ffmpeg-light-0.14.0: src/Codec/FFmpeg/Encode.hsc
{-# LANGUAGE ForeignFunctionInterface #-}
-- | 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.
module Codec.FFmpeg.Encode where
import Codec.FFmpeg.Common
import Codec.FFmpeg.Enums
import Codec.FFmpeg.Internal.Linear
import Codec.FFmpeg.Resampler
import Codec.FFmpeg.Scaler
import Codec.FFmpeg.Types
import Codec.Picture
import Control.Monad (when, void)
import Data.Bits
import Data.IORef
import Data.Maybe (fromMaybe)
import Data.Ord (comparing)
import Data.Traversable (for)
import Data.Vector.Storable (Vector)
import qualified Data.Vector.Storable as V
import qualified Data.Vector.Storable.Mutable as VM
import Foreign.C.String
import Foreign.C.Types
import Foreign.ForeignPtr (touchForeignPtr)
import Foreign.Marshal.Alloc
import Foreign.Marshal.Array (advancePtr)
import Foreign.Marshal.Utils
import Codec.FFmpeg.Internal.Debug
import Foreign.Ptr
import Foreign.Storable
#include <libavformat/avformat.h>
-- Based on the FFmpeg muxing example
-- http://www.ffmpeg.org/doxygen/2.1/doc_2examples_2muxing_8c-example.html
-- * FFI Declarations
foreign import ccall "avcodec_find_encoder"
avcodec_find_encoder :: AVCodecID -> IO AVCodec
foreign import ccall "avcodec_find_encoder_by_name"
avcodec_find_encoder_by_name :: CString -> IO AVCodec
foreign import ccall "av_opt_set"
av_opt_set :: Ptr () -> CString -> CString -> CInt -> IO CInt
foreign import ccall "avcodec_encode_video2"
avcodec_encode_video2 :: AVCodecContext -> AVPacket -> AVFrame -> Ptr CInt
-> IO CInt
foreign import ccall "av_image_alloc"
av_image_alloc :: Ptr (Ptr CUChar) -> Ptr CInt -> CInt -> CInt
-> AVPixelFormat -> CInt -> IO CInt
foreign import ccall "av_freep"
av_freep :: Ptr (Ptr a) -> IO ()
foreign import ccall "av_guess_format"
av_guess_format :: CString -> CString -> CString -> IO AVOutputFormat
foreign import ccall "avformat_alloc_output_context2"
avformat_alloc_output_context2 :: Ptr AVFormatContext -> AVOutputFormat
-> CString -> CString -> IO CInt
foreign import ccall "avformat_new_stream"
avformat_new_stream :: AVFormatContext -> AVCodec -> IO AVStream
foreign import ccall "av_write_frame"
av_write_frame :: AVFormatContext -> AVPacket -> IO CInt
foreign import ccall "av_interleaved_write_frame"
av_interleaved_write_frame :: AVFormatContext -> AVPacket -> IO CInt
foreign import ccall "avformat_write_header"
avformat_write_header :: AVFormatContext -> Ptr AVDictionary -> IO CInt
foreign import ccall "av_write_trailer"
av_write_trailer :: AVFormatContext -> IO CInt
foreign import ccall "avio_open"
avio_open :: Ptr AVIOContext -> CString -> AVIOFlag -> IO CInt
foreign import ccall "avio_close"
avio_close :: AVIOContext -> IO CInt
foreign import ccall "avformat_free_context"
avformat_free_context :: AVFormatContext -> IO ()
foreign import ccall "av_image_fill_arrays"
av_image_fill_arrays :: Ptr (Ptr CUChar) -> Ptr CInt -> Ptr CUChar
-> AVPixelFormat -> CInt -> CInt -> CInt -> IO CInt
foreign import ccall "av_image_fill_linesizes"
av_image_fill_linesizes :: Ptr CInt -> AVPixelFormat -> CInt -> IO CInt
foreign import ccall "av_frame_make_writable"
av_frame_make_writable :: AVFrame -> IO CInt
-- * FFmpeg Encoding Interface
-- | Minimal parameters describing the desired video output.
data EncodingParams = EncodingParams
{ 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@.
