Added frame data SetBytes() and FromImage()

2025-10-06 00:26:52 +08:00 · 2024-10-12 11:28:08 +02:00
parent 3e7aa4e83f
commit a5fe16a531
8 changed files with 444 additions and 93 deletions
--- a/examples/frame_data_manipulating/main.go
+++ b/examples/frame_data_manipulating/main.go
@@ -0,0 +1,108 @@
+package main
+
+import (
+	"fmt"
+	"image/png"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/asticode/go-astiav"
+)
+
+const (
+	align         = 1
+	pngPath       = "testdata/image-rgba.png"
+	rawBufferPath = "testdata/image-rgba.rgba"
+)
+
+func main() {
+	// Handle ffmpeg logs
+	astiav.SetLogLevel(astiav.LogLevelDebug)
+	astiav.SetLogCallback(func(c astiav.Classer, l astiav.LogLevel, fmt, msg string) {
+		var cs string
+		if c != nil {
+			if cl := c.Class(); cl != nil {
+				cs = " - class: " + cl.String()
+			}
+		}
+		log.Printf("ffmpeg log: %s%s - level: %d\n", strings.TrimSpace(msg), cs, l)
+	})
+
+	// Alloc frames
+	f1 := astiav.AllocFrame()
+	defer f1.Free()
+	f2 := astiav.AllocFrame()
+	defer f2.Free()
+
+	// To write data manually into a frame, proper attributes need to be set and allocated
+	for _, f := range []*astiav.Frame{f1, f2} {
+		// Set attributes
+		f.SetHeight(256)
+		f.SetPixelFormat(astiav.PixelFormatRgba)
+		f.SetWidth(256)
+
+		// Alloc buffer
+		if err := f.AllocBuffer(align); err != nil {
+			log.Fatal(fmt.Errorf("main: allocating buffer failed: %w", err))
+		}
+
+		// Alloc image
+		if err := f.AllocImage(align); err != nil {
+			log.Fatal(fmt.Errorf("main: allocating image failed: %w", err))
+		}
+	}
+
+	// When writing data manually into a frame, you usually need to make sure the frame is writable
+	// Don't forget this step above all if the frame's buffer is referenced elsewhere
+	for _, f := range []*astiav.Frame{f1, f2} {
+		// Make writable
+		if err := f.MakeWritable(); err != nil {
+			log.Fatal(fmt.Errorf("main: making frame writable failed: %w", err))
+		}
+	}
+
+	// As an example, we're going to write data manually into the first frame based on a buffer (i.e. raw data)
+	b, err := os.ReadFile(rawBufferPath)
+	if err != nil {
+		log.Fatal(fmt.Errorf("main: reading %s failed: %w", rawBufferPath, err))
+	}
+	if err := f1.Data().SetBytes(b, align); err != nil {
+		log.Fatal(fmt.Errorf("main: setting frame's data based on bytes failed: %w", err))
+	}
+
+	// As an example, we're going to write data manually into the second frame based on a Go image
+	fl1, err := os.Open(pngPath)
+	if err != nil {
+		log.Fatal(fmt.Errorf("main: opening %s failed: %w", pngPath, err))
+	}
+	defer fl1.Close()
+	i1, err := png.Decode(fl1)
+	if err != nil {
+		log.Fatal(fmt.Errorf("main: decoding %s failed: %w", pngPath, err))
+	}
+	if err := f2.Data().FromImage(i1); err != nil {
+		log.Fatal(fmt.Errorf("main: setting frame's data based on Go image failed: %w", err))
+	}
+
+	// This is the place where you do stuff with the frames
+
+	// As an example, we're going to read the first frame's data as a buffer (i.e. raw data)
+	if _, err = f1.Data().Bytes(align); err != nil {
+		log.Fatal(fmt.Errorf("main: getting frame's data as bytes failed: %w", err))
+	}
+
+	// As an example, we're going to read the second frame's data as a Go image
+	// For that we first need to guess the Go image format based on the frame's attributes before providing
+	// it to .ToImage(). You may not need this and can provide your own image.Image to .ToImage()
+	i2, err := f2.Data().GuessImageFormat()
+	if err != nil {
+		log.Fatal(fmt.Errorf("main: guessing image format failed: %w", err))
+	}
+	if err := f2.Data().ToImage(i2); err != nil {
+		log.Fatal(fmt.Errorf("main: getting frame's data as Go image failed: %w", err))
+	}
+
+	// Success
+	log.Println("success")
+}