For a very long time, the payload of integer and float elements had to
have a length > 0. Our parser treated such invalid elements as having a
value zero. But now it has been defined what an EBML element with length
zero means: It is a shorthand for the default value. This has also been
defined for strings (both ASCII and UTF-8). This commit modifies our
parser to support this.
Reviewed-by: Ridley Combs <rcombs@rcombs.me>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This has been done in order to find out whether this element is present
at all; but this can now be done in a cleaner way by using a CountedElement
for it.
Reviewed-by: Ridley Combs <rcombs@rcombs.me>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
According to the new EBML specifications, a string element of length
zero would be read as the default value by a compliant parser.
Reviewed-by: Ridley Combs <rcombs@rcombs.me>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
In the absence of an explicitly coded minimal luminance, the current
code inferred it to be -1, an invalid value. Yet it did not check the
value lateron at all, so that if a valid maximum luminance is
encountered, but no minimal luminance, an invalid minimal luminance of
-1 is exported. If an minimal luminance element with a negative value is
present, it is exported, too. This can be simply fixed by adding a check
for the value of the element.
Yet given that a minimal luminance of zero Cd/m² is legal and can be
coded with a length of zero, we must not use a fake default value to
find out whether the element is present or not. Therefore this patch
uses an explicit counter for it.
While just at it, also check for max_luminance > min_luminance.
Reviewed-by: Ridley Combs <rcombs@rcombs.me>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Up until now, the generic EBML reader used by the Matroska demuxer did
not have the capability to record whether an element was actually
present or not; instead, in cases where it mattered one typically added
an invalid default value and checked whether the value is valid (in
which case it is guaranteed to be present). This worked pretty well so
far, yet the EBML specifications have evolved: It is now legal to use
zero-length elements for floats, ints, uints and strings (both ASCII and
UTF-8); the value of these elements is the default value of the element
(if it has one) or zero for scalar types and an empty string for
strings. Furthermore, having a default value does no longer imply that
the element may be presumed to be present (with its default value) if it
is absent; this is only true if the element is mandatory, too.
These rules are designed to allow size savings as follows: Consider the
newly added FlagOriginal: It being zero means the track is not in its
original language, it being one means it is. For backward compatibility
reasons, neither of the two values may be inferred automatically in the
absence of the element. But one can still save a byte when one wants to
write the element with a value of zero, as one can write the integer with
a length of zero: 0x55AE 80 instead of 0x55AE 81 00. In the former case,
a parser has to infer the value of the element to be zero (which is the
element's default value).
When encountering an element with length zero, our parser always infers
a value of zero (or an empty string); this is wrong for values with
a different default value. It needs to infer the default value (or zero
in its absence) and this precludes using an invalid default value for
elements like FlagOriginal. Ergo one needs to be able to record whether
an element is present or not by other means. This patch allows to use a
simple counter for this. While just at it, some invalid and unnecessary
default values have been removed (mastering metadata elements used
default values of -1.0, despite these elements only being used if they
are > 0).
Reviewed-by: Ridley Combs <rcombs@rcombs.me>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Fixes: signed integer overflow: 7 - -2147483647 cannot be represented in type 'int'
Fixes: 28036/clusterfuzz-testcase-minimized-ffmpeg_dem_MICRODVD_fuzzer-5171698751766528
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The MPEG-PS muxer uses a custom queue of custom packets. To keep track
of it, it has a pointer (named predecode_packet) to the head of the
queue and a pointer to where the next packet is to be added (it points
to the next-pointer of the last element of the queue); furthermore,
there is also a pointer that points into the queue (called premux_packet).
The exact behaviour was as follows: If premux_packet was NULL when a
packet is received, it is taken to mean that the old queue is empty and
a new queue is started. premux_packet will point to the head of said
queue and the next_packet-pointer points to its next pointer. If
predecode_packet is NULL, it will also made to point to the newly
allocated element.
But if premux_packet is NULL and predecode_packet is not, then there
will be two queues with head elements premux_packet and
predecode_packet. Yet only elements reachable from predecode_packet are
ever freed, so the premux_packet queue leaks.
Worse yet, when the predecode_packet queue will be eventually exhausted,
predecode_packet will be made to point into the other queue and when
predecode_packet will be freed, the next pointer of the preceding
element of the queue will still point to the element just freed. This
element might very well be still reachable from premux_packet which
leads to use-after-frees lateron. This happened in the tickets mentioned
below.
Fix this by never creating two queues in the first place by checking for
predecode_packet to know whether the queue is empty. If premux_packet is
NULL, then it is set to the newly allocated element of the queue.