}
-- | Minimal parameters describing the desired audio/video output.
data AVEncodingParams = AVEncodingParams
{ avepWidth :: CInt
, avepHeight :: CInt
, avepFps :: Int
, avepCodec :: Maybe AVCodecID
-- ^ If 'Nothing', then the codec is inferred from
-- the output file name. If 'Just', then this codec
-- is manually chosen.
, avepPixelFormat :: Maybe AVPixelFormat
-- ^ If 'Nothing', automatically chose a pixel format
-- based on the output codec. If 'Just', force the
-- selected pixel format.
, avepChannelLayout :: CULong
-- ^ Channel layout for the audio stream
, avepSampleRate :: CInt
-- ^ Sample rate for the audio stream
, avepSampleFormat :: AVSampleFormat
-- ^ Sample format for the audio stream
, avepPreset :: 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.
, avepFormatName :: 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@.
}
-- | Minimal parameters describing the desired audio/video output.
data AEncodingParams = AEncodingParams
{ aepChannelLayout :: CULong
-- ^ Channel layout for the audio stream
, aepSampleRate :: CInt
-- ^ Sample rate for the audio stream
, aepSampleFormat :: AVSampleFormat
-- ^ Sample format for the audio stream
, aepPreset :: 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.
, aepFormatName :: 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@.
}
data VideoParams = VideoParams
{ vpWidth :: CInt
, vpHeight :: CInt
, vpFps :: Int
, vpCodec :: Maybe AVCodecID
, vpPixelFormat :: Maybe AVPixelFormat
, vpPreset :: String
}
class HasVideoParams a where
extractVideoParams :: a -> VideoParams
instance HasVideoParams EncodingParams where
extractVideoParams ep = VideoParams
{ vpWidth = epWidth ep
, vpHeight = epHeight ep
, vpFps = epFps ep
, vpCodec = epCodec ep
, vpPixelFormat = epPixelFormat ep
, vpPreset = epPreset ep
}
instance HasVideoParams AVEncodingParams where
extractVideoParams ep = VideoParams
{ vpWidth = avepWidth ep
, vpHeight = avepHeight ep
, vpFps = avepFps ep
, vpCodec = avepCodec ep
, vpPixelFormat = avepPixelFormat ep
, vpPreset = avepPreset ep
}
class HasAudioParams a where
extractAudioParams :: a -> AudioParams
instance HasAudioParams AEncodingParams where
extractAudioParams ep = AudioParams
{ apChannelLayout = aepChannelLayout ep
, apSampleRate = aepSampleRate ep
, apSampleFormat = aepSampleFormat ep
}
instance HasAudioParams AVEncodingParams where
extractAudioParams ep = AudioParams
{ apChannelLayout = avepChannelLayout ep
, apSampleRate = avepSampleRate ep
, apSampleFormat = avepSampleFormat ep
}
-- | Use default parameters for a video of the given width and
-- height, forcing the choice of the h264 encoder.
defaultH264 :: CInt -> CInt -> EncodingParams
defaultH264 w h =
EncodingParams
{ epWidth = w
, epHeight = h
, epFps = 30
, epCodec = (Just avCodecIdH264)
, epPixelFormat = Nothing
, epPreset = "medium"
, epFormatName = Nothing
}
-- | Use default parameters for a video of the given width and
-- height. The output format is determined by the output file name.
defaultParams :: CInt -> CInt -> EncodingParams
defaultParams w h =
EncodingParams
{ epWidth = w
, epHeight = h
, epFps = 30
, epCodec = Nothing
, epPixelFormat = Nothing
, epPreset = ""
, epFormatName = Nothing
}
-- | Determine if the bitwise intersection of two values is non-zero.
checkFlag :: Bits a => a -> a -> Bool
checkFlag flg = \x -> (flg .&. x) /= allZeroBits
where allZeroBits = clearBit (bit 0) 0
-- | Find and initialize the requested encoder, and add a video stream
-- to the output container.
