Before this commit, AVIOContext is to be freed with a plain av_free(),
which prevents us from adding any deeper structure to it.

In order to avoid potential integer overflow change the comparison
and make sure to use the same unsigned type for both elements.

Signed-off-by: NLuca Barbato <lu_zero@gentoo.org>

The AVFormat stream count can be larger due external factors, such as
an id3 tag appended.

Avoid an out of bound read.
Signed-off-by: NLuca Barbato <lu_zero@gentoo.org>

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: NMartin 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: NMartin Storsjö <martin@martin.st>

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.

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

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

The current implementation creates new segments comparing

  pkt->pts - first_pts > nb_segs * min_seg_duration

This works fine, but if the keyframe interval is smaller than "min_seg_duration"
segments shorter than the minimum segment duration are created.

Example: keyint=50, min_seg_duration=3000000
 segment 1 contains keyframe 1 (duration=2s <  total_duration=3s)
                and keyframe 2 (duration=4s >= total_duration=3s)
 segment 2 contains keyframe 3 (duration=6s >= total_duration=6s)
 segment 3 contains keyframe 4 (duration=8s <  total_duration=9s)
                and keyframe 5 (duration=10s >= total_duration=9s)
 ...

Segment 2 is only 2s long, shorter than min_seg_duration = 3s.

To fix this, new segments are created based on the actual written duration.
Otherwise the option name "min_seg_duration" is misleading.
Signed-off-by: NPeter Große <pegro@friiks.de>
Signed-off-by: NMartin Storsjö <martin@martin.st>

If set, adds a UTCTiming tag in the manifest.

This is part of the recommendations listed in the "Guidelines for
Implementations: DASH-IF Interoperability Points" [1][2]
Section 4.7 describes means for the Availability Time Synchronization.

A usable default is "https://time.akamai.com/?iso"

[1] http://dashif.org/guidelines/
[2] http://dashif.org/wp-content/uploads/2016/12/DASH-IF-IOP-v4.0-clean.pdf
    (current version as of writing)
Signed-off-by: NPeter Große <pegro@friiks.de>
Signed-off-by: NMartin Storsjö <martin@martin.st>

Servers seem to be happy to receive the wrapped-around value as long
as they receive a report, otherwise they timeout.

Initially reported and analyzed by Thomas Bernhard.

to avoid rebuffering on the clientside for difficult network conditions.
Signed-off-by: NAnton Schubert <ischluff@mailbox.org>
Signed-off-by: NMartin Storsjö <martin@martin.st>

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

Appends Z to timestamp to force ISO8601 datetime parsing as UTC.
Without Z, some browsers (Chrome) interpret the timestamp as
localtime and others (Firefox) interpret it as UTC.
Signed-off-by: NAnton Schubert <ischluff@mailbox.org>
Signed-off-by: NMartin Storsjö <martin@martin.st>

If a read fails, the current code will free the data but leave the size
non-zero. Make sure the size is zeroed in such a case.

CC: libav-stable@libav.org
Bug-Id: 1001
Found-By: Kamil Frankowicz
Signed-off-by: NSean McGovern <gseanmcg@gmail.com>

The codec id for SRT was changed and conditionals were not updated.

A negative chunk size is illegal and would end up used as
length for memcpy, where it would lead to memory accesses
out of bounds.
Found-by: NPaul Cher <paulcher@icloud.com>

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

This moves work from the configure to the Make stage where it can
be parallelized and ensures that pkgconfig files are updated when
library versions change.

Bug-Id: 449

When the input string is too large, so the second condition in if ()
fails, the code will erroneously execute the else branch, indexing the
mac_to_unicode table with a negative index.

CC: libav-stable@libav.org
Bug-Id: 1000
Found-By: Kamil Frankowicz

When receiving fragmented packets, the first packet declares the size,
and the later ones normally are small follow-on packets that don't repeat
the size and the other header fields. But technically, the later fragments
also can have a full header, declaring a different size than the previous
packet.

If the follow-on packet declares a larger size than the initial one, we
could end up writing outside of the allocation.

This fixes out of bounds writes.
Found-by: NPaul Cher <paulcher@icloud.com>
Reviewed-by: NPaul Cher <paulcher@icloud.com>

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

This seems to have been added by mistake in 11de006b, by not
noticing the negation for the existing condition. This block does
not contain any code that accesses the codec field in AVStream.

This function is meant to serve as a complement to compute_pkt_fields2,
which is guarded by FF_API_COMPUTE_PKT_FIELDS2 && FF_API_LAVF_AVCTX.
Signed-off-by: NMartin Storsjö <martin@martin.st>

Make avio_size() work with any write AVIOContext.