Another odd video problem

[mgoorevich]

Originally Posted by DonaldM

Well, problems arise again. What's the best program for transcoding? I need to transcode H264 to DNxHD. (Or I guess I could use ProRes, too). I've used Adobe Media Encoder in the past. Is there any other?


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The fastest one is iFFMPG
I love it since they fixed their old bugs.

[DonaldM]

Originally Posted by mgoorevich

The fastest one is iFFMPG
I love it since they fixed their old bugs.

Thanks, but I think that only works on a Mac. I'm on a Win-10 Pro system.

[DonaldM]

Originally Posted by Sonny Keyes

Have you tried transcoding the video to something Pro Tools likes, like DNxHD? The first part of this might help:

http://www.jasonmyres.com/transcodin...dia-composer-6)

Will this work on a Windows based system? It looks like this is for Macs.

[joachim]

Originally Posted by DonaldM

Thanks, but I think that only works on a Mac. I'm on a Win-10 Pro system.

https://ffmpeg.zeranoe.com/builds/

and use the command line :
ffmpeg -i "D:\H264.mov" -s 1920x1080 -r 23.976 -vcodec dnxhd -b:v 36M -acodec copy "D:\DNxHD36.mov"


"D:\H264.mov" , the path you get when shift-right-clicking the video file (copy path)
-s 1920x1080 , the pixels of HD
-vcodec dnxhd , video codec is dnxhd
-b:v 36M , bitrate video 36000 kbit/s = DNxHD36
-acodec copy , audio codec copied from original (or use -an for no audio)
"D:\DNxHD36.mov" , the desired name of the transcoded file


Other resolutions :
Project Format Resolution Frame Size Bits FPS
1080i / 59.94 DNxHD 220 1920x1080 8 29.97 220Mb
1080i / 59.94 DNxHD 145 1920x1080 8 29.97 145Mb
1080i / 50 DNxHD 185 1920x1080 8 25 185Mb
1080i / 50 DNxHD 120 1920x1080 8 25 120Mb
1080p / 25 DNxHD 185 1920x1080 8 25 185Mb
1080p / 25 DNxHD 120 1920x1080 8 25 120Mb
1080p / 25 DNxHD 36 1920x1080 8 25 36Mb
1080p / 24 DNxHD 175 1920x1080 8 24 175Mb
1080p / 24 DNxHD 115 1920x1080 8 24 115Mb
1080p / 24 DNxHD 36 1920x1080 8 24 36Mb
1080p / 23.976 DNxHD 175 1920x1080 8 23.976 175Mb
1080p / 23.976 DNxHD 115 1920x1080 8 23.976 115Mb
1080p / 23.976 DNxHD 36 1920x1080 8 23.976 36Mb
1080p / 29.7 DNxHD 45 1920x1080 8 29.97 45Mb
720p / 59.94 DNxHD 220 1280x720 8 59.94 220Mb
720p / 59.94 DNxHD 145 1280x720 8 59.94 145Mb
720p / 50 DNxHD 175 1280x720 8 50 175Mb
720p / 50 DNxHD 115 1280x720 8 50 115Mb
720p / 23.976 DNxHD 90 1280x720 8 23.976 90Mb
720p / 23.976 DNxHD 60 1280x720 8 23.976 60Mb

[DonaldM]

Thank you.


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[joachim]

ECHO OFF
REM FF Prompt 1.1
REM Open a command prompt to run ffmpeg/ffplay/ffprobe
REM Copyright (C) 2013  Kyle Schwarz

TITLE FF Prompt

IF NOT EXIST bin\ffmpeg.exe (
  CLS
  ECHO bin\ffmpeg.exe could not be found.
  GOTO:error
)

CD bin || GOTO:error
PROMPT $G
CLS
ffmpeg -version
SET PATH=%CD%;%PATH%
ECHO.
ECHO For help run: ffmpeg -h
ECHO For formats run: ffmpeg -formats ^| more
ECHO For codecs run: ffmpeg -codecs ^| more
ECHO.
ECHO Current directory is now: "%CD%"
ECHO The bin directory has been added to PATH
ECHO.

CMD /F:ON /Q /K

If you paste the above text into a notepad (text editor)document and save it as "ff-prompt.bat" and place it in the folder as displayed in the screenshot, you can just double-click it to open the command line.

I usually open another notepad, place the paths, name and instructions there and copy-paste the whole command into the ff-prompt. (Alt+Space, then edit - paste)



The speed of transcoding is approx. 5 times faster then realtime.

[fork-media]

great thread - I am currently being sent a batch of h2.64

( H.264, 1280 × 720, Millions -AAC, Stereo (L R), 48.000 kHz )

and it totally makes my system laggy.. I usually transcode to DV using stream clip - files are too big for my liking

and it is taking 12- 24 hours.. it is a series of 90 minute episodes

can I use this DNxHD? would it give me better performance?

[MIKEROPHONICS]

DV is SD and must be reduced to 720 x 576. DNxHD is HD (1920x1080).
I have never understood why editors kick out 720 HD as it is a bastard love child format size.
If you are displaying on an HD TV then it will prefer 1920x1080 and will be doing no display work to accommodate that, whereas if you make DV then it is SD and must be upscale somewhere to accommodate the TV resolution.
Personally I do this at the transcode stage within my Avid or with mpegsc. DNxHD 36 works a treat. Is is faster? I couldn't tell you - but it makes more sense.
Video is just a large stream of media, the difference in moving DV or DNxHD off drives (SSD in my case) is relatively negligible these days. To give you an example, I used to play SD DVpal and 5 or six stems from a USB2 drive to VO record (Reversioning) and record and mix the final mix and m&e simultaneously back to the same drive. Not bad for USB2! Breaks all the accepted good practice rules, but it never huffed and puffed at all or even hiccuped.
The trick with video is to do as little work as poss - i.e. Transcode to a very native file type that your software and hardware needs to little with. I am lucky my AJA IOXT can
upscale on the fly, but still I avoid even this.
DNxHD is the AVE weapon of choice with HD TVs.
DNxHD 36 8 bit is relatively efficient in file size to visual quality.


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[michaelfbates]

Originally Posted by fork-media

I usually transcode to DV using stream clip - files are too big for my liking

and it is taking 12- 24 hours.. it is a series of 90 minute episodes

can I use this DNxHD? would it give me better performance?

So Mike has given a great answer and I hadn't thought about the 720 vs 1080 thing. Thanks for that!

I get the best performance from 1920 x 1080 DNxHD 36 8 bit and have started just asking for that from editors rather than them wasting their time transcoding to H.264. Internet transfer should be fast enough now to negate the file size argument.

One thing I only discovered recently by watching this webinar: https://www.youtube.com/watch?v=6gxLZid2VR4 is that unless your video file in Pro Tools has the tick next to it, it's not "optimised" and isn't actually being processed by the AVE. Jump to 23:25 to get to that section.

Now thankfully I don't have issues in PT with video (I have always transcoded to DNxHD using MPEG Streamclip) but looking back at a few old projects I noticed that none of the video in them was "optimised".

Bouncing to quicktime within PT and importing that video resulted in an "optimised" video. But, I noticed almost no difference in performance (maybe there was a 1 or 2% change in the CPU usage).

[antonis]

Thanks Mike! I'm taking this on board as well.