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• Compressing a Video for HLS Streaming

  12 mars 2018, par jAndy

  I’m in the situation where I have a source file (very high quality, direct output from FCPX) which is in 1080p resolution.

  I use ffmpeg to create a 240, 360, 480 and 720 version to have an adaptive stream quality via HLS, so far so good. My question is about the strategy I’m using.
  Right now, I always use the original file as input for ffmpeg. I was wondering if it wouldn’t be a better idea to convert from 1080 to 720 with full compression algorithms and after that, just re-scale from 720 to 480, 360 and 240.

  I’m not really into video compression and ffmpeg, so I’d just like to hear some expert opinions on this approach. Is there any advantage to always go "all the way" (original file -> compressed/rescaled file) ?

• FFMPEG convert and codec

  11 mars 2018, par RonaldoLanhellas

  I have a CENTOS and i installed ffmpeg with : yum install ffmpeg command

  I’m trying to converting a video with the following command :

  ffmpeg -y -i "C:\home\app\cedoc\convert\TREINO_PSC_ACD_PR_02_09_14_IMAGEM_GOROTO_PRESO.MXF" -crf 18.0 -vcodec libx264 -filter:v scale=1920:1080 -preset veryslow -acodec libvo_aacenc -ar 48000 -b:a 192k -coder 1 -flags +loop -cmp chroma -partitions +parti4x4+partp8x8+partb8x8 -me_method hex -subq 6 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -b_strategy 1 -threads 0 "C:\Users\lanhellas\Documents\TREINO_PSC_ACD_PR_02_09_14_IMAGEM_GOROTO_PRESO.mp4"

  But i got the following :

  Unknown encoder 'libvo_aacenc'

  This is my ffmpeg configuration :

  ffmpeg version 2.6.8 Copyright (c) 2000-2016 the FFmpeg developers
  
    built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4)
  
    configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-gnutls --enable-ladspa --enable-libass --enable-libcdio --enable-libdc1394 --enable-libfaac --enable-nonfree --enable-libfdk-aac --enable-nonfree --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libx264 --enable-libx265 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect
  
    libavutil      54. 20.100 / 54. 20.100
  
    libavcodec     56. 26.100 / 56. 26.100
  
    libavformat    56. 25.101 / 56. 25.101
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 11.102 /  5. 11.102
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Hyper fast Audio and Video encoder
  
  usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

• Why is ffmpeg trying to produce both h.264 as well as h.265 ?

  7 mars 2018, par hydra3333

  I think I only ask for h.265 output, but the output loge below seems to indicate it is trying to produce 2 video streams as output.

  "C:\SOFTWARE\ffmpeg\0-homebuilt-x64\built_for_generic_opencl\x64_8bit\ffmpeg.exe" -hide_banner -v verbose  -threads 0 -i "G:\HDTV\0nvencc\test-mp4-03\ABC HD interlaced.aac.mp4" -t 15 -threads 0 -an  -sws_flags lanczos+accurate_rnd+full_chroma_int+full_chroma_inp -filter_complex "[0:v]yadif=0:0:0" -pixel_format yuv420p -pix_fmt yuv420p -strict -1 -f yuv4mpegpipe - 2> .\zzz1.h265.txt 
  
  | "C:\SOFTWARE\ffmpeg\0-homebuilt-x64\built_for_generic_opencl\x64_8bit\ffmpeg.exe" -strict -1 -hide_banner -v verbose  -threads 0 -i - -strict -1 -c:v:0 libx265 -crf 28 output.mp4 -an  -y .\zzz.h265.mp4 2> .\zzz2.h265.txt 
  
  
  
  -----------------------------
  
  <snip to="to" make="make" code="code" block="block" smaller="smaller">
  
      Stream mapping:
  
        Stream #0:0 (h264) -> yadif
  
        yadif -> Stream #0:0 (wrapped_avframe)
  
      Press [q] to stop, [?] for help
  
      [h264 @ 000001b78ca87c00] Reinit context to 1920x1088, pix_fmt: yuv420p
  
      [graph 0 input from stream 0:0 @ 000001b78ca264c0] w:1920 h:1080 pixfmt:yuv420p tb:1/90000 fr:25/1 sar:1/1 sws_param:flags=2
  
  </snip>

  Output file #0 (pipe:):
  
    Output stream #0:0 (video): 2 frames encoded; 2 packets muxed (1072 bytes); 
  
    Total: 2 packets (1072 bytes) muxed
  
  Conversion failed!
  
  -----------------------------
  
  Routing option strict to both codec and muxer layer
  
      Last message repeated 1 times
  
  Input #0, yuv4mpegpipe, from 'pipe:':
  
    Duration: N/A, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: rawvideo, 1 reference frame (I420 / 0x30323449), yuv420p(progressive, left), 1920x1080, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 25 tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> hevc (libx265))
  
    Stream #0:0 -> #1:0 (rawvideo (native) -> h264 (libx264))
  
  [graph 0 input from stream 0:0 @ 0000027f5ebefa00] w:1920 h:1080 pixfmt:yuv420p tb:1/25 fr:25/1 sar:1/1 sws_param:flags=2
  
  x265 [info]: HEVC encoder version 2.7613d9f443769
  
  x265 [info]: build info [Windows][GCC 7.3.0][64 bit] 8bit
  
  x265 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  x265 [info]: Main profile, Level-4 (Main tier)
  
  x265 [info]: Thread pool created using 8 threads
  
  x265 [info]: Slices                              : 1
  
  x265 [info]: frame threads / pool features       : 3 / wpp(17 rows)
  
  -----------------------------