vp9/x86: invert hu_ipred left array ordering.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'cee4490b521fd0d02476d46aa2598af24fb8d686'

* commit 'cee4490b521fd0d02476d46aa2598af24fb8d686':
  on2avc: check number of channels

See: 550f3e9df3410b3dd975e590042c0d83e20a8da3
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'd423dd72be451462c6fb1cbbe313bed0194001ab'

* commit 'd423dd72be451462c6fb1cbbe313bed0194001ab':
  smc: fix the bounds check

Conflicts:
libavcodec/smc.c

See: c727401aa9d62335e89d118a5b4e202edf39d905
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '0b39ac6f54505a538c21fe49a626de94c518c903'

* commit '0b39ac6f54505a538c21fe49a626de94c518c903':
  gifdec: refactor interleave end handling

Conflicts:
libavcodec/gifdec.c

See: 8f1457864be8fb9653643519dea1c6492f1dde57
Merged-by: Michael Niedermayer <michaelni@gmx.at>

lavf/rtp_h261: Replace restrict with av_restrict.

Fixes compilation on Windows.

Merge commit '17ba719d9ba30c970f65747f42d5fbb1e447ca28'

* commit '17ba719d9ba30c970f65747f42d5fbb1e447ca28':
  mmvideo: check frame dimensions

See: 8b0e96e1f21b761ca15dbb470cd619a1ebf86c3e
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '88626e5af8d006e67189bf10b96b982502a7e8ad'

* commit '88626e5af8d006e67189bf10b96b982502a7e8ad':
  jvdec: check frame dimensions

See: 105654e376a736d243aef4a1d121abebce912e6b
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '809c3023b699c54c90511913d3b6140dd2436550'

* commit '809c3023b699c54c90511913d3b6140dd2436550':
  mjpegdec: check for pixel format changes

Conflicts:
libavcodec/mjpegdec.c

See: 5c378d6a6df8243f06c87962b873bd563e58cd39
See: a2f680c7bc7642c687aeb4e14d00ac74833c7a09
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '64f7575fbd64e5b65d5c644347408588c776f1fe'

* commit '64f7575fbd64e5b65d5c644347408588c776f1fe':
  mov: avoid a memleak when multiple stss boxes are present

Conflicts:
libavformat/mov.c

See: 5ab882d7283f57560c889919c35f2688253b1d9c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

on2avc: check number of channels

Fixes invalid memory access.

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8549
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton@khirnov.net>

smc: fix the bounds check

Fixes invalid writes when there are more blocks in a run than total
remaining blocks.

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8548
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton@khirnov.net>

gifdec: refactor interleave end handling

Fixes invalid writes with very small image heights.

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8547
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton@khirnov.net>

mmvideo: check frame dimensions

The frame size must be set by the caller and each dimension must be a
multiple of 2.

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8543
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind

jvdec: check frame dimensions

The frame size must be set by the caller and each dimension must be a
multiple of 8.

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8542
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind

mjpegdec: check for pixel format changes

Fixes possible invalid memory access.

Based on code by Michael Niedermayer <michaelni@gmx.at>

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8541
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind

mov: avoid a memleak when multiple stss boxes are present

CC: libav-stable@libav.org
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind

Merge commit '210461c0a83a5625560fa1d92229200dc7fb869b'

* commit '210461c0a83a5625560fa1d92229200dc7fb869b':
  imgconvert: check memory allocations and propagate errors

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '596b5c488fa1d40f114a64d3b73e1863cab073fb'

* commit '596b5c488fa1d40f114a64d3b73e1863cab073fb':
  wma: check memory allocations and propagate errors

Conflicts:
libavcodec/wma.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '63be97ec403023fb664798432acedaf6e6922527'

* commit '63be97ec403023fb664798432acedaf6e6922527':
  lavfi: always check av_expr_parse_and_eval() return value

not merged, this is incorrect

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '9e06327ecb8f73c7904d10af7ad339c57cdaa788'