initStream :: EncodingParams -> AVFormatContext -> IO (AVStream, AVCodecContext)
initStream ep oc = initVideoStream (extractVideoParams ep) oc
initVideoStream :: VideoParams -> AVFormatContext -> IO (AVStream, AVCodecContext)
initVideoStream vp _
| (vpWidth vp `rem` 2, vpHeight vp `rem` 2) /= (0,0) =
error "Video dimensions must be multiples of two"
initVideoStream vp oc = do
-- Use the codec suggested by the output format, or override with
-- the user's choice.
codec <- maybe (getOutputFormat oc >>= getVideoCodecID) return (vpCodec vp)
cod <- avcodec_find_encoder codec
when (getPtr cod == nullPtr)
(error "Couldn't find encoder")
st <- avformat_new_stream oc cod
getNumStreams oc >>= setId st . subtract 1
let framePeriod = AVRational 1 (fromIntegral $ vpFps vp)
frameRate = AVRational (fromIntegral $ vpFps vp) 1
setTimeBase st framePeriod
ctx <- getCodecContext st
setWidth ctx (vpWidth vp)
setHeight ctx (vpHeight vp)
setTimeBase ctx framePeriod
setFrameRate ctx frameRate
setPixelFormat ctx $ case vpPixelFormat vp of
Just fmt -> fmt
Nothing
| codec == avCodecIdRawvideo -> avPixFmtRgb24
| codec == avCodecIdGif -> avPixFmtPal8
| otherwise -> avPixFmtYuv420p
-- Some formats want stream headers to be separate
needsHeader <- checkFlag avfmtGlobalheader <$>
(getOutputFormat oc >>= getFormatFlags)
when needsHeader $
#if LIBAVFORMAT_VERSION_MAJOR < 57
getCodecFlags ctx >>= setCodecFlags ctx . (.|. codecFlagGlobalHeader)
#else
getCodecFlags ctx >>= setCodecFlags ctx . (.|. avCodecFlagGlobalHeader)
#endif
-- _ <- withCString "vprofile" $ \kStr ->
-- withCString (preset ep) $ \vStr ->
-- av_opt_set ((#ptr AVCodecContext, priv_data) (getPtr ctx))
-- kStr vStr 0
when (not . null $ vpPreset vp) . void $
withCString "preset" $ \kStr ->
withCString (vpPreset vp) $ \vStr ->
getPrivData ctx >>= \pd -> av_opt_set pd kStr vStr 0
rOpen <- open_codec ctx cod nullPtr
when (rOpen < 0) (error "Couldn't open codec")
return (st, ctx)
initAudioStream :: AudioParams
-> AVFormatContext
-> IO (AVStream, AVCodec, AVCodecContext)
initAudioStream params oc = do
codecId <- getAudioCodecID =<< getOutputFormat oc
print codecId
cod <- avcodec_find_encoder codecId
when (getPtr cod == nullPtr) (avError "Could not find audio codec")
st <- avformat_new_stream oc cod
getNumStreams oc >>= setId st . subtract 1
setTimeBase st (AVRational 1 (apSampleRate params))
ctx <- avcodec_alloc_context3 cod
supportedSampleRates <- listSupportedSampleFormats cod
let found = not (null supportedSampleRates)
when (not found) $ avError "Could not find supported sample rate"
-- TODO: check that these are valid
setSampleFormat ctx (apSampleFormat params)
setSampleRate ctx (apSampleRate params)
setChannelLayout ctx (apChannelLayout params)
runWithError "Could not open audio codec" (open_codec ctx cod nullPtr)
codecParams <- getCodecParams st
runWithError "Could not copy params" (avcodec_parameters_from_context codecParams ctx)
return (st, cod, ctx)
-- | 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.
initTempFrame :: VideoParams -> AVPixelFormat -> IO AVFrame
initTempFrame vp fmt = do
frame <- frame_alloc_check
setPixelFormat frame fmt
setWidth frame (vpWidth vp)
setHeight frame (vpHeight vp)
setPts frame 0
-- For palettized images, we will provide our own buffer.
