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• FFmpeg encode 8192x8192@60 with high quality from image sequence

  20 décembre 2017, par Daniel R.

  I am looking for the right ffmpeg config or an alternative software to encode a long sequence of images captured with 60fps and a resolution of 8192x8192 pixel.

  What i tried is to use h264 encoding, but at this high resolution it cannot be suitable since i couldnt play the encoded video.

  Using h265/HEVC i can play the video but i have nasty compression artifacts especially at the borders of the image.

  Here is the command i used with ffmpeg-3.4.1 at Windows 64-bit static Lib :

  .\ffmpeg.exe -framerate 60 -i ""E:\RenderedFrames\img%d.jpg"" -c:v libx265 -crf 28 output.mp4

  Here is the log of ffmpeg

  C:\ffmpeg-20171218-74f408c-win64-static\bin> .\ffmpeg.exe -framerate 60 -i ""D:\SansSousi\%d.jpg"" -c:v 
  
  libx265 -crf 27 output3.mp4 
  
  ffmpeg version git-2017-12-18-74f408c Copyright (c) 2000-2017 the FFmpeg developers 
  
  built with gcc 7.2.0 (GCC) 
  
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-amf --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx 
  
  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 #0, image2, from 'D:\SansSousi\%d.jpg': 
  
  Duration: 00:00:03.02, start: 0.000000, bitrate: N/A 
  
  Stream #0:0: Video: mjpeg, yuvj420p(pc, bt470bg/unknown/unknown), 8192x8192 [SAR 1:1 DAR 1:1], 60 tbr, 60 tbn, 60 tbc 
  
  Stream mapping: 
  
  Stream #0:0 -> #0:0 (mjpeg (native) -> hevc (libx265)) 
  
  Press [q] to stop, [?] for help 
  
  [swscaler @ 0000027b64c702c0] deprecated pixel format used, make sure you did set range correctly 
  
  x265 [info]: HEVC encoder version 2.6×6b079854e56e 
  
  x265 [info]: build info [Windows][GCC 7.2.0][64 bit] 8bit 
  
  x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2 
  
  x265 [info]: Main profile, Level-8.5 (Main tier) 
  
  x265 [info]: Thread pool created using 16 threads 
  
  x265 [info]: Slices : 1 
  
  x265 [info]: frame threads / pool features : 4 / wpp(128 rows) 
  
  x265 [info]: Coding QT: max CU size, min CU size : 64 / 8 
  
  x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra 
  
  x265 [info]: ME / range / subpel / merge : hex / 57 / 2 / 2 
  
  x265 [info]: Keyframe min / max / scenecut / bias: 25 / 250 / 40 / 5.00 
  
  x265 [info]: Lookahead / bframes / badapt : 20 / 4 / 2 
  
  x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 0 
  
  x265 [info]: References / ref-limit cu / depth : 3 / on / on 
  
  x265 [info]: AQ: mode / str / qg-size / cu-tree : 1 / 1.0 / 32 / 1 
  
  x265 [info]: Rate Control / qCompress : CRF-27.0 / 0.60 
  
  x265 [info]: tools: rd=3 psy-rd=2.00 rskip signhide tmvp strong-intra-smoothing 
  
  x265 [info]: tools: lslices=8 deblock sao 
  
  Output #0, mp4, to 'output3.mp4': 
  
  Metadata: 
  
  encoder : Lavf58.3.100 
  
  Stream #0:0: Video: hevc (libx265) (hev1 / 0x31766568), yuv420p, 8192x8192 [SAR 1:1 DAR 1:1], q=2-31, 60 fps, 15360 tbn, 60 tbc 
  
  Metadata: 
  
  encoder : Lavc58.8.100 libx265 
  
  frame= 33 fps=1.8 q=-0.0 size= 1024kB time=00:00:00.00 bitrate=129060923.1kbits/s speed=3.63e-006x frame= 181 fps=1.1 q=-0.0 Lsize= 8112kB time=00:00:02.96 bitrate=22398.3kbits/s speed=0.0183x 
  
  video:8107kB audio:0kB subtitle:0kB other streams:0kB global headers:2kB muxing overhead: 0.060955% 
  
  x265 [info]: frame I: 1, Avg QP:28.18 kb/s: 528757.92 
  
  x265 [info]: frame P: 36, Avg QP:30.76 kb/s: 36726.89 
  
  x265 [info]: frame B: 144, Avg QP:35.78 kb/s: 14814.45 
  
  x265 [info]: Weighted P-Frames: Y:0.0% UV:0.0% 
  
  x265 [info]: consecutive B-frames: 2.7% 0.0% 0.0% 0.0% 97.3% 
  
  
  
  encoded 181 frames in 161.36s (1.12 fps), 22012.19 kb/s, Avg QP:34.74

  What can i do to improve the quality of the encoded video ?
  File size is secondary

• Extremely high bit rate when encoding video with libavcodec

  10 janvier 2014, par niculare

  I am trying to capture the camera output and make a video using libavcodec. As an example on how to accomplish this i have used ffmpeg muxing example.

