Input from file only works with parameter `-f`

[andimik]

https://github.com/windytan/redsea/blob/67c76f5d23454a26c1063495f123b98475305809/src/redsea.cc#L33

This hint seems not to work, I get no RDS data.

The only way is the parameter -f [FILE].

andreas@E535:~$ more Downloads/radiostetin.wav.s16 | redsea -r 192k
{"pi":"0x0000"}
andreas@E535:~$ redsea -r 192k < Downloads/radiostetin.wav.s16 | head -5
{"pi":"0x0000"}
andreas@E535:~$ redsea -r 192k -f Downloads/radiostetin.wav.s16 | head -5
{"pi":"0x34EB"}
{"pi":"0x34EB","group":"0A","di":{"dynamic_pty":false},"is_music":true,"prog_type":"No PTY","ta":false,"tp":true}
{"pi":"0x34EB","group":"0A","di":{"compressed":false},"is_music":true,"prog_type":"No PTY","ta":false,"tp":true}
{"pi":"0x34EB","group":"0A","di":{"artificial_head":false},"is_music":true,"prog_type":"No PTY","ta":false,"tp":true}
{"pi":"0x34EB","group":"0A","di":{"stereo":true},"is_music":true,"prog_type":"No PTY","ta":false,"tp":true}

radiostetin.wav.zip (just a sample file, taken from a friend)

[windytan]

Seems that although it has the extension, this file is not in the s16 format (raw 16-bit signed integer PCM), instead it is a 24-bit WAV file.

$ file radiostetin.wav.s16
radiostetin.wav.s16: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 24 bit, mono 192000 Hz

Some WAV files can works as raw PCM as the 16-bit aligned RIFF headers gets interpreted as a burst of noise, and they even can be piped to redsea as such, but the 24-bit sample width becomes a problem here.

Raw PCM normally looks like this (unless by coníncidence the noise starts looking like a file header):

$ file gen-yksi-171k.s16
gen-yksi-171k.s16: data

Edit - I've been kind of wanting to remove the default functionality of decoding stdin with no arguments given and add --input raw instead - it's sort of a surprising functionality. But alas, it could be used by many people at this point...

[andimik]

I have renamed it as I thought it might work then. The original extension of the file was .wav

[windytan]

You can convert any audio file (well, almost) into the S16LE format with sox: sox radiostetin.wav radiostetin.s16 (this format has no headers for metadata, so make sure of the correct number of channels and sample rate).

Edit: Or it can be directly piped to redsea with sox audiofile.wav -t .s16 -r 171k - | redsea

For now, I'm not planning to add WAV input via stdin, but if such a need arises this can very well be reopened.

[andimik]

-f seemes to convert 24bit into 16bit as well. So it's worth mentioning it in the wiki as well.

[windytan]

Good idea! For the wiki change, note that it’s converted direct to float32 (this also happens to the raw 16-bit input)

• https://github.com/windytan/redsea/blob/c6e6b47ac2c7a9aac9409483b00ca61cd6eb47bd/src/input.cc#L92

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