLOCK_READONLY properly corresponds to the absence of the write flag,
not to the presence of the read flag, while D3DLOCK_DISCARD is
equivalent to the overwrite flag.
This will allow implementing the allocator more fully, which is needed
by the HEVC encoder plugin with video memory input.
Signed-off-by: Maxym Dmytrychenko <maxym.dmytrychenko@intel.com>
For encoding, this avoids modifying the input surface, which we are not
allowed to do.
This will also be useful in the following commits.
Signed-off-by: Maxym Dmytrychenko <maxym.dmytrychenko@intel.com>
Uploading/downloading data through VPP may not work for some formats, in
that case we can still try to call av_hwframe_transfer_data() on the
child context.
Signed-off-by: Maxym Dmytrychenko <maxym.dmytrychenko@intel.com>
Certain pixel formats (e.g. P8) might not be supported for
download/upload through VPP operations, but can still be used otherwise.
Signed-off-by: Maxym Dmytrychenko <maxym.dmytrychenko@intel.com>
When using GPU surfaces with QSV, one needs to supply a frame allocator,
which will be invoked to pass surface pools to libmfx.
For encoding, this allocator gets invoked not only for the pool of input
frames, but also for a separate pool of (apparently) reconstructed frames
and another pool of MFX_FOURCC_P8, which on Windows needs to return
D3DFMT_P8 D3D surfaces. Those are probably used to store the encoded
bitstream on the GPU.
Signed-off-by: Maxym Dmytrychenko <maxym.dmytrychenko@intel.com>
This also fixes a minor bug introduced in the codecpar conversion, where
the termination condition for extracting the extradata does not match
the actual extradata setting code. As a result, the packet durations
made up by lavf go back to their values before the codecpar conversion.
That is of little consequence since that code should eventually be
dropped completely.
This way they can be reused by other code without including the whole
decoder-specific hevcdec.h
Also, add the HEVC_ prefix to them, since similarly named values exist
for H.264 as well and are sometimes used in the same code.
Errors during decoding are currently considered non-fatal and do not
terminate transcoding, so even if parts of the data are corrupted, the
rest may be decodable.
However, that should apply only to the actual decoding calls, not to the
failures elsewhere (e.g. configuring filters).
The filtergraph's existence is used in several places to mean that the
filtergraph is fully configured. This causes problems if it's allocated,
but the initialization fails (e.g. if a non-existent filter is
specified).
It is supposed to be a flag. The only currently defined value is
AVIO_SEEKABLE_NORMAL, but other ones may be added in the future.
However all the current lavf code treats this field as a bool (mainly
for historical reasons).
Change all those cases to properly check for AVIO_SEEKABLE_NORMAL.
Anton Khirnov
