Merge pull request #15 from mutablelogic/ffmpeg61

Updates to the media abstraction

Author: djthorpe

Makefile

@@ -22,7 +22,7 @@ BUILD_DIR := "build"
 CMD_DIR := $(filter-out cmd/ffmpeg/README.md, $(wildcard cmd/ffmpeg/*))
 BUILD_TAG := ${DOCKER_REGISTRY}/go-media-${OS}-${ARCH}:${VERSION}
 
-all: clean cmds
+all: clean cli cmds
 
 cmds: $(CMD_DIR)
 
@@ -47,6 +47,11 @@ test: go-dep
 	@${GO} test ./pkg/...
 	@${GO} test .
 
+
+cli: go-dep mkdir
+	@echo Build media tool
+	@${GO} build ${BUILD_FLAGS} -o ${BUILD_DIR}/media ./cmd/cli
+
 $(CMD_DIR): go-dep mkdir
 	@echo Build cmd $(notdir $@)
 	@${GO} build ${BUILD_FLAGS} -o ${BUILD_DIR}/$(notdir $@) ./$@

README.md

@@ -46,9 +46,79 @@ DOCKER_REGISTRY=ghcr.io/mutablelogic make docker
 
 ## Examples
 
-## Media Transcoding
+There are a variety of types of object needed as part of media processing.
+All examples require a `Manager` to be created, which is used to enumerate all supported formats
+and open media files and byte streams.
+
+* `Manager` is the main entry point for the package. It is used to open media files and byte streams,
+  and enumerate supported formats, codecs, pixel formats, etc.
+* `Media` is a hardware device, file or byte stream. It contains metadata, artwork, and streams.
+* `Decoder` is used to demultiplex media streams. Create a decoder and enumerate the streams which
+  you'd like to demultiplex. Provide the audio and video parameters if you want to resample or
+  reformat the streams.
+* `Encoder` is used to multiplex media streams. Create an encoder and send the output of the
+  decoder to reencode the streams.
+
+### Demultiplexing
+
+```go
+import (
+  media "github.com/mutablelogic/go-media"
+)
+
+func main() {
+  manager := media.NewManager()
+
+  // Open a media file for reading. The format of the file is guessed.
+  // Alteratively, you can pass a format as the second argument. Further optional
+  // arguments can be used to set the format options.
+  file, err := manager.Open(os.Args[1], nil)
+  if err != nil {
+    log.Fatal(err)
+  }
+  defer file.Close()
+
+  // Choose which streams to demultiplex - pass the stream parameters
+  // to the decoder. If you don't want to resample or reformat the streams,
+  // then you can pass nil as the function and all streams will be demultiplexed.
+  decoder, err := file.Decoder(func (stream media.Stream) (media.Parameters, error) {
+    return stream.Parameters(), nil
+  }
+  if err != nil {
+    log.Fatal(err)
+  }
+
+  // Demuliplex the stream and receive the packets. If you don't want to
+  // process the packets yourself, then you can pass nil as the function
+  if err := decoder.Demux(context.Background(), func(_ media.Packet) error {
+    // Each packet is specific to a stream. It can be processed here
+    // to receive audio or video frames, then resize or resample them,
+    // for example. Alternatively, you can pass the packet to an encoder
+    // to remultiplex the streams without processing them.
+    return nil
+  }); err != nil {
+    log.Fatal(err)  
+  })
+}
+```
+
+### Decoding
+
+TODO
+
+### Encoding
+
+TODO
 
-## Audio Fingerprinting
+### Multiplexing
+
+TODO
+
+### Retrieving Metadata and Artwork from a media file
+
+TODO
+
+### Audio Fingerprinting
 
 You can programmatically fingerprint audio files, compare fingerprints and identify music using the following packages:
 
@@ -73,5 +143,4 @@ repository for more information:
 
 ## References
 
-  * https://ffmpeg.org/doxygen/6.1/index.html
-
+* https://ffmpeg.org/doxygen/6.1/index.html

cmd/cli/decode.go

@@ -1,26 +1,61 @@
 package main
 
 import (
-	"encoding/json"
+	"context"
 	"fmt"
+	"os"
 
