VLC 3.0.19 windows: regression when seeking

There is a regression in VLC 3.0.19 compared to 3.0.18

seeking a video file was smooth in 3.0.18 but now there is a black screen lag in 3.0.19

see what's happen in 3.0.19 2023-06-15_00-39-37.mkv

see how it was good in 3.0.18 2023-06-15_00-41-42.mkv

here the log of 3.0.19 log319.txt

here the log of 3.0.18 log318.txt

and if you want the video clip that i used it's here

this regression started on 10 May with this build https://artifacts.videolan.org/vlc-3.0/nightly-win32/20230510-0218/

on all the previous builds the video seeking is smooth like in 3.0.18

i guess one of the commits of 9 May are related

Thanks for the detailed bug report !

changed milestone to %3.0.19

added Severity::blocker label

assigned to @robUx4

@robUx4 since the regression started on 10 May, this is likely (75%) a regression from one of your AV1 commits in avcodec:

avcodec: add a hardware-only lavc AV1 video decoder with higher priority
avcodec: add a flag to only allow hardware decoding for the decoder
avcodec: move the code to open a VA in a function
avcodec: split the InitVideoDec function in 2 parts

Sorry if it's not one of those.

It's restarting a decoder with each seek:

existing hardware acceleration cannot be reused

Not sure why, if I disable the hardware-only decoder, it still fails the same way.

fc7816c9c5c0f5fd8f1ca44c5aa707eebaeca818 is the first bad commit
commit fc7816c9c5c0f5fd8f1ca44c5aa707eebaeca818
Author: Steve Lhomme <robux4@ycbcr.xyz>
Date:   Tue Aug 30 13:16:26 2022 +0200

avcodec: add a flag to only allow hardware decoding for the decoder

Only use 1 decoder thread when allowing only hardware decoders.

Restarting the decoder silently is not allowed. Either we can reuse the va or
we need to reload the decoder outside of lavc.

(cherry picked from commit 1effe16f9ff83042843b2fdda6bc7abe68cb7103) (edited)
edited:
* 3.0 doesn't have a defaultfmt but uses p_sys->pix_fmt as it's missing
906ffbaa631f54714ca55731b99f20d18100938e
* 3.0 calls vlc_va_Delete() with a hwaccel_context

Signed-off-by: Steve Lhomme <robux4@ycbcr.xyz>

modules/codec/avcodec/video.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

if this can help when i disable the hardware decoder everything is fine

sotfware decoder log vlc3019sw.txt

hardware decoder log vlc3019hw.txt

And different hw decoder?

mentioned in merge request !3799 (merged)

other then automatic i have 2 other hardware choise, d3d11 and dxva in both case it's worst after one seek the screen remain black forever, iattach video and logs

dxva.mkv

vlc3019hwd3d11.txt

vlc3019hwdxva.txt

it's fixed now ...thanks

closed

added Component::Decoders Hw Platform::Windows desktop Status::fixed labels