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• Merge commit ’106b62f4ba600f24415eaded5e020aeceb23fd59’

  28 mai 2014, par Michael Niedermayer

  Merge commit ’106b62f4ba600f24415eaded5e020aeceb23fd59’
  * commit ’106b62f4ba600f24415eaded5e020aeceb23fd59’ :
  
    matroskaenc : write the channel mask for FLAC
  Conflicts :
  
  	libavformat/matroskaenc.c
  Merged-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavformat/Makefile
  • [DH] libavformat/matroskaenc.c

• How to encode video with ffmpeg using AMD h264_amf

  10 novembre 2022, par Ivy Growing

  Given :

  


  

  • Win10

  


  • AMD CPU

  


  • Video capturing card Avermedia Live Gamer Extreme 3

  


  • ffmpeg versions and encoders :

  


  


  >ffmpeg.exe -encoders | find "264"
ffmpeg version 5.1-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
// cut
 V....D libx264              libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (codec h264)
 V....D libx264rgb           libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 RGB (codec h264)
 V....D h264_amf             AMD AMF H.264 Encoder (codec h264)
 V....D h264_mf              H264 via MediaFoundation (codec h264)
 V....D h264_nvenc           NVIDIA NVENC H.264 encoder (codec h264)
 V..... h264_qsv             H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (Intel Quick Sync Video acceleration) (codec h264)


  


  Required to capture the video into H.264 encoded file using AMD's hardware accelerator in the CPU (AMF, or VCE).
Tried : ffmpeg -y -f dshow -rtbufsize 2002000k -framerate 30 -i video="Live Gamer EXTREME 3"  -t 00:00:10  -c:v h264_amf output.ts
Result :

  


  Input #0, dshow, from 'video=Live Gamer EXTREME 3':
  Duration: N/A, start: 88548.973998, bitrate: N/A
  Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422(tv, bt709/bt709/unknown), 1280x720, 30 fps, 30 tbr, 10000k tbn
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (h264_amf))
Press [q] to stop, [?] for help
[h264_amf @ 000002404328c700] DLL amfrt64.dll failed to open
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
Conversion failed!


  


  For some reason ffmpeg uses resolution 1280x720... When trying to specifiy the capture card resolution the following error appears :

  


  >ffmpeg -y -f dshow -rtbufsize 2002000k -framerate 30 -video_size 3840x2160 -i video="Live Gamer EXTREME 3" -r 30 -t 00:00:10   -c:v h264_amf -f mpegts output.ts
//cut
[dshow @ 0000029d7c0f84c0] Could not set video options
video=Live Gamer EXTREME 3: I/O error


  


  This is not unique error for Avermedia card. The same error appears with Dell web cam and for Magewell.

  


  From this answer the extra flags to be used with h264_amf. I guessed the default values should be good enough. It seems something needs to be configured or initialized when using AMF/VCE.

  


  The video encoding in software (without AMF) works just fine but loads the CPU. The goal is using dedicated hardware module and release computational power of the CPU for the other apps.

  


  Command example will be appreciated.

  


• Ideal bitrates for different video resolutions

  15 octobre 2018, par Ramesh Navi

  I am building a Video-on-demand service for a closed community. I using FFMPEG for video processing and dash.js for adaptive bitrate player with custom resolution selector. Can somebody please suggest what ideal bitrates should I use while video/audio transcoding ?

  I am talking about -b:v and -ab option

  ffmpeg -i vid.mp4 -c:v libvpx-vp9 -keyint_min 150 \
  
  -g 150 -tile-columns 4 -frame-parallel 1  -f webm -dash 1 \
  
  -an -vf scale=144:-1 -b:v 120k -dash 1 video_1.webm \
  
  -an -vf scale=240:-1 -b:v 250k -dash 1 video_2.webm \
  
  -an -vf scale=360:-1 -b:v 500k -dash 1 video_3.webm \
  
  -an -vf scale=480:-1 -b:v 750k -dash 1 video_4.webm \
  
  -an -vf scale=720:-1 -b:v 1500k -dash 1 video_5.webm

  And

  ffmpeg -i vid.mp4 -vn -acodec libvorbis -ab 96k -dash 1 audio_96k.webm

  Any suggestions/hacks or examples to tackle real-world network situations are appreciated.