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Tagged: Can I Reduce lip sync delay
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Anonymous.
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May 22, 2021 at 9:21 pm #21959
Anonymous
InactiveHello,
I recently purchased a Humax Aura 4k 2tb.
On recordings the video runs behind the audio. I can increase the interval between video and audio by using the settings but it does not allow me to reduce the delay. Eg +10ms +20ms etc but no – 10ms option.
I have tried stereo and surround settings on the Humax but no difference.
My TV is a LG CX 55 inch 4K Ultra HD Smart OLED TV and I am using TV speakers with 2 Bluetooth surround speakers.
Is there a way I can reduce the delay rather than increase it?
Thank you.
May 23, 2021 at 10:10 am #106046grahamlthompson
ParticipantA bit puzzled. Video takes longer to decode than audio so the audio should only need a delay. The actual broadcast delays the audio already so you should only need a positive audio delay to correct minor timing differences. Does your TV not have an adjustment in the settings menu ?
Example of what a digital programme stream has within it.
General
ID : 16517 (0x4085)
Complete name :
Vbox recordingsOnly the Brave__Channel 4 HD__15-02-2021_00-05.mp4Format : MPEG-TS
File size : 4.09 GiB
Duration : 2 h 14 min
Overall bit rate mode : Variable
Overall bit rate : 4 342 kb/s
FileExtension_Invalid : ts m2t m2s m4t m4s tmf ts tp trp ty
Video
ID : 301 (0x12D)
Menu ID : 17664 (0x4500)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings, CABAC : Yes
Format settings, RefFrames : 4 frames
Format settings, GOP : M=8, N=24
Codec ID : 27
Duration : 2 h 14 min
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 FPS
Standard : Component
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : MBAFF
Scan type, store method : Interleaved fields
Scan order : Top Field First
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Audio
ID : 302 (0x12E)
Menu ID : 17664 (0x4500)
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Muxing mode : LATM
Codec ID : 17
Duration : 2 h 14 min
Bit rate mode : Variable
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Delay relative to video : -1 s 152 ms
Language : English
Text
ID : 305 (0x131)
Menu ID : 17664 (0x4500)
Format : DVB Subtitle
Codec ID : 6
Language : English
Menu
ID : 300 (0x12C)
Menu ID : 17664 (0x4500)
Duration : 2 h 14 min
List : 302 (0x12E) (AAC, English) / 301 (0x12D) (AVC) / 305 (0x131) (DVB Subtitle, English)
Language : English / / English
UTC 2021-02-15 00:05:02 : en:Only the Brave / en: / / / 02:14:58 / Running
May 23, 2021 at 10:16 am #106047Anonymous
InactiveThank you Graham for taking the time to reply, yeah we are puzzled too. The TV is fine on live viewing so don’t really wish to have to change its settings back and forth everytime I use the Humax. But increasing the delay, even by 10 to 20ms makes the delay worse. So I’m assuming I cannot decrease the delay in the Humax settings? Interestingly it is intermittent eg dragons den was out of sync BBC2 yet BBC3 recording was perfect. Winer if it is to do with the broadcast and the fact we have upgraded to a 65 inch TV so it is more obvious. Unfortunately only used the Humax with the new larger screen TV
May 23, 2021 at 10:35 am #106048grahamlthompson
ParticipantSueH – 4 mins ago »
Thank you Graham for taking the time to reply, yeah we are puzzled too. The TV is fine on live viewing so don’t really wish to have to change its settings back and forth everytime I use the Humax. But increasing the delay, even by 10 to 20ms makes the delay worse. So I’m assuming I cannot decrease the delay in the Humax settings? Interestingly it is intermittent eg dragons den was out of sync BBC2 yet BBC3 recording was perfect. Winer if it is to do with the broadcast and the fact we have upgraded to a 65 inch TV so it is more obvious. Unfortunately only used the Humax with the new larger screen TV
I have a LG C9 but the audio is never used as I have 4K AVR with a Dolby Atmos speaker setup. I do feed a Kitchen TV when both the lounge TV and the Kitchen TV are watching the same source the handshake forces the audio to pcm stereo. My better half is very susceptible to lip synch errors even ones with a few milliseconds error. I just have the one delay set on the AVR and both lounge and Kitchen TV lip synch is perfect. Apps like Prime have no issues either. I use a 4K firestick for Prime, Netflix and Disney +. HD channels use a different audio codec (AAC) which the box transcodes to Dolby Digital on output. SD uses PCM stereo. I would expect your TV to cope with either.
On my LG C9 If I choose Settings All Select Sound and then additional. There are options for audio including AV sync Adjustment.
Suggest you have a play with these.
May 23, 2021 at 10:51 am #106049Anonymous
InactiveSueH – 24 mins ago »
Thank you Graham for taking the time to reply, yeah we are puzzled too. The TV is fine on live viewing so don’t really wish to have to change its settings back and forth everytime I use the Humax. But increasing the delay, even by 10 to 20ms makes the delay worse.
You will be surprised by how much adjustment you may have to do.
I have numerous sources running through my AVR and on occasion I have needed to apply well in excess of 100ms adjustment.
Just because adding “10 to 20ms makes the delay worse” don’t stop there. It may appear worse because the phase is different but try adding progressively more, you may just find that it works.
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