This improves the mathematical behavior of hypotenuse computation.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
It is known that the naive sqrt(x*x + y*y) approach for computing the
hypotenuse suffers from overflow and accuracy issues, see e.g
http://www.johndcook.com/blog/2010/06/02/whats-so-hard-about-finding-a-hypotenuse/.
This adds hypot support to FFmpeg, a C99 function.
On platforms without hypot, this patch does a reaonable workaround, that
although not as accurate as GNU libm, is readable and does not suffer
from the overflow issue. Improvements can be made separately.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
isnan and isinf are actually macros as per the standard. In particular,
the existing implementation has incorrect signature. Furthermore, this
results in undefined behavior for e.g double values outside float range
as per the standard.
This patch corrects the undefined behavior for all usage within FFmpeg.
Note that long double is not handled as it is not used in FFmpeg.
Furthermore, even if at some point long double gets used, it is likely
not needed to modify the macro in practice for usage in FFmpeg. See
below for analysis.
Getting long double to work strictly per the spec is significantly harder
since a long double may be an IEEE 128 bit quad (very rare), 80 bit
extended precision value (on GCC/Clang), or simply double (on recent Microsoft).
On the other hand, any potential future usage of long double is likely
for precision (when a platform offers extra precision) and not for range, since
the range anyway varies and is not as portable as IEEE 754 single/double
precision. In such cases, the implicit cast to a double is well defined
and isinf and isnan should work as intended.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Doing that doesn't make sense, because the only purpose of sbr_dequant
is to process the data from read_sbr_data.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
This function returns the encoded data of a frame, one slice at a time
directly when that slice is encoded, instead of waiting for the full
frame to be done. However this field has a debatable usefulness, since
it looks like it is just a convoluted way to get data at lowest
possible latency, or a somewhat hacky way to store h263 in RFC-2190
rtp encapsulation.
Moreover when multi-threading is enabled (which is by default) the order
of returned slices is not deterministic at all, making the use of this
function not reliable at all (or at the very least, more complicated
than it should be).
So, for the reasons stated above, and being used by only a single encoder
family (mpegvideo), this field is deemed unnecessary, overcomplicated,
and not really belonging to libavcodec. Libavformat features a complete
implementation of RFC-2190, for any other case.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This should fix a infinite loop
Reviewed-by: Andreas Cadhalpun <andreas.cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
server_attached is newly added so the demuxer knows if there is an attached server
that can update the write index. This is needed to fix a infinite loop
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The ad-hoc pi constant has a ludicrous number of digits that offer no
value whatsoever. M_PI is more consistent and readable across the
codebase.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
If videotoolbox_common_end_frame failed, then the AVFrame was returned
to the API user with the dummy buffer (in AVFrame.buf[0]) still set, and
the decode call indicating success.
These "half-set" AVFrames with dummy buffer are a videotoolbox specific
hack, because the decoder requires an allocated AVFrame for its internal
logic. Videotoolbox on the other hand allocates its frame itself
internally, and outputs it only on end_frame. At this point, the dummy
buffer is replaced with the real frame (unless decoding fails).
Currently, multiple slices with just one thread produce corrupted
output.
Additionally, enable slice structured mode for h263(+)
Bug-Id: 912
CC: libav-stabl@libav.org
The replaced check should have become redundant
Found-by: Andreas Cadhalpun <andreas.cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
It is used as size argument of ff_canopus_parse_info_tag, which uses it
as size argument to bytestream2_init, which only supports sizes up to
INT_MAX.
Changing it's type to unsigned simplifies the check.
Reviewed-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
* commit '1fc94724f1fd52944bb5ae571475c621da4b77a0':
xtea: Clarify that the current API works in big endian mode
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
This allows removing a special case for the fixed point decoder and will
make error checks simpler
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Previously only the edit_rate of material_track was checked.
If it's negative, it causes assertion failures in av_rescale_rnd.
Reviewed-by: Tim Nicholson <nichot20-at-yahoo.com@ffmpeg.org>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
In case of bitstream errors the deblock filter and slices can access uninitialized
top_borders from previous slices which did not fill them as they stoped halfway due
to error or where entirely missing.
This also makes code using these tables deterministic in case of missing or damaged
slices
Found-by: Tyson Smith
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Ganesh Ajjanagadde
Daniil Cherednik
Timothy Gu
Andreas Cadhalpun
Vittorio Giovara
Paul B Mahol
Michael Niedermayer
Rodger Combs
Maksym Veremeyenko
Clément Bœsch
wm4
Anton Khirnov
James Almer
Derek Buitenhuis