if fmt == avPixFmtRgb8 || fmt == avPixFmtPal8
then do r <- av_image_fill_linesizes (hasLineSize frame) fmt (vpWidth vp)
when (r < 0) (error "Error filling temporary frame line sizes")
else frame_get_buffer_check frame 32
return frame
-- | Allocate an output context inferring the codec from the given
-- file name.
allocOutputContext :: Maybe String -> FilePath -> IO AVFormatContext
allocOutputContext outputFormat fname = do
let withFormat = case outputFormat of
Just f -> withCString f
Nothing -> (\f -> f nullPtr)
oc <- alloca $ \ocTmp -> do
r <- withCString fname $ \fname' ->
withFormat $ \format ->
avformat_alloc_output_context2
ocTmp (AVOutputFormat nullPtr)
format fname'
when (r < 0)
(error "Couldn't allocate output format context")
peek ocTmp
when (getPtr oc == nullPtr)
(error "Couldn't allocate iutput AVFormatContext")
return oc
-- | Open the given file for writing.
avio_open_check :: AVFormatContext -> String -> IO ()
avio_open_check oc fname =
do r <- withCString fname $ \cstr ->
avio_open (hasIOContext oc) cstr avioFlagWrite
when (r < 0) (error "Error opening IO for writing")
-- | Close an open IO context.
avio_close_check :: AVFormatContext -> IO ()
avio_close_check oc = do r <- getIOContext oc >>= avio_close
when (r /= 0) (error "Error closing IO")
-- | Returns 'True' if the 'AVPacket' was updated with new output
-- data; 'False' otherwise.
encode_video_check :: AVCodecContext -> AVPacket -> Maybe AVFrame -> IO Bool
encode_video_check ctx pkt frame =
alloca $ \gotOutput -> do
r <- avcodec_encode_video2 ctx pkt frame' gotOutput
when (r < 0) (error "Error encoding frame")
(> 0) <$> peek gotOutput
where frame' = fromMaybe (AVFrame nullPtr) frame
-- | Allocate the stream private data and write the stream header to
-- an output media file.
write_header_check :: AVFormatContext -> IO ()
write_header_check oc =
void $ runWithError "write header" (avformat_write_header oc nullPtr)
-- | Write a packet to an output media file.
write_frame_check :: AVFormatContext -> AVPacket -> IO ()
write_frame_check oc pkt = do r <- av_write_frame oc pkt
when (r < 0) (error "Error writing frame")
-- | 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'.
write_trailer_check :: AVFormatContext -> IO ()
write_trailer_check oc = do r <- av_write_trailer oc
when (r /= 0) (error "Error writing trailer")
-- | 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.
palettizeRGB8 :: VideoParams -> V.Vector CUChar -> V.Vector CUChar
palettizeRGB8 vp = \pix -> V.create $
do let pix' = V.unsafeCast pix :: V.Vector (V3 CUChar)
m <- VM.new (numPix + 1024)
V.mapM_ (\i -> let p = searchPal $ fromIntegral <$> (pix' V.! i)
in VM.unsafeWrite m i p)
(V.enumFromN 0 numPix)
VM.set (VM.unsafeSlice numPix 1024 m) 0
return m
where numPix = fromIntegral $ vpWidth vp * vpHeight vp
pal :: V.Vector (V3 CInt)
pal = V.generate 256 $ \i' ->
let i = fromIntegral i'
in V3 ((i `shiftR` 5) * 36)
(((i `shiftR` 2) .&. 7) * 36)
((i .&. 3) * 85)
searchPal = fromIntegral . flip V.minIndexBy pal . comparing . qd
-- | 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.
