Recherche avancée

Sur d’autres sites (4497)

• [h264_nvenc : InitializeEncoder failed:supported only with separate color plane on this architecture

  4 janvier 2021, par gpuguy

  I am learning ffmpeg for the first time. What I want is to see how it performs on CPU and on GPU when it comes to transcoding.

  


  My machine is having a GT640 GPU card (GT640 is a Kepler card) and I am running a windows 7 , 64bit.
I issue the following command :

  


  ffmpeg -i lec_2.mp4 -c:v h264_nvenc -profile high444p -pixel_format yuv444p -preset default output.mp4


  


  But I am getting following errors :

  


  [h264_nvenc @ 0000000000363a80] The selected preset is deprecated. Use p1 to p7
+ -tune or fast/medium/slow.
[h264_nvenc @ 0000000000363a80] InitializeEncoder failed: invalid param (8): 444
 is supported only with separate color plane on this architecture.
Error initializing output stream 0:0 -- Error while opening encoder for output s
tream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
[aac @ 0000000000365980] Qavg: 18941.322
[aac @ 0000000000365980] 2 frames left in the queue on closing
Conversion failed!


  


  My questions are :

  


  


  1. From this output can I assume that nvenc is supported on my card since it does not complaint of no nvenc supported GPU ?

     


  


  2. How should the above command be modified so as to make it work correctly

     


  


  


• Is it possible to combine audio and video from ffmpeg-python without writing to files first ?

  22 janvier 2021, par nullUser

  I'm using the ffmpeg-python library.

  


  I have used the example code : https://github.com/kkroening/ffmpeg-python/tree/master/examples to asynchronously read in and process audio and video streams. The processing is custom and not something a built-in ffmpeg command can achieve (imagine something like tensorflow deep dreaming on both the audio and video). I then want to recombine the audio and video streams that I have created. Currently, the only way I can see to do it is to write both streams out to separate files (as is done e.g. in this answer : How to combine The video and audio files in ffmpeg-python), then use ffmpeg to combine them afterwards. This has the major disadvantage that the result cannot be streamed, i.e. the audio and video must be completely done processing before you can start playing the combined audio/video. Is there any way to combine them without going to files as an intermediate step ?

  


  Technically, the fact that the streams were initially read in from ffmpeg is irrelevant. You may as well assume that I'm in the following situation :

  


  def audio_stream():
    for i in range(10):
        yield bytes(44100 * 2 * 4) # one second of audio 44.1k sample rate, 2 channel, s32le format

def video_stream():
    for i in range(10):
        yield bytes(60 * 1080 * 1920 * 3) # one second of video 60 fps 1920x1080 rgb24 format

# how to write both streams of bytes to file without writing each one separately to a file first?


  


  I would like to use ffmpeg.concat, but this requires ffmpeg.inputs, which only accept filenames as inputs. Is there any other way ? Here are the docs : https://kkroening.github.io/ffmpeg-python/.

  


• How to get ffmpeg configuration similar to that of youtube for 480p and 1080p video ? I have got a function but the output quality is too low

  14 avril 2021, par prehistoricbeast

  Hey guys I am learning to develop a website that converts videos to youtube quality (or close enough) 480p and 1080p, I am not much familiar with ffmpeg and struggling with its documentation.

  


  I have these functions,

  


  video_480p      = subprocess.call([FFMPEG_PATH, '-i', input_file, '-codec:v', 'libx264', '-crf', '20', '-preset', 'medium',
                    '-b:v', '1000k', '-maxrate', '1000k', '-bufsize', '2000k','-vf', 'scale=-2:480', '-codec:a', 'aac', '-b:a',
                     '128k', '-strict', '-2', file_480p])


  


  similarly I have another function,

  


  new_video       = subprocess.call([FFMPEG_PATH, '-i', input_file, '-codec:v', 'libx264', '-crf', '20', '-preset', 'medium',
                    '-b:v', '1000k', '-maxrate', '1000k', '-bufsize', '2000k','-vf', 'scale=-2:1080', '-codec:a', 'aac', '-b:a',
                     '128k', '-strict', '-2', output_file])


  


  Both these functions, transcode the video, but returns low quality videos, Can anyone provide me with the right settings for 480p and 1080p which is similar or close to youtube quality ?

  


  Thanks