2023-10-31 09:16:44 CST W44D2

examples/qsvdec/main.go

@@ -1,5 +1,192 @@
+//go:build ffmpeg_hw_qsv
+
 package main
 
-func main() {
+/*
+#include <stdlib.h>
 
+struct AVCodecContext;
+
+int get_format(struct AVCodecContext *avctx, int *pix_fmts) {
+	// TODO.
+	return -1;
+}
+
+*/
+import "C"
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+
+	ffmpeg "github.com/qrtc/ffmpeg-dev-go"
+)
+
+type decodeContext struct {
+	hwDeviceRef *ffmpeg.AVBufferRef
+}
+
+func decodePacket(decode *decodeContext, decoderCtx *ffmpeg.AVCodecContext,
+	frame *ffmpeg.AVFrame, swFrame *ffmpeg.AVFrame,
+	pkt *ffmpeg.AVPacket, outputCtx *ffmpeg.AVIOContext) (ret int32) {
+	var (
+		data [][]uint8
+	)
+	if ret = ffmpeg.AvCodecSendPacket(decoderCtx, pkt); ret < 0 {
+		fmt.Fprintf(os.Stderr, "Error during decoding\n")
+		return ret
+	}
+
+	for ret >= 0 {
+		ret = ffmpeg.AvCodecReceiveFrame(decoderCtx, frame)
+		if ret == ffmpeg.AVERROR(syscall.EAGAIN) || ret == ffmpeg.AVERROR_EOF {
+			break
+		} else if ret < 0 {
+			fmt.Fprintf(os.Stderr, "Error while decoding.\n")
+			return ret
+		}
+
+		// A real program would do something useful with the decoded frame here.
+		// We just retrieve the raw data and write it to a file, which is rather
+		// useless but pedagogic.
+		if ret = ffmpeg.AvHWFrameTransferData(swFrame, frame, 0); ret < 0 {
+			fmt.Fprintf(os.Stderr, "Error transferring the data to system memory\n")
+			goto fail
+		}
+
+		data = ffmpeg.SliceSlice(&swFrame.GetData()[0], len(swFrame.GetData()),
+			swFrame.GetWidth()*swFrame.GetHeight())
+		for i := 0; i < len(swFrame.GetData()) && data[i] != nil; i++ {
+			for j := 0; j < int(swFrame.GetHeight()>>ffmpeg.CondExpr(i > 0, 1, 0)); j++ {
+				ffmpeg.AvIOWrite(outputCtx, &data[i][j*int(swFrame.GetLinesize()[i])], swFrame.GetWidth())
+			}
+		}
+	fail:
+		ffmpeg.AvFrameUnref(swFrame)
+		ffmpeg.AvFrameUnref(frame)
+
+		if ret < 0 {
+			return ret
+		}
+	}
+
+	return 0
+}
+
+func main() {
+	var (
+		intputCtx      *ffmpeg.AVFormatContext
+		videoSt        *ffmpeg.AVStream
+		decoderCtx     *ffmpeg.AVCodecContext
+		decoder        *ffmpeg.AVCodec
+		pkt            ffmpeg.AVPacket
+		frame, swFrame *ffmpeg.AVFrame
+		decode         = &decodeContext{}
+		outputCtx      *ffmpeg.AVIOContext
+		ret            int32
+	)
+
+	if len(os.Args) < 3 {
+		fmt.Fprintf(os.Stderr, "Usage: %s <input file> <output file>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	// open the input file
+	if ret = ffmpeg.AvFormatOpenInput(&intputCtx, os.Args[1], nil, nil); ret < 0 {
+		fmt.Fprintf(os.Stderr, "Cannot open input file '%s': ", os.Args[1])
+		goto finish
+	}
+
