Bad Experience on transcode a movie with PGSSUB inside

[LoyidoGu 0]

Here is my server log. My server is installed on Synology 920+ and i can use HW transcoding watching movie without PGSSUB smoothly. But if i select a PGSSUB while playing the movie. it stucked.

 

I have to wait about 15 seconds for 2-3 seconds's play time.

 

Can anyone helps me find out what's going on?

ffmpeg-transcode-a7dd33a5-d42d-42c4-8d4b-da74ec3ed329_1.txt embyserver.txt

[Luke 37218]

Hi, your server might not be able to handle transcoding pgs subtitles. What is the quality setting set to in the iOS app? Try raising it and that might allow you to avoid the transcoding altogether.

[LoyidoGu 0]

18 hours ago, Luke said:

Hi, your server might not be able to handle transcoding pgs subtitles. What is the quality setting set to in the iOS app? Try raising it and that might allow you to avoid the transcoding altogether.

Thanks a lot. I just disabled the hardware transcoding on sever part and using local decoding instead. It works well. But Some PGSSUB come to invisible in some movie (not everyone). 

 

 

Here is my quality setting. I also tried Direct play, but hte problem still here.

 

Please help me figure out which part goes wrong, thanks!

embyserver.txt ffmpeg-directstream-21dc4e72-9e92-45cf-aa9c-69799d9f9758_1.txt

[Luke 37218]

[LoyidoGu 0]

9 hours ago, Luke said:

So PGSSUB has different formats and some of them are not supported in emby? 

[Luke 37218]

No but you've restricted user access to transcoding, and this is going to cause the quality setting to not work properly. Try enabling those permissions and then see how it compares. Thanks.

[LoyidoGu 0]

14 minutes ago, Luke said:

No but you've restricted user access to transcoding, and this is going to cause the quality setting to not work properly. Try enabling those permissions and then see how it compares. Thanks.

It works!

But if i enadble those premissions, the server will automatically transcode them on server. And my server might not be able to handle transcoding pgs subtitles....The transcode process is very slow and i need to wait for a very long time. (only 2.2 fps per second)

I find that invisible PGSSUB happens on the stream transcode (MKV transcode to HLS) with server transcoding disabled. if i disable all those three option, i can see PGSSUB in this movie. 

If i just enable the last one (allow changing of conatiner formats), the PGSSUB gone. 

The reason why i need to disable the Video trancoding is because i don't need movie transcode on sever (too slow) and chaning conatiner formats to HLS is very useful while network situation is not good enough to handle direct play. 

So that's like a deadloop. If i enable transcoding premission, i can see PGSSUB, but it will transcode the movie on server and it can't even see the movie. If i disable transcoding, the playback is smooth but i can‘t see PGSSUB in some movie....

 

ffmpeg transcode fiile i posted is the playback that i enable all transcoding options. 

 

ffmpeg-transcode-f9254777-a8de-489f-9aea-51b327bdde2d_1.txt embyserver.txt

[Luke 37218]

Quote

The reason why i need to disable the Video trancoding is because i don't need movie transcode on sever

The reason why you should still enable it anyway is because the server won't transcode unless it's the only way to play.

In this case it looks like the iOS app tried to direct play, then had a problem with the file and switched to transcoding. So we should try to get to the bottom of that. Are you inside the local network or outside?

[LoyidoGu 0]

28 minutes ago, Luke said:

In this case it looks like the iOS app tried to direct play, then had a problem with the file and switched to transcoding. So we should try to get to the bottom of that. Are you inside the local network or outside?

I'm outside now. Will back in 6 hours. 

What can i do to figure out what's going on on iOS app ?

Edited November 2, 2022 by LoyidoGu

[LoyidoGu 0]

24 minutes ago, Luke said:

The reason why you should still enable it anyway is because the server won't transcode unless it's the only way to play.

Thanks, I will keep those option enabled.

[LoyidoGu 0]

3 hours ago, Luke said:

The reason why you should still enable it anyway is because the server won't transcode unless it's the only way to play.

In this case it looks like the iOS app tried to direct play, then had a problem with the file and switched to transcoding. So we should try to get to the bottom of that. Are you inside the local network or outside?

I've done some test and has some questions:

 

1.Playback information and playback logic Confuse

If Stream shows

MKV (73 mbps)

 --> HLS (40 mbps 832 fps)

Reducing bitrate due to quality setting

The playing Video must be encoded (must happen on server) to lower the Bitrate. Is that right?

