I think you are well armed, but @leelynds will be along shortly to reveal another ‘trickle down’ effect that could be of interest.
Stay tuned.
You obviously missed the 4 videos I attached within an hour or so of you asking for them here:
Please grab them and use them as further evidence. There are several sizes in that zipfile that Plex reports as 576p, in different resolutions all the way down to 720X304. I didn’t make a 720X480 or 720X576 anamorphic version set to 4:3 aspect, but I will if it helps in identifying the problem.
He got 'em.
The Transcoding issue?
Strike while the iron is hot.
Since this effects playback as well (unnecessary transcoding for playback), it will begin there. I do not have the knowledge to point to where the root cause is. Were I to guess? It’s the Scanner and the same team for all video files.
Hey - another problem has cropped up possibly because of this new resolution dispute. All of my videos, previously recognized as 480p and direct playing, are now transcoding to devices set at 480p/1.5Mbps. If you have a plex pass, you can go here:
and see the results so far. The jury is still out on the verdict, either my previously direct playable files are not encoded properly or there may be a problem with the PMS software. I’m leaning towards a PMS glitch myself, but anything’s possible
hey right back at ya. 
Another problem… another thread please?
Just got back word from engineering on ‘576p’. I filed a dupe problem issue…
- Known
- Being changed / corrected.
- No further details given
PS: I think we’re going to see the simple identifiers “SD”, “HD”, and “UHD”
It does make the most sense.
Gents,
Now i have a supplemental request.
I am searching for a log file which shows specifically where:
- MDE makes the decision to transcode
video.height 576 > 480
This should not happen unless it is given 576 interlaced input.
Who has some?
I can create something from a raw WTV file I happen to have at the moment. It’s also interlaced. What dimensions would you like? Your ‘instructions’ are a bit above my pay grade.
EVERYTHING coming off the the (only) tower broadcasting into this ravine is going to be 1920x1080, but I can probably backwards engineer something.
If someone else has something already - that would be better I think.
Above your pay grade? video.height 576 > 480 (a quote from the log file) no need to be coy 
what I seek is a sample where the content is XXX x 576i (perhaps 1024 x 576 ) and is interlaced (not progressive).
This is a ‘two birds with one stone’ trial, showing (or not)
- The ‘576p’ currently showing is an annoyance and nothing more (bad label name on somebody’s part) and should be relabeled
- PMS can or can’t handle old PAL interlaced input
I think the UK (SD) broadcasts are 576i, they are 704 or 720 in width, not 1024 though
This is the media info for one of them, if it looks like the type of file you want i can try and get a short recording for you
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Active Format Description : Letterbox 16:9 image, with alternative 14:9 center
Frame rate : 25.000 FPS
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Handbrake insists on de-interlacing/de-combing my file resulting in a progressive encode. Odd.
It seems I can’t help you.
That’s fine… I didn’t remember. Yes, they are 720 x 576 now that I look it up.
The goal here is to create a condition where Plex reports the X & Y sizes as 720 x 576 independent of the “Media Resolution” tag. This is the definitive next step. HandBrake’s anamorphic tag/flag is messing up thinking around the table therefore let’s make an easy-to-understand test/demonstration case and eliminate any over-thinking by all involved.
This is a 1 min recording i have just done, should be a 720x576i
Hope it helps
@paulsalter said:
I think the UK (SD) broadcasts are 576i, they are 704 or 720 in width, not 1024 thoughThis is the media info for one of them, if it looks like the type of file you want i can try and get a short recording for you
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Active Format Description : Letterbox 16:9 image, with alternative 14:9 center
Frame rate : 25.000 FPS
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
1024x576 will be the ultimate displayed dimensions, but stored at 720x576.
My plan was to create interlaced samples:
1024x576 - no anamorphic flag
and
720x576 - 16:9 anamorphic flag
but sadly, Handbrake will not cooperate.
I never actually tried to make an interlaced version with Handbrake so apparently I learned something new today.
@paulsalterter
Thank you very much for that. That’ precisely what I needed to see.
