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• ffmpeg status & quality / cuda (CPU/GPU)

  18 juin 2024, par cocco

  ffmpeg am I doing it right ?

  


  So much time has passed since I use ffmpeg to convert clips on my home web server, now that mp4 (h264 & aac) is the current overall standard (works on every console, smartphone, smartTV, pc) I decided to convert my old clips from various digital cameras to to this new container/codecs.

  


  

  1. less space & the same quality.

  


  2. compatibility

  


  3. support for tags (subler for mac)

  


  


  after some research I opted for ffmpeg because of various reasons

  


  

  1. commandline (I made my simple web interface with default settings which I execute with php's exec)

  


  2. the quality/size amount

  


  


  I read that many expensive video conversion software programs are not able to handle low bitrate videos properly. I also tested some of them and personally I could not find the proper export settings or I was not impressed by the results... some had fixed default export settings, most had a lower video quality at the same filesize. ffmpeg allows me to set the -crf (18-24 usually) and -preset (veryslow, fast..) which allows me to reduce the filesize drastically maintaining the same visible quality.

  


  Said that I'm using the preset at very slow (there is also placebo but the final video file is only 1% smaller in size).

  


  And here is the command I use

  


  ffmpeg
-y //overwrite the file if it exists

-i INPUTFILE // replace with the input file

-metadata title=THETITLE // set a nice title, visible on modern devices
-metadata date=THEDATE // set a nice title, visible on modern devices

-c:v libx264 // use the h264 codec
 -crf 21 // try different numbers between 18-26
 -preset veryslow // placebo,slow,fast,ultrafast==big file 
 -tune film // tune it a little
 -pix_fmt yuv420p // preferred on most modern devices
 -profile:v main // preferred on most modern devices
 -level 3.1 // preferred on most modern devices 
 -refs 4 // preferred on most modern devices

-c:a libfdk_aac // use aac
 -metadata:s:a language=eng // set a language, visible on modern devices 
 -b:a 128k // audio bitrate 128k is like mp3 192k
 -ar 48000 // 44100 ... whatever
 -ac 2 // audiochannels
 -movflags +faststart //move the metadata in the front of the video so it loads faster

OUTPUTFILE


  


  Some camcorder clips with m2ts already have the avc/h264 compatible codec so I just copy the stream.
  
some have the ac3/Dolby surround audio. I convert the audio but keep the ac3 as second audio track mapping the ffmpeg streams. this allows me to watch the mp4 on browsers and mobile devices but I'm able to keep the surround sound to playback on some tv's, advanced media players or devices like apple tv.

  


  Not that I'm not happy with the speed (using quad core's) but I recently read again about cuda opencl and there is also the simple fact that I'm not using other converters than ffmpeg since a lot of time.

  


  Is ffmpeg (with the setting I use) a good converter to keep the same video quality than the source reducing the space occupied by and average of 30-40% ?

  


  Is GPU conversion really that bad (cuda .. testing a gtx970) ?
it would be nice to add some more speed to the conversions by using both the gpu and the cpu..but for my understanding they cannot work together ??? and using only GPU is a drastically quality loss...cpu is more precise, GPU is faster in calculation are too imprecise from what I read.. so expensive software programs use cuda only for preview purpose... right ?

  


  Is ffmpeg or another software compatible with CPU+GPU encoding ?
I really don't remember where, but I read that the ffmpeg is not a good videoconverter.

  


  I'm really happy with the size/quality, I gained an average of 30% in space with no visible quality loss. With some extra parameters i can adjust some really old analog videos that are deinterlaced in a really bad way.

  


  


  maybe I could gain more size/quality with another software ???

  


  


  note : I like ffmpeg.it's free and it has commandline so I can create my own interface with php html & js and use it on various machines without the need to install it in every device I use. I upload the idevice clips directly to the ffmpeg server.

  


  EDIT :

  


  @talonmies ...cuda tag removed :

  


  http://www.nvidia.com/object/cuda_home_new.html

  


  


  CUDA® is a parallel computing platform and programming model invented
by NVIDIA. It enables dramatic increases in computing performance by
harnessing the power of the graphics processing unit (GPU). With
millions of CUDA-enabled GPUs sold to date, software developers,
scientists and researchers are finding broad-ranging uses for GPU
computing with CUDA. Here are a few examples : - See more at :
http://www.nvidia.com/object/cuda_home_new.html#sthash.dEYaqae7.dpuf

  


  


  isn't cuda the programming model that a theoretical ffmpeg library should support to handle GPU encoding on nvidia cards like the gtx 970 ?? like the badaboom software http://www.geforce.com/games-applications/pc-applications/badaboom-media-converter.

