[mythtv-users] ffmpeg-resync

[John Pilkington]

On 20/11/2021 22:09, John Pilkington wrote:
> On 12/11/2021 22:39, John Pilkington wrote:
>> I have today's merged version 076bc59 on two Fedora 34 boxes with 
>> nVidia GT 710 cards.  One is 2-core Intel, one 4-core. When using 
>> VDPAU for both decoding and deinterlacing, playback and skipping look 
>> excellent for me on previously recorded UK DVB-T/T2 content with a 
>> valid seektable.  I have seen  occasional very brief pixellation on 
>> skipping, but overall it looks good to me.
>>
>> Strangely, the 2-core box has a 'VDPAU High Quality' decoder setting 
>> while the selector on the 4-core box has only 'Normal' for VDPAU. The 
>> first card says it is PCIe Gen1 with a 64-bit memory interface, while 
>> the 2nd is Gen2, 32 bit.  In the past I tended to use NVDEC, because I 
>> thought that was the way to go...
>>
>> HTH
>>
>> John P
> 
> Just for kicks...  Here's a segment of FE log from playback of tonight's 
> 'Strictly' DVB-T2:

I've snipped that log extract, which I posted as an example of UK 
DVB-T2's rapid switching between 1080i and 1080p content during 
programme assembly.  The first paragraph describes my hardware.

One box now has recent master, and one has the ffmpeg-resync, and on 
both I have a short 1080i clip of end-of-programme rolling credits. 
I've been trying a selection of playback profiles, and VDPAU Normal with 
single-rate deinterlacing gives generally good playback and skipping; I 
don't see then the blocking after a skip that Klaas has investigated. 
Viewing is on monitors, one running at 75.02 and one at 60.00 Hz, in 
1024x576 windows.  That probably explains why the scrolling of 25 fps 
content isn't as smooth as I would like.

But on both systems I have just recognised that I see two varieties of 
still frame:

When playback is paused, by pressing either P or E, the scrolling 
characters have crisp outlines.

When skipping from that initial static display, as when trying to define 
cutpoints, the top and bottom edges of the characters are *not* crisply 
defined.  I don't think this is just a bad-interlacing artefact, and 
since I see it with both boxes it isn't from the ffmpeg-resync either.

I wondered if I should add this to my issue #344 about continuing 
niggles with the cutlist editor, but though it better to put it here first.

https://drive.google.com/file/d/1PAYMx9lLSaaLNM6vqJH45xbQ8LDvx_C1/view?usp=sharing

John P