Safe Haskell	None
Language	Haskell2010

Codec.FFmpeg.Encode

Contents

FFI Declarations
FFmpeg Encoding Interface

Description

Video encoding API. Includes FFI declarations for the underlying FFmpeg functions, wrappers for these functions that wrap error condition checking, and high level Haskellized interfaces.

Note: If you need to import this module, consider qualifying the import.

Synopsis

avcodec_find_encoder :: AVCodecID -> IO AVCodec
avcodec_find_encoder_by_name :: CString -> IO AVCodec
av_opt_set :: Ptr () -> CString -> CString -> CInt -> IO CInt
avcodec_encode_video2 :: AVCodecContext -> AVPacket -> AVFrame -> Ptr CInt -> IO CInt
av_image_alloc :: Ptr (Ptr CUChar) -> Ptr CInt -> CInt -> CInt -> AVPixelFormat -> CInt -> IO CInt
av_freep :: Ptr (Ptr a) -> IO ()
av_guess_format :: CString -> CString -> CString -> IO AVOutputFormat
avformat_alloc_output_context2 :: Ptr AVFormatContext -> AVOutputFormat -> CString -> CString -> IO CInt
avformat_new_stream :: AVFormatContext -> AVCodec -> IO AVStream
av_write_frame :: AVFormatContext -> AVPacket -> IO CInt
av_interleaved_write_frame :: AVFormatContext -> AVPacket -> IO CInt
avformat_write_header :: AVFormatContext -> Ptr AVDictionary -> IO CInt
av_write_trailer :: AVFormatContext -> IO CInt
avio_open :: Ptr AVIOContext -> CString -> AVIOFlag -> IO CInt
avio_close :: AVIOContext -> IO CInt
avformat_free_context :: AVFormatContext -> IO ()
av_image_fill_arrays :: Ptr (Ptr CUChar) -> Ptr CInt -> Ptr CUChar -> AVPixelFormat -> CInt -> CInt -> CInt -> IO CInt
av_image_fill_linesizes :: Ptr CInt -> AVPixelFormat -> CInt -> IO CInt
data EncodingParams = EncodingParams {
- epWidth :: CInt
- epHeight :: CInt
- epFps :: Int
- epCodec :: Maybe AVCodecID
- epPixelFormat :: Maybe AVPixelFormat
- epPreset :: String
- epFormatName :: Maybe String
}
defaultH264 :: CInt -> CInt -> EncodingParams
defaultParams :: CInt -> CInt -> EncodingParams
checkFlag :: Bits a => a -> a -> Bool
initStream :: EncodingParams -> AVFormatContext -> IO (AVStream, AVCodecContext)
initTempFrame :: EncodingParams -> AVPixelFormat -> IO AVFrame
allocOutputContext :: Maybe String -> FilePath -> IO AVFormatContext
avio_open_check :: AVFormatContext -> String -> IO ()
avio_close_check :: AVFormatContext -> IO ()
encode_video_check :: AVCodecContext -> AVPacket -> Maybe AVFrame -> IO Bool
write_header_check :: AVFormatContext -> IO ()
write_frame_check :: AVFormatContext -> AVPacket -> IO ()
write_trailer_check :: AVFormatContext -> IO ()
palettizeRGB8 :: EncodingParams -> Vector CUChar -> Vector CUChar
palettizeJuicy :: EncodingParams -> Vector CUChar -> Vector CUChar
frameWriter :: EncodingParams -> FilePath -> IO (Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ())
frameWriterRgb :: EncodingParams -> FilePath -> IO (Maybe (Vector CUChar) -> IO ())

FFI Declarations

avcodec_find_encoder :: AVCodecID -> IO AVCodec Source #

avcodec_find_encoder_by_name :: CString -> IO AVCodec Source #

av_opt_set :: Ptr () -> CString -> CString -> CInt -> IO CInt Source #

avcodec_encode_video2 :: AVCodecContext -> AVPacket -> AVFrame -> Ptr CInt -> IO CInt Source #

av_image_alloc :: Ptr (Ptr CUChar) -> Ptr CInt -> CInt -> CInt -> AVPixelFormat -> CInt -> IO CInt Source #

av_freep :: Ptr (Ptr a) -> IO () Source #

av_guess_format :: CString -> CString -> CString -> IO AVOutputFormat Source #

avformat_alloc_output_context2 :: Ptr AVFormatContext -> AVOutputFormat -> CString -> CString -> IO CInt Source #

