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• FFmpeg make video from figures and speed up a chosen part

  11 juin 2020, par user13720066

  Make a video from a series of 100 figures

  



  ffmpeg -framerate 10 -i input_figure%01d.png out.mp4


  



  How can I only make figure numbers from [0-49] with a slower speed like -framerate 5 ?

  



  My try is

  



  ffmpeg -start_number 1 -framerate 5 -i input_figure%01d.png -vframes 49 \
-start_number 50 -framerate 10 -i input_figure%01d.png \
out.mp4 


  



  Doesn't work

  


• ffmpeg blured bars on vertical movie - Error while opening encoder

  14 mars 2021, par hexedecimal

  I'm trying to use ffmpeg to prepare a mp4 file which is vertical recorded for upload to youtube.
(on a synology DS220+)
In the output file I want to have no black bars on the side but blured sodebars of the movie itself.
This I'm trying to do whit this code (in the end I want to automate this process, but maybe there is a better way to do this) :

  


  ffmpeg -i input.mp4 -lavfi "[0:v]scale=1920*2:1080*2,boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=1[bg];[0:v]scale=-1:1080[ov];[bg][ov]overlay=(W-w)/2:(H-h)/2,crop=w=1920:h=1080" output.mp4 


  


  unfortunaly i get a error message :

  


  Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height


  


  In mine search on the internet I have tried multiple ways to get this done but whit all the same error result.
This was making me think that the ffmpeg install is faulty or I was trying wrong code.

  


  Could somebody help me whit this "project"

  


  full responce below :

  


  username@ip:/volume1/location$ ffmpeg -i input.mp4 -lavfi "[0:v]scale=1920*2:1080*2,boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=1[bg];[0:v]scale=-1:1080[ov];[bg][ov]overlay=(W-w)/2:(H-h)/2,crop=w=1920:h=1080" output.mp4
ffmpeg version 2.7.7 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.3 (crosstool-NG 1.20.0) 20150311 (prerelease)
  configuration: --prefix=/usr --incdir='${prefix}/include/ffmpeg' --arch=i686 --target-os=linux --cross-prefix=/usr/local/x86_64-pc-linux-gnu/bin/x86_64-pc-linux-gnu- --enable-cross-compile --enable-optimizations --enable-pic --enable-gpl --enable-shared --disable-static --enable-version3 --enable-nonfree --enable-libfaac --enable-encoders --enable-pthreads --disable-bzlib --disable-protocol=rtp --disable-muxer=image2 --disable-muxer=image2pipe --disable-swscale-alpha --disable-ffserver --disable-ffplay --disable-doc --disable-devices --disable-bzlib --disable-altivec --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libmp3lame --disable-vaapi --disable-decoder=amrnb --disable-decoder=ac3 --disable-decoder=ac3_fixed --disable-encoder=zmbv --disable-encoder=dca --disable-encoder=ac3 --disable-encoder=ac3_fixed --disable-encoder=eac3 --disable-decoder=dca --disable-decoder=eac3 --disable-decoder=truehd --disable-decoder=hevc --disable-muxer=hevc --disable-demuxer=hevc --disable-parser=hevc --cc=/usr/local/x86_64-pc-linux-gnu/bin/x86_64-pc-linux-gnu-ccache-gcc --enable-yasm --enable-libx264 --enable-encoder=libx264
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 41.100 / 56. 41.100
  libavformat    56. 36.100 / 56. 36.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 16.101 /  5. 16.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.36.100
  Duration: 00:00:36.12, start: 0.000000, bitrate: 2529 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, smpte170m/bt709/bt709), 406x720 [SAR 405:406 DAR 9:16], 2394 kb/s, 30 fps, 30 tbr, 12k tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
File 'output.mp4' already exists. Overwrite ? [y/N] y
[libx264 @ 0x1cdc4a0] using SAR=81/256
[libx264 @ 0x1cdc4a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
[libx264 @ 0x1cdc4a0] profile High, level 4.0
[libx264 @ 0x1cdc4a0] 264 - core 148 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.36.100
    Stream #0:0: Video: h264 (libx264), yuv420p, 1920x1080 [SAR 81:256 DAR 9:16], q=-1--1, 30 fps, 30 tbn, 30 tbc (default)
    Metadata:
      encoder         : Lavc56.41.100 libx264
    Stream #0:1(und): Audio: aac, 0 channels, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc56.41.100 libfaac
Stream mapping:
  Stream #0:0 (h264) -> scale (graph 0)
  Stream #0:0 (h264) -> scale (graph 0)
  crop (graph 0) -> Stream #0:0 (libx264)
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfaac))
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height


  


• Pipe video frames from ffmpeg to numpy array without loading whole movie into memory

  2 mai 2021, par marcman

  I'm not sure whether what I'm asking is feasible or functional, but I'm experimenting with trying to load frames from a video in an ordered, but "on-demand," fashion.

  


  Basically what I have now is to read the entire uncompressed video into a buffer by piping through stdout, e.g. :

  


  H, W = 1080, 1920 # video dimensions
video = '/path/to/video.mp4' # path to video

# ffmpeg command
command = [ "ffmpeg",
            '-i', video,
            '-pix_fmt', 'rgb24',
            '-f', 'rawvideo',
            'pipe:1' ]

# run ffmpeg and load all frames into numpy array (num_frames, H, W, 3)
pipe = subprocess.run(command, stdout=subprocess.PIPE, bufsize=10**8)
video = np.frombuffer(pipe.stdout, dtype=np.uint8).reshape(-1, H, W, 3)

# or alternatively load individual frames in a loop
nb_img = H*W*3 # H * W * 3 channels * 1-byte/channel
for i in range(0, len(pipe.stdout), nb_img):
    img = np.frombuffer(pipe.stdout, dtype=np.uint8, count=nb_img, offset=i).reshape(H, W, 3)


  


  I'm wondering if it's possible to do this same process, in Python, but without first loading the entire video into memory. In my mind, I'm picturing something like :

  


  

  1. open the a buffer

  


  2. seeking to memory locations on demand

  


  3. loading frames to numpy arrays

  


  


  I know there are other libraries, like OpenCV for example, that enable this same sort of behavior, but I'm wondering :

  


  

  • Is it possible to do this operation efficiently using this sort of ffmpeg-pipe-to-numpy-array operation ?

  


  • Does this defeat the speed-up benefit of ffmpeg directly rather than seeking/loading through OpenCV or first extracting frames and then loading individual files ?