palettizeJuicy :: VideoParams -> V.Vector CUChar -> V.Vector CUChar
palettizeJuicy vp pix =
let (pix', pal) = palettize (PaletteOptions MedianMeanCut doDither 256)
(mkImage $ V.unsafeCast pix)
pal' = V.map (\(V3 r g b) -> V4 b g r (255::CUChar))
(V.unsafeCast $ imageData pal)
in V.unsafeCast (imageData pix') V.++ V.unsafeCast pal'
where mkImage = Image (fromIntegral $ vpWidth vp) (fromIntegral $ vpHeight vp)
doDither = vpPreset vp == "dither"
{-# DEPRECATED frameWriter "Please use videoWriter instead." #-}
frameWriter :: EncodingParams -> FilePath
-> IO (Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ())
frameWriter ep fname = do
let sp = JustVideo (extractVideoParams ep)
writerContext <- avWriter (epFormatName ep) sp fname
return (avwVideoWriter writerContext)
-- | 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.
videoWriter :: EncodingParams -> FilePath
-> IO (Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ())
videoWriter ep fname = do
let sp = JustVideo (extractVideoParams ep)
writerContext <- avWriter (epFormatName ep) sp fname
return (avwVideoWriter writerContext)
data StreamParams =
JustVideo VideoParams
| JustAudio AudioParams
| AudioVideo AudioParams VideoParams
withVideoParams :: StreamParams -> a -> (VideoParams -> a) -> a
withVideoParams sp def f =
case sp of
JustVideo vp -> f vp
AudioVideo _ vp -> f vp
_ -> def
withAudioParams :: StreamParams -> a -> (AudioParams -> a) -> a
withAudioParams sp def f =
case sp of
JustAudio ap -> f ap
AudioVideo ap _ -> f ap
_ -> def
-- | Open a target for writing an audio stream.
audioWriter :: AEncodingParams
-> FilePath
-> IO (Maybe AVCodecContext, Maybe AVFrame -> IO ())
audioWriter ep fname = do
let sp = JustAudio (extractAudioParams ep)
writerContext <- avWriter (aepFormatName ep) sp fname
return (avwAudioCodecContext writerContext, avwAudioWriter writerContext)
data AVWriterContext = AVWriterContext
{ avwVideoCodecContext :: Maybe AVCodecContext
, avwAudioCodecContext :: Maybe AVCodecContext
, avwVideoWriter :: Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ()
, avwAudioWriter :: Maybe AVFrame -> IO ()
}
-- | Open a target for writing a video and audio file.
audioVideoWriter :: AVEncodingParams -> FilePath -> IO AVWriterContext
audioVideoWriter ep fname = do
let sp = AudioVideo (extractAudioParams ep) (extractVideoParams ep)
avWriter (avepFormatName ep) sp fname
-- | For internal use only. Use 'videoWriter', 'audioWriter', or 'audioVideoWriter' instead.
avWriter :: Maybe String
-> StreamParams
-> FilePath
-> IO AVWriterContext
avWriter outputFormat sp fname = do
oc <- allocOutputContext outputFormat fname
outputFormat <- getOutputFormat oc
audioCodecId <- getAudioCodecID outputFormat
videoCodecId <- getVideoCodecID outputFormat
-- Initializing the streams needs to be done before opening the file
-- and checking the header because it can modify fields that are used
-- for time scaling so we have this rather ugly code.
mVideoStream <- withVideoParams sp (return Nothing) $ \vp ->
(Just <$> initVideoStream vp oc)
mAudioStream <- withAudioParams sp (return Nothing) $ \ap ->
(Just <$> initAudioStream ap oc)
avio_open_check oc fname
numStreams <- getNumStreams oc
write_header_check oc
alreadyClosedRef <- newIORef False
let writeClose = do
alreadyClosed <- readIORef alreadyClosedRef
when (not alreadyClosed) $ do
write_trailer_check oc
modifyIORef alreadyClosedRef (const True)
initializeVideo :: AVStream
-> AVCodecContext
-> VideoParams
-> IO (Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ())
initializeVideo st ctx vp = do
dstFmt <- getPixelFormat ctx
dstFrame <- initTempFrame vp dstFmt
let dstInfo = ImageInfo (vpWidth vp) (vpHeight vp) dstFmt
-- Initialize the scaler that we use to convert RGB -> dstFmt
-- Note that libswscaler does not support Pal8 as an output format.
