不输出Opus原始音频

Question

I'm currently writing a small script that coverts an MP4 to Opus audio on the fly and sends it to Discord in golang. Initially my script would pass an MP4 as it was downloading to ffmpeg through stdin and then pass stdout to an Opus encoder, then to Discord (exactly like this). After learning I could build ffmpeg with Opus, I'd like to cut out the opus encoder I previous had and pass ffmpeg's output directly to Discord.

Previous, my ffmpeg command looked like this (with using the second opus encoder)

ffmpeg -i - -f s16le -ar 48000 -ac 2 pipe:1

Now, without the encoder and letting ffmpeg do all the work, this is what I've come up with so far.

ffmpeg -i - -f s16le -ar 48000 -ac 2 -acodec libopus -b:a 192k -vbr on -compression_level 10 pipe:1

With this command however the audio doesn't get accepted by Discord's server, meaning I'm suspecting opus audio isn't coming out the other end. No errors outputted. Have I done something wrong with ffmpeg that could of caused this?

Answer 1

Try

ffmpeg -i - -sample_fmt s16 -ar 48000 -ac 2 -acodec libopus -b:a 192k -vbr on -compression_level 10 -f opus pipe:1

You can't use -f s16le as that specifies an uncompressed output format (of a specific sample type), whereas you need a compressed data stream of a certain codec. Instead, you can use sample_fmt and -f opus