Question

1

How to list/access all the available audio input and output ports/channels of a USB soundcard from a particular PC

rated 0 times [ 1] [ 0] / answers: 1 / hits: 56967 / 1 Year ago, sat, april 15, 2023, 9:04:54

In Windows 7, I used to use pymedia, a python library, to list the available interfaces as well as use them for playing and recording audio. A typical query would look like this:

Now, I'm no longer using Windows 7 as I have migrated to Ubuntu 16.04. So, I used ALSA commands to see the available audio interfaces. The following is the output of the same:

skrowten_hermit@PC-760:~$ aplay -l

**** List of PLAYBACK Hardware Devices ****

card 0: Intel [HDA Intel], device 0: AD1984A Analog [AD1984A Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 0: Intel [HDA Intel], device 2: AD1984A Alt Analog [AD1984A Alt Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 1: Eight [M-Track Eight], device 0: USB Audio [USB Audio]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

skrowten_hermit@PC-760:~$ arecord -l

**** List of CAPTURE Hardware Devices ****

card 0: Intel [HDA Intel], device 0: AD1984A Analog [AD1984A Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 0: Intel [HDA Intel], device 2: AD1984A Alt Analog [AD1984A Alt Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 1: Eight [M-Track Eight], device 0: USB Audio [USB Audio]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

As we can see, my external soundcard M-Audio is listed as an ALSA card here, which means it is being detected properly. Now, as I read through ALSA related articles, I learnt about devices and then used -L to view the available devices as follows:

skrowten_hermit@PC-760:~$ aplay -L

default

    Playback/recording through the PulseAudio sound server

null

    Discard all samples (playback) or generate zero samples (capture)

pulse

    PulseAudio Sound Server

sysdefault:CARD=Intel

    HDA Intel, AD1984A Analog

    Default Audio Device

front:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Front speakers

surround21:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    2.1 Surround output to Front and Subwoofer speakers

surround40:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    4.0 Surround output to Front and Rear speakers

surround41:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    4.1 Surround output to Front, Rear and Subwoofer speakers

surround50:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    5.0 Surround output to Front, Center and Rear speakers

surround51:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    5.1 Surround output to Front, Center, Rear and Subwoofer speakers

surround71:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

dmix:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Direct sample mixing device

dmix:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Direct sample mixing device

dsnoop:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Direct sample snooping device

dsnoop:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Direct sample snooping device

hw:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Direct hardware device without any conversions

hw:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Direct hardware device without any conversions

plughw:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Hardware device with all software conversions

plughw:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Hardware device with all software conversions

sysdefault:CARD=Eight

    M-Track Eight, USB Audio

    Default Audio Device

front:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Front speakers

surround21:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    2.1 Surround output to Front and Subwoofer speakers

surround40:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    4.0 Surround output to Front and Rear speakers

surround41:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    4.1 Surround output to Front, Rear and Subwoofer speakers

surround50:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    5.0 Surround output to Front, Center and Rear speakers

surround51:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    5.1 Surround output to Front, Center, Rear and Subwoofer speakers

surround71:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

iec958:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    IEC958 (S/PDIF) Digital Audio Output

dmix:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Direct sample mixing device

dsnoop:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Direct sample snooping device

hw:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Direct hardware device without any conversions

plughw:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Hardware device with all software conversions

skrowten_hermit@PC-760:~$ arecord -L

default

    Playback/recording through the PulseAudio sound server

null

    Discard all samples (playback) or generate zero samples (capture)

pulse

    PulseAudio Sound Server

sysdefault:CARD=Intel

    HDA Intel, AD1984A Analog

    Default Audio Device

front:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Front speakers

surround21:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    2.1 Surround output to Front and Subwoofer speakers

surround40:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    4.0 Surround output to Front and Rear speakers

surround41:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    4.1 Surround output to Front, Rear and Subwoofer speakers

surround50:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    5.0 Surround output to Front, Center and Rear speakers

surround51:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    5.1 Surround output to Front, Center, Rear and Subwoofer speakers

surround71:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

dmix:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Direct sample mixing device

dmix:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Direct sample mixing device

dsnoop:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Direct sample snooping device

dsnoop:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Direct sample snooping device

hw:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Direct hardware device without any conversions

hw:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Direct hardware device without any conversions

plughw:CARD=Intel,DEV=0

    HDA Intel, AD1984A Analog

    Hardware device with all software conversions

plughw:CARD=Intel,DEV=2

    HDA Intel, AD1984A Alt Analog

    Hardware device with all software conversions

sysdefault:CARD=Eight

    M-Track Eight, USB Audio

    Default Audio Device

front:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Front speakers

surround21:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    2.1 Surround output to Front and Subwoofer speakers