sws <- if dstFmt /= avPixFmtPal8 && dstFmt /= avPixFmtRgb8
then swsInit (ImageInfo (vpWidth vp) (vpHeight vp) avPixFmtRgb24)
dstInfo swsBilinear
>>= fmap Just . newIORef
else return Nothing
pkt <- AVPacket <$> av_malloc (fromIntegral packetSize)
setPts pkt 0
stIndex <- getStreamIndex st
-- Frame number ioref. We use this to determine whether we should
-- increment the frame PTS; we only want to do this for frames after
-- the first one since we want the first frame PTS to be zero.
frameNum <- newIORef (0::Int)
let framePeriod = AVRational 1 (fromIntegral $ vpFps vp)
fps <- getFps ctx
-- The stream time_base can be changed by the call to
-- 'write_header_check', so we read it back here to establish a way
-- of scaling the nominal, desired frame rate (given by
-- 'framePeriod') to the stream's time_base.
tb <- getTimeBase st
#if LIBAVFORMAT_VERSION_MAJOR < 57
isRaw <- checkFlag avfmtRawpicture <$> (getOutputFormat oc >>= getFormatFlags)
#endif
let checkPalCompat
| dstFmt /= avPixFmtPal8 && dstFmt /= avPixFmtRgb8 = const True
| otherwise = \(srcFmt, V2 srcW srcH, _) ->
srcFmt == avPixFmtRgb24 &&
srcW == vpWidth vp &&
srcH == vpHeight vp
palettizer | dstFmt == avPixFmtPal8 = Just $ palettizeJuicy vp
| dstFmt == avPixFmtRgb8 = Just $ palettizeRGB8 vp
| otherwise = Nothing
frameTime = av_rescale_q 1 framePeriod tb
resetPacket = do init_packet pkt
setPktData pkt nullPtr
setSize pkt 0
writePacket = do setStreamIndex pkt stIndex
write_frame_check oc pkt
copyDstData (_,_,pixels) =
void . V.unsafeWith pixels $ \ptr ->
av_image_fill_arrays (castPtr $ hasData dstFrame)
(hasLineSize dstFrame)
(castPtr ptr)
dstFmt
(vpWidth vp)
(vpHeight vp)
1
scaleToDst sws' img = void $ swsScale sws' img dstFrame
fillDst = maybe copyDstData scaleToDst
-- | Gets the PTS to be used for the current frame by reading the
-- PTS from dstFrame. If the current frame is the first frame
-- (zero), the existing timestamp is left unmodified. Otherwise it
-- is incremented by frameTime.
--
-- This also increments the current frame number stored in the
-- frameNum IORef so the caller needn't worry about it.
getCurrentFrameTimestamp = do
curFrame <- readIORef frameNum
ts <- case curFrame == 0 of
True -> getPts dstFrame
False -> (+ frameTime) <$> getPts dstFrame
modifyIORef frameNum (+1)
return ts
#if LIBAVFORMAT_VERSION_MAJOR < 57
addRaw Nothing = return ()
addRaw (Just (_, _, pixels)) =
do resetPacket
getPacketFlags pkt >>= setPacketFlags pkt . (.|. avPktFlagKey)
--setSize pkt (fromIntegral $ V.length pixels)
setSize pkt (fromIntegral pictureSize)
timeStamp <- getCurrentFrameTimestamp
setPts dstFrame timeStamp
setPts pkt timeStamp
-- getPts dstFrame >>= setDts pkt
V.unsafeWith pixels $ \ptr -> do
setData pkt (castPtr ptr)
writePacket
#endif
addEncoded Nothing = do resetPacket
encode_video_check ctx pkt Nothing >>=
flip when (writePacket >> addEncoded Nothing)
addEncoded (Just srcImg@(srcFmt, V2 srcW srcH, pixels)) =
do resetPacket
when (not $ checkPalCompat srcImg)
(error $
unlines [ "Palettized output requires source images to be the "
, "same resolution as the output video" ])
let pixels' = maybe pixels ($ V.unsafeCast pixels) palettizer
sws' <- for sws $ \sPtr -> do
s <- readIORef sPtr
