func NewCapture(driver, device string) (*Capture, error) {
id := Capture{index: -1}
id.context = C.avformat_alloc_context()
if id.context == (*C.AVFormatContext)(null) {
return nil, fmt.Errorf("allocate output format context failed")
}
_driver := C.CString(driver)
defer C.free(unsafe.Pointer(_driver))
ifmt := C.av_find_input_format(_driver)
if ifmt == (*C.AVInputFormat)(null) {
return nil, fmt.Errorf("cannot find input driver: %s", driver)
}
dev := C.CString(device)
defer C.free(unsafe.Pointer(dev))
if C.avformat_open_input(&(id.context), dev, ifmt, (**C.AVDictionary)(null)) < 0 {
return nil, fmt.Errorf("cannot open device %s", device)
}
if C.avformat_find_stream_info(id.context, (**C.AVDictionary)(null)) < 0 {
return nil, fmt.Errorf("cannot find stream information")
}
num := int(id.context.nb_streams)
streams := (*[1 << 30]*C.AVStream)(unsafe.Pointer(id.context.streams))
var deCtx *C.AVCodecContext
for i := 0; i < num; i++ {
if streams[i].codec.codec_type == C.AVMEDIA_TYPE_VIDEO {
deCtx = streams[i].codec
id.index = i
break
}
}
if id.index == -1 {
return nil, fmt.Errorf("cannot find video stream")
}
codec := C.avcodec_find_decoder(deCtx.codec_id)
if codec == (*C.AVCodec)(null) {
return nil, fmt.Errorf("cannot find decode codec")
}
id.codec = C.avcodec_alloc_context3(codec)
if C.avcodec_copy_context(id.codec, deCtx) != 0 {
return nil, fmt.Errorf("cannot copy codec context")
}
if C.avcodec_open2(id.codec, codec, (**C.struct_AVDictionary)(null)) < 0 {
return nil, fmt.Errorf("cannot open decode codec")
}
id.sws = C.sws_getContext(id.codec.width,
id.codec.height,
id.codec.pix_fmt,
id.codec.width,
id.codec.height,
C.AV_PIX_FMT_YUV420P, C.SWS_BILINEAR, (*C.struct_SwsFilter)(null), (*C.struct_SwsFilter)(null), (*C.double)(null))
id.frame = C.av_frame_alloc()
return &id, nil
}
func (this *FmtCtx) FindStreamInfo() error {
if averr := C.avformat_find_stream_info(this.avCtx, nil); averr < 0 {
return errors.New(fmt.Sprintf("unable to find stream info: %s", AvError(int(averr))))
}
return nil
}
func Open(name string) (*MediaFile, error) {
file := &MediaFile{
Name: name,
packets: make(chan *C.AVPacket, 8),
}
cName := C.CString(name)
defer C.free(unsafe.Pointer(cName))
if C.avformat_open_input(&file.fmtctx, cName, nil, nil) < 0 {
return nil, errors.New("cannot open file " + name)
}
runtime.SetFinalizer(file, (*MediaFile).Close)
if C.avformat_find_stream_info(file.fmtctx, nil) < 0 {
return nil, errors.New("cannot find stream info for file " + name)
}
file.Streams = make([]Stream, file.fmtctx.nb_streams)
for i := range file.Streams {
file.Streams[i] = Stream{
avstream: C.AVFormatContext_GetStream(file.fmtctx, C.int(i)),
}
}
return file, nil
}
func NewDecoder(filename string) (*Decoder, error) {
self := new(Decoder)
// format context
var formatContext *C.AVFormatContext
if C.avformat_open_input(&formatContext, C.CString(filename), nil, nil) != C.int(0) {
return nil, errors.New(fmt.Sprintf("can't open %d", filename))
}
if C.avformat_find_stream_info(formatContext, nil) < 0 {
return nil, errors.New("find stream info error")
}
C.av_dump_format(formatContext, 0, C.CString(filename), 0)
self.FormatContext = formatContext
// streams
var streams []*C.AVStream
header := (*reflect.SliceHeader)(unsafe.Pointer(&streams))
header.Cap = int(formatContext.nb_streams)
header.Len = int(formatContext.nb_streams)
header.Data = uintptr(unsafe.Pointer(formatContext.streams))
self.Streams = streams
for _, stream := range streams {
switch stream.codec.codec_type {
case C.AVMEDIA_TYPE_VIDEO:
self.VideoStreams = append(self.VideoStreams, stream)
case C.AVMEDIA_TYPE_AUDIO:
self.AudioStreams = append(self.AudioStreams, stream)
default: //TODO other stream
}
}
// codecs
for _, stream := range self.Streams {
