4 Replies Latest reply on May 28, 2018 3:50 PM by akravchenko188

    AMF encoding with FFMPEG




      I tried to encode video files using FFMPEG built with AMF support and found some unexpected behavior.


      I tried to get maximum quality with an encoded bitrate limit. Some videos are encoded pretty nice, but some are encoded with bitrate too much over limit. For example, the desired 8M bitrate encoded as 98M.


      The command line used is

      ffmpeg.exe -i input.y4m -c:v hevc_amf -quality quality -usage transcoding -b:v 8M -bufsize 16M -maxrate 12M output.hevc


      Tried many other parameters but none of them get encoded bitrate to the limits.


      Driver version: 18.Q1.1-March22

      Board: Vega Frontier Edition


      Could you suggest what can be wrong?


      Thank you!

        • Re: AMF encoding with FFMPEG

          I have seen problems occasionally with FFMPEG and I use it to transcode video a alot


          I have seen problems with HEVC so I am wondering if there is an updated version available yet


          maybe handbrake is more capable?

          • Re: AMF encoding with FFMPEG


            could you provide the following information?

            1) FFmpeg version

            2) could you share stream you are trying to encode?

            3) FFmpeg output after encoding like:


            Output #0, hevc, to 'video.mp4.issue1.hevc':


                major_brand     : isom

                minor_version   : 512

                compatible_brands: isomiso2avc1mp41

                encoder         : Lavf58.12.100

                Stream #0:0(und): Video: hevc (hevc_amf), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 8000 kb/s, 60 fps, 60 tbn, 60 tbc (default)


                  handler_name    : VideoHandler

                  encoder         : Lavc58.18.100 hevc_amf

            frame= 9780 fps=199 q=-0.0 Lsize=  159000kB time=00:02:43.00 bitrate=7991.0kbits/s speed=3.32x

            video:159000kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%