* commit '9e06327ecb8f73c7904d10af7ad339c57cdaa788':
  xcbgrab: Move NULL check before pointer dereference

Conflicts:
libavdevice/xcbgrab.c

See: e86df0206f06b8d1e97e2b60db8f74a398d53127
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '5ac06633cb63fcc51f2471a3478b44d3f010b16b'

* commit '5ac06633cb63fcc51f2471a3478b44d3f010b16b':
  takdec: check av_samples_get_buffer_size() return value

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '16c7a8a142277aa3c98b4802ee57daaebe6999e5'

* commit '16c7a8a142277aa3c98b4802ee57daaebe6999e5':
  aacps: invert the order of parameters of ipdopd_reset()

See: 9f36ec6aa936515a703f6d7ff32826aa28684f1e
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '76ccf114a6c107218e2a1948afc1d0fb3ac7ba0b'

* commit '76ccf114a6c107218e2a1948afc1d0fb3ac7ba0b':
  rtsp: check ffurl_get_file_handle() return value

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'b1306823d0b3ae998c8e10ad832004eb13bdd93e'

* commit 'b1306823d0b3ae998c8e10ad832004eb13bdd93e':
  check memory errors from av_strdup()

Conflicts:
avprobe.c
libavformat/matroskaenc.c
libavutil/opt.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '9745f19ffc9031ce480e43d7cf1053b58100d70f'

* commit '9745f19ffc9031ce480e43d7cf1053b58100d70f':
  assdec: check the right variable

Conflicts:
libavcodec/assdec.c

See: cc7342f712c0822c3e8f4c36fc55632c59aabac9
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '971099ff5a85377579eb5b8d3620e283957f097e'

* commit '971099ff5a85377579eb5b8d3620e283957f097e':
  aacenc: correctly check returned value

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'ac467d94fa6d9d626f77d4ca8125a5eb1ad5425d'

* commit 'ac467d94fa6d9d626f77d4ca8125a5eb1ad5425d':
  lcl: return an appropriate error code

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '8b263331c5ebbb10b6ea521e9fd56751ba94254b'

* commit '8b263331c5ebbb10b6ea521e9fd56751ba94254b':
  mpegts: check get16() return value

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '430a8168594b3cb29f44141d4da88f2c642de06f'

* commit '430a8168594b3cb29f44141d4da88f2c642de06f':
  oggdec: add support for VP8 demuxing

Conflicts:
Changelog
libavformat/oggparsevp8.c
libavformat/version.h

See: d890db5f537bdfc9d73e7fdac1ff4216e5a43fc2
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '38129c26c51b933d7db423f904ba0cd6a88ca1ed'

* commit '38129c26c51b933d7db423f904ba0cd6a88ca1ed':
  cmdutils: check file access functions return values

Conflicts:
cmdutils.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'c63dd3f0a48a9f6389d253597ab51caddc0118db'

* commit 'c63dd3f0a48a9f6389d253597ab51caddc0118db':
  a64multi: check elbg return values

Conflicts:
libavcodec/a64multienc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '3beb9cbad35218ed1fb3473eeb3cfc97a931bff4'

* commit '3beb9cbad35218ed1fb3473eeb3cfc97a931bff4':
  roqvideo: check memory allocations and propagate errors

Conflicts:
libavcodec/roqvideoenc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'ae2d41ec875965ce4ab9fdd88a5e8ba57cada67a'

* commit 'ae2d41ec875965ce4ab9fdd88a5e8ba57cada67a':
  elbg: check memory allocations and propagate errors

Conflicts:
libavcodec/elbg.c
libavcodec/elbg.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '5d839778b9f3edb682b7f71dde4f80f07c75b098'

* commit '5d839778b9f3edb682b7f71dde4f80f07c75b098':
  lavu: Refactor side data wiping

Conflicts:
libavutil/frame.c

See: a400edbb6d00c0211de38e4f1b4f593681db91d8
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'effa7d2a6a260ca3ce801c180ee6131d67d665fb'