codec := C.avcodec_find_decoder(stream.codec.codec_id)
if codec == nil {
continue
}
var options *C.AVDictionary
if C.avcodec_open2(stream.codec, codec, &options) < 0 {
return nil, errors.New(fmt.Sprintf("open codec error %v", stream.codec))
}
self.openedCodecs = append(self.openedCodecs, stream.codec)
}
// output channels
self.audioFrames = make(chan *AudioFrame, 1024)
self.timedFrames = make(chan *C.AVFrame)
return self, nil
}
func (this *FmtCtx) OpenInput(filename string) error {
cfilename := C.CString(filename)
defer C.free(unsafe.Pointer(cfilename))
if averr := C.avformat_open_input(&this.avCtx, cfilename, nil, nil); averr < 0 {
return errors.New(fmt.Sprintf("Error opening input '%s': %s", filename, AvError(int(averr))))
}
if averr := C.avformat_find_stream_info(this.avCtx, nil); averr < 0 {
return errors.New(fmt.Sprintf("Unable to find stream info: %s", AvError(int(averr))))
}
// C.av_opt_set_int(this.avCtx.codec, "refcounted_frames", 1, 0)
return nil
}
func (ctx *Context) FindStreamInfo(options []*avutil.Dictionary) error {
var cOptions **C.AVDictionary
count := ctx.NumberOfStreams()
if count > 0 && options != nil {
if uint(len(options)) < count {
return ErrInvalidArgumentSize
}
cOptions = newCAVDictionaryArrayFromDictionarySlice(options[:count])
defer freeCAVDictionaryArray(cOptions)
}
code := C.avformat_find_stream_info(ctx.CAVFormatContext, cOptions)
if code < 0 {
return avutil.NewErrorFromCode(avutil.ErrorCode(code))
}
return nil
}
func main() {
var (
fmt_ctx *C.AVFormatContext
video_stream_idx C.int
pkt C.AVPacket
fn string
)
flag.StringVar(&fn, "i", fn, "Input filename")
flag.Parse()
if fn == "" {
flag.PrintDefaults()
os.Exit(1)
}
cfn := C.CString(fn)
defer C.free(unsafe.Pointer(cfn))
C.av_register_all()
if err := C.avformat_open_input(&fmt_ctx, cfn, nil, nil); err < 0 {
log.Fatalf("Could not open source file %s, %d\n", fn, err)
}
// The smd codecs aren't too happy with missing PTS
fmt_ctx.flags |= C.AVFMT_FLAG_GENPTS
defer C.avformat_close_input(&fmt_ctx)
if err := C.avformat_find_stream_info(fmt_ctx, nil); err < 0 {
log.Fatalf("Could not find stream information: %d", err)
}
if err := open_codec_context(&video_stream_idx, fmt_ctx, C.AVMEDIA_TYPE_VIDEO); err < 0 {
log.Fatalf("Could not open codec context: %d", err)
}
log.Printf("fmt_ctx: %+v", fmt_ctx)
streams := (*[32]*C.AVStream)(unsafe.Pointer(fmt_ctx.streams))
log.Printf("video stream codec: %+v", streams[video_stream_idx].codec.codec_id)
log.Printf("time_base: %+v", streams[video_stream_idx].time_base)
num := 1000000 * float64(streams[video_stream_idx].time_base.num)
den := float64(streams[video_stream_idx].time_base.den)
var codec C.ismd_codec_type_t
switch vc := streams[video_stream_idx].codec.codec_id; vc {
case C.AV_CODEC_ID_H264:
codec = C.ISMD_CODEC_TYPE_H264
case C.AV_CODEC_ID_MPEG1VIDEO:
fallthrough
case C.AV_CODEC_ID_MPEG2VIDEO:
codec = C.ISMD_CODEC_TYPE_MPEG2
case C.AV_CODEC_ID_MPEG4:
codec = C.ISMD_CODEC_TYPE_MPEG4
default:
log.Fatalf("Unhandled video codec: %d", vc)
}
Init(codec, C.GDL_PLANE_ID_UPP_C)
defer Destroy()
C.av_init_packet(&pkt)
pkt.data = nil
pkt.size = 0
running := true
go func() {
os.Stdin.Read(make([]byte, 1))
running = false
}()
frame := 0
for running && C.av_read_frame(fmt_ctx, &pkt) >= 0 {
orig_pkt := pkt
wrote := false
for pkt.stream_index == video_stream_idx && (pkt.size > 0) {
pts := num * float64(pkt.pts) / den
WriteToInputPort(uintptr(unsafe.Pointer(pkt.data)), C.size_t(pkt.size), pts, 32*1024)
wrote = true
break
}
if wrote {
frame++
if frame%100 == 0 {
var stat C.ismd_vidrend_stats_t
C.ismd_vidrend_get_stats(m_video_render, &stat)
log.Printf("%+v", stat)
}
}
C.av_free_packet(&orig_pkt)
}
}
//Read packets of a media file to get stream information.
