[linux-audio-user] Wave file conversion (multi-mono->stereo, then downsample/downsize, then dither)

[Mark Knecht]

On Thu, 2004-09-09 at 14:07, Eric Dantan Rzewnicki wrote:

> Here is one way to be sure ecasound uses libsamplerate:
> 
> ecasound -f:16,2,44100 -i:resample-hq,auto,hi-quality.wav -o:lower-quality.wav
> 
> The resample-hq input object type, with the auto flag, is a special type
> that causes ecasound to automatically read the format of the input .wav
> and resample it using libsamplerate to match the format set for the rest
> of the chain. I imagine the above command will fail if ecasound is not 
> compiled with src support. There is a similar resample object that uses
> the internal linear interpolation. For both object types auto can be
> replaced with the actual sample format if your input file format lacks 
> that info. One example would be raw input files.

It ran, but it did not apparently downsample. Granted I took a mono file
as input and wrote a stereo file out, but the output sample rate is
still reported as 96K. I will try your 2-mono to stereo example in a
minute.

 ecasound -f:16,2,44100 -i:resample-hq,auto,
data/GTSB-96K-24bit-Audio/T01-Startdust.L.wav -o:TEST1.wav
****************************************************************************
*               ecasound v2.3.3 (C) 1997-2004 Kai
Vehmanen                 
****************************************************************************
- [ Session created ]
------------------------------------------------------
- [ Chainsetup created (cmdline) ]
-----------------------------------------
(eca-chainsetup-parser) Note! Interpreting option
data/GTSB-96K-24bit-Audio/T01-Startdust.L.wav as
-i:data/GTSB-96K-24bit-Audio/T01-Startdust.L.wav.
- [ Connecting chainsetup ]
------------------------------------------------
(eca-chainsetup) 'nonrt' buffering mode selected.
Warning: DBC_CHECK failed - "samples_per_second() > 0", audioio.cpp,
195.
Warning: DBC_CHECK failed - "samples_per_second() > 0", audioio.cpp,
195.
(eca-chainsetup) Audio object "", mode "read".
(audio-io) Format: s16_le, channels 2, srate 44100, interleaved.
(eca-chainsetup) Audio object
"data/GTSB-96K-24bit-Audio/T01-Startdust.L.wav", mode "read".
(audio-io) Format: s24_le, channels 1, srate 96000, interleaved.
(eca-chainsetup) Audio object "TEST1.wav", mode "read/write".
(audio-io) Format: s16_le, channels 2, srate 96000, interleaved.
- [ Chainsetup connected ]
-------------------------------------------------
(eca-controller) Connected chainsetup:  "command-line-setup".
- [ Controller/Starting batch processing ]
---------------------------------
- [ Engine init - Driver start ]
-------------------------------------------
- [ Controller/Batch processing finished ]
---------------------------------
- [ Engine exiting ]
-------------------------------------------------------
(eca-controller) Disconnecting chainsetup:  "command-line-setup".
- [ Chainsetup disconnected ]
----------------------------------------------
flash mark $

flash mark $ sndfile-info TEST1.wav 

Version : libsndfile-1.0.10

========================================
File : TEST1.wav
Length : 81780116
RIFF : 81780104
WAVE
fmt  : 16
  Format        : 0x1 => WAVE_FORMAT_PCM
  Channels      : 2
  Sample Rate   : 96000
  Block Align   : 4
  Bit Width     : 16
  Bytes/sec     : 384000
data : 81780072
End

----------------------------------------
Sample Rate : 96000
Frames      : 20445018
Channels    : 2
Format      : 0x00010002
Sections    : 1
Seekable    : TRUE
Duration    : 00:03:32.968
Signal Max  : 30318 (-0.67 dB)

flash mark $


flash mark $ sndfile-info
data/GTSB-96K-24bit-Audio/T01-Startdust.L.wav         
Version : libsndfile-1.0.10

========================================
File : data/GTSB-96K-24bit-Audio/T01-Startdust.L.wav
Length : 61336078
RIFF : 61336070
WAVE
bext : 602
fmt  : 16
  Format        : 0x1 => WAVE_FORMAT_PCM
  Channels      : 1
  Sample Rate   : 96000
  Block Align   : 3
  Bit Width     : 24
  Bytes/sec     : 288000
*** minf : 16 (unknown marker)
*** elmo : 338 (unknown marker)
data : 61175574
*** regn : 92 (unknown marker)
*** ovwf : 159340 (unknown marker)
*** umid : 24 (unknown marker)
End

----------------------------------------
Sample Rate : 96000
Frames      : 20391858
Channels    : 1
Format      : 0x00010003
Sections    : 1
Seekable    : TRUE
Duration    : 00:03:32.415
Signal Max  : 4.20391e+06 (-6.00 dB)

flash mark $