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xiph / opus

Modern audio compression for the internet.
https://opus-codec.org/
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How can I verify if FEC is working? I am not hearing any changes with fec enabled vs disabled with 30% packet loss #353

Open sumanth-murali-skydio opened 2 months ago

sumanth-murali-skydio commented 2 months ago

I am running an opus encode decode pipelein. This takes in a raw pcm at 16 KHz mono and encodes with FEC enabled at 16 kbps and complexity = 10. The frame size is 40 ms and I am simulating packet loss by not dropping the encoded packets. The decoder then decodes with decode_fec = true if it sees a packet missing (using sequence numbers) and decodes the packet again with decode_fec = false. I dont hear any difference when I enable FEC or if I disable FEC. Are there specific settings for the encoder that allow the FEC to work??

jmvalin commented 2 months ago

I suggest you test with opus_demo. Also, make sure you're setting the -loss to something non-zero and using a high enough bitrate for FEC to get used.

sumanth-murali-skydio commented 2 months ago

What is the minimum bit rate needed??