{-# OPTIONS -fglasgow-exts #-}
module AVCodec where

#include "ffmpeg/avcodec.h"
#include "ffmpeg/avutil.h"

import Data.Int
import Data.Word

import Foreign.Ptr
import Foreign.C.String
import Foreign.Storable

-- * CodecType

#enum Int32, , CODEC_TYPE_UNKNOWN, CODEC_TYPE_VIDEO, CODEC_TYPE_AUDIO, CODEC_TYPE_DATA, CODEC_TYPE_SUBTITLE

-- * AVCodecContext

newtype AVCodecContext = AVCodecContext (Ptr AVCodecContext)

codecName :: AVCodecContext -> IO String
codecName (AVCodecContext ccPtr) = peekCString (#{ptr AVCodecContext, codec_name} ccPtr)

codecType :: AVCodecContext -> IO #{type enum CodecType}
codecType (AVCodecContext ccPtr) = #{peek AVCodecContext, codec_type} ccPtr

codecId :: AVCodecContext -> IO #{type enum CodecID}
codecId (AVCodecContext ccPtr) = #{peek AVCodecContext, codec_id} ccPtr

pictureWidth :: AVCodecContext -> IO Int
pictureWidth (AVCodecContext ccPtr) = #{peek AVCodecContext, width} ccPtr

pictureHeight :: AVCodecContext -> IO Int
pictureHeight (AVCodecContext ccPtr) = #{peek AVCodecContext, height} ccPtr

pixFmt :: AVCodecContext -> IO Int
pixFmt (AVCodecContext ccPtr) = #{peek AVCodecContext, pix_fmt} ccPtr

-- * 

newtype AVCodec = AVCodec (Ptr AVCodec)

newtype AVPicture = AVPicture (Ptr AVPicture)

-- * AVFrame

newtype AVFrame = AVFrame (Ptr AVFrame)

castAVFrameToAVPicture (AVFrame ptr) = (AVPicture (castPtr ptr))

frameData :: AVFrame -> IO (Ptr Word8)
frameData (AVFrame ptr) = #{peek AVFrame, data} ptr

foreign import ccall unsafe "avcodec_find_decoder" c_findDecoder :: #{type enum CodecID} -> IO AVCodec
foreign import ccall unsafe "avcodec_open" open :: AVCodecContext -> AVCodec -> IO Int
foreign import ccall unsafe "avcodec_alloc_frame" allocFrame :: IO AVFrame -- FIXME: could this be null ?
foreign import ccall unsafe "avcodec_decode_video" decodeVideo :: AVCodecContext -> AVFrame -> Ptr Int -> Ptr Word8 -> Int -> IO Int
foreign import ccall unsafe "img_convert" imgConvert :: AVPicture -> Int -> AVPicture -> Int -> Int -> Int -> IO Int
foreign import ccall unsafe "avpicture_get_size" pictureGetSize :: Int -> Int -> Int -> Int
foreign import ccall unsafe "avpicture_fill" pictureFill :: AVPicture -> Ptr Word8 -> Int -> Int -> Int -> IO Int
foreign import ccall unsafe "avcodec_close" close :: AVCodecContext -> IO Int


findDecoder :: #{type enum CodecID} -> IO (Maybe AVCodec)
findDecoder codecId =
    do avcPtr@(AVCodec ptr) <- c_findDecoder codecId
       if ptr == nullPtr
        then return Nothing
        else return (Just avcPtr)

-- * PixelFormat 

#enum Int, , PIX_FMT_NONE, PIX_FMT_YUV420P, PIX_FMT_YUYV422, PIX_FMT_RGB24, PIX_FMT_BGR24, PIX_FMT_YUV422P, PIX_FMT_YUV444P, PIX_FMT_RGB32, PIX_FMT_YUV410P, PIX_FMT_YUV411P, PIX_FMT_RGB565, PIX_FMT_RGB555, PIX_FMT_GRAY8, PIX_FMT_MONOWHITE, PIX_FMT_MONOBLACK, PIX_FMT_PAL8, PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ444P, PIX_FMT_XVMC_MPEG2_MC, PIX_FMT_XVMC_MPEG2_IDCT, PIX_FMT_UYVY422, PIX_FMT_UYYVYY411, PIX_FMT_NB