• Takashi Sakamoto's avatar
    ALSA: firewire: remove support for 16 bit PCM samples in playback substream · a02cb8f8
    Takashi Sakamoto authored
    In IEC 61883-6, AM824 is described as format of data block. In this
    format, one data block consists of several data channels, which is aligned
    to 32 bit. One data channel has 8 bit label field and 24 bit data field.
    PCM frames are transferred in Multi Bit Linear Audio (MBLA) data channel.
    This channel can include 16/20/24 bit PCM sample.
    As long as I know, models which support IEC 61883-1/6 doesn't allow to
    switch bit length of PCM sample in MBLA data channel. They always
    transmit/receive PCM frames of 24 bit length. This can be seen for the
    other models which support protocols similar to IEC 61883-1/6.
    On the other hand, current drivers for these protocols supports 16 bit
    length PCM sample in playback substream. In this case, PCM sample is put
    into the MBLA data channel with 8 bit padding in LSB side. Although 16
    bit PCM sample is major because it's in CD format, this doesn't represent
    device capability as is.
    This commit removes support for 16 bit PCM samples in playback substream.
    Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
    Acked-by: default avatarClemens Ladisch <clemens@ladisch.de>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
amdtp-am824.h 1.53 KB