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clarkss12

Transcoding VC1 slow

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clarkss12

Been testing running Emby server on device with Amlogic S922X-H SoC, have some issues.

Is there anything that can be done to utilize the power of that CPU??  Trying to play a movie that uses the Microsoft VC-1 video codec has to be transcoded since NONE of the Amlogic SoC's support that video codec (that includes the Miboxes, Tvio stream 4k, etc. ).

Perhaps there is some hardware decoder that is not being used, I have no knowledge of how the decoders work.

 

embyserver.txt embyserver-63732517750.txt ffmpeg-transcode-4a64cdcc-6c65-47fb-bcdd-187ab2ace654_1.txt hardware_detection-63732517764.txt

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rbjtech

VC-1 is notoriously hard in terms of transcoding and will give even a modern CPU a hard time.  My advice is to convert whatever it is to h264 using an external conversion tool (handbrake etc) and then remove the original VC-1 encode.

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clarkss12
6 hours ago, rbjtech said:

VC-1 is notoriously hard in terms of transcoding and will give even a modern CPU a hard time.  My advice is to convert whatever it is to h264 using an external conversion tool (handbrake etc) and then remove the original VC-1 encode.

 I could do that, but prefer not to.......  Even my low powered miniPCs can transcode without issue........

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cayars

That box just doesn't have the muscle CPU wise to handle VC-1 smoothly. 

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clarkss12
2 hours ago, cayars said:

That box just doesn't have the muscle CPU wise to handle VC-1 smoothly. 

Yes, sadly it does appear that way.  I am still testing it........

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clarkss12

Advice needed.  Again, I tried converting my VC-1 videos to MP4, but I can NEVER get the subtitles to play in sync........  I tried two different videos, and same thing.  Through out the years, I have tried to convert videos, but never had any success........  Something was never correct.

I have adding pics of the HandBrake settings that I will be using, what do I need to change?  This is my 3rd try, the other two, the subtiles were out of sync.  Even if I download subtitles they are still out of sync.......

Also, I included the Mediainfo information for that video......

HandBrake 1.jpg

HandBrake 2.jpg

HandBrake 3.jpg

HandBrake 4.jpg

Back to the Future (1985).mkv.txt

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clarkss12

Installing it now, will keep you updated....... thanks

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clarkss12
Posted (edited)
3 hours ago, cayars said:

Try using XMedia Recode instead of Handbrake.

https://www.xmedia-recode.de/en/

That app worked like a charm.  The subtitles are now in sync........   One question, the original VC-1 version was around 30 gigs, now the MP4 is around 3 gigs, will that be a lesser video quality???

 

Edit:  Ran two test, Back to the Future on one computer and Back to the Future on second computer.  CC was perfect, but the audio on both test were only PCM........ No DD or DTS HD, etc.........  Any clue??

Will try again......  

Edited by clarkss12

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cayars
Posted (edited)

You fully control the video quality as well as bitrate for audio.

For Video try switching to CRF mode and setting the quality to 23. When converting audio you can choose how to convert, what codec to use, the bitrate.  I often create a 2 channel stereo channel marked as default then copy the DTS,  DD or other tracks in my language.  Same with subs.

Takes a small amount of getting used to but quite a powerful program with full control.

Edited by cayars

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clarkss12
40 minutes ago, cayars said:

You fully control the video quality as well as bitrate for audio.

For Video try switching to CBR mode and setting the quality to 23. When converting audio you can choose how to convert, what codec to use, the bitrate.  I often create a 2 channel stereo channel marked as default then copy the DTS,  DD or other tracks in my language.  Same with subs.

Takes a small amount of getting used to but quite a powerful program with full control.

Thanks for this info.......  I will keep testing, but takes about hour and half to do one conversion.

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clarkss12
1 hour ago, cayars said:

You fully control the video quality as well as bitrate for audio.

For Video try switching to CBR mode and setting the quality to 23. When converting audio you can choose how to convert, what codec to use, the bitrate.  I often create a 2 channel stereo channel marked as default then copy the DTS,  DD or other tracks in my language.  Same with subs.

Takes a small amount of getting used to but quite a powerful program with full control.

What is CBR mode?

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cayars

That was supposed to say CRF (corrected) which is short for Constant Rate Factor.  In xmedia Recode this will be the "rate control mode" setting and "Quality" setting.

The idea of this mode and what I always use when converting to save storage space is this Constant Quality mode.  Instead of converting using some bitrate threshold you instead do you conversion based on a quality level.  For DVD quality a CRF of 23 is recommended but I preferred 20.  For Bluray or higher quality generally a 28 is recommended by I use 23 to 25.

With the constant quality setting you never know how small your file will convert because the conversion is based on quality not bitrate.  It will use whatever bits is needed to hold detail at a specific quality level.  So in scenes without much detail or change the bitrate needed to support the compression will be low but is fast changing scenes as often found is action movies more bits will be needed to hold the constant quality.  Switching to Constant Quality makes sense because it guarantees that you get consistent results from file to file without having to know the media well and works great in batch processing of files.

In CRF a lower number means a "better" result.  Do you'll see a default of 23 for DVD quality and 28 for Bluray quality which might seem backward but it's not. The Bluray media can use a worse constant quality setting because there is a lot more bits to start with and with more detail the algorithms have more flexibility.

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rbjtech

Handbrake lost sync because you select 1080p/30 as the preset according to your screen grabs - the original is likely 23.976 (film - to note, this is not 24 fps) so effectively you speeded up the video.  The Quality Preset was also low.

I'm of a differing opinion to @cayars on the CRF and preset values to use for what is one off 'master' version of the film.  ie you want the best quality possible as the original will be archived.  The fact the original was 30 Gig and you are using a 'comparable' codec (vc-1/h264), I personally would not want to use less than ~25 Gig for my master 'copy'.  Again, imo, I would bump CRF to 18 or use 2 pass to target 25-30 Gig in filesize. 

 

 

 

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cayars

I don't worry to much about the starting size of a file other than a rough guess of quality if I don't know how it was created.  What I do usually, is drop the default CRF down about 3 points below the default.  So 23 becomes 20 for DVD, 25 instead of 28 for Bluray.  That produces better quality than the defaults but isn't using crazy low rates with diminishing returns.That works pretty well for processing lots of files at one time.  If you're doing specific movies like The Notebook you can likely use a higher number as there isn't much action or fast scenes, where a Transformers movie might want a lower number to hold more detail.

However I think each person should try different values themselves to learn what they like.  For DVD material try 18 to 23.  For BluRay try 20 to 28.  If you can't tell the difference in quality between say 18 or 20 then look at file size difference as likely the 18 will be bigger and have a higher overall bitrate.  Depending if you are limited on your bandwidth up from your server the difference in bitrate between an 18 to 20 change could be the difference in direct play or a transcode on top of your conversions.  So these are things worth looking at and testing in your environment.

You can "micro manage" the CRF based on content or types of content or just experiment with dramas, action, sports to find the "one number" that always works for you quality wise and stick with it to make life simpler.

One thing is certain and that is that every time you transcode/convert a file using a LOSSY compression mechanism you ARE degrading quality.  So it's always better to convert from a "pure rip" then to convert something that has already been converted previously.

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clarkss12
1 hour ago, rbjtech said:

Handbrake lost sync because you select 1080p/30 as the preset according to your screen grabs - the original is likely 23.976 (film - to note, this is not 24 fps) so effectively you speeded up the video.  The Quality Preset was also low.

I'm of a differing opinion to @cayars on the CRF and preset values to use for what is one off 'master' version of the film.  ie you want the best quality possible as the original will be archived.  The fact the original was 30 Gig and you are using a 'comparable' codec (vc-1/h264), I personally would not want to use less than ~25 Gig for my master 'copy'.  Again, imo, I would bump CRF to 18 or use 2 pass to target 25-30 Gig in filesize. 