 

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

If So, this kind of playback information confused me. What's the stream shows? It Compressed what from 73 mbps to 40 mbps?

Looks like the PGSSUB gose to transcoding path which i disabled (because stream shows the movie need to reducing bitrate) but the movie use direct playing path (different from encoding path), so that it becomes invisible.

 

In order to reproduce this situation, i have changed thoese setting: 

quality setting: 

User playback Setting: (I know this kind of setting is not correct, just for discussing) 

 

 

2. IOS app Playback Problem

From the play back information, it's trying to encode it to a higher bitrate.

Here is my Quality Setting. I'm testing it outside. 

 

The FFmpeg and server file is IOS playback log with transcoding (should be direct play). 

embyserver.txt ffmpeg-transcode-715942c1-1fba-4933-9825-849c85c9154c_1.txt

Edited November 2, 2022 by LoyidoGu
add more detail

[Happy2Play 8351]

4 hours ago, LoyidoGu said:

The FFmpeg and server file is IOS playback log with transcoding (should be direct play). 

But you are trying to play unsupported codecs that will not direct play

device returned capabilities

http://xxxxxx.xxxxxx.xxe:8100/emby/videos/34334/main.m3u8?DeviceId=97ABBE1C-7E69-4227-8A8F-7EF3EAB6132B&MediaSourceId=a07108ee3865b78579eddb7b46b4ac88&PlaySessionId=5e89093cfa7a433aa4586dae7fc96861&api_key=cfd802b209d94449800f805bd10ee7c1&VideoCodec=h264,hevc,mpeg2video&AudioCodec=ac3,mp3,aac&VideoBitrate=79616000&AudioBitrate=384000&AudioStreamIndex=1&TranscodingMaxAudioChannels=6&SegmentContainer=ts&SegmentLength=3&MinSegments=1&BreakOnNonKeyFrames=True&hevc-profile=Main,Main10&TranscodeReasons=AudioCodecNotSupported,DirectPlayError&allowVideoStreamCopy=false

Audio conversion must happen as TrueHD is not supported.  Which in the end triggers a full transcode.

 

But in reality, I would expect failures at that bitrate across the internet.  As I can't get that from and online gigabit server.

[LoyidoGu 0]

4 hours ago, Happy2Play said:

Audio conversion must happen as TrueHD is not supported.  Which in the end triggers a full transcode.

Thanks a lot! I have done some tests. If i use TureHD to play other Movie, they also triggers a full transcode! 

So it's a bug in IOS app?

Becauce I can play the movie in IOS app with user transcoding setting disabled. So my IOS device should support TrueHD direct playback?

 

 

Edited November 2, 2022 by LoyidoGu

[Luke 37218]

iOS does not support TrueHD.

[LoyidoGu 0]

5 minutes ago, Luke said:

iOS does not support TrueHD.

Ok, Thanks for reply.

There is one question left. 

 

Otherwise, Will ios support TrueHD in the future? (maybe with Spatial Audio)

Edited November 2, 2022 by LoyidoGu

[Happy2Play 8351]

1 hour ago, LoyidoGu said:

Thanks a lot! I have done some tests. If i use TureHD to play other Movie, they also triggers a full transcode! 

So it's a bug in IOS app?

Becauce I can play the movie in IOS app with user transcoding setting disabled. So my IOS device should support TrueHD direct playback?

 

 

Are you saying you actually get sound while direct playing?

 

1 hour ago, LoyidoGu said:

Ok, Thanks for reply.

There is one question left. 

 

Otherwise, Will ios support TrueHD in the future? (maybe with Spatial Audio)

This would be a question to ask iOS as if they provided support we would use it.

But same question asked about ATV also.

Is there a technical reason why Apple TV’s can’t pass through Dolby TrueHD or DTS HD-MA? : appletv (reddit.com)

 

[LoyidoGu 0]

7 hours ago, Happy2Play said:

Are you saying you actually get sound while direct playing?

Yes, I can hear the sound while playing.

In my mind, If IOS doesn't support TrueHD, i should not hear the sound.

 

 

7 hours ago, Happy2Play said:

This would be a question to ask iOS as if they provided support we would use it.

But same question asked about ATV also.

Is there a technical reason why Apple TV’s can’t pass through Dolby TrueHD or DTS HD-MA? : appletv (reddit.com)

Got it. Thanks for reply. 

[Luke 37218]

You should still get sound via server transcoding.