s' <- swsReset s (ImageInfo srcW srcH srcFmt) dstInfo
swsBilinear
writeIORef sPtr s'
return s'
timeStamp <- getCurrentFrameTimestamp
setPts dstFrame timeStamp
fillDst sws' (srcFmt, V2 srcW srcH, pixels')
encode_video_check ctx pkt (Just dstFrame) >>= flip when writePacket
-- Make sure the GC hasn't clobbered our palettized pixel data
let (fp,_,_) = V.unsafeToForeignPtr pixels'
touchForeignPtr fp
#if LIBAVFORMAT_VERSION_MAJOR < 57
addFrame = if isRaw then addRaw else addEncoded
#else
addFrame = addEncoded
#endif
go Nothing = do addFrame Nothing
writeClose
_ <- codec_close ctx
with dstFrame av_frame_free
av_free (getPtr pkt)
avio_close_check oc
avformat_free_context oc
go img@(Just _) = addFrame img
return go
initializeAudio :: AVStream
-> AVCodec
-> AVCodecContext
-> IO (Maybe AVFrame -> IO ())
initializeAudio st codec ctx = do
if audioCodecId /= avCodecIdNone
then do
pkt <- av_packet_alloc
init_packet pkt
frameNum <- newIORef (0::Int)
timeBase <- getTimeBase ctx
lastPts <- newIORef 0
let read_pkts = do
ret <- avcodec_receive_packet ctx pkt
-- TODO: Distinguish between temp and permanent errors with EAGAIN
if ret /= 0
then return ()
else do
timeBase2 <- getTimeBase st
packet_rescale_ts pkt timeBase timeBase2
setStreamIndex pkt =<< getStreamIndex st
-- TODO: Not sure this pts will be exactly accurate.
-- Also, we need to set duration too because it doesn't seem to be set.
setPts pkt =<< readIORef lastPts
runWithError "Error while writing audio frame"
(av_interleaved_write_frame oc pkt)
return ()
writeAudioFrame :: Maybe AVFrame -> IO ()
writeAudioFrame Nothing = do
read_pkts
writeClose
codec_close ctx
return ()
writeAudioFrame (Just frame) = writeAudioFrame' frame
writeAudioFrame' :: AVFrame -> IO ()
writeAudioFrame' frame = do
numSamples <- getNumSamples frame
sampleRate <- getSampleRate ctx
onGoingSampleCount <- readIORef frameNum
let samplesCount = av_rescale_q (fromIntegral onGoingSampleCount)
(AVRational 1 sampleRate) timeBase
setPts frame (av_rescale_q samplesCount (AVRational 1 sampleRate) timeBase)
newPts <- getPts frame
modifyIORef lastPts (const newPts)
modifyIORef frameNum (+ fromIntegral numSamples)
runWithError "Error encoding audio"
(avcodec_send_frame ctx frame)
read_pkts
return writeAudioFrame
else
return $ \_ -> return ()
videoWriter <- case mVideoStream of
Just (vs, ctx) ->
withVideoParams sp (return (\_ -> return ()))
(initializeVideo vs ctx)
Nothing -> return (\_ -> return ())
audioWriter <- case mAudioStream of
Just (as, codec, ctx) ->
withAudioParams sp (return $ \_ -> return ())
(const (initializeAudio as codec ctx))
Nothing -> return $ \_ -> return ()
return $ AVWriterContext
{ avwVideoCodecContext = snd <$> mVideoStream
, avwAudioCodecContext = (\(_, _, ctx) -> ctx) <$> mAudioStream
, avwVideoWriter = videoWriter
, avwAudioWriter = audioWriter
}
-- | 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. Throws an error if you do not
-- provide a 'EncodingParams' without 'VideoParams'
frameWriterRgb :: EncodingParams -> FilePath
-> IO (Maybe (Vector CUChar) -> IO ())
frameWriterRgb ep f = do
let aux pixels = (avPixFmtRgb24, V2 (epWidth ep) (epHeight ep), pixels)
videoWriter <- frameWriter ep f
return $ \pix -> videoWriter (aux <$> pix)