photoprism/internal/ffmpeg/encode/options.go
Michael Mayer 67811d87fa Videos: Create fragmented MP4s when transcoding with FFmpeg #4892
Signed-off-by: Michael Mayer <michael@photoprism.app>
2025-03-24 20:47:57 +01:00

78 lines
2.6 KiB
Go

package encode
import (
"fmt"
"time"
)
// Options represents FFmpeg encoding options.
type Options struct {
Bin string // FFmpeg binary filename, e.g. /usr/bin/ffmpeg.
Encoder Encoder // Supported FFmpeg output Encoder.
SizeLimit int // Maximum width and height of the output video file in pixels.
BitrateLimit string // See https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate.
MapVideo string // See https://trac.ffmpeg.org/wiki/Map#Videostreamsonly.
MapAudio string // See https://trac.ffmpeg.org/wiki/Map#Audiostreamsonly.
TimeOffset string // See https://trac.ffmpeg.org/wiki/Seeking and https://ffmpeg.org/ffmpeg-utils.html#time-duration-syntax.
Duration time.Duration // See https://ffmpeg.org/ffmpeg.html#Main-options.
MovFlags string
}
// NewVideoOptions creates and returns new FFmpeg video transcoding options.
func NewVideoOptions(ffmpegBin string, encoder Encoder, sizeLimit int, bitrateLimit, mapVideo, mapAudio string) Options {
if ffmpegBin == "" {
ffmpegBin = FFmpegBin
}
if encoder == "" {
encoder = DefaultAvcEncoder()
}
if sizeLimit < 1 {
sizeLimit = 1920
} else if sizeLimit > 15360 {
sizeLimit = 15360
}
if bitrateLimit == "" {
bitrateLimit = "50M"
}
if mapVideo == "" {
mapVideo = MapVideo
}
if mapAudio == "" {
mapAudio = MapAudio
}
return Options{
Bin: ffmpegBin,
Encoder: encoder,
SizeLimit: sizeLimit,
BitrateLimit: bitrateLimit,
MapVideo: mapVideo,
MapAudio: mapAudio,
MovFlags: MovFlags,
}
}
// NewPreviewImageOptions generates encoding options for extracting a video preview image.
func NewPreviewImageOptions(ffmpegBin string, videoDuration time.Duration) *Options {
return &Options{
Bin: ffmpegBin,
TimeOffset: PreviewTimeOffset(videoDuration),
}
}
// VideoFilter returns the FFmpeg video filter string based on the size limit in pixels and the pixel format.
func (o *Options) VideoFilter(format PixelFormat) string {
// scale specifies the FFmpeg downscale filter, see http://trac.ffmpeg.org/wiki/Scaling.
if format == "" {
return fmt.Sprintf("scale='if(gte(iw,ih), min(%d, iw), -2):if(gte(iw,ih), -2, min(%d, ih))'", o.SizeLimit, o.SizeLimit)
} else if format == FormatQSV {
return fmt.Sprintf("scale_qsv=w='if(gte(iw,ih), min(%d, iw), -1)':h='if(gte(iw,ih), -1, min(%d, ih))':format=nv12", o.SizeLimit, o.SizeLimit)
} else {
return fmt.Sprintf("scale='if(gte(iw,ih), min(%d, iw), -2):if(gte(iw,ih), -2, min(%d, ih))',format=%s", o.SizeLimit, o.SizeLimit, format)
}
}