// extract extracts the original sound from the input video. func extract(in string) error { // Probe to determine the audio codec. cmd := exec.Command("ffprobe", "-show_streams", "-select_streams", "a", in) buf, err := cmd.Output() if err != nil { return fmt.Errorf("audio codec probe failed; %v", err) } re := regexp.MustCompile("codec_name=(.*)") matches := re.FindSubmatch(buf) if len(matches) < 2 { return fmt.Errorf("unable to locate codec_name") } codec := string(matches[1]) // Copy the original sound from the input video. stderr := new(bytes.Buffer) out := fmt.Sprintf("%s.%s", pathutil.TrimExt(in), codec) cmd = exec.Command("ffmpeg", "-i", in, "-vn", "-y", "-acodec", "copy", out) cmd.Stderr = stderr err = cmd.Run() if err != nil { log.Println(stderr.String()) return err } fmt.Printf("Created %q.\n", out) return nil }
// dump stores the graph as a DOT file and an image representation of the graph // as a PNG file with filenames based on "-o" flag. func dump(graph *dot.Graph) error { // Store graph to DOT file. dotPath := flagOut if !flagQuiet { log.Printf("Creating: %q\n", dotPath) } err := ioutil.WriteFile(dotPath, []byte(graph.String()), 0644) if err != nil { return errutil.Err(err) } // Generate an image representation of the graph. if flagImage { pngPath := pathutil.TrimExt(dotPath) + ".png" if !flagQuiet { log.Printf("Creating: %q\n", pngPath) } cmd := exec.Command("dot", "-Tpng", "-o", pngPath, dotPath) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr err = cmd.Run() if err != nil { return errutil.Err(err) } } return nil }
// flac2wav converts the provided FLAC file to a WAV file. func flac2wav(path string) error { // Open FLAC file. stream, err := flac.Open(path) if err != nil { return err } defer stream.Close() // Create WAV file. wavPath := pathutil.TrimExt(path) + ".wav" if !flagForce { exists, err := osutil.Exists(wavPath) if err != nil { return err } if exists { return fmt.Errorf("the file %q exists already", wavPath) } } fw, err := os.Create(wavPath) if err != nil { return err } defer fw.Close() // Create WAV encoder. conf := audio.Config{ Channels: int(stream.Info.NChannels), SampleRate: int(stream.Info.SampleRate), } enc, err := wav.NewEncoder(fw, conf) if err != nil { return err } defer enc.Close() for { // Decode FLAC audio samples. frame, err := stream.ParseNext() if err != nil { if err == io.EOF { break } return err } // Encode WAV audio samples. samples := make(audio.Int16, 1) for i := 0; i < int(frame.BlockSize); i++ { for _, subframe := range frame.Subframes { samples[0] = int16(subframe.Samples[i]) _, err = enc.Write(samples) if err != nil { return err } } } } return nil }
// ll2go parses the provided LLVM IR assembly file and decompiles it to Go // source code. func ll2go(llPath string) error { // File name and file path without extension. baseName := pathutil.FileName(llPath) basePath := pathutil.TrimExt(llPath) // TODO: Create graphs in /tmp/xxx_graphs/*.dot // Create temporary foo.dot file, e.g. // // foo.ll -> foo_graphs/*.dot dotDir := basePath + "_graphs" if ok, _ := osutil.Exists(dotDir); !ok { if !flagQuiet { log.Printf("Creating control flow graphs for %q.\n", filepath.Base(llPath)) } cmd := exec.Command("ll2dot", "-q", "-funcs", flagFuncs, "-f", llPath) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr err := cmd.Run() if err != nil { return errutil.Err(err) } } // Create temporary foo.bc file, e.g. // // foo.ll -> foo.bc bcPath := fmt.Sprintf("/tmp/%s.bc", baseName) cmd := exec.Command("llvm-as", "-o", bcPath, llPath) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr err := cmd.Run() if err != nil { return errutil.Err(err) } // Remove temporary foo.bc file. defer func() { err = os.Remove(bcPath) if err != nil { log.Fatalln(errutil.Err(err)) } }() // Parse foo.bc module, err := llvm.ParseBitcodeFile(bcPath) if err != nil { return errutil.Err(err) } defer module.Dispose() // Get function names. var funcNames []string if len(flagFuncs) > 0 { // Get function names from command line flag: // // -funcs="foo,bar" funcNames = strings.Split(flagFuncs, ",") } else { // Get all function names. for llFunc := module.FirstFunction(); !llFunc.IsNil(); llFunc = llvm.NextFunction(llFunc) { if llFunc.IsDeclaration() { // Ignore function declarations (e.g. functions without bodies). continue } funcNames = append(funcNames, llFunc.Name()) } } // Locate package name. pkgName := flagPkgName if len(flagPkgName) == 0 { pkgName = baseName for _, funcName := range funcNames { if funcName == "main" { pkgName = "main" break } } } // Create foo.go. file := &ast.File{ Name: newIdent(pkgName), } // TODO: Implement support for global variables. // Parse each function. for _, funcName := range funcNames { if !flagQuiet { log.Printf("Parsing function: %q\n", funcName) } graph, err := parseCFG(basePath, funcName) if err != nil { return