Original mail and my own followup on ffmpeg-user earlier today:
I have a device sending out a MJPEG/RTP stream on a low quality setting.
Decoding and displaying the video with libavformat results in a washed
out, low contrast, greyish image. Playing the same stream with VLC results
in proper color representation.
Screenshots for comparison:
http://zevv.nl/div/libav/shot-ffplay.jpghttp://zevv.nl/div/libav/shot-vlc.jpg
A pcap capture of a few seconds of video and SDP file for playing the
stream are available at
http://zevv.nl/div/libav/mjpeg.pcaphttp://zevv.nl/div/libav/mjpeg.sdp
I believe the problem might be in the calculation of the quantization
tables in the function create_default_qtables(), the attached patch
solves the issue for me.
The problem is that the argument 'q' is of the type uint8_t. According to the
JPEG standard, if 1 <= q <= 50, the scale factor 'S' should be 5000 / Q.
Because the create_default_qtables() reuses the variable 'q' to store the
result of this calculation, for small values of q < 19, q wil subsequently
overflow and give wrong results in the calculated quantization tables. The
patch below uses a new variable 'S' (same name as in RFC2435) with the proper
range to store the result of the division.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit e3e6a2cff4)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This should theoretically improve the randomness slightly
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 2540d884f3)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Trying to make heads and tails out of DTS 6.1 I can across this typo.
I also noticed that this wiki page is incorrect or misleading, the
channel order for 6.1 given does not match the source code. At the
least it should be clarified that the layout given does not apply to
DTS. https://trac.ffmpeg.org/wiki/AudioChannelManipulation
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 73d1398f0c)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This is safer, as a selected demuxer could still mean that it was auto-detected
by a user application
Reviewed-previously-by: Nicolas George <george@nsup.org>
Reviewed-previously-by: Andreas Cadhalpun <andreas.cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 689211d572)
Conflicts:
libavformat/concatdec.c
RTCP synchronization packet was broken since commit in ffmpeg version > 2.8.3
(commit: e04b039b15) Since this commit (2e814d0329)
"rtpenc: Simplify code by introducing a macro for rescaling NTP timestamps", NTP_TO_RTP_FORMAT
uses av_rescale_rnd() function to add the data to the packet.
This causes an overflow in the av_rescale_rnd() function and it will return INT64_MIN.
Causing the NTP stamp in the RTCP packet to have an invalid value.
Github: Closes#182
Reverting commit '2e814d0329aded98c811d0502839618f08642685' solves the problem.
(cherry picked from commit 1109ed7973)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This zeroes the WebPAnimEncoderOptions.verbose field, silencing library info messages
printed to stderr.
Reviewed-by: James Zern <jzern@google.com>
Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit 626b6b769c)
Previously errors could result in random entries to be lost.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit f3ace85d88)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Sample rate of 11025 takes 16 bits but previous code would pick only 8.
Fixes assertion failure.
Reviewed-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Signed-off-by: Paul B Mahol <onemda@gmail.com>
(cherry picked from commit 3e7d684912)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This feature is not know much or used much AFAIK, and it might be helpfull in
exploits.
No specific case is known where it can be used in an exploit though
subsequent commits depend on this commit though
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 984d58a344)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
With this, user applications which use custom IO and have set a IO context will not have
their already opened IO context ignored and glob/seq being interpreted
Comments and tests from maintainers of user apps are welcome!
Liked-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 7ccedc1c78)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This feature is mostly only used by NLE software, and is
both of dubious value being enabled by default, and a
possible security risk.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 712d962a6a)
Conflicts:
libavformat/isom.h
libavformat/mov.c
libavformat/version.h
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes out of array access
Fixes: aaa479088e6fb40b04837b3119f47b04/asan_heap-oob_e38c68_8576_9d653078b2470700e2834636f12ff557.tga
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 03d83ba34b)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