  The problem is that a 4 seconds video has a size of 15mb and a bitrate of 30000 kb/s, although I have set the bitrate on AVCodecContext to 400000 (I consider this value is in bits / sec, not kb/s).

  I have also tried to record the video using ffmpeg from command line and it has a bitrate of 700 kb/s.

  Does anybody have an idea why the bitrate is not preserved and thus the resulting file is very large ? The code I have used to initialize the codec context is below :

  initialization part :

  avformat_alloc_output_context2(&m_formatContext, NULL, NULL, filename);
  
  outputFormat = m_formatContext->oformat;
  
  
  
  codec = avcodec_find_encoder(outputFormat->video_codec);
  
  
  
  m_videoStream = avformat_new_stream(m_formatContext, codec);
  
  
  
  m_videoStream->id = m_formatContext->nb_streams - 1;
  
  
  
  codecContext = m_videoStream->codec;
  
  
  
  codecContext->codec_id = outputFormat->video_codec;
  
  
  
  codecContext->width = m_videoResolution.width();
  
  codecContext->height = m_videoResolution.height();
  
  
  
  int m_bitRate = 400000;
  
  codecContext->bit_rate = m_bitRate;
  
  codecContext->rc_min_rate = m_bitRate;
  
  codecContext->rc_max_rate = m_bitRate;
  
  codecContext->bit_rate_tolerance = 0;
  
  
  
  codecContext->time_base.den = 20;
  
  codecContext->time_base.num = 1;
  
  
  
  codecContext->pix_fmt = AV_PIX_FMT_YUV422P;
  
  
  
  if (m_formatContext->oformat->flags & AVFMT_GLOBALHEADER)
  
      codecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
  /* open it */
  
  ret = avcodec_open2(codecContext, codec, NULL);
  
  
  
  avFrame = avcodec_alloc_frame();
  
  
  
  ret = avpicture_alloc(&avPicture, codecContext->pix_fmt, codecContext->width, codecContext->height);
  
  
  
  *((AVPicture *)avFrame) = avPicture;
  
  
  
  av_dump_format(m_formatContext, 0, filename, 1);
  
  
  
  if (!(outputFormat->flags & AVFMT_NOFILE)) {
  
      ret = avio_open(&m_formatContext->pb, filename, AVIO_FLAG_WRITE);
  
  }
  
  
  
  ret = avformat_write_header(m_formatContext, NULL);
  
  
  
  if (avFrame)
  
      avFrame->pts = 0;

• ffmpeg : is vidstab multithreaded, and/or is there a way to make it perform better on a very high # of cores ?

  30 juillet 2016, par ljwobker

  I’m working on a project where I use the vidstab ffmpeg plugin to stabilize some videos. I’m lucky enough to have access to an extremely fast x86 machine (2 socket, 16 core, 32 thread) but I can’t seem to keep it busy and I’m trying to figure out if it’s a limitation of the toolchain or the config/commands. The workflow is basically 3 steps :

  1. crop the video in terms of both time and dimension (ffmpeg "crop"
     filter)
  2. run vidstabdetect to identify the transformation corrections
  3. run vidstabtransform to apply the transformation and output the
     final video

  When I run the transcode script on this machine, the "crop" pass executes extremely fast, and the htop output from the machine clearly shows all 32 cores(threads) running at nearly 100%.

  When I run the pass with vidstabdetect, htop clearly shows one core running at/near 100%, with all of the other cores hovering in the "few percent" range, and total CPU utilization for the parent PID hovers near 130%. This leads me to believe there must be only one main processing thread, but also several other smaller threads that are consuming at least some parallel time.

  the vidstabtransform pass looks similar, with one core constantly near 100%, and the rest of the cores hovering in the few percent.

  As far as I can tell, there is no way to parallelize the two vidstab processes, as the transform step is completely dependent on the results of the detection pass. There is a single pass option described in the vidstab docs, but the quality isn’t as good so I’m trying to avoid that.