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• Convert wav file from WAV_FORMAT_EXTENSIBLE to WAV_FORMAT_PCM

  22 juillet 2022, par michaeljan

  I have a 16-bit 44.1kHz wav file in WAV_FORMAT_EXTENSIBLE format. What is a simple and efficient way to convert it to WAV_FORMAT_PCM on the command-line ?

  


  In case it helps, here's a sample file. It's (a part of) a file that a client sent to me, so I'm not sure how it was created. But it is understood by ffmpeg and playable by VLC.

  


  Also, I've seen this question, but it's 7 years old and the accepted answer doesn't answer the question. Also, that question asks for ffmpeg-only solutions, whereas I am open to other command-line solutions as well. (Although I do prefer ffmpeg.)

  


• ffmpeg resize video then over lay on top of image using nvidia cuda

  16 mars 2021, par user72261

  i have a bunch of old family videos that are 4:3 SD format i am looking to change them to 16:9 and over lay the video on top of a 720p background

  


  i can do this fine using standard ffmpeg and everything works but it takes for ever with over 10 years of videos to convert

  


  i have a desktop pc i use for work with 2070 super installed so i was looking to use that to speed it up a little i tried adding cuda hardware support and i just hit errors

  


  ffmpeg -y -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -loop 1 -i image.jpg -i video.mp4 -filter_complex "[1]hwupload_cuda,scale=1280:720:force_original_aspect_ratio=decrease[inner];[0][inner]overlay_cuda=x=10:y=10:shortest=1[out]" -map "[out]" -map 1:a -c:a aac -map 0:v -c:v  h264_nvenc -b:v 5M -y output.mp4


  


  the errors i keep getting are

  


  decoder->cvdl->cuvidDecodePicture(decoder->decoder, &ctx->pic_params) failed -> CUDA_ERROR_INVALID_IMAGE: device kernel image is invalid


  


• FFMPEG : How to not loose quality when increasing the volume of MP3 file ?

  1er août 2021, par user7858768

  When increasing the volume of MP3 file (re-encoding the file to have higher volume) using the following command :

  


  ffmpeg -y -i /tmp/input.mp3 -af volume=2 -ab 48k /tmp/output.mp3


  


  When volume increase (volume=2) is below 2 (below 200%) the audio quality sounds clean. However, when the audio is increased past 2, example : volume=3 there are distortions that can be heard.

  


  The bitrate of the original file is 48k (hence I am setting it to 48k otherwise ffmpeg drops output bitrate to 32k)

  


  Are there any settings that can be set to avoid distortions from appearing when adjusted volume is at rate of 3 and above ?