http: Support auth method detection for POST

Inspired by a patch by Jakob van Bethlehem. But instead of doing
an empty POST first to trigger the WWW-Authenticate header (which
would succeed if no auth actually was required), add an Expect:
100-continue header, which is meant to be used exactly for
cases like this.

The header is added if doing a post, and the user has specified
authentication but we don't know the auth method yet.

Not all common HTTP servers support the Expect: 100-continue header,
though, so we only try to use it when it really is needed. The user
can request it to be added for other POST requests as well via
an option - which would allow the caller to know immediately that
the POST has failed (e.g. if no auth was provided but the server
required it, or if the target URL simply doesn't exist).

This is only done for write mode posts (e.g. posts without pre-set
post_data) - for posts with pre-set data, we can just redo the post
if it failed due to 401.

Signed-off-by: Martin Storsjö <martin@martin.st>
cavs: K&R formatting cosmetics
cavs: Return meaningful error values
cavs: Check for negative cbp

Sample-Id: 00000647-google
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Merge commit '71549a857b13edf4c4f95037de6ed5bb4c4bd4af'

* commit '71549a857b13edf4c4f95037de6ed5bb4c4bd4af':
  http: Support auth method detection for POST

Conflicts:
	libavformat/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avformat/http: check the auth string contents not the pointer which cannot be NULL

It appears this bug originates from a "work in progress" patch from
ffmpeg-devel that was heavily redesigned by and integrated in libav

And that patch even had a reply and review on the mailing list pointing
out that it had a bug.

This fixes a deadlock with ffserver

See: [FFmpeg-devel] [PATCH] Fix HTTP authentication problem for POST actions.
     [FFmpeg-devel] [PATCH 1/3] Introduce auth_phase flag, which will be true if authorization needs to be sent, but the type of authorization is not known yet Partial fix #3036
     [FFmpeg-devel] [PATCH 2/3] Only add Transfer-Encoding header when not in authorization phase, because server will wait (indefinitely) for data when receiving this header Partial fix #3036
     [FFmpeg-devel] [PATCH 3/3] Only allow posting data and/or forcing a 200 code, enabling posting isml chunks, -after- we did a possible first request to get a 403 from the server telling us which type of authentication to apply Final part fix #3036
See: 71549a857b13edf4c4f95037de6ed5bb4c4bd4af
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '14ddbb477faef359983151b763fd8b20e578651b'

* commit '14ddbb477faef359983151b763fd8b20e578651b':
  cavs: K&R formatting cosmetics

Conflicts:
	libavcodec/cavs.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '1b20d0f581f01f2df601c9e68d0d321672d97af7'

* commit '1b20d0f581f01f2df601c9e68d0d321672d97af7':
  cavs: Return meaningful error values

Conflicts:
	libavcodec/cavsdec.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  cavs: Check for negative cbp

Conflicts:
	libavcodec/cavsdec.c

See: 9f06c1c61e876e930753da200bfe835817e30a53
Merged-by: Michael Niedermayer <michaelni@gmx.at>
oggparseopus: use ff_alloc_extradata()

Signed-off-by: James Almer <jamrial@gmail.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
oggparsecelt: use ff_alloc_extradata()

Signed-off-by: James Almer <jamrial@gmail.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
movenc: use ff_alloc_extradata()

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
rtmp: Allocate the prev_pkt arrays dynamically

Normally, all channel ids are between 0 and 10, while they in
uncommon cases can have values up to 64k.

This avoids allocating two arrays for up to 64k entries (at a total
of over 6 MB in size) each when most of them aren't used at all.

Signed-off-by: Martin Storsjö <martin@martin.st>
avresample/x86: Switch operand order for mulps

With the forthcoming VEX instruction emulation, mulps
must have only the third operand point to memory, as
this is what vmulps expects.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
x86inc: Use VEX-encoded instructions in AVX functions

Automatically use VEX-encoding in AVX/AVX2/XOP/FMA3/FMA4
functions for all instructions that exists in a VEX-encoded
version.

This change makes it easier to extend existing code to use AVX2.

Also add support for AVX emulation of a few instructions that
were missing before.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
x86inc: Remove our FMA4 support

This is so we can sync to x264's version of FMA4 support.

This partialy reverts commit 79687079a97a039c325ab79d7a95920d800b791f.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
x86inc: FMA3/4 Support

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
x86: more AVX2 framework

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Merge commit '84a125c4c28f3e3e215d2e6c32f7f0ec43bbc04c'

* commit '84a125c4c28f3e3e215d2e6c32f7f0ec43bbc04c':
  rtmp: Allocate the prev_pkt arrays dynamically

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '15748773bf33c110e6e2e9526c7ba5478274c74c'

* commit '15748773bf33c110e6e2e9526c7ba5478274c74c':
  avresample/x86: Switch operand order for mulps

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