func (s *Context) AvformatFindStreamInfo(d **Dictionary) int {
return int(C.avformat_find_stream_info((*C.struct_AVFormatContext)(s), (**C.struct_AVDictionary)(unsafe.Pointer(d))))
}
func av_find_stream_info(ctx *FormatContext) int {
return int(C.avformat_find_stream_info(ctx.ctx, nil))
}
//int avformat_find_stream_info (AVFormatContext *ic, AVDictionary **options)
//Read packets of a media file to get stream information.
func Avformat_find_stream_info(ic *AVFormatContext, d **AVDictionary) int {
return int(C.avformat_find_stream_info((*C.struct_AVFormatContext)(ic), (**C.struct_AVDictionary)(unsafe.Pointer(d))))
}
// NewGenerator returns new generator of screenshots for the video file fn.
func NewGenerator(fn string) (_ *Generator, err error) {
avfCtx := C.avformat_alloc_context()
cfn := C.CString(fn)
defer C.free(unsafe.Pointer(cfn))
if C.avformat_open_input(&avfCtx, cfn, nil, nil) != 0 {
return nil, errors.New("can't open input stream")
}
defer func() {
if err != nil {
C.avformat_close_input(&avfCtx)
}
}()
if C.avformat_find_stream_info(avfCtx, nil) < 0 {
return nil, errors.New("can't get stream info")
}
duration := int64(avfCtx.duration) / 1000
bitrate := int(avfCtx.bit_rate) / 1000
numberOfStreams := int(avfCtx.nb_streams)
hdr := reflect.SliceHeader{
Data: uintptr(unsafe.Pointer(avfCtx.streams)),
Len: numberOfStreams,
Cap: numberOfStreams,
}
streams := *(*[]*C.struct_AVStream)(unsafe.Pointer(&hdr))
vStreamIndex := -1
aStreamIndex := -1
for i := 0; i < numberOfStreams; i++ {
if streams[i].codec.codec_type == C.AVMEDIA_TYPE_VIDEO {
vStreamIndex = i
} else if streams[i].codec.codec_type == C.AVMEDIA_TYPE_AUDIO {
aStreamIndex = i
}
}
if vStreamIndex == -1 {
return nil, errors.New("no video stream")
}
avcCtx := streams[vStreamIndex].codec
vCodec := C.avcodec_find_decoder(avcCtx.codec_id)
if vCodec == nil {
return nil, errors.New("can't find decoder")
}
if C.avcodec_open2(avcCtx, vCodec, nil) != 0 {
return nil, errors.New("can't initialize codec context")
}
width := int(avcCtx.width)
height := int(avcCtx.height)
fps := (float64(streams[vStreamIndex].r_frame_rate.num) /
float64(streams[vStreamIndex].r_frame_rate.den))
vCodecName := strings.ToUpper(C.GoString(vCodec.name))
vCodecHuman := C.GoString(vCodec.long_name)
aCodecName := ""
aCodecHuman := ""
if aStreamIndex != -1 {
aacCtx := streams[aStreamIndex].codec
aCodec := C.avcodec_find_decoder(aacCtx.codec_id)
if aCodec != nil {
aCodecName = strings.ToUpper(C.GoString(aCodec.name))
aCodecHuman = C.GoString(aCodec.long_name)
}
}
return &Generator{
Width: width,
Height: height,
Duration: duration,
VideoCodec: vCodecName,
VideoCodecLongName: vCodecHuman,
AudioCodec: aCodecName,
AudioCodecLongName: aCodecHuman,
numberOfStreams: numberOfStreams,
vStreamIndex: vStreamIndex,
aStreamIndex: aStreamIndex,
FPS: fps,
Bitrate: bitrate,
streams: streams,
avfContext: avfCtx,
avcContext: avcCtx,
}, nil
}