package formats import ( "fmt" "image" "runtime" "unsafe" "github.com/bluenviron/mediacommon/v2/pkg/codecs/h264" ) // #cgo pkg-config: libavcodec libavutil libswscale // #include // #include // #include import "C" func frameDataH265(frame *C.AVFrame) **C.uint8_t { return (**C.uint8_t)(unsafe.Pointer(&frame.data[0])) } func frameLineSizeH265(frame *C.AVFrame) *C.int { return (*C.int)(unsafe.Pointer(&frame.linesize[0])) } // H265Decoder is a wrapper around FFmpeg's H265 decoder. type H265Decoder struct { codecCtx *C.AVCodecContext yuv420Frame *C.AVFrame rgbaFrame *C.AVFrame rgbaFramePtr []uint8 swsCtx *C.struct_SwsContext } // Initialize initializes a H265Decoder. func (d *H265Decoder) Initialize() error { codec := C.avcodec_find_decoder(C.AV_CODEC_ID_H265) if codec == nil { return fmt.Errorf("avcodec_find_decoder() failed") } d.codecCtx = C.avcodec_alloc_context3(codec) if d.codecCtx == nil { return fmt.Errorf("avcodec_alloc_context3() failed") } res := C.avcodec_open2(d.codecCtx, codec, nil) if res < 0 { C.avcodec_close(d.codecCtx) return fmt.Errorf("avcodec_open2() failed") } d.yuv420Frame = C.av_frame_alloc() if d.yuv420Frame == nil { C.avcodec_close(d.codecCtx) return fmt.Errorf("av_frame_alloc() failed") } return nil } // Close closes the decoder. func (d *H265Decoder) Close() { if d.swsCtx != nil { C.sws_freeContext(d.swsCtx) } if d.rgbaFrame != nil { C.av_frame_free(&d.rgbaFrame) } C.av_frame_free(&d.yuv420Frame) C.avcodec_close(d.codecCtx) } func (d *H265Decoder) reinitDynamicStuff() error { if d.swsCtx != nil { C.sws_freeContext(d.swsCtx) } if d.rgbaFrame != nil { C.av_frame_free(&d.rgbaFrame) } d.rgbaFrame = C.av_frame_alloc() if d.rgbaFrame == nil { return fmt.Errorf("av_frame_alloc() failed") } d.rgbaFrame.format = C.AV_PIX_FMT_RGBA d.rgbaFrame.width = d.yuv420Frame.width d.rgbaFrame.height = d.yuv420Frame.height d.rgbaFrame.color_range = C.AVCOL_RANGE_JPEG res := C.av_frame_get_buffer(d.rgbaFrame, 1) if res < 0 { return fmt.Errorf("av_frame_get_buffer() failed") } d.swsCtx = C.sws_getContext(d.yuv420Frame.width, d.yuv420Frame.height, int32(d.yuv420Frame.format), d.rgbaFrame.width, d.rgbaFrame.height, (int32)(d.rgbaFrame.format), C.SWS_BILINEAR, nil, nil, nil) if d.swsCtx == nil { return fmt.Errorf("sws_getContext() failed") } rgbaFrameSize := C.av_image_get_buffer_size((int32)(d.rgbaFrame.format), d.rgbaFrame.width, d.rgbaFrame.height, 1) d.rgbaFramePtr = (*[1 << 30]uint8)(unsafe.Pointer(d.rgbaFrame.data[0]))[:rgbaFrameSize:rgbaFrameSize] return nil } // Decode decodes a RGBA image from H265. func (d *H265Decoder) Decode(au [][]byte) (*image.RGBA, error) { // encode access unit into Annex-B annexb, err := h264.AnnexB(au).Marshal() if err != nil { return nil, err } // send access unit to decoder var pkt C.AVPacket ptr := &annexb[0] var p runtime.Pinner p.Pin(ptr) pkt.data = (*C.uint8_t)(ptr) pkt.size = (C.int)(len(annexb)) res := C.avcodec_send_packet(d.codecCtx, &pkt) p.Unpin() if res < 0 { return nil, nil } // receive frame if available res = C.avcodec_receive_frame(d.codecCtx, d.yuv420Frame) if res < 0 { return nil, nil } // if frame size has changed, reallocate needed objects if d.rgbaFrame == nil || d.rgbaFrame.width != d.yuv420Frame.width || d.rgbaFrame.height != d.yuv420Frame.height { err := d.reinitDynamicStuff() if err != nil { return nil, err } } // convert color space from YUV420 to RGBA res = C.sws_scale(d.swsCtx, frameDataH265(d.yuv420Frame), frameLineSizeH265(d.yuv420Frame), 0, d.yuv420Frame.height, frameDataH265(d.rgbaFrame), frameLineSizeH265(d.rgbaFrame)) if res < 0 { return nil, fmt.Errorf("sws_scale() failed") } // embed frame into an image.RGBA return &image.RGBA{ Pix: d.rgbaFramePtr, Stride: 4 * (int)(d.rgbaFrame.width), Rect: image.Rectangle{ Max: image.Point{(int)(d.rgbaFrame.width), (int)(d.rgbaFrame.height)}, }, }, nil }