Table of Contents

ffmpeg - Conversions - Convert H264 to H265

Convert h.264 to h.265 (no change in resolution)

ffmpeg -i input.mp4 -c:v libx265 -vtag hvc1 -c:a copy output.mp4

Software Encoding

ffmpeg -i a.mp4 -c:v libx265 a.mkv
 
ffmpeg -i a.mp4 -c:v libx265 -map 0:v -c:a copy -map 0:a -c:s copy b.mkv
 
ffmpeg -i a.mp4 -c:v libx265 -map 0:v -c:a copy -map 0:a? -c:s copy -map 0:s? b.mkv

NOTE: libx265 is a software encoder.

  • It does not support hardware encoding.

Using GPU Hardware Encoding

ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i a.mp4 -c:v hevc_vaapi a.mkv
 
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i a.mp4 -c:v hevc_vaapi -map 0:v -c:a copy -map 0:a -c:s copy a.mkv
 
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i a.mp4 -c:v hevc_vaapi -map 0:v -c:a copy -map 0:a? -c:s copy -map 0:s? a.mkv

NOTE: This allows the GPU to be used: 

-hwaccel vaapi -hwaccel_output_format vaapi -vaapi_device /dev/dri/renderD128

Encoding formats

Try replacing scale with scale_vaapi and replace -c:v h264 with -c:v: h264_vaapi

The supported encoders are:

H.262 / MPEG-2 part 2mpeg2_vaapi
H.264 / MPEG-4 part 10 (AVC)h264_vaapi
H.265 / MPEG-H part 2 (HEVC)hevc_vaapi
MJPEG / JPEGmjpeg_vaapi
VP8vp8_vaapi
VP9vp9_vaapi

Keeping the output size low, similar to Software encoding

ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i input.mp4 -c:v hevc_vaapi -b:v 0.589M output.mp4

NOTE: I had to set the bitrate smaller because the transcoded one was even bigger than the original file.

  • You can change bitrate at 0.589M
    • 0.589M is 0.589 Megabytes.
  • Change it accordingly to your desired bitrate. I will use 2x - 3x smaller than the orginal. In this example h.264 to hevc.

Other examples

ffmpeg -i a.mp4 -vaapi_device /dev/dri/renderD128 -vf format=nv12,hwupload -c:v hevc_vaapi -map 0:v:0 -map 0:a? -c:a copy -map 0:s? -c:s copy -rc_mode 1 -qp 25 -map_chapters 0 b.mkv
 
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i a.mp4 -c:v hevc_vaapi -map 0:v:0 -map 0:a? -c:a copy -map 0:s? -c:s copy -b:a 320k -global_quality 25 k.mkv
 
ffmpeg -init_hw_device vaapi=amd:/dev/dri/renderD128 -hwaccel vaapi -hwaccel_output_format vaapi -hwaccel_device amd -filter_hw_device amd -i a.mp4 -vf 'format=nv12|vaapi,hwupload' -y -c:v hevc_vaapi -map 0:v:0 -map 0:a? -c:a copy -map 0:s? -c:s copy -qp:v 28 b.mkv
 
 
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i a.mp4 -c:v hevc_vaapi b.mkv
 
ffmpeg -threads 16 -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i a.mp4 -c:v hevc_vaapi c.mkv

References

https://trac.ffmpeg.org/wiki/Encode/H.265