Theora-1.0

Theora.Encoding

Contents

Description

This module calls the libtheora C library to generate video ogg files from YCbCr images. As explained on http://theora.org/doc/libtheora-1.0/group__encfuncs.html, the basic steps for creating a video are the following :

Synopsis

Theora structures and function

data Info Source

Constructors

Info 

Fields

frameWidth :: Int32
 
frameHeight :: Int32
 
picWidth :: Int32
 
picHeight :: Int32
 
picX :: Int32
 
picY :: Int32
 
colorSpace :: ColorSpace
 
pixelFmt :: PixelFmt
 
targetBitRate :: CInt
 
quality :: CInt
 
keyframeGranuleShift :: CInt
 

Instances

data Comment Source

Constructors

Comment 

Fields

user :: [String]

Your comments

vendor :: String

Name of the encoder, i.e. your application

Instances

data PixelFmt Source

Theora supports 4 different pixel formats, listed in http://theora.org/doc/Theora.pdf. YCbCr chroma frames (Cb and Cr) may be resized for compression (see http://en.wikipedia.org/Ycbcr). The resulting pixel formats are as follows :

Constructors

Pf420

Chroma decimation by 2 in both directions

Pf422

Chroma decimation by 2 in the x direction

Pf444

No chroma decimation

Instances

data ColorSpace Source

Constructors

Unspecified 
ItuRec470M

A color space designed for NTSC content

ItuRec470BG

A color space designed for PAL/SECAM content

Instances

encodeAlloc :: Info -> IO (Maybe EncCtx)Source

Makes an encoder (EncCtx) instance out of an Info record

flushHeader :: EncCtx -> Comment -> IO [OggPacket]Source

Returns the last header packets. This function should be called before encoding actual video.

data ImgPlane Source

Instances

data YCbCrBuffer Source

YCbCrBuffer is the type of raw YCbCr frames

Constructors

YCbCr 

Fields

y :: ImgPlane

the Y plane

cb :: ImgPlane

the Cb plane

cr :: ImgPlane

the Cr plane

Instances

newYCbCr :: Int -> Int -> PixelFmt -> IO YCbCrBufferSource

Allocate a new YCbCrBuffer object

encodeIn :: EncCtx -> YCbCrBuffer -> IO ()Source

Submits a frame for encoding

encodeOut :: EncCtx -> Bool -> IO [OggPacket]Source

Retrieve all the ready encoded packets

Ogg-related functions

data OggPacket Source

Instances

newOggStreamState :: Int -> IO OggStreamStateSource

Initializes an Ogg container stream

data OggPage Source

Instances

streamPacketIn :: OggStreamState -> OggPacket -> IO ()Source

Submits an encoded packet into the streams

streamPageOut :: OggStreamState -> IO (Maybe OggPage)Source

Get an outputable Ogg page

streamFlush :: OggStreamState -> IO (Maybe OggPage)Source

Retrieve the last pages of the stream