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• FFMPEG low bitrate at starting frames

  21 janvier 2018, par Y. T

  So I noticed that the first 1-4s of the videos that I’m converting start with a low bitrate and gradually increase untill its around the specified bitrate (-crf 17 -minrate 2000k -maxrate 3000k -bufsize 2000k).

  ...
  
  frame= 37 fps= 0.0 q=24.0 size = 113kB time=00:00:02.08 bitrate= 443.5kbits/s
  
  frame= 66 fps= 64 q=30.0 size = 619kB time=00:00:03.20 bitrate= 1581.6kbits/s
  
  frame= 99 fps= 64 q=28.0 size = 1106kB time=00:00:04.52 bitrate= 2002.2kbits/s
  
  frame= 131 fps= 63 q=23.0 size = 1599kB time=00:00:05.82 bitrate= 2247.8kbits/s
  
  ...

  I already tried changing several settings like -crf, -b:v, -minrate, -maxrate and -bufsize. From my trial-and-error experience, the lower the -crf / higher -b:v, the faster it reaches an appropriate bitrate, but it still has this "lagg" in the beginning of the conversion.

  Is it possible to immediately start with, for example 2000kbits/s, at the start of the conversion ?

  EDIT

  Around the first 1-30s (roughly), the clips are more pixelated than the rest of the clip. See this image for a comparison (zoomed in on area of an 1080p clip). The rest of the clip doesn’t have any visible loss like this (1850kbps encoded vs 2000kbps original), so I still assume it has something to do with the start of the encoding.

• FFmpeg with Nvidia GPU - full HW transcode with 50i to 50p deinterlacing

  5 janvier 2018, par Jernej Stopinšek

  I’m trying to do a full hardware transcode of an udp stream to hls
  with 50i to 50p deinterlacing.

  I’m using ffmpeg and Nvidia GPU.

  Since HLS requires deinterlacing

  https://developer.apple.com/library/content/documentation/General/Reference/HLSAuthoringSpec/Requirements.html

  I would like to deinterlace an interlaced source stream and preserve
  as much smooth motion and picture quality as possible.

  My hardware, software and driver info :

  GPU : Tesla P100-PCIE-12GB
  Nvidia Driver Version : 387.26
  Cuda compilation tools, release 9.1, V9.1.85
  FFmpeg from git on 20171218
  
  

  ffmpeg version N-89520-g3f88744067 Copyright (c) 2000-2017 the FFmpeg
  developers built with gcc 6.3.0 (Debian 6.3.0-18) 20170516
  configuration : —enable-gpl
  —enable-cuda-sdk —enable-libx264 —enable-libx265 —enable-nonfree —enable-libnpp —enable-opengl —enable-opencl —enable-libfreetype —enable-openssl —enable-libzvbi —enable-libfontconfig —enable-libfreetype —enable-libfribidi —extra-cflags=-I/usr/local/cuda/include —extra-ldflags=-L/usr/local/cuda/lib64 —arch=x86_64

  libavutil 56. 6.100 / 56. 6.100
  libavcodec 58. 8.100 / 58.
  8.100
  libavformat 58. 3.100 / 58. 3.100
  libavdevice 58. 0.100 / 58. 0.100
  libavfilter 7. 7.100 / 7. 7.100
  libswscale 5.
  0.101 / 5. 0.101
  libswresample 3. 0.101 / 3. 0.101
  libpostproc 55. 0.100 / 55. 0.100

  Input stream info :

  ffmpeg -t 00:05:00 -i udp://xxx.xxx.xxx.xxx:xxxx -map 0:0 -vf idet -c rawvideo -y -f rawvideo /dev/null

  ---

  Input #0, mpegts, from ’udp ://xxx.xxx.xxx.xxx:xxxx’ :
  Duration :
  N/A, start : 49634.159411, bitrate : N/A
  Program xxxxx
  Metadata : service_name :
  service_provider : Stream
  #0:0[0x44d] : Video : h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, bt709, top first), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 50 tbr, 90k
  tbn, 50 tbc
  Stream #0:10x19de : Audio : mp2 ([3][0][0][0] /
  0x0003), 48000 Hz, stereo, s16p, 192 kb/s
  Stream
  #0:20x19e1 : Subtitle : dvb_subtitle ([6][0][0][0] / 0x0006)
  