* commit 'effa7d2a6a260ca3ce801c180ee6131d67d665fb':
  fate: add test for offset theora

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '67fc8a15e4182ea111cfcd05897709f09d99a33a'

* commit '67fc8a15e4182ea111cfcd05897709f09d99a33a':
  theora: support different visible and coded frame size

Conflicts:
libavcodec/vp3.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'a381e0cec87bcb28ebc05fe840bb937a495de736'

* commit 'a381e0cec87bcb28ebc05fe840bb937a495de736':
  fate: add a DPX parser test

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '87bd298abeb901fe16383a0d267502cc7fc03878'

* commit '87bd298abeb901fe16383a0d267502cc7fc03878':
  DPX parser

Conflicts:
libavcodec/dpx_parser.c
libavcodec/version.h

See: 8ec328668a7d10c8224ae5f591add5b388ea82ed
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '3a3790b8f8b56ee6abc93ccac280eb693675e294'

* commit '3a3790b8f8b56ee6abc93ccac280eb693675e294':
  tiff: support encoding and decoding 64bit images

Conflicts:
libavcodec/tiff.c
libavcodec/tiffenc.c
libavcodec/version.h

See: c714cd3bd4af70e0cba1db399ca420b1f51a773d
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '59f0275dd0a42a7f90271a83a78e9ca5e69ff5b0'

* commit '59f0275dd0a42a7f90271a83a78e9ca5e69ff5b0':
  movenc: Adjust the pts of new fragments similarly to what is done for dts

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '8a70ef94b9c377293b3dfa7d92cdc81a4fe1543a'

* commit '8a70ef94b9c377293b3dfa7d92cdc81a4fe1543a':
  libavformat: Add a muxer wrapping mpegts encoding into RTP

Conflicts:
Changelog
libavformat/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'a505c0d7373336a4cc5aa2022111c46bdd388b1f'

* commit 'a505c0d7373336a4cc5aa2022111c46bdd388b1f':
  rtp: Initial H.261 support

Conflicts:
Changelog
libavformat/rtpdec_h261.c
libavformat/rtpenc_h261.c
libavformat/sdp.c
libavformat/version.h

See: 50a4d5cfc6749932347ee38c25b5040aea4b13a0
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'adc214e6797750285a5e62634b8521db521162ad'

* commit 'adc214e6797750285a5e62634b8521db521162ad':
  rtpenc: Avoid brittle switch fallthroughs

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '3bb465245fed6069512e6821000391beae8a6066'

* commit '3bb465245fed6069512e6821000391beae8a6066':
  h261dec: Fix context initialization sequence

See: 6c1ee1a11446abbe662fc89b9dff0f0a3d5fdd55
Merged-by: Michael Niedermayer <michaelni@gmx.at>

qdm2: Allow hard-coding VLC tables.

Also adds a lot of infrastructure necessary for it.
Some of it is a bit ugly though.
Increases binary size for hardcoded tables by about 12 kB,
which is about 15 kB from qdm2_table minus data and code
saved that was only used for creating it.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

aacps.c: Move large arrays to context to reduce stack usage.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

imgconvert: check memory allocations and propagate errors

wma: check memory allocations and propagate errors

lavfi: always check av_expr_parse_and_eval() return value

CC: libav-stable@libav.org
Bug-Id: CID 703624

xcbgrab: Move NULL check before pointer dereference

Bug-Id: CID 1254668

takdec: check av_samples_get_buffer_size() return value

CC: libav-stable@libav.org
Bug-Id: CID 747734

aacps: invert the order of parameters of ipdopd_reset()

This is the order that the caller uses in the rest of the file. The
same operation is applied to both parameters, so this change is only
done for consistency, it doesn't change the actual behaviour.

