AudioDownmixMeta.hs


{- |
Copyright  : Will Thompson, Iñaki García Etxebarria and Jonas Platte
License    : LGPL-2.1
Maintainer : Iñaki García Etxebarria (garetxe@gmail.com)

Extra buffer metadata describing audio downmixing matrix. This metadata is
attached to audio buffers and contains a matrix to downmix the buffer number
of channels to @channels.

@matrix is an two-dimensional array of @to_channels times @from_channels
coefficients, i.e. the i-th output channels is constructed by multiplicating
the input channels with the coefficients in @matrix[i] and taking the sum
of the results.
-}

module GI.GstAudio.Structs.AudioDownmixMeta
    ( 

-- * Exported types
    AudioDownmixMeta(..)                    ,
    newZeroAudioDownmixMeta                 ,
    noAudioDownmixMeta                      ,


 -- * Methods
-- ** audioDownmixMetaGetInfo
    audioDownmixMetaGetInfo                 ,




 -- * Properties
-- ** FromChannels
    audioDownmixMetaReadFromChannels        ,


-- ** FromPosition
    audioDownmixMetaReadFromPosition        ,


-- ** Matrix
    audioDownmixMetaReadMatrix              ,


-- ** Meta
    audioDownmixMetaReadMeta                ,


-- ** ToChannels
    audioDownmixMetaReadToChannels          ,


-- ** ToPosition
    audioDownmixMetaReadToPosition          ,




    ) where

import Prelude ()
import Data.GI.Base.ShortPrelude

import qualified Data.Text as T
import qualified Data.ByteString.Char8 as B
import qualified Data.Map as Map

import GI.GstAudio.Types
import GI.GstAudio.Callbacks
import qualified GI.Gst as Gst

newtype AudioDownmixMeta = AudioDownmixMeta (ForeignPtr AudioDownmixMeta)
-- | Construct a `AudioDownmixMeta` struct initialized to zero.
newZeroAudioDownmixMeta :: MonadIO m => m AudioDownmixMeta
newZeroAudioDownmixMeta = liftIO $ callocBytes 48 >>= wrapPtr AudioDownmixMeta

noAudioDownmixMeta :: Maybe AudioDownmixMeta
noAudioDownmixMeta = Nothing

audioDownmixMetaReadMeta :: AudioDownmixMeta -> IO Gst.Meta
audioDownmixMetaReadMeta s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 0) :: IO (Ptr Gst.Meta)
    val' <- (newPtr 16 Gst.Meta) val
    return val'

audioDownmixMetaReadFromPosition :: AudioDownmixMeta -> IO AudioChannelPosition
audioDownmixMetaReadFromPosition s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 16) :: IO CUInt
    let val' = (toEnum . fromIntegral) val
    return val'

audioDownmixMetaReadToPosition :: AudioDownmixMeta -> IO AudioChannelPosition
audioDownmixMetaReadToPosition s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 24) :: IO CUInt
    let val' = (toEnum . fromIntegral) val
    return val'

audioDownmixMetaReadFromChannels :: AudioDownmixMeta -> IO Int32
audioDownmixMetaReadFromChannels s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 32) :: IO Int32
    return val

audioDownmixMetaReadToChannels :: AudioDownmixMeta -> IO Int32
audioDownmixMetaReadToChannels s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 36) :: IO Int32
    return val

audioDownmixMetaReadMatrix :: AudioDownmixMeta -> IO Float
audioDownmixMetaReadMatrix s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 40) :: IO CFloat
    let val' = realToFrac val
    return val'

-- method AudioDownmixMeta::get_info
-- method type : MemberFunction
-- Args : []
-- Lengths : []
-- returnType : TInterface "Gst" "MetaInfo"
-- throws : False
-- Skip return : False

foreign import ccall "gst_audio_downmix_meta_get_info" gst_audio_downmix_meta_get_info :: 
    IO (Ptr Gst.MetaInfo)


audioDownmixMetaGetInfo ::
    (MonadIO m) =>
    m Gst.MetaInfo                          -- result
audioDownmixMetaGetInfo  = liftIO $ do
    result <- gst_audio_downmix_meta_get_info
    checkUnexpectedReturnNULL "gst_audio_downmix_meta_get_info" result
    result' <- (newPtr 80 Gst.MetaInfo) result
    return result'

type family ResolveAudioDownmixMetaMethod (t :: Symbol) (o :: *) :: * where
    ResolveAudioDownmixMetaMethod l o = MethodResolutionFailed l o

instance (info ~ ResolveAudioDownmixMetaMethod t AudioDownmixMeta, MethodInfo info AudioDownmixMeta p) => IsLabelProxy t (AudioDownmixMeta -> p) where
    fromLabelProxy _ = overloadedMethod (MethodProxy :: MethodProxy info)

#if MIN_VERSION_base(4,9,0)
instance (info ~ ResolveAudioDownmixMetaMethod t AudioDownmixMeta, MethodInfo info AudioDownmixMeta p) => IsLabel t (AudioDownmixMeta -> p) where
    fromLabel _ = overloadedMethod (MethodProxy :: MethodProxy info)
#endif