  Output #0, rawvideo, to ’/dev/null’ :
  Metadata :
  encoder :
  Lavf58.3.100
  Stream #0:0 : Video : rawvideo (I420 / 0x30323449),
  yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 622080 kb/s, 25 fps, 25
  tbn, 25 tbc
  Metadata :
  encoder : Lavc58.8.100 rawvideo
  frame= 7538 fps= 25 q=-0.0 Lsize=22896675kB time=00:05:01.52
  bitrate=622080.0kbits/s dup=38 drop=0 speed=1.02x
  video:22896675kB audio:0kB subtitle:0kB other streams:0kB global
  headers:0kB muxing overhead : 0.000000%
  [Parsed_idet_0 @
  0x56370b3c5080] Repeated Fields : Neither : 7458 Top : 24 Bottom : 18
  [Parsed_idet_0 @ 0x56370b3c5080] Single frame detection : TFF : 281 BFF :
  13 Progressive : 5639 Undetermined : 1567
  [Parsed_idet_0 @
  0x56370b3c5080] Multi frame detection : TFF : 380 BFF : 0 Progressive :
  7120 Undetermined : 0
  

  ---

  This is my command for adaptive hardware deinterlacing. It gives great results with picture, but sound is out of sync.

  ffmpeg -y -err_detect ignore_err -loglevel debug -vsync -1 -hwaccel cuvid -hwaccel_device 1 -c:v h264_cuvid -deint adaptive -r:v 50 -gpu:v 1 -i "udp://xxx.xxx.xxx.xxx:xxxx=?overrun_nonfatal=1&fifo_size=84450&buffer_size=33554432" -map 0:0 -map 0:1 -c:a aac -b:a 196k -c:v h264_nvenc -flags -global_header+cgop -gpu:v 1 -g:v 50 -bf:v 4 -coder:v cabac -b_adapt:v false -b:v 5184000 -minrate:v 5184000 -maxrate:v 5184000 -bufsize:v 2488320 -rc:v cbr_hq -2pass:v true -rc-lookahead:v 25 -no-scenecut:v 1 -profile:v high -preset:v slow -color_range:v 1 -color_trc:v 1 -color_primaries:v 1 -colorspace:v 1 -f hls -hls_time 5 -hls_list_size 3 -start_number 0 -hls_flags delete_segments /srv/hls/program_01/1080p/index.m3u8

  If I add option "-drop_second_field 1" to h264_cuvid and remove -r:v 50 from input and put it to h264_nvenc - then transcoded stream has synced audio, but I think I’m losing quality due to drop_second_field option.

  ffmpeg -y -err_detect ignore_err -loglevel debug -vsync -1 -hwaccel cuvid -hwaccel_device 1 -c:v h264_cuvid -deint adaptive -drop_second_field 1 -gpu:v 1 -i "udp://xxx.xxx.xxx.xxx:xxxx=?overrun_nonfatal=1&fifo_size=84450&buffer_size=33554432" -map 0:0 -map 0:1 -c:a aac -b:a 196k -c:v h264_nvenc -flags -global_header+cgop -gpu:v 1 -g:v 50 -r:v 50 -bf:v 4 -coder:v cabac -b_adapt:v false -b:v 5184000 -minrate:v 5184000 -maxrate:v 5184000 -bufsize:v 2488320 -rc:v cbr_hq -2pass:v true -rc-lookahead:v 25 -no-scenecut:v 1 -profile:v high -preset:v slow -color_range:v 1 -color_trc:v 1 -color_primaries:v 1 -colorspace:v 1 -f hls -hls_time 5 -hls_list_size 3 -start_number 0 -hls_flags delete_segments /srv/hls/program_01/1080p/index.m3u8

  Could someone please point me in the right direction how to properly deinterlace with cuvid and minimal possible loss of quality ?

• FFMPEG : watermark 4k Video failed

  10 janvier 2018, par Diaa Saada

  I’m using FFMPEG to watermark my videos and it is working fine when the output is 1080p or lower even if the input is 4K

  ffmpeg -i 4k.mkv -i watermark.png -filter_complex "scale=-2:1080,overlay=10:10" output1080.mp4

  But if I tried to output a 4K video

  ffmpeg -i 4k.mkv -i watermark.png -filter_complex "overlay=10:10" output4k.mp4

  I get this error message

      x264 [error]: malloc of size 26199520 failedme=00:00:00.88 bitrate=   0.0kbits/s speed=1.72x
  
  Video encoding failed
  
  [aac @ 0xaa42240] Qavg: 17612.034
  
  [aac @ 0xaa42240] 2 frames left in the queue on closing
  
  Conversion failed!

  the linux I am working on is 32x so I’m using 32 version of ffmpeg

  how can I fix this ?