Encoder and Decoder hardware boxes with 60ms latency
- 4k or 4 parallel HD streams
- also available 4 parallel 4k streams
- single/multi-bitrate, ABR
I have pretty detailed experience with the Makito X boxes (not the UHD-capable version, just the HD ones which did H264 only and not HEVC).
I don’t recall that Haivision ever claimed anything like a 60ms latency, and at least with the „old“ H264-only-boxes that would be unrealistic (or do you have a source for the 60ms claim?)… their H264 compression/decompression path takes so long that it’s almost impossible to get below 500ms end-to-end latency for non-50p/60p framerates, and the audio is delayed appropriately so that video and audio remain in sync. Then, under normal circumstances, you would enable SRT, which adds further latency. So in my opinion, the Haivision Makito X boxes I know don’t really qualify as „low latency“. Maybe the newer generation of Haivision products has improved though; I’ve seen other H264-based systems which achieve far lower latency (albeit at the cost of higher bandwidth usage) so it’s clear that lower latencies are technically possible – but they generally use clever workarounds; MPEG-family codecs don’t naturally lend themselves to low latency requirements.
For really low latencies on video devices, if one has to use compression, then systems based around intraframe codecs like Jpeg2000, TICO or BBC Dirac / VC-2 are the better way.
HaiVision’s SRT error correction is best ARQ-based system I’ve ever seen – it’s possible to configure it so that it can deal with 10-20% constant packet loss. The idea of ARQ has been around for a while, but SRT is a surprisingly well implemented and tuned version of it.
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Good to have you here, thanks for your points!
Only the latest makito can achieve 60ms inside one box, so 120 roundtrip or including decoder. That is very cool indeed. I have it from the horses mouth-Haivision employee. I did not measure it myself yet.
You must always add wire latency and buffer 4x that value.
For low latency you can’t beat I-frame only codec. That said, I implemented AVB connected prototypes with less than one frame latency between local screen and h264 enc+transmitted+dec picture on Monitor of other PC.
SRT is not considered by digital-stage.org for general live music, but for some Theater performances and used to CDN and downstream to listeners.