* sfu/buffer: stop allocating per ingested packet
Buffer.Write allocated six objects for every RTP packet. They were
the parsed rtp.Packet, a copy of it in patchExtPacket, and the flow
state, whose address two rare log calls took. The rest were an
AbsCaptureTime, present on about one packet per second, and the
extension slice that pion grows with append.
Unmarshal into a pooled scratch packet. Give ExtPacket its own backing
rtp.Packet and an [8]rtp.Extension array, and copy the header into
them. Patch the payload in place. If the abs-capture-time extension is
present, parse it. Log a copy of the flow state.
Per packet, Write plus ReadExtended. Opus: 6 allocs, 448 B -> 0.
VP8: 6 allocs, 416 B -> 1 alloc, 32 B. Opus 240 -> 142 ns, VP8 269 -> 204 ns.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
* sfu/buffer: point extension payloads at the bucket copy on read
Queued ExtPackets kept extension payload slices into the write input,
which the transport reuses for the next packet. ReadExtended now parses
the header again from the bucket copy, so extensions and CSRCs point
into RawPacket like the payload does.
The test writes every packet through one input buffer and checks the
audio level of each packet read back.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
* sfu/buffer: test that a dropped padding packet keeps the shifted sequence number on read
The bucket stores the shifted number, so re-parsing the header on read
returns it. This test guards that.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
---------
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
* Do not restart receiver on codec change mid-session.
This is not supported and was an erroneous change during the
receiver_base/buffer_base + RTP stream restart consolidation. Also make
the codec munger creation more resilient.
* fix test
* Rework receiver restart.
- Protect against concurrent restarts
- Clean up and consolidate code around restarts
- Use `RestartStream` of buffer rather than creating new buffers.
* fix test
This is not all of it as it is not possible (or at least I do not know
of a way) to get all suggestions for a repo/project. Did this via loop
searching mainly and taking the modernize suggestions.
* Use sync.Pool for objects in packet path.
Seeing cases of forwarding latency spikes that aling with GC.
This might be a bit overkill, but using sync.Pool for small +
short-lived objects in packet path.
Before this, all these were increasing in alloc_space heap profile
samples over time. With these, there is no increase (actually the lines
corresponding to geting from pool does not even show up in heap
accounting when doing `list` in `pprof`)
* merge
* Paul feedback
* Remove alloc in packet forwarding path.
Unlikely logger creation was doing allocs. Replace it with a function
like in rtpstats_receiver.go so that allocations do not happen
unnecessarily.
* variable rename
* one more place
* Splitting out rtp stats stuff into its own package.
Going to be making some lighter versions of these.
Will be cleaner to have all of these grouped together.
So, as a first step, just making a package for it.
* tests
* Validate RTP packets.
Check version, payload type (if available) and SSRC (if available)
and drop bad packets. And let repair mechanisms take effect for those
packets.
* address data race reported by test
* fix an unlock and test packets
* Disable audio loss proxying.
Added a config which is off by default.
With audio NACKs, that is the preferred repair mechanism.
With RED, repair is built in via packet redundancy to recover from
isolated losses.
So, proxying is not required. But, leaving it in there with a config
that is disabled by default.
* fix test
* Prevent rtx buffer and forwarding path colliding
Received packets are put into RTX buffer which is
a circular buffer and the packet (sequence number) is
queued for forwarding. If the RTX buffer fills up
and cycles before forwarding happens, forwarding
would pick the wrong packet (as it is holding a
reference to a byte slice in the RTX buffer) to forward.
Prevent it by moving reading from RTX buffer just
before forwarding. Adds an extra copy from RTX buffer
-> temp buffer for forwarding, but ensures that forwarding
buffer is not used by another go routine.
* Revert some changes from previous commit
Details:
- Do all forward processing as before.
- One difference is not load raw packet into ExtPacket.
- Load raw packet into provided buffer when module that reads
using ReadExtended calls that function. If the packet is
not there in the retransmission buffer, that packet will be
dropped. This is the case we are trying to fix, i. e. the RTX
buffer has cycled before ReadExtended could pull the packet.
This makes a copy into the provided buffer so that the data
does not change underneath.
* Remove debug comment
* Oops missed a function call
* WIP commit
* fix test
* More clean up
* cast to right size
* use local variable
* set a default RTT
* Do not log RTX, although need to figure out source of RTX
* fix test
* Cleaning/simplifying some buffer bits
1. NACKs are always inserted in order. So, get rid of
bunch of out-of-order handling in there and simplify.
2. For now, removing triggering a key frame from NACKs.
Let subs drive it.
3. Move to 16-bit sequence numbers except for receiver
report handling. Simplify bits about unwrapping sequence
number on all packets.
4. Remove unused code.
* remove unused field
* Handle multiple codecs in renegotiation
update pion to v3.1.9 for answer same order of codec as publisher.
register enable codecs in subscriber peerconnectin created.
add codec parameter to buffer.bind
buffer should use the codec of TrackRemote as it's codec mime.
sent h264blankframe when DownTrack closing
* Separate from ion-sfu
changes:
1. extract pkg/buffer, twcc, sfu, relay, stats, logger
2. to solve cycle import, move ion-sfu/pkg/logger to pkg/sfu/logger
3. replace pion/ion-sfu => ./
reason: will change import pion/ion-sfu/pkg/* to livekit-server/pkg/*
after this pr merged. Just not change any code in this pr, because it
will confused with the separate code from ion-sfu in review.
* Move code from ion-sfu to pkg/sfu
* fix build error for resovle conflict
Co-authored-by: cnderrauber <zengjie9004@gmail.com>