avformat_new_stream :: AVFormatContext -> AVCodec -> IO AVStream Source #

av_write_frame :: AVFormatContext -> AVPacket -> IO CInt Source #

av_interleaved_write_frame :: AVFormatContext -> AVPacket -> IO CInt Source #

avformat_write_header :: AVFormatContext -> Ptr AVDictionary -> IO CInt Source #

av_write_trailer :: AVFormatContext -> IO CInt Source #

avio_open :: Ptr AVIOContext -> CString -> AVIOFlag -> IO CInt Source #

avio_close :: AVIOContext -> IO CInt Source #

avformat_free_context :: AVFormatContext -> IO () Source #

av_image_fill_arrays :: Ptr (Ptr CUChar) -> Ptr CInt -> Ptr CUChar -> AVPixelFormat -> CInt -> CInt -> CInt -> IO CInt Source #

av_image_fill_linesizes :: Ptr CInt -> AVPixelFormat -> CInt -> IO CInt Source #

FFmpeg Encoding Interface

data EncodingParams Source #

Minimal parameters describing the desired video output.

Constructors

EncodingParams

Fields

epWidth :: CInt
epHeight :: CInt
epFps :: Int
epCodec :: Maybe AVCodecID
If Nothing, then the codec is inferred from the output file name. If Just, then this codec is manually chosen.
epPixelFormat :: Maybe AVPixelFormat
If Nothing, automatically chose a pixel format based on the output codec. If Just, force the selected pixel format.
epPreset :: String
Encoder-specific hints. For h264, the default preset is "medium" (other options are "fast", "slow", etc.). For the GIF codec, setting this to "dither" will enable dithering during the palettization process. This will improve image quality, but result in a larger file.
epFormatName :: Maybe String
FFmpeg muxer format name. If Nothing, tries to infer from the output file name. If Just, the string value should be the one available in ffmpeg -formats.

defaultH264 :: CInt -> CInt -> EncodingParams Source #

Use default parameters for a video of the given width and height, forcing the choice of the h264 encoder.

defaultParams :: CInt -> CInt -> EncodingParams Source #

Use default parameters for a video of the given width and height. The output format is determined by the output file name.

checkFlag :: Bits a => a -> a -> Bool Source #

Determine if the bitwise intersection of two values is non-zero.

initStream :: EncodingParams -> AVFormatContext -> IO (AVStream, AVCodecContext) Source #

Find and initialize the requested encoder, and add a video stream to the output container.

initTempFrame :: EncodingParams -> AVPixelFormat -> IO AVFrame Source #

Initialize a temporary YUV frame of the same resolution as the output video stream. We well convert RGB frames using this frame as a destination before encoding the video frame.

allocOutputContext :: Maybe String -> FilePath -> IO AVFormatContext Source #

Allocate an output context inferring the codec from the given file name.

avio_open_check :: AVFormatContext -> String -> IO () Source #

Open the given file for writing.

avio_close_check :: AVFormatContext -> IO () Source #

Close an open IO context.

encode_video_check :: AVCodecContext -> AVPacket -> Maybe AVFrame -> IO Bool Source #

Returns True if the AVPacket was updated with new output data; False otherwise.

write_header_check :: AVFormatContext -> IO () Source #

Allocate the stream private data and write the stream header to an output media file.

write_frame_check :: AVFormatContext -> AVPacket -> IO () Source #

Write a packet to an output media file.

write_trailer_check :: AVFormatContext -> IO () Source #

Write the stream trailer to an output media file and free the private data. May only be called after a successful call to write_header_check.

palettizeRGB8 :: EncodingParams -> Vector CUChar -> Vector CUChar Source #

Quantize RGB24 pixels to the systematic RGB8 color palette. The image data has space for a palette appended to be compliant with av_image_fill_arrays's expectations. This is slow.

palettizeJuicy :: EncodingParams -> Vector CUChar -> Vector CUChar Source #

High quality dithered, median cut palette using palettize. The result is packed such that the BGRA palette is laid out contiguously following the palettized image data.

frameWriter :: EncodingParams -> FilePath -> IO (Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ()) Source #

Open a target file for writing a video stream. The function returned may be used to write image frames (specified by a pixel format, resolution, and pixel data). If this function is applied to Nothing, then the output stream is closed. Note that Nothing must be provided to properly terminate video encoding.

Support for source images that are of a different size to the output resolution is limited to non-palettized destination formats (i.e. those that are handled by libswscaler). Practically, this means that animated gif output only works if the source images are of the target resolution.

frameWriterRgb :: EncodingParams -> FilePath -> IO (Maybe (Vector CUChar) -> IO ()) Source #

Open a target file for writing a video stream. The function returned may be used to write RGB images of the resolution given by the provided EncodingParams (i.e. the same resolution as the output video). If this function is applied to Nothing, then the output stream is closed. Note that Nothing must be provided to properly terminate video encoding.