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• Noobs approach to automate x264 cmd

  16 novembre 2012, par nightcrawler

  so here is my script to loop through specific video extensions » add a manual profile » generate necessary *.bat & finally a final 'loader' batch file to execute previous *.bat files sequentially & necessary logging (this gives quiet a deal of freedom if you so want)

  ::==
  :: gets lines into vars c1 v2 v...
  @echo off
  :: user input required
  cd /d "d:\Trainers\out\"
  setLocal EnableDelayedExpansion
  dir /B /O:N | findstr ".wmv$ " >filename.txt
  echo. >log.txt
  :: user input required
  for /f "tokens=* delims= " %%a in ('type filename.txt ^|findstr ".wmv$"') do (
  set /a n+=1
  echo. >file!n!.bat
  set in=%in%%%a
  :: user input required
  set out=!in:.wmv=.mp4!
  :: user input required
  set v=x264 --crf 23  --level 3.1 --tune film -o "d:\Trainers\out\!in!" "d:\Trainers\out\!out!"
  echo. !v!>file!n!.bat
  )
  dir /B /O:N | findstr ".bat$ " >x264_home.txt
  for /f "tokens=* delims= " %%a in (x264_home.txt) do (
  set /a n+=1
  :: mtee is an external library Google it
  set "z=call %%a | mtee /d/c/t/+ log.txt"
  echo. !z! >> x264_home.bat
  )
  echo. @echo off > newFile.bat
  type x264_home.bat >> newFile.bat
  type newFile.bat > x264_home.bat
  del newFile.bat,x264_home.txt,filename.txt
  echo. pause >> x264_home.bat
  echo. @echo All Operation done... >> x264_home.bat
  :: user input required
  move "d:\Trainers\out\*.bat" "d:\Program Files\x264_auto\test\"
  :: user input required
  move "d:\Trainers\out\log.txt" "d:\Program Files\x264_auto\test\"
  ::==
  

  Now the above code which is fairly easy to understand (bcz its written by a noob) run perfectly & create necessary files. For instance one of the file1.bat looks like this:

  x264 --crf 23  --level 3.1 --tune film --preset veryslow --deblock -2:-1 --zones 24233,25324,q=20 --acodec aac --abitrate 80 -o "d:\Trainers\out\1.wmv" "d:\Trainers\out\1.mp4"
  

  ...& the loader .bat file looks like

   @echo off 
   call file1.bat | mtee /d/c/t/+ log.txt 
   call file2.bat | mtee /d/c/t/+ log.txt
   call file3.bat | mtee /d/c/t/+ log.txt
   @echo All Operation done... 
  

  You see this is a quiet flexible approach in that you can use special filestr » set another loop » set another profile. Furthermore every batch file can be latter edited especiialy when you heavily use --zone x264 feature I am successful because there is no error in any output ...but its the x264.exe (provider/compiler x264GUI) throws error which it otherwise don't?

  d:\Program Files\x264_auto\test>x264 --crf 23  --level 3.1 --tune film --preset
  veryslow --deblock -2:-1 --zones 24233,25324,q=20 --acodec aac --abitrate 80 -o
  "d:\Trainers\out\1.wmv" "d:\Trainers\out\1.mp4"
  ffms [error]: could not create index
  lavf [error]: could not open input file
  raw [error]: raw input requires a resolution.
  x264 [error]: could not open input file `d:\Trainers\out\1.mp4' via any method!
  

  its the x264 thats the culprit perhaps a senior guide is required here

• gstreamer muxing with x264enc

  2 novembre 2012, par Paul Praet

  I am trying to convert a DVD to mkv file with gstreamer. The pipeline I use is:

  gst-launch -evv multifilesrc location="VTS_01_%d.VOB" index=1 ! dvddemux name=demuxer \
   matroskamux name=mux ! filesink location=test.mkv \
   demuxer.current_video ! queue ! mpeg2dec ! x264enc ! mux. \
   demuxer.current_audio ! queue ! ffdec_ac3 ! lamemp3enc ! mux.
  

  Unfortunately the pipeline does not go beyond prerolling. When I replace x264enc with for instance ffenc_mpeg4, then everything works fine..

• Bitrate variation in x264 encode ? [closed]

  21 octobre 2012, par nightcrawler

  Under win732bit The following picture is the analysis of bitrateviewer from 2 different encodings: After learning a great deal I want to ask some basic questions

  • Are the jitters (huge variation of bitrate) in the encoded files (relative to original .wmv) usual or they refer to poor results? (I used CBR this should have given me a nice smooth bitrate histogram?)
  • Am I correct in setting level to 3.1 because this is enough to handle the input resolution & bitrate? (http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Levels)
  • Would you recommend me for CBR(currently used at 23) or 2pass(2500kb/s) or ABR(2500kb/s) for this file? (I assume that the latter of the two will reduce jitters but increase filesize because bitrate is kept constant even in those frames where its not needed or willlnt produce influential results)
  • Provided that I want good result under ~260mb what are the setting I have to use?

• Is it possible to force I_PCM mode in x264 ?

  10 octobre 2012, par cloudraven

  I need to use I_PCM mode in all blocks for some of I frames in video being compressed using x264. I know those frames will take a huge amount of space, but it is a requirement to keep them as faithful to the source as possible and to make them very fast to encode / decode (I_PCM should be super fast and lossless). Is there a way to force x264 to programatically do this. I am using libx264 to do this, but I haven't found a way to specify custom macroblock type within a given frame. If it is not supported, how hard would it be to modify the library to do so and where should I look at first?

• EC2 for video-encoding

  24 septembre 2012, par TK Kocheran

  I have a potential job which will require me to do some video encoding with FFMPEG and x264. I'll have a series of files which I'll need to encode once, then I'll be able to bring down the instances. Since I'm not really sure of the resource utilization of x264 and FFMPEG, what kind of instances should I get? I'm thinking either a

  High-CPU Extra Large Instance

  7 GB of memory
  20 EC2 Compute Units (8 virtual cores with 2.5 EC2 Compute Units each)
  1690 GB of instance storage
  64-bit platform
  I/O Performance: High
  API name: c1.xlarge

  or, alternatively a

  Cluster GPU Quadruple Extra Large Instance

  22 GB of memory
  33.5 EC2 Compute Units (2 x Intel Xeon X5570, quad-core “Nehalem” architecture)
  2 x NVIDIA Tesla “Fermi” M2050 GPUs
  1690 GB of instance storage
  64-bit platform
  I/O Performance: Very High (10 Gigabit Ethernet)
  API name: cg1.4xlarge

  What should I use? Does x264/FFMPEG perform better with faster/more CPUs or does it really pound the GPU more? In any case, it seems that the Cluster GPU seems to be the higher performance instance. What should I prefer?