Sur d’autres sites (7519)

• Recording audio with FFMPEG works in terminal but not through exec() of PHP

  8 août 2013, par lucasalmeida92

  I use this command to RECORD audio and video from my webcam in terminal and it works !

  ffmpeg -f video4linux2 -r 25 -sameq -s 640x480 -i /dev/video0 -f alsa -i plughw:0,0 -ar 22050 -ab 128k -y webcam.flv

  But when I do it through PHP, like this :

  echo shell_exec('ffmpeg -f video4linux2 -r 25 -sameq -s 640x480 -i /dev/video0 -f alsa -i plughw:0,0 -ar 22050 -ab 128k -y webcam.flv 2>&1 &') ;

  I receive that log :

  ffmpeg version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers built on Apr 2 2013 17:02:36 with gcc 4.6.3 * THIS PROGRAM IS DEPRECATED * This program is only provided for compatibility and will be removed in a future release. Please use avconv instead. [video4linux2 @ 0x23579a0] Estimating duration from bitrate, this may be inaccurate Input #0, video4linux2, from '/dev/video0' : Duration : N/A, start : 4868.729067, bitrate : 122880 kb/s Stream #0.0 : Video : rawvideo, yuyv422, 640x480, 122880 kb/s, 25 tbr, 1000k tbn, 25 tbc Home directory /var/www not ours.

  ALSA lib pcm_hw.c:1401 :(_snd_pcm_hw_open) Invalid value for card [alsa @ 0x23589e0] cannot open audio device plughw:0,0 (No such file or directory) plughw:0,0 : Input/output error

  Before I got that Mic device problem I was having problem with the Webcam device's permissions, then i did :

      sudo chmod -R 777 /dev/video0

  And the video capture was ready to be used ! But now I got this Mic device problem !

  I think it can be about permissions too, but I dont know linux very well and have no idea how to fix that !

  Thanks !

  ---

  I just found the solution ! =x

  sudo chmod -R 666 /dev/snd/*

• Is Replacing Dynamic Resolution with scale_amf in FFmpeg Command a Good Direction ?

  21 novembre 2024, par fred

  I'm working on a Lua script for MPV that processes 360-degree videos using FFmpeg's v360 filter. The original command dynamically calculates the output resolution based on a res variable, like this :

  


  mp.command_native_async({
    "no-osd", "vf", "add", 
    string.format(
        "@vrrev:v360=%s:%s:reset_rot=1:in_stereo=%s:out_stereo=2d:
id_fov=%s:d_fov=%.3f:yaw=%.3f:pitch=%s:roll=%.3f:
w=%s*192.0:h=%.3f*108.0:h_flip=%s:interp=%s",
        in_flip, inputProjection, outputProjection, in_stereo, idfov, dfov, yaw, pitch, roll, res, res, h_flip, scaling
    )
}, updateComplete)


  


  Change Proposal :

  


  I am considering replacing the dynamic width and height calculations with a scale_amf filter to handle scaling more efficiently and leverage GPU acceleration. The updated command would look like this :

  


  mp.command_native_async({
    "no-osd", "vf", "add", 
    string.format(
        "@vrrev:v360=%s:%s:reset_rot=1:in_stereo=%s:out_stereo=2d:
id_fov=%s:d_fov=%.3f:yaw=%.3f:pitch=%s:roll=%.3f,
%sscale_amf=w=%.0f:h=%.0f",
        inputProjection, outputProjection, in_stereo, idfov, dfov, yaw, pitch, roll, in_flip, res * 192.0, res * 108.0
    )


  


  Hardware Specifications :

  


  I am using an AMD Ryzen 5 5600G, no display card, 16GB RAM, Windows 10.

  


  Questions :

  


  Is using scale_amf for scaling a good direction in terms of performance and efficiency ?
Are there any potential drawbacks to this approach that I should be aware of ?
How does using scale_amf compare to the original dynamic resolution method in terms of output quality and processing speed ?
}, updateComplete)

  


  Any insights or experiences with this change would be greatly appreciated !

  


• "Automatic" switchable graphics on desktop, is there a way to disable them ?

  14 août 2021, par Hab-Land0

  Recently, I've updated my graphic drivers for a new system I built, a mix between an amd apu and an nvidia quadro. But I stumbled upon a rare problem, every time I tried to use OpenCL acceleration on ffmpeg for libx264 encoding, ffmpeg notifies me with the next line :

  


  [libx264 @ 0000028149222780] OpenCL acceleration disabled, switchable graphics detected


  


  When searching this line on ffmpeg's code, apparently occurs when the "main OpenCL driver" (if you can call it that) is redirected in such a way that tries to use both devices (Code).

  


  My obvious next step was to search everything I could around this "switchable graphics", but almost all the tutorials on websites told me that I should search around the driver's settings, but literally either Radeon Software or Nvidia's control panel don't display any option about it (It is worth to say that almost all of the tutorials refer to laptops with dedicated graphics and were very outdated).

  


  Another way I use OpenCL is for vapoursynth's filters, such as KNLMeansCL. And, when I make use of this filter, task manager detects that both AMD's APU and Nvidia's gpu are being used simultaneously (I guess that's how the switchable graphics actually works, and partially complementing why x264 OpenCL doesn't work).

  


  My main complain with this is that I attempt to use AMD as a display driver and let Nvidia do the hard work, and I actually was able to do that before updating my drivers. And, talking about the "updates" more in-depth, I updated nvidia's from "462.59" to "471.11" and, unfortunately, I can't remember what versions were my AMD drivers.

  


  Edit : the only way I can make full use of NVIDIA's card is by using it as my main display, but that also apparently disables AMD's igpu, I am not sure if its even able to be used on small tasks (like those that were previously mentioned)