Fixes tickets #6887, #8188 and #8266.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Normally, video packets are muxed before audio packets for mxf (there is
a dedicated interleave function for this); furthermore the first (video)
packet triggers writing the actual header. Yet when the first video packet
fails the checks performed on it, it will be an audio packet that leads
to writing the header and codec_ul (a value set based upon
properties of the bitstream which necessitates actually inspecting
packets) may be wrong. Therefore this commit discards audio packets until
a valid video packet has been received.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
mxf distinguishes codec profiles by different UIDs and therefore needs
to check that the input is actually compatible with mxf (i.e. if there
is a defined UID for it). If not, then sometimes the UID would be set to
NULL and writing the (video) packet would fail. Yet the following audio
packet would trigger writing the header (which has been postponed because
the UID is not known at the start) and if the UID is NULL, this can lead
to segfaults. This commit therefore stops setting the UID to NULL if the
input is incompatible with mxf (it has initially been set to a generic
value in mxf_write_header()).
Fixes#7993.
Reviewed-by: Tomas Härdin <tjoppen@acc.umu.se>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Fixes: signed integer overflow: 2147483647 + 64 cannot be represented in type 'int'
Fixes: 30333/clusterfuzz-testcase-minimized-ffmpeg_dem_RM_fuzzer-5175286983426048
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Such a scenario is undefined behaviour and would also indicate a bug
in our code.
Suggested-by: James Almer <jamrial@gmail.com>
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This is undefined behaviour in C, so use data = len ? data + len : data
instead of data += len. GCC optimizes the branch away in this case;
Clang unfortunately doesn't.
Fixes ticket #8592.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
It has been added in 6db42a2b6b,
yet since then none of the necessary create/free_device_capabilities
functions has been implemented, making this API completely useless.
Because of this one can already simplify
avdevice_capabilities_free/create and can already remove the function
pointers at the next major bump; given that the documentation explicitly
states that av_device_capabilities is not to be used by a user, it's
options can already be removed (save for the sentinel).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The choosen value is arbitrary. I am not sure if this is a good idea
but i dont immedeately see an alternative better way, it seems either
an arbitrary limit or OOM
Fixes: OOM
Fixes: 27492/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6194970578649088
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
And make it const, so the caller doesn't attempt to change it.
ff_get_muxer_ts_offset() should be used to get the muxer timestamp offset.
Signed-off-by: James Almer <jamrial@gmail.com>
Fixes: Infinite loop
Fixes: 30165/clusterfuzz-testcase-minimized-ffmpeg_dem_EA_fuzzer-6224642371092480
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: signed integer overflow: -4611686024827895807 + -4611686016279904256 cannot be represented in type 'long'
Fixes: 30161/clusterfuzz-testcase-minimized-ffmpeg_dem_R3D_fuzzer-5694406713802752
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The buffer is read by using the bit reader
Fixes: out of array read
Fixes: 27539/clusterfuzz-testcase-minimized-ffmpeg_dem_WAV_fuzzer-5650565572591616
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: left shift of 255 by 24 places cannot be represented in type 'int'
Fixes: 27516/clusterfuzz-testcase-minimized-ffmpeg_dem_KUX_fuzzer-5152854660349952
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
These made sense before 3ebf449766
when the creation of these boxes was specifically requested by the
user, but now they have become unnecessary as they are just like
many other boxes: If the input has the information required, they
are written, otherwise they are not.
They were moved to verbose verbosity level (which happens to be
the last level still relatively usable), and now appear either once
(normal MP4 muxing), or thrice (with the faststart flag set) in
any normal MP4 usage, without giving much useful information. Thus,
remove them in their current form.
Fixes: signed integer overflow: 0 - -9223372036854775808 cannot be represented in type 'long'
Fixes: 29743/clusterfuzz-testcase-minimized-ffmpeg_dem_SAMI_fuzzer-5499256859394048
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: signed integer overflow: 2147483424 + 8224 cannot be represented in type 'int'
Fixes: 29619/clusterfuzz-testcase-minimized-ffmpeg_dem_AVI_fuzzer-5191424373030912
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: out of array access
Fixes: 29446/clusterfuzz-testcase-minimized-ffmpeg_dem_AAC_fuzzer-5096222622875648
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: signed integer overflow: 2147483647 + 7 cannot be represented in type 'int'
Fixes: 30084/clusterfuzz-testcase-minimized-ffmpeg_dem_WTV_fuzzer-6192261941559296
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: OOM
Fixes: 30066/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_fuzzer-6182309126602752
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: signed integer overflow: -1268324762623155200 * 8 cannot be represented in type 'long'
Fixes: 30123/clusterfuzz-testcase-minimized-ffmpeg_dem_THREEDOSTR_fuzzer-6710765123928064
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The way SRT's async / epoll-based IO works is that the event status is stored
in the epoll containers. That is, if an event occurs on an SRT socket, and that
SRT socket isn't part of any epoll container, then that event is lost. If we
later add that socket to an epoll container, we still won't receive the event
even if it wasn't serviced.
Therefore we create the epoll and put the fd into it right after the connection
is established.
See http://lists.ffmpeg.org/pipermail/ffmpeg-devel/2021-January/275334.html
Signed-off-by: Marton Balint <cus@passwd.hu>
Andreas Rheinhardt
Michael Niedermayer
Paul B Mahol
Carl Eugen Hoyos
James Almer
Jan Ekström
Marton Balint