refer to SPEC:
Annex E. The FLV File Format said:
E.3 TheFLVFileBody have a table:
Field            Type    Comment
PreviousTagSize0 UI32    Always 0
Reviewed-by: Bela Bodecs <bodecsb@vivanet.hu>
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

Fixes memleak.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

adding demuxer and other logs should be easy
This forces single threaded decoding for simplicity
It also requires pthreads, this could be avoided either with
some lockless tricks or simply by assuming av_log would never be called from
another thread.

Fixes Ticket5521

Previous version reviewed by Stefano
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

They are unofficial extensions to the format for the time being, not
an experimental feature.

Signed-off-by: James Almer <jamrial@gmail.com>

* commit '064f19f3':
  avconv: support parsing bitstream filter options

This commit is a noop, see 5ef19590Merged-by: James Almer <jamrial@gmail.com>

* commit 'ecd2ec69':
  mov: Evaluate the movie display matrix

This commit is a noop, see 7010ebdfMerged-by: James Almer <jamrial@gmail.com>

* commit 'b90c8a3d':
  fate: Add tests for mov display matrix

Adapted to use ffprobe -show_entries
Merged-by: James Almer <jamrial@gmail.com>

* commit '7d308bf8':
  avprobe: Add -show_stream_entry to get a single stream property

This commit is a noop, we have a generic -show_entry option.
Merged-by: Clément Bœsch <u@pkh.me>

* commit '218ed725':
  openssl: Allow newer TLS versions than TLSv1

This commit is a noop, see e8634fb9Merged-by: Clément Bœsch <u@pkh.me>

* commit 'dad7514f':
  xcb: Add all the libraries to the link line explicitly

This commit is a noop. It appears we already link against the xcb shape
library since 54170a33.
Merged-by: Clément Bœsch <u@pkh.me>

* commit 'c541a44e':
  Revert "rtmpproto: Don't include a client version in the unencrypted C1 handshake"
Merged-by: Clément Bœsch <u@pkh.me>

* commit '801ac715':
  qsv: Be informative when reporting that no data has been consumed
Merged-by: Clément Bœsch <u@pkh.me>

* commit '30015305':
  Use avpriv_request_sample() where appropriate

Only the roqvideo chunk is merged because we actually support 24bpp
flic, see 5781c983.
Merged-by: Clément Bœsch <u@pkh.me>

* commit '07cac07c':
  dash: Use correct ISO C scanf conversion specifier

This commit is a noop: the use of SCN (scanf) format is wrong here.
Merged-by: Clément Bœsch <u@pkh.me>

* commit '3ec6f855':
  srt: Adjust signedness of sscanf format strings

This commit is a noop, a different fix is included in the big -Wformat
patch under review
(http://ffmpeg.org/pipermail/ffmpeg-devel/2017-March/209239.html)
Merged-by: Clément Bœsch <u@pkh.me>

* commit '7a2b2b6a':
  dxtory: Drop nonsense ISO C printf conversion specifiers for standard types
Merged-by: Clément Bœsch <u@pkh.me>

* commit 'c454dfcf':
  Use ISO C printf conversion specifiers where appropriate

This commit is a noop, an equivalent patch is currently under review on
the mailing-list: http://ffmpeg.org/pipermail/ffmpeg-devel/2017-March/209239.htmlMerged-by: Clément Bœsch <u@pkh.me>

Ends up identical to Libav.

This reduces diff with Libav.

Imported from Libav

For consistency with Libav.

This reduces diff with Libav. It also prevents a potential confusion
between the private context and the AVCodecContext.

This is following Libav layout to ease merges.

Entries are organized in descending chronological order.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

Long overdue for removal, af_aresample should be used instead.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

Could lead to random behavior. This possibly happened due to commit
32a5b631. This should/could probably be simplified, but for no apply
a minimal fix to quell the errors.
Tested-by: Michael Niedermayer <michael@niedermayer.cc>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>

async_mutex has is used in a very strange but intentional way: it is
locked by default, and unlocked only in regions that can be run
concurrently.

If the user was calling API functions to the same context from different
threads (in a safe way), this could unintentionally unlock the mutex on
a different thread than the previous lock operation. It's not allowed by
the pthread API.

Fix this by emulating a binary semaphore using a mutex and condition
variable. (Posix semaphores are not available on all platforms.)
Tested-by: Michael Niedermayer <michael@niedermayer.cc>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>

The old "API" that signaled rotation as a metadata value has been
replaced by DISPLAYMATRIX side data quite a while ago.

There is no reason to make muxers/demuxers/API users support both. In
addition, the metadata API is dangerous, as user tags could "leak" into
it, creating unintended features or bugs.

ffmpeg CLI has to be updated to use the new API. In particular, we must
not allow to leak the "rotate" tag into the muxer. Some muxers will
catch this properly (like mov), but others (like mkv) can add it as
generic tag. Note applications, which use libavformat and assume the
old rotate API, will interpret such "rotate" user tags as rotate
metadata (which it is not), and incorrectly rotate the video.

The ffmpeg/ffplay tools drop the use of the old API for muxing and
demuxing, as all muxers/demuxers support the new API. This will mean
that the tools will not mistakenly interpret per-track "rotate" user
tags as rotate metadata. It will _not_ be treated as regression.

Unfortunately, hacks have been added, that allow the user to override
rotation by setting metadata explicitly, e.g. via

  -metadata:s:v:0 rotate=0

See references to trac #4560. fate-filter-meta-4560-rotate0 tests this.
It's easier to adjust the hack for supporting it than arguing for its
removal, so ffmpeg CLI now explicitly catches this case, and essentially
replaces the "rotate" value with a display matrix side data. (It would
be easier for both user and implementation to create an explicit option
for rotation.)

When the code under FF_API_OLD_ROTATE_API is disabled, one FATE
reference file has to be updated (because "rotate" is not exported
anymore).
Tested-by: Michael Niedermayer <michael@niedermayer.cc>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>

Squelches the following compiler warnings:

libavcodec/opusenc.c:1051:16: warning: format specifies type 'long' but
the argument has type 'long long' [-Wformat]
               avctx->bit_rate/1000, clipped_rate/1000);
               ^~~~~~~~~~~~~~~~~~~~
libavcodec/opusenc.c:1051:38: warning: format specifies type 'long' but
the argument has type 'long long' [-Wformat]
               avctx->bit_rate/1000, clipped_rate/1000);
                                     ^~~~~~~~~~~~~~~~~

Reviewed-by: "Ronald S. Bultje" <rsbultje@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

This was skipped in c17563c5 because
it depended on the filter setup merge, but was forgotten after that
actually happened.

Fixes hwaccel fate for stream size change tests.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>