[mythtv-users] Status of ffmpeg 4.4.1

[James Abernathy]

On Fri, Nov 12, 2021 at 11:45 AM Stephen Worthington <
stephen_agent at jsw.gen.nz> wrote:

> On Fri, 12 Nov 2021 10:25:27 -0500, you wrote:
>
> >On Fri, Nov 12, 2021 at 9:26 AM Peter Bennett <pb.mythtv at gmail.com>
> wrote:
> >
> >>
> >> On 11/12/21 8:42 AM, James Abernathy wrote:
> >>
> >> More testing on ffmpeg 4.1.1.
> >>
> >> I have a Gen 11 Intel Core i7 with Intel Iris GFX.  If I use OpenGL High
> >> Quality, it looks great on all types of video.
> >>
> >> If I use VAAPI Normal, the same results except the first 1 second at the
> >> start of play either at the beginning or at a bookmark.  What I see is 1
> >> second of the video with only a green color.  Kind of like a black and
> >> white movie but green and white movie.  After 1 second, it plays
> perfectly.
> >>
> >> Jim A
> >>
> >>
> >> _______________________________________________
> >>
> >> What type of video is it MPEG2, H264, etc. Also is it interlaced? There
> >> have been some reported problems with interlaced H264 causing problems
> at
> >> start or after a jump and I am looking into that.
> >>
> >> Can you supply a sample video?
> >>
> >> Peter
> >>
> >
> >Sorry, that was significant and I forgot to include.
> >
> >The Videos with the "Green" 1 sec issue with VAAPI are all interlaced,
> >1080i MPEG2 ATSC USA OTA TV broadcast recordings.
> >
> >With 720P MPEG2 ATCS USA OTA TV broadcast, there is no "Green" 1 sec
> issue.
> >
> >All videos tested were from the primary channel within the multi-cast.
> >i.e. 5-1 NBC 1080i, or 50-1 720P FOX.
> >
> >Let me know if you can't reproduce and I'll got back in an just record a
> >few seconds on these videos.  Currently both are hours long sports event.
> >
> >Jim A
>
> I presume that the broadcasts are transport streams, so you can just
> take part of any recording file you cut out using dd and post that.
> The main difference between transport streams and other sorts of video
> files is that they regularly have the headers needed to tell how to
> decode them, and they are encoded in a way that you can just start
> anywhere in a stream and will be able to play as soon as the headers
> have been seen.  It has to be that way, otherwise how would you be
> able to start recording at any time?
>
> Appropriate dd commands here:
>
>
> https://stackoverflow.com/questions/1423346/how-do-i-extract-a-single-chunk-of-bytes-from-within-a-file/40792605
>
> Thanks,  Below is a link to a folder on my Google Drive with 2 10 second
videos. The one called lawandorder.ts is a 1080i  with the green issue.
The nfl.ts is 720p without any green problem.

https://drive.google.com/drive/folders/13pqTj_Q3F85w3QGyJXiFSsfyHctmlHi1?usp=sharing

Jim A
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