Kyoo/transcoder/src/videostream.go

110 lines
2.6 KiB
Go

package src
import (
"fmt"
"log"
)
type VideoStream struct {
Stream
video *Video
quality Quality
}
func (t *Transcoder) NewVideoStream(file *FileStream, idx uint32, quality Quality) (*VideoStream, error) {
log.Printf(
"Creating a new video stream for %s (n %d) in quality %s",
file.Info.Path,
idx,
quality,
)
keyframes, err := t.metadataService.GetKeyframes(file.Info, true, idx)
if err != nil {
return nil, err
}
ret := new(VideoStream)
ret.quality = quality
for _, video := range file.Info.Videos {
if video.Index == idx {
ret.video = &video
break
}
}
NewStream(file, keyframes, ret, &ret.Stream)
return ret, nil
}
func (vs *VideoStream) getFlags() Flags {
if vs.quality == Original {
return VideoF | Transmux
}
return VideoF
}
func (vs *VideoStream) getOutPath(encoder_id int) string {
return fmt.Sprintf("%s/segment-%s-%d-%%d.ts", vs.file.Out, vs.quality, encoder_id)
}
func closestMultiple(n int32, x int32) int32 {
if x > n {
return x
}
n = n + x/2
n = n - (n % x)
return n
}
func (vs *VideoStream) getTranscodeArgs(segments string) []string {
args := []string{
"-map", fmt.Sprintf("0:V:%d", vs.video.Index),
}
if vs.quality == Original {
args = append(args,
"-c:v", "copy",
)
return args
}
args = append(args, Settings.HwAccel.EncodeFlags...)
quality := vs.quality
if vs.quality != NoResize {
width := int32(float64(vs.quality.Height()) / float64(vs.video.Height) * float64(vs.video.Width))
// force a width that is a multiple of two else some apps behave badly.
width = closestMultiple(width, 2)
args = append(args,
"-vf", fmt.Sprintf(Settings.HwAccel.ScaleFilter, width, vs.quality.Height()),
)
} else {
args = append(args, "-vf", Settings.HwAccel.NoResizeFilter)
// NoResize doesn't have bitrate info, fallback to a know quality higher or equal.
for _, q := range Qualities {
if q.Height() >= vs.video.Height {
quality = q
break
}
}
}
args = append(args,
// Even less sure but bufsize are 5x the average bitrate since the average bitrate is only
// useful for hls segments.
"-bufsize", fmt.Sprint(quality.MaxBitrate()*5),
"-b:v", fmt.Sprint(quality.AverageBitrate()),
"-maxrate", fmt.Sprint(quality.MaxBitrate()),
// Force segments to be split exactly on keyframes (only works when transcoding)
// forced-idr is needed to force keyframes to be an idr-frame (by default it can be any i frames)
// without this option, some hardware encoders uses others i-frames and the -f segment can't cut at them.
"-forced-idr", "1",
"-force_key_frames", segments,
// make ffmpeg globally less buggy
"-strict", "-2",
)
return args
}