surround40:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    4.0 Surround output to Front and Rear speakers

surround41:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    4.1 Surround output to Front, Rear and Subwoofer speakers

surround50:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    5.0 Surround output to Front, Center and Rear speakers

surround51:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    5.1 Surround output to Front, Center, Rear and Subwoofer speakers

surround71:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

iec958:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    IEC958 (S/PDIF) Digital Audio Output

dmix:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Direct sample mixing device

dsnoop:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Direct sample snooping device

hw:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Direct hardware device without any conversions

plughw:CARD=Eight,DEV=0

    M-Track Eight, USB Audio

    Hardware device with all software conversions

The above is a bit different from what I was expecting (I was hoping to get the channel identifiers, but instead ended up getting parameters like sysdefault, front, surround21, dsnoop, hw etc.). My sound card has Eight I/O pairs. So, I was expecting the channels/port identifiers or something like that.

After a bit more digging into the web, I stumbled upon pyAudio and sounddevice python libraries. The former gave the following output:

skrowten_hermit@PC-760:~$ python

Python 2.7.12 (default, Nov 19 2016, 06:48:10)

[GCC 5.4.0 20160609] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> import pyaudio

>>> p = pyaudio.PyAudio()

ALSA lib pcm_dmix.c:1029:(snd_pcm_dmix_open) unable to open slave

ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear

ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe

ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side

ALSA lib pcm_route.c:867:(find_matching_chmap) Found no matching channel map

ALSA lib pcm_dmix.c:1029:(snd_pcm_dmix_open) unable to open slave

Cannot open PortAudio client

JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for 4294967295, skipping unlock

JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for 4294967295, skipping unlock

JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for 4294967295, skipping unlock

>>> for i in range(p.get_device_count()):

...     print p.get_device_info_by_index(i).get('name')

...

HDA Intel: AD1984A Analog (hw:0,0)

HDA Intel: AD1984A Alt Analog (hw:0,2)

M-Track Eight: USB Audio (hw:1,0)

sysdefault

pulse

default

>>> import pyaudio

>>> p = pyaudio.PyAudio()

>>> for i in range(p.get_device_count()):

...     print p.get_device_info_by_index(i)

...

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': 0.008707482993197279, 'maxInputChannels': 2L, 'structVersion': 2L, 'hostApi': 0L, 'index': 0, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 2L, 'name': u'HDA Intel: AD1984A Analog (hw:0,0)', 'defaultHighInputLatency': 0.034829931972789115}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': -1.0, 'defaultLowInputLatency': 0.008707482993197279, 'maxInputChannels': 2L, 'structVersion': 2L, 'hostApi': 0L, 'index': 1, 'defaultHighOutputLatency': -1.0, 'maxOutputChannels': 0L, 'name': u'HDA Intel: AD1984A Alt Analog (hw:0,2)', 'defaultHighInputLatency': 0.034829931972789115}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': 0.008707482993197279, 'maxInputChannels': 8L, 'structVersion': 2L, 'hostApi': 0L, 'index': 2, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 8L, 'name': u'M-Track Eight: USB Audio (hw:1,0)', 'defaultHighInputLatency': 0.034829931972789115}

{'defaultSampleRate': 48000.0, 'defaultLowOutputLatency': 0.021333333333333333, 'defaultLowInputLatency': 0.021333333333333333, 'maxInputChannels': 128L, 'structVersion': 2L, 'hostApi': 0L, 'index': 3, 'defaultHighOutputLatency': 0.021333333333333333, 'maxOutputChannels': 128L, 'name': u'sysdefault', 'defaultHighInputLatency': 0.021333333333333333}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': -1.0, 'maxInputChannels': 0L, 'structVersion': 2L, 'hostApi': 0L, 'index': 4, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 2L, 'name': u'front', 'defaultHighInputLatency': -1.0}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': -1.0, 'maxInputChannels': 0L, 'structVersion': 2L, 'hostApi': 0L, 'index': 5, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 2L, 'name': u'surround40', 'defaultHighInputLatency': -1.0}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': -1.0, 'maxInputChannels': 0L, 'structVersion': 2L, 'hostApi': 0L, 'index': 6, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 2L, 'name': u'surround51', 'defaultHighInputLatency': -1.0}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': -1.0, 'maxInputChannels': 0L, 'structVersion': 2L, 'hostApi': 0L, 'index': 7, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 2L, 'name': u'surround71', 'defaultHighInputLatency': -1.0}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': 0.008707482993197279, 'maxInputChannels': 32L, 'structVersion': 2L, 'hostApi': 0L, 'index': 8, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 32L, 'name': u'pulse', 'defaultHighInputLatency': 0.034829931972789115}

{'defaultSampleRate': 48000.0, 'defaultLowOutputLatency': 0.021333333333333333, 'defaultLowInputLatency': -1.0, 'maxInputChannels': 0L, 'structVersion': 2L, 'hostApi': 0L, 'index': 9, 'defaultHighOutputLatency': 0.021333333333333333, 'maxOutputChannels': 2L, 'name': u'dmix', 'defaultHighInputLatency': -1.0}

{'defaultSampleRate': 44100.0, 'defaultLowOutputLatency': 0.008707482993197279, 'defaultLowInputLatency': 0.008707482993197279, 'maxInputChannels': 32L, 'structVersion': 2L, 'hostApi': 0L, 'index': 10, 'defaultHighOutputLatency': 0.034829931972789115, 'maxOutputChannels': 32L, 'name': u'default', 'defaultHighInputLatency': 0.034829931972789115}

The above too was not satisfying enough. A closer look at the enumerated output of the device list reveals that, the one corresponding to 'name': u'M-Track Eight: USB Audio (hw:1,0)' does show that the number of input and output channels are 8, but listed as a single device. Then, next up, sounddevice gave me the following output:

skrowten_hermit@PC-760:~$ python

Python 2.7.12 (default, Nov 19 2016, 06:48:10)

[GCC 5.4.0 20160609] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> import sounddevice as sd

>>> sd.query_devices()

   0 HDA Intel: AD1984A Analog (hw:0,0), ALSA (2 in, 2 out)

   1 HDA Intel: AD1984A Alt Analog (hw:0,2), ALSA (2 in, 0 out)

   2 M-Track Eight: USB Audio (hw:1,0), ALSA (8 in, 8 out)

   3 sysdefault, ALSA (128 in, 128 out)

   4 front, ALSA (0 in, 2 out)

   5 surround40, ALSA (0 in, 2 out)

   6 surround51, ALSA (0 in, 2 out)

   7 surround71, ALSA (0 in, 2 out)

   8 pulse, ALSA (32 in, 32 out)

   9 dmix, ALSA (0 in, 2 out)

* 10 default, ALSA (32 in, 32 out)

Here too, device 2 shows 8 in, 8 out.

What I don't understand is:

When pyaudio and sounddevice can see my soundcard as having 8 pairs of I/O channels, why aren't they listing them as separate devices?

And that ALSA doesn't even see that at all (which is the basic requirement for using ALSA commands aplay or arecord)?

Or even if my understanding that devices correspond to physical analog channels/ports, where I would connect devices, is correct?

Is this a limitation of the driver?

My requirements in a nutshell:

I should be able to play out audio to (any) input port(s) of my M-Audio M-Track Eight soundcard and record as well as play out audio from (any) output port(s) of my M-Audio M-Track Eight soundcard and play.

I should be able to use ALSA commands to play and record as mentioned above.

I should be able to play and record in separate threads.

How can I achieve this? Can I get a clearer picture of ALSA and its role here? Any drivers available which can satisfy my requirements?

UPDATE:

I created the following ~/.asoundrc from the inputs I recieved:

pcm.!default {

    type plug

    slave {

       pcm "hw:1,0"

    }

}



ctl.!default {

    type hw

    card 1

}



pcm_slave.eightchannels {

    pcm "hw:1,0"

    channels 8

    rate 44100

    buffer_size 4096

    period_size 2048

}



pcm.ch12 {

    type asym

    playback.pcm {

        type dshare

        ipc_key 1111

        slave eightchannels

        bindings [ 0 1 ]

    }

    capture.pcm {

        type dsnoop

        ipc_key 1111

        slave eightchannels

        bindings [ 0 1 ]

    }

    hint.description "M-Audio channels 1,2"

}

pcm.ch34 {

    type asym

    playback.pcm {

        type dshare

        ipc_key 2222

        slave eightchannels

        bindings [ 2 3 ]

    }

    capture.pcm {

        type dsnoop

        ipc_key 2222

        slave eightchannels

        bindings [ 2 3 ]

    }

    hint.description "M-Audio channels 3,4"

}

So, with the above configuration, when I try running aplay, the following is what I receive:

skrowten_hermit@PC-760:~$ aplay -D ch12 -c 1 -r 8000 male_8k.wav

Playing WAVE 'male_8k.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Mono

aplay: set_params:1233: Sample format non available

Available formats:

- S32_LE

Assuming it's a mismatch with the format as indicated, I tried passing the format as argument for aplay as below:

skrowten_hermit@PC-760:~$ aplay -D ch12 -c 1 -r 8000 -f S32_LE male_8k.wav

Warning: format is changed to S16_LE

Playing WAVE 'male_8k.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Mono

aplay: set_params:1233: Sample format non available

Available formats:

- S32_LE

Does this error have something to do with the PCM devices or the .wav file being played?

