e4373454ba
HDR (HDR10/HLG/Dolby Vision) transcoded to SDR came out washed-out and desaturated because the filter chain never tonemapped. buildHLSFFmpegArgsAt now inserts a zscale linearise -> hable tonemap -> BT.709 chain after the scale and before format=, but only when the source is HDR and the ffmpeg build has zscale (FFmpegSupportsZscale, cached). Builds without zimg keep the old behaviour (plays, just desaturated) instead of erroring. It's a CPU filter, valid for every encoder here: the decode hwaccel deliberately leaves frames in system memory (no -hwaccel_output_format), so zscale runs ahead of format=/hwupload exactly like the existing scale filter. Verified on a real 4K HDR10 file — vivid colour and deep blacks vs the washed-out baseline.
68 lines
2.4 KiB
Go
68 lines
2.4 KiB
Go
package engine
|
|
|
|
// TranscodeRuntime carries the resolved ffmpeg/ffprobe paths + tunables so
|
|
// each session can decide whether to passthrough or pipe through ffmpeg.
|
|
type TranscodeRuntime struct {
|
|
FFmpegPath string
|
|
FFprobePath string
|
|
HWAccel HWAccel
|
|
Preset string
|
|
VideoBitrate string
|
|
AudioBitrate string
|
|
MaxHeight int
|
|
// Disabled forces passthrough for every file even when codecs are not
|
|
// browser-friendly. Useful when the user explicitly turns transcoding
|
|
// off in config.
|
|
Disabled bool
|
|
// TonemapHDR enables HDR→SDR tonemapping of HDR sources during transcode.
|
|
// Set only when the ffmpeg build has zscale (FFmpegSupportsZscale); without
|
|
// it the tonemap filter would error and break playback, so it stays off.
|
|
TonemapHDR bool
|
|
}
|
|
|
|
// qualityCap maps a session's Quality label to a (MaxHeight, VideoBitrate)
|
|
// pair. An empty label or "original" returns zero-values, signalling "no
|
|
// override" to the caller.
|
|
type qualityCap struct {
|
|
MaxHeight int
|
|
VideoBitrate string // ffmpeg -b:v string, e.g. "3500k"
|
|
}
|
|
|
|
func resolveQualityCap(label string) qualityCap {
|
|
switch label {
|
|
case "2160p":
|
|
return qualityCap{MaxHeight: 2160, VideoBitrate: "25000k"}
|
|
case "1080p":
|
|
return qualityCap{MaxHeight: 1080, VideoBitrate: "6000k"}
|
|
case "720p":
|
|
return qualityCap{MaxHeight: 720, VideoBitrate: "3500k"}
|
|
case "480p":
|
|
return qualityCap{MaxHeight: 480, VideoBitrate: "1500k"}
|
|
default:
|
|
// "original", "auto", "" → defer to config.
|
|
return qualityCap{}
|
|
}
|
|
}
|
|
|
|
// capForHeight returns the bitrate-cap pair appropriate for an effective
|
|
// output height. Used after clamping outputHeight to the source's resolution:
|
|
// asking ffmpeg for "2160p" bitrate (25 Mbps) on a 1080p source overshoots
|
|
// the H.264 level we derived from the EFFECTIVE height (4.0, max 20 Mbps) and
|
|
// makes libx264 refuse with "VBV bitrate > level limit". This helper picks
|
|
// the bitrate that matches the level libx264 will actually accept.
|
|
func capForHeight(height int) qualityCap {
|
|
switch {
|
|
case height <= 0:
|
|
return qualityCap{}
|
|
case height <= 480:
|
|
return qualityCap{MaxHeight: 480, VideoBitrate: "1500k"}
|
|
case height <= 720:
|
|
return qualityCap{MaxHeight: 720, VideoBitrate: "3500k"}
|
|
case height <= 1080:
|
|
return qualityCap{MaxHeight: 1080, VideoBitrate: "6000k"}
|
|
case height <= 1440:
|
|
return qualityCap{MaxHeight: 1440, VideoBitrate: "12000k"}
|
|
default:
|
|
return qualityCap{MaxHeight: 2160, VideoBitrate: "25000k"}
|
|
}
|
|
}
|