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Alsa driver limited to 16-bit / 48kHz audio files #494

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@GeorgeIoak

Description

@GeorgeIoak

While trying to play 24-bit/96kHz or 24-bit 192kHz files with aplay the files are downsampled to 16-bit

pi@raspberrypi ~ $ aplay -v audio/JimmyAndTheCrows96kHz.wav
Playing WAVE 'audio/JimmyAndTheCrows96kHz.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
Plug PCM: Rate conversion PCM (48000, sformat=S16_LE)
Converter: linear-interpolation
Protocol version: 10002
Its setup is:
  stream       : PLAYBACK
  access       : RW_INTERLEAVED
  format       : S24_3LE
  subformat    : STD
  channels     : 2
  rate         : 96000
  exact rate   : 96000 (96000/1)
  msbits       : 24
  buffer_size  : 32768
  period_size  : 8192
  period_time  : 85333
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 8192
  period_event : 0
  start_threshold  : 32768
  stop_threshold   : 32768
  silence_threshold: 0
  silence_size : 0
  boundary     : 1073741824
Slave: Hardware PCM card 0 'bcm2835 ALSA' device 0 subdevice 0
Its setup is:
  stream       : PLAYBACK
  access       : MMAP_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 2
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 16384
  period_size  : 4096
  period_time  : 85333
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 4096
  period_event : 0
  start_threshold  : 16384
  stop_threshold   : 16384
  silence_threshold: 0
  silence_size : 0
  boundary     : 1073741824
  appl_ptr     : 0
  hw_ptr       : 0

pi@raspberrypi ~ $ mplayer -ao alsa audio/test32bit_44.1kHz.wav
MPlayer svn r34540 (Debian), built with gcc-4.6 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing audio/test32bit_44.1kHz.wav.
libavformat version 53.21.1 (external)
Mismatching header version 53.19.0
Audio only file format detected.
Load subtitles in audio/
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 44100 Hz, 2 ch, s32le, 2822.4 kbit/100.00% (ratio: 352800->352800)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
==========================================================================
AO: [alsa] 44100Hz 2ch s32le (4 bytes per sample)
Video: no video
Starting playback...
A:  23.5 (23.5) of 66.0 (01:06.0)  1.8%


MPlayer interrupted by signal 2 in module: play_audio
A:  23.6 (23.5) of 66.0 (01:06.0)  1.8%

Exiting... (Quit)
pi@raspberrypi ~ $ mplayer -ao alsa audio/JimmyAndTheCrows96kHz.wav
MPlayer svn r34540 (Debian), built with gcc-4.6 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing audio/JimmyAndTheCrows96kHz.wav.
libavformat version 53.21.1 (external)
Mismatching header version 53.19.0
libavformat file format detected.
[wav @ 0xb63ecc78]max_analyze_duration reached
[lavf] stream 0: audio (pcm_s24le), -aid 0
Clip info:
 comment: Jimmy And The Crows
 encoded_by: Keith Greeninger, Chris Kee & Br
 date: 2013-07-25
 creation_time: 14:58:00
 time_reference: 0
 coding_history: A=PCM,F=96000,W=24,M=stereo,T=KORG AudioGate ver.2.3.2 (Windows 7),

 artist: Keith Greeninger, Chris Kee & Brain
 title: Jimmy And The Crows
Load subtitles in audio/
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 96000 Hz, 2 ch, s24le, 4608.0 kbit/100.00% (ratio: 576000->576000)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
==========================================================================
AO: [alsa] 48000Hz 2ch s24le (3 bytes per sample)
Video: no video
Starting playback...
A:  36.9 (36.9) of 475.2 (07:55.2)  9.2%


MPlayer interrupted by signal 2 in module: decode_audio
A:  37.0 (36.9) of 475.2 (07:55.2)  9.2%

Exiting... (Quit)

But playing with omxplayer they "appear" to play back correctly:

pi@raspberrypi ~ $ omxplayer -p audio/JimmyAndTheCrows96kHz.wav
Audio codec pcm_s24le channels 2 samplerate 96000 bitspersample 24
Subtitle count: 0, state: off, index: 1, delay: 0
have a nice day ;)

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