P.S : The .!defaults were added later. Removing them makes no difference!

Answers

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antorchestr

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4 Years ago

answered 1 Year ago rmiend · Accepted Answer

After playing around a lot and experimenting with plugins, I was able to find a solution to the above problem. It was nothing but an extension of the above answer and the hints I got from here. To start with, the following is the .asoundrc I used to get it working:

pcm.!default {

    type plug

    slave {

       pcm "hw:1,0"

    }

}



ctl.!default {

    type hw

    card 1

}



pcm_slave.m-audio_m-track_eight_1 {

    pcm "hw:1,0"

    channels 8

    rate 44100

    buffer_size 4096

    period_size 1024

}



pcm.outch1 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 0 ]

    hint.description "M-Audio M-Track Eight output/playback channel 1"

}



pcm.inch1 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 0 ]

    hint.description "M-Audio M-Track Eight input/capture channel 1"

}



pcm.outch2 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 1 ]

    hint.description "M-Audio M-Track Eight output/playback channel 2"

}



pcm.inch2 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 1 ]

    hint.description "M-Audio M-Track Eight input/capture channel 2"

}



pcm.outch3 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 2 ]

    hint.description "M-Audio M-Track Eight output/playback channel 3"

}



pcm.inch3 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 2 ]

    hint.description "M-Audio M-Track Eight input/capture channel 3"

}



pcm.outch4 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 3 ]

    hint.description "M-Audio M-Track Eight output/playback channel 4"

}



pcm.inch4 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 3 ]

    hint.description "M-Audio M-Track Eight input/capture channel 4"

}



pcm.outch5 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 4 ]

    hint.description "M-Audio M-Track Eight output/playback channel 5"

}



pcm.inch5 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 4 ]

    hint.description "M-Audio M-Track Eight input/capture channel 5"

}



pcm.outch6 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 5 ]

    hint.description "M-Audio M-Track Eight output/playback channel 6"

}



pcm.inch6 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 5 ]

    hint.description "M-Audio M-Track Eight input/capture channel 6"

}



pcm.outch7 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 6 ]

    hint.description "M-Audio M-Track Eight output/playback channel 7"

}



pcm.inch7 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 6 ]

    hint.description "M-Audio M-Track Eight input/capture channel 7"

}



pcm.outch8 {

    type dshare

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 7 ]

    hint.description "M-Audio M-Track Eight output/playback channel 8"

}



pcm.inch8 {

    type dsnoop

    ipc_key 1111

    slave m-audio_m-track_eight_1

    bindings [ 7 ]

    hint.description "M-Audio M-Track Eight input/capture channel 8"

}

I've tried to keep the whole thing simple. The ALSA commands aplay and arecord, which are command-line sound player and recorder respectively, then allowed me to do what was required, i.e, play a speech file as well as to play a speech file at one channel (connected to an analog output port) and record it with another mono channel (connected to an analog input port).

In order to test the configuration file, I used the following aplay command:

skrowten_hermit@PC-760:~$ aplay -D plug:outch1 -c 1 -r 8000 male_8k.wav

With the above, playback works just fine. Now, in order to get down to business, and to see if both playback and capture and working, the following was used:

skrowten_hermit@PC-760:~$ aplay -D plug:outch1 -c 1 -r 8000 /home/sreekanth/Downloads/male_8k.wav | arecord -D plug:inch2 -c 1 -r 8000 -d 10 /home/sreekanth/Downloads/out_12.wav

The above uses channel-1 (connected to analog output port 1 on my M-Audio M-Track Eight soundcard) to playing device and channel-2 (connected to analog input port 2 on my M-Audio M-Track Eight soundcard) as recording device. To use other devices, outch1 can be replaced by any of outch2, outch3, outch4, outch5, outch6, outch7, outch8 and inch2 by any of inch1, inch3, inch4, inch5, inch6, inch7, inch8 (in accordance with what was defined in .asoundrc).

It was a bit hard to find the right and well documented literature for ALSA. But, from my experience, it is the parameter bindings you need to tinker with in order to route audio from analog ports (possibly a client channel) to ALSA channels (slave channels defined as above in .asoundrc).