Piped export, allow export as float32le not just s16le

Feedback and Discussion Forum Adding Features
1

export audio via external program

e.g. for
ffmpeg -loglevel “verbose” -v 99 -i - “%f” -c:a:0 libopus -b:a:0 200k

with show-output option checked i get
…
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, wav, from ‘pipe:’:
Duration: N/A, bitrate: 1411 kb/s
Stream #0:0, 50, 1/44100: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
…
Stream mapping:
Stream #0:0 → #0:0 (pcm_s16le (native) → opus (libopus))
…
Output #0, opus, to ‘/tmp/audacity.opus’
…
Stream #0:0, 0, 1/48000: Audio: opus (libopus), 48000 Hz, stereo, s16, delay 312, 96 kb/s
…

but if via command-line
…
Input #0, wav, from ‘/tmp/01.wav’:
Duration: 00:00:24.32, bitrate: 2822 kb/s
Stream #0:0, 50, 1/44100: Audio: pcm_f32le ([3][0][0][0] / 0x0003), 44100 Hz, stereo, flt, 2822 kb/s
…
Stream mapping:
Stream #0:0 → #0:0 (pcm_f32le (native) → opus (libopus))
…
Output #0, opus to ‘/tmp/ffmpeg.opus’
…
Stream #0:0, 0, 1/48000: Audio: opus (libopus), 48000 Hz, stereo, flt, delay 312, 200 kb/s

don’t know where err is that caused the bit-rate to be lower than specified…


also there is the question if audio is [outputted to/processed by] effects by what?/ a possibly sub-optimal level
and if debug info could be shown
also can you tell from the output-audio if that happened, its effects

2

Are you talking about “named pipes” (https://manual.audacityteam.org/man/scripting.html) or just about additional export formats?

3

i mean
@ menubar〉 file〉export〉 audio
format type 🡒 external program

[attachment=1]anire01.png[/attachment]
[attachment=0]ani02.png[/attachment]

with show-output option checked
[attachment=2]Screenshot from 2019-08-15 20-53-56.png[/attachment]
ani02.png
anire01.png
Screenshot from 2019-08-15 20-53-56.png

4

This works fine for me:

ffmpeg -i - -c:a pcm_f32le "%f.wav"

Produces:

General
Complete name                            : myfile.wav
Format                                   : Wave
File size                                : 5.05 MiB
Duration                                 : 30 s 0 ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 1 411 kb/s
Writing application                      : Lavf57.83.100

Audio
Format                                   : PCM
Format profile                           : Float
Codec ID                                 : 00000003-0000-0010-8000-00AA00389B71
Codec ID/Hint                            : IEEE 
Duration                                 : 30 s 0 ms
Bit rate mode                            : Constant
Bit rate                                 : 1 411.2 kb/s
Channel(s)                               : 1 channel
Channel layout                           : C
Sampling rate                            : 44.1 kHz
Bit depth                                : 32 bits
Stream size                              : 5.05 MiB (100%)
5

‘ffmpeg’ -loglevel “verbose” -v 99 -i - -c:a pcm_f32le “%f”

how is this it like making a 24-(8x3)bit-image out of 8-bit(256 color) data? :confused::confounded:
but do appreciate the honesty about the nauseating waveforms earlier…

‘ffmpeg’ -loglevel “verbose” -v 99 -i - -c:a pcm_f32le “/tmp/01 .wav.wav”
…
Input #0, wav, from ‘pipe:’:
Duration: N/A, bitrate: 1411 kb/s
Stream #0:0, 50, 1/44100: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
…
Stream mapping:
Stream #0:0 → #0:0 (pcm_s16le (native) → pcm_f32le (native))
…
Output #0, wav, to ‘/tmp/01 .wav’:
Metadata:
ISFT : Lavf58.30.100
Stream #0:0, 0, 1/44100: Audio: pcm_f32le ([3][0][0][0] / 0x0003), 44100 Hz, stereo, flt, 2822 kb/s


Format : Wave
File size : 8.18 MiB
Duration : 24 s 324 ms
Overall bit rate mode : Constant
Overall bit rate : 2 823 kb/s
Writing application : Lavf58.30.100

Audio
Format : PCM
Format profile : Float
Codec ID : 00000003-0000-0010-8000-00AA00389B71
Codec ID/Hint : IEEE
Duration : 24 s 324 ms
Bit rate mode : Constant
Bit rate : 2 822 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 kHz
Bit depth : 32 bits
Stream size : 8.18 MiB (100%)

it seems a 16-bit wav data is being used to make a 32-bit wav file

also it seems the wrong bit-rate was because i ordered the command flags in opus wrong order

6

Please write in proper sentences. I doubt anyone here is interested in wasting their time trying to fathom what you are writing about.

7

maybe dont know, not nessarily,

also the about

was for a previous post

what part is unclear that you not get?

sorry for my english

but put downs - and hoops jumping might not…

you say that audacity has a small team (volunteers)
also i am in no place to make demands

also internet connectivity problems,
often have to post quickly or get cut out,


BBcodes dont work, and cant re-edit past posts

please understand,

the 3rd post was

was audacity’s debug output



failed to mention
ffmpeg -loglevel “verbose” -v 99 -i - “%f” -c:a:0 libopus -b:a:0 200k (wrong)
ffmpeg -loglevel “verbose” -v 99 -i - -c:a:0 libopus -b:a:0 200k “%f” (correct)

8

Steve did not say that. Please do not misquote me, it’s not polite.

9

but sometimes my prob’s
sometimes not always, not excuse for me to be sloppy as had


haven’t yet done - and how to
make low amplitude sound [test-file] that
would distinguish between 16-bit vs higher bit rates

10

Are you saying that; “when exporting as 32-bit using FFmpeg with Audacity’s “external program” export option, that the audio appears to be reduced to 16-bit prior to the conversion”?

If that’s what you mean, then I think that is a bug in Audacity.
I shall log this bug on Audacity’s bug tracker.

11

Done.

12

:+1: