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• Information about ffmpeg what algorithm does it use if any [closed]

  15 janvier 2021, par Education 4Fun

  I'm in search of some info about FFmpeg.I did search for the info but did not find answers for most of my questions.
  

  


  FFmpeg is a framework written in C++ which helps in editing videos from the command line.
  
So what does FFmpeg use to do editing like are there any algorithms which it uses or any ?
  
If I'm building a project then I can say the project comes under image processing as a video is made up of images and the framework works on images right ?
  
or video processing ?
  
FFmpeg is a stand-alone framework right or it depends on any other ?
  
Sorry for asking noncoding questions here
  

  


• Translating Handbrake options to a FFMPEG command

  9 mai 2020, par Arif

  I want to convert a bunch of videos from x264 to x265, but I need to do so with ffmpeg in terminal because it's a remote server. These are my Handbrake options (listed items are ticked) :

  



  Summary tab

  



  

  • Web optimized

  


  • Align A/V Start

  


  



  Dimensions tab unchanged

  



  Filters tab

  



  

  • Sharpen - LapSharp, preset : Medium

  


  



  Video tab

  



  


  • Video codec - H.265 (x265)

  


  • Framerate (FPS) - 30 - Peak Framerate

  


  • Quality - Constant Quality - 28

  


  • Encoder preset - Medium

  


  • Encoder tune - None

  


  • Encoder profile - Auto

  


  



  Audio tab

  



  

  • Audio track - AAC, bitrate : 128

  


  



  Subtitles tab - No subtitles (remove if exists)

  



  This is the ffmpeg command that I've managed to compile so far :

  



  ffmpeg -i input.mp4 -c:v libx265 -crf 28 -c:a aac -b:a 128k -max_muxing_queue_size 400 -movflags +faststart output.mp4

  



  I have the following two questions :

  



  

  1. Does the ffmpeg command provided list all the options except the peak framerate, sharpening filter and removing subtitle ones ? How do I incorporate these three ?

  


  2. Slightly unrelated, but does having -max_muxing_queue_size 400 negatively affect file size or video quality ? I've only included this because I'd ran into encoding errors in the past.

  


  



  Thank you.

  



  My Handbrake log with the above options, if it helps :

  