 

 

 

I am trying your method again, this time I changed the frame rate to 23.98 as you suggested.

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clarkss12
34 minutes ago, cayars said:

I don't worry to much about the starting size of a file other than a rough guess of quality if I don't know how it was created.  What I do usually, is drop the default CRF down about 3 points below the default.  So 23 becomes 20 for DVD, 25 instead of 28 for Bluray.  That produces better quality than the defaults but isn't using crazy low rates with diminishing returns.That works pretty well for processing lots of files at one time.  If you're doing specific movies like The Notebook you can likely use a higher number as there isn't much action or fast scenes, where a Transformers movie might want a lower number to hold more detail.

However I think each person should try different values themselves to learn what they like.  For DVD material try 18 to 23.  For BluRay try 20 to 28.  If you can't tell the difference in quality between say 18 or 20 then look at file size difference as likely the 18 will be bigger and have a higher overall bitrate.  Depending if you are limited on your bandwidth up from your server the difference in bitrate between an 18 to 20 change could be the difference in direct play or a transcode on top of your conversions.  So these are things worth looking at and testing in your environment.

You can "micro manage" the CRF based on content or types of content or just experiment with dramas, action, sports to find the "one number" that always works for you quality wise and stick with it to make life simpler.

One thing is certain and that is that every time you transcode/convert a file using a LOSSY compression mechanism you ARE degrading quality.  So it's always better to convert from a "pure rip" then to convert something that has already been converted previously.

My last trial that just completed seemed to work well.  However, my AV Receiver shows PCM instead of DD, DTS, etc..... From what I read, PCM is better that DTS or DD, not sure......

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cayars

If using Recode, you can change or add an audio track of your choosing to match your system.

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clarkss12
49 minutes ago, cayars said:

If using Recode, you can change or add an audio track of your choosing to match your system.

I am still tinkering with it, just takes so long for each test....... I am using 2 different computers for testing.

I appreciate all the information....   I am making progress..........

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cayars

Progress is good. :)  What you're learning will be invaluable moving forward so take your time and find what works well for you.  All any of us can do is give guidance and point you in the right direction but you have to test on your media and determine what you like/don't like!

2 computers is nice. :)

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rbjtech
1 hour ago, clarkss12 said:

...just takes so long for each test....... 

If you are tinkering (which is excellent!) then a couple of options here - 1 is to choose a short film to play with, or 2 is to just encode a small portion of the file (which I'm pretty sure these tools can do, ffmpeg certainly can) - that way, you don't have to encode the whole thing each time to see the results. 😉

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rbjtech

ps - if you have two computers are REALLY want to play, then RipBot264 allows distributed processing - ie it splits the file across up to 16 (I think) machines ! 😃

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cayars
Posted (edited)

RipBot264 unless it changed never split files but split the queue so first file to computer 1 and 2nd file to computer 2,  File 3 in the queue goes to first computer done.

At least that's how it was the last time I played with it.  Could be different now.

Something else worth doing if you can for testing is download movie trailers.  Usually only a few minutes long and this way you can pick DVD quality, Bluray quality, actions and dramas.  That or test on tv show episodes which are roughly 20-22 minutes long without the commercials for a half hour show.  That's better than a 1:45 hour movie for testing.

Edited by cayars

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rbjtech
33 minutes ago, cayars said:

RipBot264 unless it changed never split files but split the queue so first file to computer 1 and 2nd file to computer 2,  File 3 in the queue goes to first computer done.

 

It always split the file into sections and then recombined them at the end - I remember experimenting with 4 PC's to do a single file and it worked very well.   you may be thinking of the batch processing ?

Anyway - this was a cheeky suggestion to the OP - For 1080p content and a relatively modern CPU, it's no longer worth the setup time. 😉

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cayars

Ahh, ok, been a LONG TIME since I messed with it.

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