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: analyzing media item 61630
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: E4 - Emancipation: Direct Play is disabled
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: E4 - Emancipation: no direct play video profile exists for http/mpegts/mpeg2video
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: E4 - Emancipation: no direct play video profile exists for http/mpegts/mpeg2video/mp2
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: E4 - Emancipation: no direct play video profile exists for http/mpegts/mpeg2video/mp2
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: E4 - Emancipation: no remuxable profile found, so video stream will be transcoded
Apr 25, 2017 11:18:53.873 [0x7f28ff9e5700] DEBUG - MDE: computed resolution bounding box of 720x576.
Exactly as expected PMS did analyze the video correctly.
- The video is captured and placed in a transport stream file.
- It is 576i
- MDE determined it needed to be transcoded for playback in Chrome (Plex/Web)
- The XML is correct.
And most importantly, the “media resolution” label is just that … A label. It’s not misidentifying because what matters shows up where it matters in the width and height.
This is cosmetic and was written up some 3 weeks ago by a Plex employee on a similar matter.
I’m sorry it’s slipped through the cracks but now we have the answers.
Input #0, mpegts, from 'Stargate SG-1 - S01E04.mp4':
Duration: 00:00:59.19, start: 19606.224200, bitrate: 2459 kb/s
Program 8274
Stream #0:0[0x6a5]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0:1[0x6a6](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, stereo, s16p, 192 kb/s
Stream #0:2[0x6a7](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, mono, s16p, 64 kb/s (visual impaired)
Stream #0:3[0x6c3](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
and
<Media videoResolution="576" id="61630" duration="59190" bitrate="2459" width="720" height="576" aspectRatio="1.78" audioChannels="2" audioCodec="mp2" videoCodec="mpeg2video" container="mpegts" videoFrameRate="PAL" videoProfile="main">
<Part accessible="1" exists="1" id="61649" key="/library/parts/61649/1493133216/file.mp4" duration="59190" file="/syno/test/tv/Stargate SG-1/Season 1/Stargate SG-1 - S01E04.mp4" size="18195016" container="mpegts" packetLength="188" videoProfile="main">
<Stream id="104148" streamType="1" codec="mpeg2video" index="0" bitrate="2203" bitDepth="8" chromaSubsampling="4:2:0" colorRange="tv" frameRate="25.000" height="576" level="8" profile="main" refFrames="1" scanType="interlaced" streamIdentifier="1701" width="720"/>
<Stream id="104149" streamType="2" selected="1" codec="mp2" index="1" channels="2" bitrate="192" language="English" languageCode="eng" audioChannelLayout="stereo" samplingRate="48000" streamIdentifier="1702"/>
<Stream id="104150" streamType="2" codec="mp2" index="2" channels="1" bitrate="64" language="English" languageCode="eng" audioChannelLayout="mono" samplingRate="48000" streamIdentifier="1703"/>
<Stream id="104151" streamType="3" codec="dvb_subtitle" index="3" language="English" languageCode="eng" streamIdentifier="1731"/>
</Part>
</Media>
with this reporting in PMS.
@JuiceWSA said:
1024x576 will be the ultimate displayed dimensions, but stored at 720x576.
(Please don’t take this as criticism – I’m just trying to clear things up in my own mind since I’ve seen 1024x576 referred to several times as the “actual display size” of the image, and I’m asking the forum in general but happen to replying to your post simply because it’s the latest one to mention it.)
I’m not quite sure what is meant by the ultimate displayed dimensions being 1024x576. The proportions will be 1024:576 = 16:9 = 32:18 = …, but the dimensions?
As far as I know, if I watch a 720x576 16:9 recording on my TV and I’m not transcoding anything, then the TV should decode the original movie stored as 720x576 pixels and expand each frame directly to 1920x1080 display pixels. If I watch the same recording on my iPad in landscape mode, it should presumably scale directly to 2048x1152. On my phone it should become 2560x1440. If I get it running on my old iPod Touch, it should scale to 960x540, expanding along the X axis but shrinking along the Y axis. Unless I’m holding it in portrait orientation for some odd reason, in which case it should scale down to 640x360 pixels. On an XGA monitor, it should indeed be 1024x576 pixels.
This all assumes square pixels. On my old PAL Amiga from a couple of decades ago, running at a resolution of 640x256, the pixels were approximately twice as tall as they were wide. Then the display resolution should be something like 640x180, if the computer had had the power to run a full screen video player.
