stash/pkg/ffmpeg/encoder_scene_preview_chunk.go

128 lines
3.1 KiB
Go

package ffmpeg
import (
"fmt"
"strconv"
"github.com/stashapp/stash/pkg/utils"
)
type ScenePreviewChunkOptions struct {
StartTime float64
Duration float64
Width int
OutputPath string
Audio bool
}
func (e *Encoder) ScenePreviewVideoChunk(probeResult VideoFile, options ScenePreviewChunkOptions, preset string, fallback bool) error {
var fastSeek float64
var slowSeek float64
fallbackMinSlowSeek := 20.0
args := []string{
"-v", "error",
}
argsAudio := []string{
"-c:a", "aac",
"-b:a", "128k",
}
if !options.Audio {
argsAudio = []string{
"-an",
}
}
// Non-fallback: enable xerror.
// "-xerror" causes ffmpeg to fail on warnings, often the preview is fine but could be broken.
if !fallback {
args = append(args, "-xerror")
fastSeek = options.StartTime
slowSeek = 0
} else {
// In fallback mode, disable "-xerror" and try a combination of fast/slow seek instead of just fastseek
// Commonly with avi/wmv ffmpeg doesn't seem to always predict the right start point to begin decoding when
// using fast seek. If you force ffmpeg to decode more, it avoids the "blocky green artifact" issue.
if options.StartTime > fallbackMinSlowSeek {
// Handle seeks longer than fallbackMinSlowSeek with fast/slow seeks
// Allow for at least fallbackMinSlowSeek seconds of slow seek
fastSeek = options.StartTime - fallbackMinSlowSeek
slowSeek = fallbackMinSlowSeek
} else {
// Handle seeks shorter than fallbackMinSlowSeek with only slow seeks.
slowSeek = options.StartTime
fastSeek = 0
}
}
if fastSeek > 0 {
args = append(args, "-ss")
args = append(args, strconv.FormatFloat(fastSeek, 'f', 2, 64))
}
args = append(args, "-i")
args = append(args, probeResult.Path)
if slowSeek > 0 {
args = append(args, "-ss")
args = append(args, strconv.FormatFloat(slowSeek, 'f', 2, 64))
}
args2 := []string{
"-t", strconv.FormatFloat(options.Duration, 'f', 2, 64),
"-max_muxing_queue_size", "1024", // https://trac.ffmpeg.org/ticket/6375
"-y",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-profile:v", "high",
"-level", "4.2",
"-preset", preset,
"-crf", "21",
"-threads", "4",
"-vf", fmt.Sprintf("scale=%v:-2", options.Width),
"-strict", "-2",
}
args3 := append(args, args2...)
args3 = append(args3, argsAudio...)
finalArgs := append(args3, options.OutputPath)
_, err := e.run(probeResult, finalArgs)
return err
}
func (e *Encoder) ScenePreviewVideoChunkCombine(probeResult VideoFile, concatFilePath string, outputPath string) error {
args := []string{
"-v", "error",
"-f", "concat",
"-i", utils.FixWindowsPath(concatFilePath),
"-y",
"-c", "copy",
outputPath,
}
_, err := e.run(probeResult, args)
return err
}
func (e *Encoder) ScenePreviewVideoToImage(probeResult VideoFile, width int, videoPreviewPath string, outputPath string) error {
args := []string{
"-v", "error",
"-i", videoPreviewPath,
"-y",
"-c:v", "libwebp",
"-lossless", "1",
"-q:v", "70",
"-compression_level", "6",
"-preset", "default",
"-loop", "0",
"-threads", "4",
"-vf", fmt.Sprintf("scale=%v:-2,fps=12", width),
"-an",
outputPath,
}
_, err := e.run(probeResult, args)
return err
}