I followed your instructions. I changed localhost to 127.0.0.1:10000, and I was using input from an rtsp.
Here is my command. It worked for me. I was able to get the stream in VLC player.
ffmpeg -i "rtsp://someurl/" -c:v copy -c:a aac -listen 1 -ar 44100 -ab 64000 \
-f flv rtmp://127.0.0.1:10000/live
I've been running some tests lately (2H2020) concerning reducing the size of some high quality movies of my collection, just for PC to TV 1080p viewing, from 20-30mbps videos to 2-3mbps ones. To that end, I run some ffmpeg (latest gyan.dev version at the time) tests comparing same-bitrate encodes between: codecs (x264,x265,VP9,AV1), presets (slow, slower etc)...
h264_nvenc is able to encode in constant quality, at least from Pascal onwards. I had to do quite some digging around the internet to figure out how to properly use it, but finally found a working formula.
A command like below will record in constant quality, and the CQ value 26 will produce about the same but slightly better quality, measured with VMAF, as ...
About your other question regarding the -coder option, I was also looking for more info on this.
The current (Dec. 2020) IETF/cellar WG draft "FFV1 Video Coding Format Version 0, 1, and 3" mentions in it's "4.2.3. coder_type" chapter :
If coder_type is 0, then bits_per_raw_sample SHOULD NOT be > 8.
At the ...