+	// find the first H.264 video stream
+	for i := 0; i < int(intputCtx.GetNbStreams()); i++ {
+		st := intputCtx.GetStreams()[i]
+		if st.GetCodecpar().GetCodecId() == ffmpeg.AV_CODEC_ID_H264 && videoSt == nil {
+			videoSt = st
+		} else {
+			st.SetDiscard(ffmpeg.AVDISCARD_ALL)
+		}
+	}
+	if videoSt == nil {
+		fmt.Fprintf(os.Stderr, "No H.264 video stream in the input file\n")
+		goto finish
+	}
+
+	// open the hardware device
+	if ret = ffmpeg.AvHWDeviceCtxCreate(&decode.hwDeviceRef, ffmpeg.AV_HWDEVICE_TYPE_QSV,
+		"auto", nil, 0); ret < 0 {
+		fmt.Fprintf(os.Stderr, "Cannot open the hardware device\n")
+		goto finish
+	}
+
+	// initialize the decoder
+	if decoder = ffmpeg.AvCodecFindDecoderByName("h264_qsv"); decoder == nil {
+		fmt.Fprintf(os.Stderr, "The QSV decoder is not present in libavcodec\n")
+		goto finish
+	}
+
+	decoderCtx.SetCodecId(ffmpeg.AV_CODEC_ID_H264)
+	if videoSt.GetCodecpar().GetExtradataSize() != 0 {
+		decoderCtx.SetExtradata((*uint8)(ffmpeg.AvMallocz(videoSt.GetCodecpar().GetExtradataSize() +
+			ffmpeg.AV_INPUT_BUFFER_PADDING_SIZE)))
+		if decoderCtx.GetExtradata() == nil {
+			ret = ffmpeg.AVERROR(syscall.ENOMEM)
+			goto finish
+		}
+		copy(unsafe.Slice(decoderCtx.GetExtradata(), videoSt.GetCodecpar().GetExtradataSize()),
+			unsafe.Slice(videoSt.GetCodecpar().GetExtradata(), videoSt.GetCodecpar().GetExtradataSize()))
+	}
+
+	decoderCtx.SetOpaque(decode.hwDeviceRef)
+	decoderCtx.SetGetFormat((ffmpeg.AVCodecContextGetFormatFunc)(C.get_format))
+
+	if ret = ffmpeg.AvCodecOpen2(decoderCtx, nil, nil); ret < 0 {
+		fmt.Fprintf(os.Stderr, "Error opening the decoder: ")
+		goto finish
+	}
+
+	// open the output stream
+	if ret = ffmpeg.AvIOOpen(&outputCtx, os.Args[2], ffmpeg.AVIO_FLAG_WRITE); ret < 0 {
+		fmt.Fprintf(os.Stderr, "Error opening the output context: ")
+		goto finish
+	}
+
+	frame = ffmpeg.AvFrameAlloc()
+	swFrame = ffmpeg.AvFrameAlloc()
+	if frame == nil || swFrame == nil {
+		ret = ffmpeg.AVERROR(syscall.ENOMEM)
+		goto finish
+	}
+
+	// actual decoding
+	for ret >= 0 {
+		if ret = ffmpeg.AvReadFrame(intputCtx, &pkt); ret < 0 {
+			break
+		}
+
+		if pkt.GetStreamIndex() == videoSt.GetIndex() {
+			ret = decodePacket(decode, decoderCtx, frame, swFrame, &pkt, outputCtx)
+		}
+
+		ffmpeg.AvPacketUnref(&pkt)
+	}
+
+finish:
+	if ret < 0 {
+		fmt.Fprintf(os.Stderr, "%s\n", ffmpeg.AvErr2str(ret))
+	}
+
+	ffmpeg.AvFormatCloseInput(&intputCtx)
+
+	ffmpeg.AvFrameFree(&frame)
+	ffmpeg.AvFrameFree(&swFrame)
+
+	ffmpeg.AvCodecFreeContext(&decoderCtx)
+
+	ffmpeg.AvBufferUnref(&decode.hwDeviceRef)
+
+	ffmpeg.AvIOClose(outputCtx)
+
+	os.Exit(int(ret))
 }