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• Is there a built-in audio preprocessing within Android OS ?

  29 août 2022, par Larry lu

  I am running a dev team to build an Android application the major feature is to record a user's voice and merge it into a long movie. It's a dub film application.

  


  One struggle thing to my dev team is whether the Android OS pre-processes the recorded audio file. because we want the very original audio data from the built-in Microphone.
If there is a built-in pre-processing inside of Android OS that keeps updating some data of the recorded audio file, we want to know what is changed. We can't find any official post from Android speaking about it but would like to confirm from a professional.

  


  Many thanks

  


• Sporadic "Error parsing Cues... Operation not permitted" errors when trying to generate a DASH manifest

  22 novembre 2023, par kshetline

  I have already-generated .webm audio and video files (1 audio, 3 video resolutions for each video I want to stream). The video has been generated not (directly) by ffmpeg, but HandbrakeCLI 1.7.0, with V9 encoding. The audio (which has never caused an error) is generated by ffmpeg using libvorbis.

  


  Most of the time ffmpeg (version 6.1) creates a manifest without any problem. Sporadically, however, "Error parsing Cues" comes up (frequently with the latest videos I've been trying to process) and I can't create a manifest. Since this is happening during an automated process to process many videos for streaming, the audio and video sources are being created exactly the same way whether ffmpeg succeeds or fails in generating a manifest, making this all the more confusing.

  


  The video files ffmpeg chokes on play perfectly well using VLC, and mediainfo doesn't show any problems with these files.

  


  Here's the way I've been (sometimes successfully, sometimes not) generating a manifest, with extra logging added :

  


  ffmpeg -v 9 -loglevel 99 \
  -f webm_dash_manifest -i '.\Sample Video.v480.webm' \
  -f webm_dash_manifest -i '.\Sample Video.v720.webm' \
  -f webm_dash_manifest -i '.\Sample Video.v1080.webm' \
  -f webm_dash_manifest -i '.\Sample Video.audio.webm' \
  -c copy -map 0 -map 1 -map 2 -map 3 \
  -f webm_dash_manifest -adaptation_sets "id=0,streams=0,1,2 id=1,streams=3" \
  '.\Sample Video.mpd'


  


  Here's the result when it fails :

  


  ffmpeg version 6.1-full_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 12.2.0 (Rev10, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --pkg-config=pkgconf --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-dxva2 --enable-d3d11va --enable-libvpl --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2 --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      58. 29.100 / 58. 29.100
  libavcodec     60. 31.102 / 60. 31.102
  libavformat    60. 16.100 / 60. 16.100
  libavdevice    60.  3.100 / 60.  3.100
  libavfilter     9. 12.100 /  9. 12.100
  libswscale      7.  5.100 /  7.  5.100
  libswresample   4. 12.100 /  4. 12.100
  libpostproc    57.  3.100 / 57.  3.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument '9'.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '99'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'webm_dash_manifest'.
Reading option '-i' ... matched as output url with argument '.\Sample Video.v480.webm'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'webm_dash_manifest'.
Reading option '-i' ... matched as output url with argument '.\Sample Video.v720.webm'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'webm_dash_manifest'.
Reading option '-i' ... matched as output url with argument '.\Sample Video.v1080.webm'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'webm_dash_manifest'.
Reading option '-i' ... matched as output url with argument '.\Sample Video.audio.webm'.
Reading option '-c' ... matched as option 'c' (codec name) with argument 'copy'.
Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '0'.
Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '1'.
Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '2'.
Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '3'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'webm_dash_manifest'.
Reading option '-adaptation_sets' ... matched as AVOption 'adaptation_sets' with argument 'id=0,streams=0,1,2 id=1,streams=3'.
Reading option '.\Sample Video.mpd' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument 9.
Successfully parsed a group of options.
Parsing a group of options: input url .\Sample Video.v480.webm.
Applying option f (force format) with argument webm_dash_manifest.
Successfully parsed a group of options.
Opening an input file: .\Sample Video.v480.webm.
[webm_dash_manifest @ 000002bbcb41dc80] Opening '.\Sample Video.v480.webm' for reading
[file @ 000002bbcb41e300] Setting default whitelist 'file,crypto,data'
st:0 removing common factor 1000000 from timebase
[webm_dash_manifest @ 000002bbcb41dc80] Error parsing Cues
[AVIOContext @ 000002bbcb41e5c0] Statistics: 102283 bytes read, 4 seeks
[in#0 @ 000002bbcb41dac0] Error opening input: Operation not permitted
Error opening input file .\Sample Video.v480.webm.
Error opening input files: Operation not permitted


  


  This is mediainfo for the offending input file, Sample Video.v480.webm :

  


  General
Complete name                            : .\Sample Video.v480.webm
Format                                   : WebM
Format version                           : Version 2
File size                                : 628 MiB
Duration                                 : 1 h 34 min
Overall bit rate                         : 926 kb/s
Frame rate                               : 23.976 FPS
Encoded date                             : 2023-11-21 16:48:35 UTC
Writing application                      : HandBrake 1.7.0 2023111500
Writing library                          : Lavf60.16.100

Video
ID                                       : 1
Format                                   : VP9
Format profile                           : 0
Codec ID                                 : V_VP9
Duration                                 : 1 h 34 min
Bit rate                                 : 882 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Bits/(Pixel*Frame)                       : 0.106
Stream size                              : 598 MiB (95%)
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709


  


  I don't know if I need different command line options, or whether this might be an ffmpeg or Handbrake bug. It has taken many, many hours to generate these video files (VP9 is painfully slow to encode), so I hate to do a lot of this over again, especially doing it again encoding the video with ffmpeg instead of Handbrake, as Handbrake is (oddly enough, considering it uses ffmpeg under the hood) noticeably faster.

  


  I have no idea what these "Cues" are that ffmpeg wants and can't parse, or how I would change them.

  


• Use NVIDIA GPU to speed up drawtext with ffmpeg

  28 février 2020, par Garrett

  I use the following ffmpeg command add text to a video, which takes longer than I would like.

  ffmpeg -i input.mp4 -vf "[in] drawbox= x=iw*0.75:y=ih*0.88:w=iw*0.25:h=ih*0.12:color=black@0.7:t=fill, drawtext=fontsize=20:fontcolor=White:text='Test Text Row 1':x=(w*.75)+15:y=(h*.88)+15, drawtext=fontsize=20:fontcolor=White:text='Test Text Row 2':x=(w*.75)+15:y=((h*.88)+25)+15, drawtext=fontsize=20:fontcolor=White:text='Test Text Row 3':x=(w*.75)+15:y=((h*.88)+50)+15, drawtext=fontsize=20:fontcolor=White:text='Test Text Row 4':x=(w*.75)+15:y=((h*.88)+75)+15 [out]" -y out.mp4

  I believe I have successfully configured ffmpeg to use the GPU on my laptop by following NVIDIA’s guide, which can be found https://developer.nvidia.com/ffmpeg

  However I am having trouble integrating the commands to utilize the GPU with my command above. I tested the following command from NVIDIA’s site to test configuration and it worked without error.

  ffmpeg -vsync 0 -c:v h264_cuvid -i  -f rawvideo 

  I have not found any examples yet of the integration of drawtext and GPU acceleration so any guidance appreciated.