Server Version#: 1.18.0.1944
Player Version#: 7.23.0.12998
I made a video of the problem. You should download it instead of just viewing it on dropbox in order to have the full quality and clearly see the video grains.
Sometimes when remotely watching a show (auto quality off, 720p 2Mbps default) the playback will get a lot of grain, and sometimes it goes as far as looking like worse than a 480p transcode, like really pixelated. It doesn’t happen on all frames and not everytime. Once I switch to Original quality, and back again to 720p 2Mbps it goes back to normal transcoding.
I looked at your second log with Supergirl. I can’t see anything significantly different between the 2 transcoding sessions. The only thing I see is that originally, the audio was being direct streamed (i.e. copied, not transcoded) then when you changed it, it does transcode. Since the quality is set to 2 Mbps, it is possible that in the original stream, the audio was higher so there was less room for the video so it used slightly less bitrate for the video than on the retry. Seems like a bug in changing that decision between the 2 attempts. I’m not sure which would be better. I’m thinking some would prefer to have the un-transcoded audio. What do you think?
Note that your videos were actually being transcoded to 480p. That 2 Mbps is a maximum, and PMS found that there wasn’t enough data to produce 720p so it ended up with 480p.
there was less room for the video so it used slightly less bitrate
slightly is a bit of an understatement in my opinion. The first attempt was so pixelated that I couldn’t event make out some expressions.
Seems like a bug in changing that decision between the 2 attempts. I’m not sure which would be better. I’m thinking some would prefer to have the un-transcoded audio. What do you think?
Theorically I would agree with you: direct stream/play should always be the preferred choice.
But because this is causing me real pain (my HD-crazy-eyes hurts seeing so much pixels ) in watching my shows, if this is really causing the video bitrates to go down so much, I can only say that I disagree.
What’s bothering me though is that I’ve been watching episodes after episodes for months this summer (and before) on 720p 2Mbps default and never ever having any pixelated shows (even if in the back it is really a 480p transcode).
I tested this episode of supergirl in 240p 0.3 Mbps:
I know it’s surely not the real transcoded resolution as you pointed out earlier, but when you compare the resulted transcode of the first attempt of 720p 2 Mbps (took from the video at 0:08):
Well, that’s not very big so I doubt the audio is taking up space. I’m not sure why the video looks so bad.
But something else doesn’t look right. The info for the file says 16 Mbps, but the video is 7.9 and the audio is .126. Where is the other 8 Mbps? Something doesn’t look right. Can you get me the xml using Plex Web?
Oh, ok. My guess is that the original decision used the entire stream and scaled it (i.e. 16 Mpbs -> 2 Mbps), while the retry used just the video (8 -> 2). You can see that this would cause a big difference in the quality.
Let me run this past our transcoder expert and see what he says.
I agree that is a promising lead, as the first log/video I submitted here on show Black Lightning S03E01 with this problem also have an embedded sub EIA_608 with a big bitrate.
EDIT: I just checked and almost all the episodes of the show I’ve been watching since the beginning of October have a sub like this. That could be it.
Plex is updating the transcoder to support newer processors, the downside is that the newer display drivers don’t support the older Haswell processors quite like they use to. Not that they did well with anything less than 4MB before. You can turn off HW transcoding or possibly Plex will be able to work out the issue.
yes you’re right: I definitely started seing signs of this bug since the upgrade of the transcoder, but haven’t thought to test HW vs CPU.
I just tested and it looks that this is happenning only when HW.
I’m using HW on a i7-4790k 4GHz.
Unfortunately I really don’t want to go back to CPU transcode as this was really painful to watch.
I just noticed something, I’m syncing a lot of TV Shows, all HW transcoding at Original or “2Mbps 720p” and not a single one was more pixelated than expected. I just tested again and same result. 2Mbps 720p HW transcode is pixelated, same episode synced at 2Mbps 720p by HW transcode is fine.
With the new PMS update release I wanted to try again HW transcode: it’s different this time as the stream is mainly less pixelated, except for the moving form edges which are now visually buggy. On an episode with external SRT.
I don’t really know how to describe this, better to watch it.
I’m going back again to SW
Server Version#: 1.18.2.2015
Player Android mobile Version#: 7.24.0.13466
) in watching my shows, if this is really causing the video bitrates to go down so much, I can only say that I disagree.
