This is possible now that the next-API is gone.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Signed-off-by: James Almer <jamrial@gmail.com>
Reading the header terminates when an fcTL chunk is encountered in which
case read_header returned success without checking the length of said
chunk. Yet when read_packet processes this chunk, it checks for the
length to be 26 and errors out otherwise. So do so when reading the header,
too.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
apng data consists of parts containing a small header (including a
four-byte size field) and a data part; the size field does not account
for everything and is actually twelve bytes short of the actual size. In
order to make sure that the size fits into an int, the size field is
checked for being > INT_MAX; yet this does not account for the + 12 and
upon conversion to int (which happens when calling append_extradata()),
the size parameter can still wrap around. In this case the currently
used check would lead to undefined signed integer overflow.
Furthermore, append_extradata() appends the new data to the already
existing extradata and therefore needs to make sure that the combined
size of new and old data as well as padding fits into an int. The check
used for this is "if (old_size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE -
new_size)". If new_size is > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE
the right side becomes negative if the types are signed (as they are
now); yet changing this to "if (new_size > INT_MAX -
AV_INPUT_BUFFER_PADDING_SIZE - old_size)" is better as this also works
for unsigned types (where it is of course presumed that INT_MAX is
replaced by the corresponding maximum for the new type).
Both of these issues have been fixed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
If avio_read() could read anything, it returns the number of bytes read,
even if it could not read as much as the caller desired.
apng_read_header() only checked the return value of its avio_read() calls
for being negative and this meant that it was possible for an incomplete
header to not be detected. The return value of the last successfull call
has been returned instead. This commit changes this.
Fixes: OOM
Fixes: 26608/clusterfuzz-testcase-minimized-ffmpeg_dem_APNG_fuzzer-4839491644424192
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The extradata will be freed automatically when the corresponding stream
gets freed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Zeroing the padding has been forgotten.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
And let the generic code figure out the proper PTS. This is needed because apng
does not provide seek functions, but after a generic seek (e.g. to file start)
timestamps are not reset which causes broken timestamps when looping apngs,
like in ticket #6121.
Signed-off-by: Marton Balint <cus@passwd.hu>
This reverts commit e0c6b32046.
Said commit changed the behavior of the demuxer and decoder in a non
backwards compatible way.
Demuxers should make extradata available at init if possible, and send
new extradata as side data within a packet if needed.
A better fix for the remuxing crash will follow.
Signed-off-by: James Almer <jamrial@gmail.com>
Fixes remuxing apng streams coming from the apng demuxer.
This is a regression since 940b8908b9.
Found-by: James Almer <jamrial@gmail.com>
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
When the dimensions are the entire frame ones, and the dispose operation
is to reset to background, or the new frame overwrites the new one, then
consider the frame as a key one.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
In order to support multiple IDAT of fdAT chunks following an fcTL one,
transmit all the chunks between two fcTL ones (or between fcTL and IEND
one).
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