Bug-Id: CID 732285 / CID 732286

rtsp: check ffurl_get_file_handle() return value

CC: libav-stable@libav.org
Bug-Id: CID 717844

check memory errors from av_strdup()

assdec: check the right variable

CC: libav-stable@libav.org
Bug-Id: CID 1257815

aacenc: correctly check returned value

CC: libav-stable@libav.org

lcl: return an appropriate error code

mpegts: check get16() return value

And break flow of execution rather than exiting the function.

CC: libav-stable@libav.org
Bug-Id: CID 732186

oggdec: add support for VP8 demuxing

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

cmdutils: check file access functions return values

CC: libav-stable@libav.org
Bug-Id: CID 703706

a64multi: check elbg return values

roqvideo: check memory allocations and propagate errors

elbg: check memory allocations and propagate errors

lavu: Refactor side data wiping

And make sure the nb_side_data field is reset as well.

Based on an initial patch from wm4 <nfxjfg@googlemail.com>.

CC: libav-stable@libav.org

fate: add test for offset theora

theora: support different visible and coded frame size

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

fate: add a DPX parser test

DPX parser

Additional improvements and fixes by Michael Niedermayer <michaelni@gmx.at>.

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

tiff: support encoding and decoding 64bit images

movenc: Adjust the pts of new fragments similarly to what is done for dts

The pts and the corresponding duration is written in sidx
atoms, thus make sure these match up correctly.

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat: Add a muxer wrapping mpegts encoding into RTP

Since this structurally is quite different from normal RTP
(multiple streams are muxed into one single mpegts stream,
which is packetized into one single RTP session), it is kept
as a separate muxer.

Since this structurally also behaves differently than normal
RTP, all of the other muxers that do chained RTP muxing
(rtsp, sap, mp4) would need to be updated similarly to handle
this - in particular, creating one single rtp_mpegts muxer
for the whole presentation instead of one rtp muxer per stream.

Signed-off-by: Martin Storsjö <martin@martin.st>

rtp: Initial H.261 support

The packetizer only supports splitting at GOB headers - if
such aren't available frequently enough, it splits at any
random byte offset (not at a macroblock boundary either, which
would be allowed by the spec) and sends a payload header pretend
that it starts with a GOB header.

As long as a receiver doesn't try to handle such cases cleverly
but just drops broken frames, this shouldn't matter too much
in practice.

Signed-off-by: Martin Storsjö <martin@martin.st>

rtpenc: Avoid brittle switch fallthroughs

Instead explicitly jump to the default case in the cases where
it is wanted, and avoid fallthrough between different codecs,
which could easily introduce bugs if people editing the code
aren't careful.

Signed-off-by: Martin Storsjö <martin@martin.st>

h261dec: Fix context initialization sequence

ff_mpv_common_init sets s->context_initialized.

This fixes decoding of h261 in the cases where the demuxer
hasn't already set the frame size.

CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>

avfilter/lut: reduce dereference in the inner loop

For rgb, with a 1080p source, 69 to 74fps on core i5(2 core, 1.8GHz),
and 136 to 160 fps on an core i7(4770R, 3.2Ghz)
Changed the yuv code for consistency, even though the performance
increase is not as obvious as rgb

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '91bfac759dfd536e439ad3e35964705012c6a5a7'

* commit '91bfac759dfd536e439ad3e35964705012c6a5a7':
  h261enc: Disallow sliced encoding

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'df07c07b3de0a5e8890078944de1eb5cb8372ef8'

* commit 'df07c07b3de0a5e8890078944de1eb5cb8372ef8':
  rtpdec_h263_rfc2190: Clear the stored bits if discarding buffered data

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '42181740a3972e17d0097d28fabc9a1a60322d47'

* commit '42181740a3972e17d0097d28fabc9a1a60322d47':
  rtpenc: Set the AVFMT_TS_NONSTRICT flag

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '01f251c44d83eedc819625d2caac9ff9697a085d'

* commit '01f251c44d83eedc819625d2caac9ff9697a085d':
  rtpenc: Set the timestamp properly when sending mpegts data, too

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit 'f2c614e8c4a935b52bbf86819128d9e797230c20'

