This swaps which field is set when the Window Acknowledgement Size
and Set Peer BW packets are received, renames the fields in
order to clarify their role further and adds verbose comments
explaining their respective roles and how well the code currently
does what it is supposed to.

The Set Peer BW packet tells the receiver of the packet (which
can be either client or server) that it should not send more data
if it already has sent more data than the specified number of bytes,
without receiving acknowledgement for them. Actually checking this
limit is currently not implemented.

In order to be able to check that properly, one can send the
Window Acknowledgement Size packet, which tells the receiver of the
packet that it needs to send Acknowledgement packets
(RTMP_PT_BYTES_READ) at least after receiving a given number of bytes
since the last Acknowledgement.

Therefore, when we receive a Window Acknowledgement Size packet,
this sets the maximum number of bytes we can receive without sending
an Acknowledgement; therefore when handling this packet we should set
the receive_report_size field (previously client_report_size).
Signed-off-by: Martin Storsjö <martin@martin.st>

Also rename comments and log messages accordingly,
and add clarifying comments for some hardcoded values.

The previous names were taken from older, reverse engineered
references.

These names match the official public rtmp specification, and
matches the names used by wirecast in annotating captured
streams. These names also avoid hardcoding the roles of server
and client, since the handling of them is irrelevant of whether
we act as server or client.

The RTMP_PT_PING type maps to RTMP_PT_USER_CONTROL.

The SERVER_BW and CLIENT_BW types are a bit more intertwined;
RTMP_PT_SERVER_BW maps to RTMP_PT_WINDOW_ACK_SIZE and
RTMP_PT_CLIENT_BW maps to RTMP_PT_SET_PEER_BW.
Signed-off-by: Martin Storsjö <martin@martin.st>

Simplifies checking for conditions in external library headers and
aborting if said conditions are not met.

Simplifies checking for external library headers and aborting if
the external library support was requested, but is not available.

Weak dependencies on external libraries do not obviate having to
explicitly enable these libraries, so the weak dependency does not
simplify the configure command line nor have any real effect.

No deprecation guards, because the old decode API (for which this field
is needed) doesn't have any either.

This field should be removed together with the old decode calls.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

Copied and modified from hwcontext_qsv.c.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

In this mode it tells the muxer about the bitrate of the input stream.

The code relies on their validity and otherwise can try to access a NULL
object->rle pointer, causing segmentation faults.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Diego Biurrun <diego@biurrun.de>

The string codec name need not be as long as the value we are
comparing it to, so memcmp may make decisions derived from
uninitialised data that valgrind then complains about (though the
overall result of the function will always be the same).  Use
strncmp instead, which will stop at the first zero byte and
therefore not encounter this issue.

Only do this when building for a recent VAAPI version - initial
driver implementations were confused about the interpretation of the
framerate field, but hopefully this will be consistent everywhere
once 0.40.0 is released.

Default to using VBR when a target bitrate is set, unless the max rate
is also set and matches the target.  Changes to the Intel driver mean
that min_qp is also respected in this case, so set a codec default to
unset the value rather than using the current default inherited from
the MPEG-4 part 2 encoder.

This includes a backward-compatibility hack to choose CBR anyway on
old drivers which have no CBR support, so that existing programs will
continue to work their options now map to VBR.

Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Use webm muxer for VP8, VP9 and Opus codec, mp4 muxer otherwise.
Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

The dash_write function drops data, if no IOContext is initialized.

Since the mp4 muxer is used in "frag_custom" mode, data is only
written when calling av_write_frame(NULL) explicitly and thus
there will be no data loss.

To add support for webm as subordinate muxer, which doesn't have
such a mode, a dynamic buffer is required to provide an always
initialized IOContext.
Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Previously all mapped streams of a media type (video, audio) where assigned
to a single AdaptationSet. Using the DASH live profile it is mandatory, that
the segments of all representations are aligned, which is currently not
enforced. This leads to problems when using video streams with different
key frame intervals. So to play safe, default to one AdaptationSet per stream,
unless overwritten by explicit assignment.

To get the old assignment scheme, use

  -adaptation_sets "id=0,streams=v id=1,streams=a"
Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Using the characters "v" or "a" instead of stream index numbers for assigning
streams in the adaption_set option, all streams matching that given type will
be added to the AdaptationSet.
Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Also makes sure all streams are assigned to exactly one AdaptationSet.

This patch is originally based partially on code by Vignesh Venkatasubramanian.
Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Bandwidth information is required in the manifest, but not always
provided by the demuxer. In that case calculate the bandwith based
on the size and duration of the first segment.
Signed-off-by: Peter Große <pegro@friiks.de>
Signed-off-by: Martin Storsjö <martin@martin.st>