Am I missing some reason why there is a point at which a frame is actually defined as 1024 x 576 pixels? Or is this just referring to the minimum size where you would have square pixels without shrinking anything, which isn’t necessarily related to any actual rescaling that takes place?
We’re dealing with DVDs in this thread and DVDs are unique in that the DVD can only hold media at 720x480 NTSC or 720x576 PAL. It’s a limitation of the DVD disc at the time the industry standard was ‘invented’. That medium may have changed, but the industry standard has not.
In order for an item to be displayed at and maintain 480p or 576p a method needed to be invented so that the maximum storage possible on DVD could be expanded into a full 16:9 display. That was by storing the information in non-square pixels at 720x480 or 720x576 then telling the player through an anamorphic flag what to ultimately do with the video during playback.
For decades, the proper way to encode a DVD was to simply mimic what was stored on the DVD then through it’s anamorphic flag tell the player what to do with it for playback. That’s still the right way - there was/is no need to try and re-invent the wheel.
If the DVD says it’s Widescreen 16:9, the video will be stored on disc at 720x480 (or 720x576) and finally displayed at 854x480 (or 1024x576). Every player on the planet knows what to do with a DVD - so you won’t have to worry about it.
TV, Phone, Monitor, Wristwatch - whatever you put it on it’ll work. It doesn’t matter in the slightest what that video looks like in storage. You’re not watching storage. You’re watching it after it’s been hatched and walks out onto your display device.
This thread’s issue in one of Plex figuring that wheel wasn’t round enough - so they’re going to throw in some corners to make it better.
@jonkv said:
As far as I know, if I watch a 720x576 16:9 recording on my TV and I’m not transcoding anything, then the TV should decode the original movie stored as 720x576 pixels and expand each frame directly to 1920x1080 display pixels.
Yes that’s exactly what should happen. Let’s say that 1024x576 is a way to tell the display resolution with fixed vertical resolution (remember in the good old times of CRT displays, vertical resolution was the only “fixed” resolution 
), it’s an easy number to remember and to use for discussion but when I encode my videos they are in “720x576 16:9 display aspect ratio”, I don’t specify the “display resolution”. And even if it’s defined, I think players are smart enough to avoid “double scaling” (one to stretch to 1024x576 and one to stretch to 1920x1080 on an HD TV screen).
This 1024x576 on the other hand can be a storage resolution when you want to encode a 720x576 16:9 DVD with square pixels, that is you are “pre-enlarging” your image before encoding it, therefore you don’t need to apply anamorphism. Of course we can debate forever if scaling from 720 to 1024 is a loss of definition, and if we should let the TV do the scaling instead (is scaling 720 to 1920 better? depends largely on the upscale algorithm). What’s sure is that encoding a DVD to 1024x576 is much better than encoding the same DVD at 720x404 as you often find “in the wild”. People used to be mad at majors using letterboxed 16:9 DVDs and now we accept as “DVD quality” something that’s basically the same 
This all assumes square pixels. On my old PAL Amiga from a couple of decades ago, running at a resolution of 640x256, the pixels were approximately twice as tall as they were wide. Then the display resolution should be something like 640x180, if the computer had had the power to run a full screen video player.
When you find someone with a good, deep understanding of anamorphic resolution, PAL resolution and non-square pixel, you can bet it was an Amiga user Do you remember how you could use a 768x576 doublePal resolution filling the entire 4:3 screen with square pixels? Ah the good old times ;D
@zpaolo11x said:
What’s sure is that encoding a DVD to 1024x576 is much better than encoding the same DVD at 720x404 as you often find “in the wild”.
You also find it in Plex, unfortunately. When transcoding is required, Plex applies the following to my 720x576 DVR recordings:
-filter_complex [0:0]scale=w=min(720\,iw):h=min(576\,ih):force_original_aspect_ratio=decrease,...
So it wants square pixels within a 720x576 frame, which turns into 720x404. My Chromecast then scales it up to 1920x1080. There are a few threads about this, going back a few years, but apparently no reply from Plex.
When you find someone with a good, deep understanding of anamorphic resolution, PAL resolution and non-square pixel, you can bet it was an Amiga user
I’m not sure I ever did that, but they sure were good 