  


• ffmpeg status & quality / cuda (CPU/GPU)

  18 avril 2015, par cocco

  ffmpeg am i doing it right ?

  So much time has passed since i use ffmpeg to convert clips on my home web server, now that mp4 (h264 & aac) is the current overall standard (works on every console, smartphone, smartTV, pc) i decided to convert my old clips from various digital cameras to to this new container/codecs.

  1. less space & the same quality.
  2. compatibility
  3. support for tags (subler for mac)

  after some research i opted for ffmpeg because of various reasons

  1. commandline (i made my simple web interface with default settings wich i execute with php’s exec)
  2. the quality/size amount

  I read that many expensive video conversion softwares are not able to handle low bitrate videos properly. I also tested some of them and personally i could not find the proper export settings or i was not impressed by the results... some had fixed default export setings, most had a lower video quality at the same filesize. ffmpeg allows me to set the -crf (18-24 usually) and -preset (veryslow, fast..) witch allows me to reduce the filesize drastically mantaining the same
  visible quality.

  Said that i’m using the preset at veryslow.(there is also placebo but the final video file is only 1% smaller in size).

  And here is the command i use

  ffmpeg
  
  -y //overwrite the file if it exists
  
  
  
  -i INPUTFILE // replace with the input file
  
  
  
  -metadata title=THETITLE // set a nice title, visible on modern devices
  
  -metadata date=THEDATE // set a nice title, visible on modern devices
  
  
  
  -c:v libx264 // use the h264 codec
  
   -crf 21 // try different numbers between 18-26
  
   -preset veryslow // placebo,slow,fast,ultrafast==big file 
  
   -tune film // tune it a little
  
   -pix_fmt yuv420p // preferred on most modern devices
  
   -profile:v main // preferred on most modern devices
  
   -level 3.1 // preferred on most modern devices 
  
   -refs 4 // preferred on most modern devices
  
  
  
  -c:a libfdk_aac // use aac
  
   -metadata:s:a language=eng // set a language, visible on modern devices 
  
   -b:a 128k // audio bitrate 128k is like mp3 192k
  
   -ar 48000 // 44100 ... whatever
  
   -ac 2 // audiochannels
  
   -movflags +faststart //move the metadata in the front of the video so it loads faster
  
  
  
  OUTPUTFILE

  some camcorder clips with m2ts already have the avc/h264 compatible codec so i just copy the stream.
  some have the ac3/dolby sorround audio. I convert the audio but keep the ac3 as second audio track mapping the ffmpeg streams.this allows me to watch the mp4 on browsers and mobile devices but i’m able to keep the surround sound to playback on some tv’s, advanced media players or devices like apple tv.

  not that i’m not happy with the speed (using quad core’s) but i recently read again about cuda opencl and there is also the simple fact that i’m not using other converters than ffmpeg since alot of time.

  Is ffmpeg (with the setting i use) a good converter to keep the same video quality than the source reducing the space occupied by and average of 30-40% ?

  Is GPU conversion really that bad (cuda .. testing a gtx970) ?
  it would be nice to add some more speed to the conversions by using both the gpu and the cpu..but for my understanding they cannot work together ??? and using only gpu is a drastical quality loss...cpu si more precise, gpu is faster in calculation are too imprecise from what i read.. so expensive softwares use cuda only for preview purpose... right ?

  Is ffmpeg or another software compatible with CPU+GPU encoding ?
  i really don’t remember where, but i read that the ffmpeg is not a good videoconverter.

  i’m really happy with the size/quality, i gained an average of 30% in space with no visible quality loss. With some extra parameters i can adjust some really old analog videos that are deinterlaced in a really bad way.

  maybe i could gain more size/quality with another software ???

  note : i like ffmpeg.it’s free and it has commandline so i can create my own interface with php html & js and use it on various machines without the need to install it in every device i use. i uplad the idevice clips directly to the ffmpeg server.

  btw. : explain the downvotes...