errutil.Err(err) } // Structure the CFG. dotDir := basePath + "_graphs" dotName := funcName + ".dot" dotPath := path.Join(dotDir, dotName) jsonName := funcName + ".json" jsonPath := path.Join(dotDir, jsonName) if ok, _ := osutil.Exists(jsonPath); !ok { cmd := exec.Command("restructure", "-o", jsonPath, dotPath) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr if !flagQuiet { log.Printf("Structuring function: %q\n", funcName) } err = cmd.Run() if err != nil { return errutil.Err(err) } } var hprims []*xprimitive.Primitive fr, err := os.Open(jsonPath) if err != nil { return errutil.Err(err) } defer fr.Close() dec := json.NewDecoder(fr) err = dec.Decode(&hprims) if err != nil { return errutil.Err(err) } f, err := parseFunc(graph, module, funcName, hprims) if err != nil { return errutil.Err(err) } file.Decls = append(file.Decls, f) if flagVerbose && !flagQuiet { printFunc(f) } } // Store Go source code to file. goPath := basePath + ".go" if !flagQuiet { log.Printf("Creating: %q\n", goPath) } return storeFile(goPath, file) }
// ll2dot parses the provided LLVM IR assembly file and generates a control flow // graph for each of its defined functions using one node per basic block. func ll2dot(llPath string) error { // File name and file path without extension. baseName := pathutil.FileName(llPath) basePath := pathutil.TrimExt(llPath) // Create temporary foo.bc file, e.g. // // foo.ll -> foo.bc bcPath := fmt.Sprintf("/tmp/%s.bc", baseName) cmd := exec.Command("llvm-as", "-o", bcPath, llPath) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr err := cmd.Run() if err != nil { return errutil.Err(err) } // Remove temporary foo.bc file. defer func() { err = os.Remove(bcPath) if err != nil { log.Fatalln(errutil.Err(err)) } }() // Create output directory for the control flow graphs. dotDir := basePath + "_graphs" if flagForce { // Force remove existing graph directory. err = os.RemoveAll(dotDir) if err != nil { return errutil.Err(err) } } err = os.Mkdir(dotDir, 0755) if err != nil { return errutil.Err(err) } // Parse foo.bc module, err := llvm.ParseBitcodeFile(bcPath) if err != nil { return errutil.Err(err) } defer module.Dispose() // Get function names. var funcNames []string if len(flagFuncs) > 0 { // Get function names from command line flag: // // -funcs="foo,bar" funcNames = strings.Split(flagFuncs, ",") } else { // Get all function names. for f := module.FirstFunction(); !f.IsNil(); f = llvm.NextFunction(f) { if f.IsDeclaration() { // Ignore function declarations (e.g. functions without bodies). continue } funcNames = append(funcNames, f.Name()) } } // Generate a control flow graph for each function. for _, funcName := range funcNames { // Generate control flow graph. if !flagQuiet { log.Printf("Parsing function: %q\n", funcName) } graph, err := createCFG(module, funcName) if err != nil { return errutil.Err(err) } // Store the control flow graph. // // For a source file "foo.ll" containing the functions "bar" and "baz" the // following DOT files will be created: // // foo_graphs/bar.dot // foo_graphs/baz.dot dotName := funcName + ".dot" dotPath := filepath.Join(dotDir, dotName) if !flagQuiet { log.Printf("Creating: %q\n", dotPath) } buf := []byte(graph.String()) err = ioutil.WriteFile(dotPath, buf, 0644) if err != nil { return errutil.Err(err) } // Generate an image representation of the control flow graph. if flagImage { pngName := funcName + ".png" pngPath := filepath.Join(dotDir, pngName) if !flagQuiet { log.Printf("Creating: %q\n", pngPath) } cmd := exec.Command("dot", "-Tpng", "-o", pngPath, dotPath) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr err = cmd.Run() if err != nil { return errutil.Err(err) } } } return nil }
// flac2wav converts the provided FLAC file to a WAV file. func flac2wav(path string) error { // Open FLAC file. fr, err := os.Open(path) if err != nil { return err } defer fr.Close() // Create FLAC decoder. dec, magic, err := audio.NewDecoder(fr) if err != nil { return err } fmt.Println("magic:", magic) conf := dec.Config() fmt.Println("conf:", conf) // Create WAV file. wavPath := pathutil.TrimExt(path) + ".wav" if !flagForce { exists, err := osutil.Exists(wavPath) if err != nil { return err } if exists { return fmt.Errorf("the file %q exists already", wavPath) } } fw, err := os.Create(wavPath) if err != nil { return err } defer fw.Close() // Create WAV encoder. enc, err := wav.NewEncoder(fw, conf) if err != nil { return err } defer enc.Close() // Encode WAV audio samples copied from the FLAC decoder. // TODO(u): Replace with audio.Copy as soon as that doesn't cause audio // sample conversions. buf := make(audio.PCM16Samples, (32*1024)/8) for { nr, er := dec.Read(buf) if nr > 0 { nw, ew := enc.Write(buf[0:nr]) if ew != nil { return ew } if nr != nw { return audio.ErrShortWrite } } if er == audio.EOS { return nil } if er != nil { return er } } }