  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'E:\input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.10.100
  Duration: 00:02:20.52, start: 0.000000, bitrate: 1487 kb/s
    Stream #0:0(und): Video: h264 (High) [avc1 / 0x31637661]
      yuv420p, tv, bt709/bt709/bt709
      1280x720 [PAR 1:1 DAR 16:9], 1288 kb/s, PAR 1:1 DAR 16:9
      29.97 fps, 30k tbn (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(eng): Audio: aac (LC) [mp4a / 0x6134706D]
      44100 Hz, stereo, fltp, 192 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
[04:26:49] scan: decoding previews for title 1
[04:26:49] scan: audio 0x1: aac, rate=44100Hz, bitrate=192025 English (AAC) (2.0 ch)
[04:26:50] scan: 10 previews, 1280x720, 29.970 fps, autocrop = 0/0/0/0, aspect 16:9, PAR 1:1
[04:26:50] scan: supported video decoders: avcodec qsv
[04:26:50] libhb: scan thread found 1 valid title(s)
[04:26:50] starting job
[04:26:50] decomb filter thread started for segment 0
[04:26:50] decomb filter thread started for segment 1
[04:26:50] decomb filter thread started for segment 3
[04:26:50] decomb check thread started for segment 0
[04:26:50] decomb check thread started for segment 1
[04:26:50] yadif thread started for segment 0
[04:26:50] decomb check thread started for segment 3
[04:26:50] mask filter thread started for segment 0
[04:26:50] work: track 1, dithering not supported by codec
[04:26:50] mask filter thread started for segment 1
[04:26:50] work: only 1 chapter, disabling chapter markers
[04:26:50] job configuration:
[04:26:50]  * source
[04:26:50]    + E:\input.mp4
[04:26:50]    + title 1, chapter(s) 1 to 1
[04:26:50]    + container: mov,mp4,m4a,3gp,3g2,mj2
[04:26:50] mask filter thread started for segment 3
[04:26:50]    + data rate: 1487 kbps
[04:26:50]  * destination
[04:26:50]    + C:\Users\Hp\Desktop\output.mp4
[04:26:50]    + container: MPEG-4 (libavformat)
[04:26:50]      + optimized for HTTP streaming (fast start)
[04:26:50]      + align initial A/V stream timestamps
[04:26:50]  * video track
[04:26:50]    + decoder: h264
[04:26:50]      + bitrate 1288 kbps
[04:26:50]    + filters
[04:26:50] mask filter thread started for segment 2
[04:26:50]      + Comb Detect (mode=3:spatial-metric=2:motion-thresh=1:spatial-thresh=1:filter-mode=2:block-thresh=40:block-width=16:block-height=16)
[04:26:50]      + Decomb (mode=39)
[04:26:50]      + Framerate Shaper (mode=2:rate=27000000/900000)
[04:26:50]        + frame rate: 29.970 fps -> peak rate limited to 30.000 fps
[04:26:50] mask erode thread started for segment 1
[04:26:50]      + Crop and Scale (width=1280:height=720:crop-top=0:crop-bottom=0:crop-left=0:crop-right=0)
[04:26:50]        + source: 1280 * 720, crop (0/0/0/0): 1280 * 720, scale: 1280 * 720
[04:26:50]      + Sharpen (lapsharp) (y-strength=0.2:y-kernel=isolap:cb-strength=0.2:cb-kernel=isolap)
[04:26:50]    + Output geometry
[04:26:50]      + storage dimensions: 1280 x 720
[04:26:50]      + pixel aspect ratio: 1 : 1
[04:26:50]      + display dimensions: 1280 x 720
[04:26:50]    + encoder: H.265 (libx265)
[04:26:50]      + preset:  medium
[04:26:50]      + profile: auto
[04:26:50]      + quality: 28.00 (RF)
[04:26:50]  * audio track 1
[04:26:50] mask erode thread started for segment 2
[04:26:50]    + decoder: English (AAC) (2.0 ch) (track 1, id 0x1)
[04:26:50]      + bitrate: 192 kbps, samplerate: 44100 Hz
[04:26:50]    + mixdown: Stereo
[04:26:50]    + encoder: AAC (libavcodec)
[04:26:50]      + bitrate: 128 kbps, samplerate: 48000 Hz
[04:26:50] mask erode thread started for segment 3
[04:26:50] mask dilate thread started for segment 0
[04:26:50] mask dilate thread started for segment 1
[04:26:50] mask dilate thread started for segment 2
[04:26:50] decomb check thread started for segment 2
[04:26:50] yadif thread started for segment 1
[04:26:50] yadif thread started for segment 2
[04:26:50] yadif thread started for segment 3
[04:26:50] MTFrame thread started for segment 1
[04:26:50] MTFrame thread started for segment 2
[04:26:50] MTFrame thread started for segment 3
[04:26:50] mask dilate thread started for segment 3
[04:26:50] sync: expecting 4211 video frames
[04:26:50] mask erode thread started for segment 0
[04:26:50] decomb filter thread started for segment 2
[04:26:50] MTFrame thread started for segment 0
x265 [info]: HEVC encoder version 2.6
x265 [info]: build info [Windows][GCC 7.2.0][64 bit] 8bit+10bit+12bit
x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
x265 [info]: Main profile, Level-3.1 (Main tier)
x265 [info]: Thread pool created using 4 threads
x265 [info]: Slices                              : 1
x265 [info]: frame threads / pool features       : 2 / wpp(12 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: 30 / 300 / 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-28.0 / 0.60
x265 [info]: tools: rd=3 psy-rd=2.00 rskip signhide tmvp strong-intra-smoothing
x265 [info]: tools: lslices=4 deblock sao
[04:26:50] sync: first pts video is 0
[04:26:50] sync: "Chapter 1" (1) at frame 1 time 0
[04:26:50] sync: first pts audio 0x1 is 0
[04:40:02] reader: done. 1 scr changes
[04:40:13] work: average encoding speed for job is 5.245789 fps
[04:40:13] comb detect: heavy 3 | light 10 | uncombed 4198 | total 4211
[04:40:13] decomb: deinterlaced 3 | blended 10 | unfiltered 4198 | total 4211
[04:40:13] vfr: 4211 frames output, 0 dropped and 0 duped for CFR/PFR
[04:40:13] vfr: lost time: 0 (0 frames)
[04:40:13] vfr: gained time: 0 (0 frames) (0 not accounted for)
[04:40:13] aac-decoder done: 6052 frames, 0 decoder errors
[04:40:13] h264-decoder done: 4211 frames, 0 decoder errors
[04:40:13] sync: got 4211 frames, 4211 expected
[04:40:13] sync: framerate min 18.394 fps, max 29.970 fps, avg 29.966 fps
x265 [info]: frame I:     18, Avg QP:24.13  kb/s: 2900.85
x265 [info]: frame P:   1079, Avg QP:26.64  kb/s: 1040.14
x265 [info]: frame B:   3114, Avg QP:33.15  kb/s: 235.18
x265 [info]: Weighted P-Frames: Y:0.4% UV:0.4%
x265 [info]: consecutive B-frames: 4.0% 1.4% 20.1% 55.7% 18.8%
encoded 4211 frames in 802.93s (5.24 fps), 452.83 kb/s, Avg QP:31.44
[04:40:13] mux: track 0, 4211 frames, 7970061 bytes, 453.68 kbps, fifo 8192
[04:40:13] mux: track 1, 6588 frames, 2254132 bytes, 128.31 kbps, fifo 8192
[04:40:13] libhb: work result = 0

# Encode Completed ...


  


• Is 8K video encoding possible on MoviePy or OpenCV for python ?

  10 avril 2020, par Ahabbscience Studio

  just wanted to ask if this is possible. I am trying to make an 8k video, but due to low specs of my computer, I had to do this project on colab. I have some footages that I have upscaled to 8k via ESRGAN, and wanted to encode an 8K video out of them - reason being curiosity. I tried using OpenCV, and MoviePy but it turned out that more RAM was required than available in free tier. However, I also realized that my code wasn't utilitising the GPU/CUDA. Is it possible to implement CUDA in my case, and how can it be done on colab. I am not so fluent in python. Is this even possible with FFMPEG or not, or python as a whole.
Thanks