  EDIT :

  @talonmies ...cuda tag removed :

  http://www.nvidia.com/object/cuda_home_new.html

  CUDA® is a parallel computing platform and programming model invented
  by NVIDIA. It enables dramatic increases in computing performance by
  harnessing the power of the graphics processing unit (GPU). With
  millions of CUDA-enabled GPUs sold to date, software developers,
  scientists and researchers are finding broad-ranging uses for GPU
  computing with CUDA. Here are a few examples : - See more at :
  http://www.nvidia.com/object/cuda_home_new.html#sthash.dEYaqae7.dpuf

  isn’t cuda the programming model that a theoretical ffmpeg library should support to handle GPU encoding on nvidia cards like the gtx 970 ?? like the badaboom software http://www.geforce.com/games-applications/pc-applications/badaboom-media-converter.

• How can I capture simple video input with audio from a capture device

  17 décembre 2020, par Geoff Sweet

  I'm using ffmpeg on Arch linux and trying to convert some old video to digital. The setup is pretty straightforward and if I connect to the capture device with VLC I get the video and audio just fine. So now I want to capture that with ffmpeg and write it to a file so I can edit it and clean it up. I'm only so-so familiar with ffmpeg and I've been digging through the man pages and here is where I am at.

  


  This command captures perfect audio, but no video :

  


  ffmpeg -f alsa -ac 2 -i front:CARD=Capture,DEV=0 out.mpeg


  


  This command captures perfect video ;

  


  ffmpeg -f video4linux2 -i /dev/video0 out.mpeg


  


  captures the video signal great, but with no audio. So combining them together should give me :

  


  ffmpeg -y -f alsa -ac 2 -i front:CARD=Capture,DEV=0 -f video4linux2 -i /dev/video0 out.mpeg


  


  But that command kinda falls on it's face. I get the audio, but no video :

  


  ffmpeg -y -f alsa -ac 2 -i front:CARD=Capture,DEV=0 -f video4linux2 -i /dev/video0 out.mpeg
ffmpeg version n4.3.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 10.2.0 (GCC)
  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-shared --enable-version3
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, alsa, from 'front:CARD=Capture,DEV=0':
  Duration: N/A, start: 1608093176.894565, bitrate: 1536 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
[video4linux2,v4l2 @ 0x56248fe0ab80] Dequeued v4l2 buffer contains corrupted data (0 bytes).
Input #1, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 0.000000, bitrate: 995328 kb/s
    Stream #1:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1920x1080, 995328 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
Stream mapping:
  Stream #1:0 -> #0:0 (rawvideo (native) -> mpeg1video (native))
  Stream #0:0 -> #0:1 (pcm_s16le (native) -> mp2 (native))
Press [q] to stop, [?] for help
[video4linux2,v4l2 @ 0x56248fe0ab80] Dequeued v4l2 buffer contains corrupted data (0 bytes).
    Last message repeated 30 times
[alsa @ 0x56248fdb3840] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8)
[mpeg @ 0x56248fe0dfc0] VBV buffer size not set, using default size of 230KB
If you want the mpeg file to be compliant to some specification
Like DVD, VCD or others, make sure you set the correct buffer size
Output #0, mpeg, to 'out.mpeg':
  Metadata:
    encoder         : Lavf58.45.100
    Stream #0:0: Video: mpeg1video, yuv420p(progressive), 1920x1080, q=2-31, 200 kb/s, 30 fps, 90k tbn, 30 tbc
    Metadata:
      encoder         : Lavc58.91.100 mpeg1video
    Side data:
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
    Stream #0:1: Audio: mp2, 48000 Hz, stereo, s16, 384 kb/s
    Metadata:
      encoder         : Lavc58.91.100 mp2
frame=    2 fps=0.0 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=2.0 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=1.3 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=1.0 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.8 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.7 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.6 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.5 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.4 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.4 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.4 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.3 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.3 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.3 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.3 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.2 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/sframe=    2 fps=0.1 q=3.2 size=       0kB time=01:48:49.26 bitrate=   0.0kbits/s[video4linux2,v4l2 @ 0x56248fe0ab80] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8)
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=0 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=2020 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=4061 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=6102 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=8143 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=10184 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=12225 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=14266 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=16307 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=18348 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=20389 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=22430 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=24471 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=26512 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=28553 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=30594 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=32635 size=36451
[mpeg @ 0x56248fe0dfc0] buffer underflow st=0 bufi=34676 size=36451
frame=    2 fps=0.1 q=2.0 Lsize=    1470kB time=01:48:49.30 bitrate=   1.8kbits/s speed= 221x    
video:63kB audio:1388kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.314351%
Exiting normally, received signal 2.


  


  what I would ideally like is just a fairly raw 2ch stereo "dump" of what comes through the capture card.

  


  As always, I super appreciate any advice