* commit 'f2c614e8c4a935b52bbf86819128d9e797230c20':
  srtpproto: fix option flag type

Merged-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/indeo3: ensure offsets are non negative

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avfilter/vf_spp: add gbrp support

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avfilter/vf_spp: add gray8 support

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avfilter/vf_spp: Fix pointer type warning

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/adpcm: Check idelta

Fixes integer overflow
Fixes: signal_sigsegv_1b0a4da_1865_cov_2167818389_computer_anger.avi
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

h261enc: Disallow sliced encoding

This avoids trying to do sliced encoding, even if a slice/packet
size is requested (via the -ps option or the rtp_payload_size
field), since the encoder currently doesn't support it (or at least
our decoder can't decode it, even if the h261_encode_gob_header
function is hooked up to be called from the slicing part in
mpegvideo_enc.c).

Signed-off-by: Martin Storsjö <martin@martin.st>

rtpdec_h263_rfc2190: Clear the stored bits if discarding buffered data

If we throw away the buffered incomplete frame, make sure to also
throw away the buffered bits of an incomplete byte at the same
time.

CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>

rtpenc: Set the AVFMT_TS_NONSTRICT flag

In particular, when packetizing mpegts into rtp, the input packet
timestamp may come from more than one stream, which could cause
multiple packets be written with the same timestamp.

Signed-off-by: Martin Storsjö <martin@martin.st>

rtpenc: Set the timestamp properly when sending mpegts data, too

Signed-off-by: Martin Storsjö <martin@martin.st>

srtpproto: fix option flag type

Signed-off-by: Martin Storsjö <martin@martin.st>

avcodec/h264: Check *log2_weight_denom

Fixes undefined behavior
Fixes: signal_sigsegv_14768d2_2248_cov_3629497219_h264_h264___pi_20070614T182942.h264
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/hevc_ps: Check diff_cu_qp_delta_depth

Fixes undefined behavior
Fixes: asan_static-oob_17aa046_582_cov_1577759978_DBLK_G_VIXS_1.bit
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/hevc: move qp_block_mask to where its used

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

wavdec: RIFX file format support

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/h264: Clear delayed_pic on deallocation

Fixes use of freed memory

Fixes: case5_av_frame_copy_props.mp4
Found-by: Michal Zalewski <lcamtuf@coredump.cx>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/hevc: clear filter_slice_edges() on allocation

This avoids use of uninitialized memory
Fixes: asan_static-oob_17aa046_582_cov_212287884_DBLK_G_VIXS_1.bit
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

avcodec/dcadec: Check that the added xch channel isnt already there

Fixes null pointer dereference
Fixes: signal_sigsegv_369609d_623_cov_2008234281_ES_6.1_16bit.dts
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '456e93bfdd4cbc5e995dea415019abd0703d0e16'

* commit '456e93bfdd4cbc5e995dea415019abd0703d0e16':
  dashenc: Adjust the start time of a segment to the end of the previous segment

Merged-by: Michael Niedermayer <michaelni@gmx.at>

Merge commit '2f628d5943c12389c07d652d23d3916997f9f0f6'

* commit '2f628d5943c12389c07d652d23d3916997f9f0f6':
  dashenc: Write segment timelines properly if the timeline has gaps

Merged-by: Michael Niedermayer <michaelni@gmx.at>

dashenc: Adjust the start time of a segment to the end of the previous segment

This is the same adjustment that the mp4 muxer does to the start
timestamp of fragments, since the timestamp of a sample in an mp4
file is implicit from the sum of earlier sample durations.

This avoids gaps in the timeline (which can stop dash.js from
playing it back), and makes sure the timestamp on the segmenter
level matches what the mp4 muxer actually writes into the segments.

This is only an issue if the AVPacket duration of the last
packet of a segment doesn't point to the actual start timestamp
of the next packet (the first in the next segment).

Signed-off-by: Martin Storsjö <martin@martin.st>