 	// Packages
+	"github.com/djthorpe/go-tablewriter"
 	"github.com/mutablelogic/go-media"
 )
 
 type DecodeCmd struct {
-	Path string `arg:"" required:"" help:"Media file" type:"path"`
+	Path   string `arg:"" required:"" help:"Media file" type:"path"`
+	Format string `name:"format" short:"f" help:"Format of input file (name, .extension or mimetype)" type:"string"`
+	Audio  *bool  `name:"audio" short:"a" help:"Output raw audio stream" type:"bool"`
+	Video  *bool  `name:"video" short:"v" help:"Output raw video stream" type:"bool"`
 }
 
 func (cmd *DecodeCmd) Run(globals *Globals) error {
-	reader, err := media.Open(cmd.Path, "")
+	var format media.Format
+
+	manager := media.NewManager()
+	if cmd.Format != "" {
+		if formats := manager.InputFormats(media.NONE, cmd.Format); len(formats) == 0 {
+			return fmt.Errorf("unknown format %q", cmd.Format)
+		} else if len(formats) > 1 {
+			return fmt.Errorf("ambiguous format %q", cmd.Format)
+		} else {
+			format = formats[0]
+		}
+	}
+
+	// Open media file
+	reader, err := manager.Open(cmd.Path, format)
 	if err != nil {
 		return err
 	}
 	defer reader.Close()
 
-	data, _ := json.MarshalIndent(reader, "", "  ")
-	fmt.Println(string(data))
+	// Create a decoder - copy streams
+	decoder, err := reader.Decoder(nil)
+	if err != nil {
+		return err
+	}
 
-	return nil
+	// Demultiplex the stream
+	header := []tablewriter.TableOpt{tablewriter.OptHeader()}
+	tablewriter := tablewriter.New(os.Stdout, tablewriter.OptOutputText())
+	return decoder.Demux(context.Background(), func(packet media.Packet) error {
+		if packet == nil {
+			return nil
+		}
+		if err := tablewriter.Write(packet, header...); err != nil {
+			return err
+		}
+		// Reset the header
+		header = header[:0]
+		return nil
+	})
 }

cmd/cli/demuxers.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"os"
+
+	// Packages
+	"github.com/djthorpe/go-tablewriter"
+	"github.com/mutablelogic/go-media"
+)
+
+type SampleFormatsCmd struct{}
+
+type ChannelLayoutsCmd struct{}
+
+type PixelFormatsCmd struct{}
+
+func (cmd *SampleFormatsCmd) Run(globals *Globals) error {
+	manager := media.NewManager()
+	writer := tablewriter.New(os.Stdout, tablewriter.OptHeader(), tablewriter.OptOutputText())
+	return writer.Write(manager.SampleFormats())
+}
+
+func (cmd *ChannelLayoutsCmd) Run(globals *Globals) error {
+	manager := media.NewManager()
+	writer := tablewriter.New(os.Stdout, tablewriter.OptHeader(), tablewriter.OptOutputText())
+	return writer.Write(manager.ChannelLayouts())
+}
+
+func (cmd *PixelFormatsCmd) Run(globals *Globals) error {
+	manager := media.NewManager()
+	writer := tablewriter.New(os.Stdout, tablewriter.OptHeader(), tablewriter.OptOutputText())
+	return writer.Write(manager.PixelFormats())
+}

