Will Kelleher [Wed, 11 Nov 2015 21:37:29 +0000 (15:37 -0600)]
hevc: Fix a53 caption extraction
Just realized my previous patch doesn't work quite right. I uploaded a better
sample file that actually has visible captions to /incoming/hevc_cc.ts. I
tested with that file doing hevc->x264 and it works.
This is basically an exact copy of the existing h264 logic.
Signed-off-by: Will Kelleher <wkelleher@gogoair.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Bryan Huh [Tue, 10 Nov 2015 19:11:26 +0000 (11:11 -0800)]
avformat/mov: Add option to ignore chapters during parsing
Chapter-indexing can be expensive since chapters may be interspersed
throughout the entire file and may require many seeks - especially
costly when consuming a video over a remote protocol like http.
Furthermore it is often unnecessary, especially when only trying to get
video info (e.g. via ffprobe).
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
avformat/mxfenc: Only store user comment related tags when needed
Also support disabling them as they seem to cause problems to some
Users. They are also not allowed in IRT D-10 thus the default for
mxf_d10 is not to write them
This also decreases the filesize when no user comment are stored
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Martin Storsjö [Fri, 6 Nov 2015 23:18:05 +0000 (01:18 +0200)]
movenc: Automatically flush after writing the initial moov
In most other cases when writing fragmented mp4 files, the output
IO context is flushed after each fragment. Also flush it after
writing the initial moov, to have it behave in the same way.
wm4 [Tue, 10 Nov 2015 12:47:01 +0000 (13:47 +0100)]
mmaldec: send only a single EOS packet on flushing
Fixes apparent mmal_port_disable() freezes in ffmmal_stop_decoder() when
calling ffmmal_decode() with flush semantics a large number of times in
a row.
Somewhat ironic that this "safe" interface is actually being used
unsafely here. This fixes the usage preventing potential null pointer
dereference, where the old code was doubly broken: ctime can return
NULL, and ctime can return an arbitrarily long buffer.
Reviewed-by: Mark Harris <mark.hsj@gmail.com> Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
swresample/resample: speed up Blackman Nuttall filter
This may be a slightly surprising optimization, but is actually based on
an understanding of how math libraries compute trigonometric functions.
Explanation is given here so that future development uses libm more effectively
across the codebase.
All libm's essentially compute transcendental functions via some kind of
polynomial approximation, be it Taylor-Maclaurin or Chebyshev.
Correction terms are added via polynomial correction factors when needed
to squeeze out the last bits of accuracy. Lookup tables are also
inserted strategically.
In the case of trigonometric functions, periodicity is exploited via
first doing a range reduction to an interval around zero, and then using
some polynomial approximation.
This range reduction is the most natural way of doing things - else one
would need polynomials for ranges in different periods which makes no
sense whatsoever.
To avoid the need for the range reduction, it is helpful to feed in
arguments as close to the origin as possible for the trigonometric
functions. In fact, this also makes sense from an accuracy point of view:
IEEE floating point has far more resolution for small numbers than big ones.
This patch does this for the Blackman-Nuttall filter, and yields a
non-negligible speedup.
swresample/resample: speed up upsampling by precomputing sines
When upsampling, factor is set to 1 and sines need to be evaluated only
once for each phase, and the complexity should not depend on the number
of filter taps. This does the desired precomputation, yielding
significant speedups. Hard guarantees on the gain are not possible, but gains
themselves are obvious and are illustrated below.
Note that this does not statically allocate the sin lookup table. This
may be done for the default 1024 phases, yielding a 512*8 = 4kB array
which should be small enough.
This should yield a small improvement. Nevertheless, this is separate from
this patch, is more ambiguous due to the binary increase, and requires a
lut to be generated offline.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Bryan Huh [Mon, 9 Nov 2015 00:35:01 +0000 (16:35 -0800)]
avformat/cache: Avoid int-overflow in cache compare function
cache protocol indexes its cache using AVTreeNodes which require a cmp
function for inserting and searching new cache-entries. This cmp
function expects a 32-bit int return value (negative, zero, or positive)
but the cache cmp function returns an int64_t which can overflow the
int, giving negative numbers for when it should be positive, vice versa.
This manifests itself only for very large files (e.g. 4GB+)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from ffmpeg commit 227b4458fb434875b127a0c2306fa3b899a770bf) Signed-off-by: Anton Khirnov <anton@khirnov.net>
Anton Khirnov [Wed, 7 Oct 2015 13:51:11 +0000 (15:51 +0200)]
lavf: deprecate compute_pkt_fields2
All encoders set pts and dts properly now (and have been doing that for
a while), so there is no good reason to do any timestamp guessing in the
muxer.
The newly added AVStreamInternal will be later used for storing all the
private fields currently living in AVStream.
swresample/resample: improve bessel function accuracy and speed
This improves accuracy for the bessel function at large arguments, and this in turn
should improve the quality of the Kaiser window. It also improves the
performance of the bessel function and hence build_filter by ~ 20%.
Details are given below.
Algorithm: taken from the Boost project, who have done a detailed
investigation of the accuracy of their method, as compared with e.g the
GNU Scientific Library (GSL):
http://www.boost.org/doc/libs/1_52_0/libs/math/doc/sf_and_dist/html/math_toolkit/special/bessel/mbessel.html.
Boost source code (also cited and licensed in the code):
https://searchcode.com/codesearch/view/14918379/.
Accuracy: sample values may be obtained as follows. i0 denotes the old bessel code,
i0_boost the approach here, and i0_real an arbitrary precision result (truncated) from Wolfram Alpha:
type "bessel i0(6.0)" to reproduce. These are evaluation points that occur for
the default kaiser_beta = 9.
Reason for accuracy: Main accuracy benefits come at larger bessel arguments, where the
Taylor-Maclaurin method is not that good: 23+ iterations
(at large arguments, since the series is about 0) can cause
significant floating point error accumulation.
Benchmarks: Obtained on x86-64, Haswell, GNU/Linux via a loop calling
build_filter 1000 times:
test: fate-swr-resample-dblp-44100-2626
new: 995894468 decicycles in build_filter(loop 1000), 256 runs, 0 skips 1029719302 decicycles in build_filter(loop 1000), 512 runs, 0 skips 984101131 decicycles in build_filter(loop 1000), 1024 runs, 0 skips
old: 1250020763 decicycles in build_filter(loop 1000), 256 runs, 0 skips 1246353282 decicycles in build_filter(loop 1000), 512 runs, 0 skips 1220017565 decicycles in build_filter(loop 1000), 1024 runs, 0 skips
A further ~ 5% may be squeezed by enabling -ftree-vectorize. However,
this is a separate issue from this patch.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
swresample: allow double precision beta value for the Kaiser window
Kaiser windows inherently don't require beta to be an integer. This was
an arbitrary restriction. Moreover, soxr does not require it, and in
fact often estimates beta to a non-integral value.
Thus, this patch allows greater flexibility for swresample clients.
Micro version is updated.