func (m *Muxer) AddVideoStream(codecId uint32, width, height int) bool {
codec := C.avcodec_find_encoder(codecId)
if codec == (*C.AVCodec)(null) {
return false
}
m.context.oformat.video_codec = codecId
stream := C.avformat_new_stream(m.context, codec)
if stream == (*C.AVStream)(null) {
return false
}
m.videoStream = Stream{stream, 0}
c := m.videoStream.stream.codec
c.codec_id = codecId
c.codec_type = C.AVMEDIA_TYPE_VIDEO
c.bit_rate = 400000
c.width = C.int(width)
c.height = C.int(height)
m.videoStream.stream.time_base = C.AVRational{1, 30}
c.time_base = m.videoStream.stream.time_base
c.gop_size = 12
c.pix_fmt = C.AV_PIX_FMT_YUV420P
if m.context.oformat.flags&C.AVFMT_GLOBALHEADER != 0 {
c.flags |= C.CODEC_FLAG_GLOBAL_HEADER
}
if C.avcodec_open2(c, (*C.AVCodec)(null), (**C.AVDictionary)(null)) < 0 {
return false
}
m.recl = append(m.recl, func() {
C.avcodec_close(c)
})
return true
}
func FindEncoder(i interface{}) (*Codec, error) {
var avc *C.AVCodec
switch t := i.(type) {
case string:
cname := C.CString(i.(string))
defer C.free(unsafe.Pointer(cname))
avc = C.avcodec_find_encoder_by_name(cname)
break
case int:
avc = C.avcodec_find_encoder(uint32(i.(int)))
break
default:
return nil, errors.New(fmt.Sprintf("Unable to find codec, unexpected arguments type '%v'", t))
}
if avc == nil {
return nil, errors.New(fmt.Sprintf("Unable to find codec by value '%v'", i))
}
return &Codec{avCodec: avc}, nil
}
func (m *Muxer) AddAudioStream(codecId uint32) bool {
codec := C.avcodec_find_encoder(codecId)
if codec == (*C.AVCodec)(null) {
return false
}
m.context.oformat.audio_codec = codecId
stream := C.avformat_new_stream(m.context, codec)
if stream == (*C.AVStream)(null) {
return false
}
m.audioStream = Stream{stream, 0}
c := m.audioStream.stream.codec
c.bit_rate = 48000
c.sample_fmt = C.AV_SAMPLE_FMT_S16
if C.check_sample_fmt(codec, c.sample_fmt) == 0 {
return false
}
c.channels = 1
c.channel_layout = C.uint64_t(C.av_get_default_channel_layout(c.channels))
c.sample_rate = 44100
m.audioStream.stream.time_base = C.AVRational{1, c.sample_rate}
c.time_base = m.audioStream.stream.time_base
if m.context.oformat.flags&C.AVFMT_GLOBALHEADER != 0 {
c.flags |= C.CODEC_FLAG_GLOBAL_HEADER
}
if codecId == C.AV_CODEC_ID_AAC {
m.fifo = C.av_audio_fifo_alloc(c.sample_fmt, c.channels, 1)
if m.fifo == (*C.AVAudioFifo)(null) {
return false
}
m.recl = append(m.recl, func() {
C.av_audio_fifo_free(m.fifo)
})
}
if C.avcodec_open2(c, (*C.AVCodec)(null), (**C.AVDictionary)(null)) < 0 {
return false
}
m.recl = append(m.recl, func() {
C.avcodec_close(c)
})
if c.codec.capabilities&C.CODEC_CAP_VARIABLE_FRAME_SIZE != 0 {
c.frame_size = 10000
}
return true
}
func NewEncoder(codec uint32, in image.Image, out io.Writer) (*Encoder, error) {
_codec := C.avcodec_find_encoder(codec)
if _codec == nil {
return nil, fmt.Errorf("could not find codec")
}
c := C.avcodec_alloc_context3(_codec)
f := C.avcodec_alloc_frame()
c.bit_rate = 400000
// resolution must be a multiple of two
w, h := C.int(in.Bounds().Dx()), C.int(in.Bounds().Dy())
if w%2 == 1 || h%2 == 1 {
return nil, fmt.Errorf("Bad image dimensions (%d, %d), must be even", w, h)
}
log.Printf("Encoder dimensions: %d, %d", w, h)
c.width = w
c.height = h
c.time_base = C.AVRational{1, 25} // FPS
c.gop_size = 10 // emit one intra frame every ten frames
c.max_b_frames = 1
underlying_im := image.NewYCbCr(in.Bounds(), image.YCbCrSubsampleRatio420)
c.pix_fmt = C.PIX_FMT_YUV420P
f.data[0] = ptr(underlying_im.Y)
f.data[1] = ptr(underlying_im.Cb)
f.data[2] = ptr(underlying_im.Cr)
f.linesize[0] = w
f.linesize[1] = w / 2
f.linesize[2] = w / 2
if C.avcodec_open2(c, _codec, nil) < 0 {
return nil, fmt.Errorf("could not open codec")
}
_swscontext := C.sws_getContext(w, h, C.PIX_FMT_RGB0, w, h, C.PIX_FMT_YUV420P,
C.SWS_BICUBIC, nil, nil, nil)
e := &Encoder{codec, in, underlying_im, out, _codec, c, _swscontext, f, make([]byte, 16*1024)}
return e, nil
}
func avcodec_find_encoder(codec_id int32) _Codec {
return _Codec{codec: C.avcodec_find_encoder(uint32(codec_id))}
}
//Find a registered encoder with a matching codec ID.
func AvcodecFindEncoder(id CodecId) *Codec {
return (*Codec)(C.avcodec_find_encoder((C.enum_AVCodecID)(id)))
}
//Find a registered encoder with a matching codec ID.
//AVCodec *avcodec_find_encoder (enum AVCodecID id)
func Avcodec_find_encoder(id AVCodecID) *AVCodec {
return (*AVCodec)(C.avcodec_find_encoder((C.enum_AVCodecID)(id)))
}
func avcodec_find_encoder(codec_id int32) Codec {
var codec Codec
codec.codec = C.avcodec_find_encoder(uint32(codec_id))
return codec
}