cmd/cli/formats.go

@@ -14,11 +14,15 @@ type Globals struct {
 
 type CLI struct {
 	Globals
-	Version  VersionCmd  `cmd:"version" help:"Print version information"`
-	Demuxers DemuxersCmd `cmd:"demuxers" help:"List media demultiplex (input) formats"`
-	Muxers   MuxersCmd   `cmd:"muxers" help:"List media multiplex (output) formats"`
-	Metadata MetadataCmd `cmd:"metadata" help:"Display media metadata information"`
-	Decode   DecodeCmd   `cmd:"decode" help:"Decode media"`
+	Version        VersionCmd        `cmd:"version" help:"Print version information"`
+	Demuxers       DemuxersCmd       `cmd:"demuxers" help:"List media demultiplex (input) formats"`
+	Muxers         MuxersCmd         `cmd:"muxers" help:"List media multiplex (output) formats"`
+	SampleFormats  SampleFormatsCmd  `cmd:"samplefmts" help:"List audio sample formats"`
+	ChannelLayouts ChannelLayoutsCmd `cmd:"channellayouts" help:"List audio channel layouts"`
+	PixelFormats   PixelFormatsCmd   `cmd:"pixelfmts" help:"List video pixel formats"`
+	Metadata       MetadataCmd       `cmd:"metadata" help:"Display media metadata information"`
+	Probe          ProbeCmd          `cmd:"probe" help:"Probe media file or device"`
+	Decode         DecodeCmd         `cmd:"decode" help:"Decode media"`
 }
 
 func main() {

cmd/cli/main.go

@@ -14,7 +14,8 @@ type MetadataCmd struct {
 }
 
 func (cmd *MetadataCmd) Run(globals *Globals) error {
-	reader, err := media.Open(cmd.Path, "")
+	manager := media.NewManager()
+	reader, err := manager.Open(cmd.Path, nil)
 	if err != nil {
 		return err
 	}

cmd/cli/metadata.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	// Packages
+	"github.com/djthorpe/go-tablewriter"
+	"github.com/mutablelogic/go-media"
+)
+
+type DemuxersCmd struct {
+	Filter string `arg:"" optional:"" help:"Filter by mimetype, name or .ext" type:"string"`
+}
+
+type MuxersCmd struct {
+	Filter string `arg:"" optional:"" help:"Filter by mimetype, name or .ext" type:"string"`
+}
+
+func (cmd *MuxersCmd) Run(globals *Globals) error {
+	manager := media.NewManager()
+	var formats []media.Format
+	if cmd.Filter == "" {
+		formats = manager.OutputFormats(media.ANY)
+	} else {
+		formats = manager.OutputFormats(media.ANY, cmd.Filter)
+	}
+	return Run(cmd.Filter, formats)
+}
+
+func (cmd *DemuxersCmd) Run(globals *Globals) error {
+	manager := media.NewManager()
+	var formats []media.Format
+	if cmd.Filter == "" {
+		formats = manager.InputFormats(media.ANY)
+	} else {
+		formats = manager.InputFormats(media.ANY, cmd.Filter)
+	}
+	return Run(cmd.Filter, formats)
+}
+
+func Run(filter string, formats []media.Format) error {
+	writer := tablewriter.New(os.Stdout, tablewriter.OptHeader(), tablewriter.OptOutputText())
+	if len(formats) == 0 {
+		fmt.Printf("No (de)muxers found for %q\n", filter)
+		return nil
+	} else {
+		return writer.Write(formats)
+	}
+}

cmd/cli/muxers.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+
+	// Packages
+	"github.com/mutablelogic/go-media"
+)
+
+type ProbeCmd struct {
+	Path string `arg:"" required:"" help:"Media file or device name" type:"string"`
+	Opts string `name:"opts" short:"o" help:"Options for opening the media file or device, (ie, \"framerate=30 video_size=176x144\")"`
+}
+
+var (
+	reDevice = regexp.MustCompile(`^([a-zA-Z0-9]+):(.*)$`)
+)
+
+func (cmd *ProbeCmd) Run(globals *Globals) error {
+	var format media.Format
+
+	manager := media.NewManager()
+	filter := media.NONE
+
+	// Try device first
+	if m := reDevice.FindStringSubmatch(cmd.Path); m != nil {
+		cmd.Path = m[2]
+		fmts := manager.InputFormats(filter|media.DEVICE, m[1])
+		if len(fmts) > 0 {
+			format = fmts[0]
+		}
+	}
+
+	// Open the media file or device
+	reader, err := manager.Open(cmd.Path, format, cmd.Opts)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
+	// Print out probe data
+	data, _ := json.MarshalIndent(reader, "", "  ")
+	fmt.Println(string(data))
+
+	// Return success
+	return nil
+}