ffmpeg: add ffprobe support

ffmpeg/convert.go

@@ -22,10 +22,11 @@ import (
 
 var ffmpegDefaultParams = []string{"-hide_banner", "-loglevel", "warning"}
 
-var ffmpegPath string
+var ffmpegPath, ffprobePath string
 
 func init() {
 	ffmpegPath, _ = exec.LookPath("ffmpeg")
+	ffprobePath, _ = exec.LookPath("ffprobe")
 }
 
 // Supported returns whether ffmpeg is available on the system.
@@ -41,6 +42,15 @@ func SetPath(path string) {
 	ffmpegPath = path
 }
 
+func ProbeSupported() bool {
+	return ffprobePath != ""
+}
+
+// SetPath overrides the path to the ffprobe binary.
+func SetProbePath(path string) {
+	ffprobePath = path
+}
+
 // ConvertPath converts a media file on the disk using ffmpeg and auto-generates the output file name.
 //
 // Args:

ffmpeg/probe.go

@@ -0,0 +1,132 @@
+// Copyright (c) 2024 Tulir Asokan
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package ffmpeg
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os/exec"
+
+	"github.com/rs/zerolog"
+
+	"go.mau.fi/util/exzerolog"
+)
+
+type Format struct {
+	Filename       string            `json:"filename"`
+	NBStreams      int               `json:"nb_streams"`
+	NBPrograms     int               `json:"nb_programs"`
+	FormatName     string            `json:"format_name"`
+	FormatLongName string            `json:"format_long_name"`
+	StartTime      float64           `json:"start_time,string"`
+	Duration       float64           `json:"duration,string"`
+	Size           int               `json:"size,string"`
+	BitRate        int               `json:"bit_rate,string"`
+	ProbeScore     int               `json:"probe_score"`
+	Tags           map[string]string `json:"tags"`
+}
+
+type Disposition struct {
+	Default         int `json:"default"`
+	Dub             int `json:"dub"`
+	Original        int `json:"original"`
+	Comment         int `json:"comment"`
+	Lyrics          int `json:"lyrics"`
+	Karaoke         int `json:"karaoke"`
+	Forced          int `json:"forced"`
+	HearingImpaired int `json:"hearing_impaired"`
+	VisualImpaired  int `json:"visual_impaired"`
+	CleanEffects    int `json:"clean_effects"`
+	AttachedPic     int `json:"attached_pic"`
+	TimedThumbnails int `json:"timed_thumbnails"`
+	NonDiegetic     int `json:"non_diegetic"`
+	Captions        int `json:"captions"`
+	Descriptions    int `json:"descriptions"`
+	Metadata        int `json:"metadata"`
+	Dependent       int `json:"dependent"`
+	StillImage      int `json:"still_image"`
+}
+
+type Stream struct {
+	Index            int               `json:"index"`
+	CodecName        string            `json:"codec_name"`
+	CodecLongName    string            `json:"codec_long_name"`
+	Profile          string            `json:"profile"`
+	CodecType        string            `json:"codec_type"`
+	CodecTagString   string            `json:"codec_tag_string"`
+	CodecTag         string            `json:"codec_tag"`
+	Width            int               `json:"width"`
+	Height           int               `json:"height"`
+	CodedWidth       int               `json:"coded_width"`
+	CodedHeight      int               `json:"coded_height"`
+	ClosedCaptions   int               `json:"closed_captions"`
+	FilmGrain        int               `json:"film_grain"`
+	HasBFrames       int               `json:"has_b_frames"`
+	PixFmt           string            `json:"pix_fmt"`
+	Level            int               `json:"level"`
+	ColorRange       string            `json:"color_range"`
+	ColorSpace       string            `json:"color_space"`
+	ColorTransfer    string            `json:"color_transfer"`
+	ColorPrimaries   string            `json:"color_primaries"`
+	ChromaLocation   string            `json:"chroma_location"`
+	FieldOrder       string            `json:"field_order"`
+	Refs             int               `json:"refs"`
+	IsAvc            string            `json:"is_avc"`
+	NalLengthSize    string            `json:"nal_length_size"`
+	ID               string            `json:"id"`
+	RFrameRate       string            `json:"r_frame_rate"`
+	AvgFrameRate     string            `json:"avg_frame_rate"`
+	TimeBase         string            `json:"time_base"`
+	StartPts         int               `json:"start_pts"`
+	StartTime        float64           `json:"start_time,string"`
+	DurationTS       int               `json:"duration_ts"`
+	Duration         float64           `json:"duration,string"`
+	BitRate          int               `json:"bit_rate,string"`
+	BitsPerRawSample int               `json:"bits_per_raw_sample,string"`
+	NumberOfFrames   int               `json:"nb_frames,string"`
+	ExtradataSize    int               `json:"extradata_size"`
+	Disposition      Disposition       `json:"disposition"`
+	Tags             map[string]string `json:"tags"`
+	SampleFormat     string            `json:"sample_fmt"`
+	SampleRate       int               `json:"sample_rate,string"`
+	Channels         int               `json:"channels"`
+	ChannelLayout    string            `json:"channel_layout"`
+	BitsPerSample    int               `json:"bits_per_sample"`
+	InitialPadding   int               `json:"initial_padding"`
+}
+
+type ProbeResult struct {
+	Streams []*Stream `json:"streams"`
+	Format  *Format   `json:"format"`
+}
+
+var ffprobeDefaultParams = []string{"-print_format", "json", "-show_format", "-show_streams"}
+
+func Probe(ctx context.Context, path string) (*ProbeResult, error) {
+	ctxLog := zerolog.Ctx(ctx).With().Str("command", "ffmpeg").Logger()
+	logWriter := exzerolog.NewLogWriter(ctxLog).WithLevel(zerolog.WarnLevel)
+	cmd := exec.CommandContext(ctx, ffprobePath, append(ffprobeDefaultParams, path)...)
+	cmd.Stderr = logWriter
+	output, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("failed to probe file: %w", err)
+	}
+	defer output.Close()
+	err = cmd.Run()
+	if err != nil {
+		return nil, fmt.Errorf("failed to run ffprobe: %w", err)
+	}
+
+	var result ProbeResult
+	err = json.NewDecoder(output).Decode(&result)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse ffmpeg output: %w", err)
+	}
+
+	return &result, nil
+}