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• Convert png to mp4

  9 septembre 2018, par user3073118

  I have a lot of png files that I want to convert to mp4 in R.

  I used to convert it to .gif using ImageMagick, then converting it using a free online website from .gif to MP4.

  library(magick)
  
  system(command = "convert -delay 70 '/Users/Desktop/figures/*.png' '/Users/Desktop/figures/animation.gif'")

  But the current file size is too big, such that even converting it to .gif takes hours.

  Is there a way I can convert it directly from png to mp4 in R ?

  I tried to look up ffmpeg but I have a MAC and installing it is a little confusing...

  Thanks !

• Background transparency lost on new machine using matplotlib and ffmpeg

  23 octobre 2023, par Jan Turowski

  I am creating animated physics graphs with a transparent background for later use in a NLE. On my old machine at work they display and render with background transparency just fine. The exact same code however loses background transparency in the ffmpeg render on both my Linux and my Windows machine at home. The animations are displayed just fine on all machines.

  


  As I first thought it was a Linux issue, I tried to run the code on my Windows machine expecting it to work again. Unfortunately it did not.

  


  Reduced code :

  


  import numpy as np
import matplotlib.pylab as plt
from matplotlib.animation import FuncAnimation
import matplotlib.animation as animation
from matplotlib.pyplot import figure
from matplotlib import style
import locale
from matplotlib.ticker import (MultipleLocator, AutoMinorLocator)
# Set to German locale to get comma decimal separater
locale.setlocale(locale.LC_NUMERIC, "de_DE")
# Tell matplotlib to use the locale we set above
plt.rcParams['axes.formatter.use_locale'] = True

# plt.clf()
# plt.rcdefaults()

# Style und Font definieren

style.use('dark_background')

# Pfeile erstellen
def arrowed_spines(fig, ax):

    xmin, xmax = ax.get_xlim()
    ymin, ymax = ax.get_ylim()

    # removing the default axis on all sides:
    for side in ['bottom','right','top','left']:
        ax.spines[side].set_visible(False)

    # removing the axis ticks
    # plt.xticks([]) # labels
    # plt.yticks([])
    # ax.xaxis.set_ticks_position('none') # tick markers
    # ax.yaxis.set_ticks_position('none')

    # get width and height of axes object to compute
    # matching arrowhead length and width
    dps = fig.dpi_scale_trans.inverted()
    bbox = ax.get_window_extent().transformed(dps)
    width, height = bbox.width, bbox.height

    # manual arrowhead width and length
    hw = 1./20.*(ymax-ymin)
    hl = 1./20.*(xmax-xmin)
    lw = 1. # axis line width
    ohg = 0.3 # arrow overhang

    # compute matching arrowhead length and width
    yhw = hw/(ymax-ymin)*(xmax-xmin)* height/width
    yhl = hl/(xmax-xmin)*(ymax-ymin)* width/height

    # draw x and y axis
    ax.arrow(xmin, 0, xmax-xmin, 0., fc='w', ec='w', lw = lw,
             head_width=hw, head_length=hl, overhang = ohg,
             length_includes_head= True, clip_on = False)

    ax.arrow(0, ymin, 0., ymax-ymin, fc='w', ec='w', lw = lw,
             head_width=yhw, head_length=yhl, overhang = ohg,
             length_includes_head= True, clip_on = False)

# Meine easing-Funktion
def ease(n):
    if n < 0.0:
        return 0
    elif n > 1.0:
        return 1
    else:
        return 3*n**2-2*n**3

# Meine Floor/Warte Funktion
def wait(n):
    if n < 0.0:
        return 0
    else:
        return n

# Canvas erstellen
fig = plt.figure()
ax = fig.add_subplot(111)
fig.set_size_inches([8,9])

def f(x):
    return -0.05*x**2+125
xlin = np.linspace(0,60,100)


# Beschriftung und Optik

plt.xlabel(r"$x$ in $\rm{m}$", horizontalalignment='right', x=1.0)
plt.ylabel(r"$y$ in $\rm{m}$", horizontalalignment='right', y=1.0)
ax.set_xlim(0,100)
ax.set_ylim(0,139)
plt.grid(alpha=.4)
plt.xticks(np.arange(0, 100, 20))
plt.yticks(np.arange(0, 140, 20))
ax.yaxis.set_minor_locator(MultipleLocator(10))
ax.xaxis.set_minor_locator(MultipleLocator(10))
ax.tick_params(axis='x', direction = "inout", length= 10.0, which='both', width=3)
ax.tick_params(axis='y', direction = "inout", length= 10.0, which='both', width=3)


xsub = np.array([0])

# statische Linien definieren
line2, = ax.plot(xsub,f(xsub),linewidth=5,zorder=0,c = 'b')
arrowed_spines(fig, ax)
plt.tight_layout()

# Linien animieren
def animate(i):

    xsub = xlin[0:wait(i-20)]
    global line2
    line2.remove()
    line2, = ax.plot(xsub, f(xsub), linewidth=5, zorder=0,c = "b")
    plt.tight_layout()

animation = FuncAnimation(fig, animate, np.arange(0, 130, 1), interval=100)

plt.show()

# animation.save(r"YOUR\PATH\HERE\reduced_x-y.mov", codec="png",
         dpi=100, bitrate=-1,
         savefig_kwargs={'transparent': True, 'facecolor': 'none'})



  


• ffmpeg drops time delay on last frame of animated GIF

  13 août 2014, par Austin

  I am trying to convert animated GIFs to MP4 files using ffmpeg and x264. However, I seem be suffering from the effects of this bug in ffmpeg that causes the delay time of the last frame of the GIF to be ignored. For very short GIFs, this is quite a problem.

  As a work around, I was thinking that I should be able to manually tell ffmpeg to freeze on the last frame for a certain amount of time, specifically the proper duration of that frame (which I can extract from the GIF). However, I can’t seem to find a good way to do this. Any suggestions ? I would really like to be able to do this without having to split to the GIF into frames before putting it into ffmpeg since that will mess up GIFs with a non-constant framerate (in addition to being much slower).

  I am using ffmpeg version 2.3, though I have also tried this with the latest git code without any improvement. The full ffmpeg commands I’m using look like this :

  ffmpeg -i animation.gif -vf "scale=trunc(in_w/2)*2:trunc(in_h/2)*2" -c:v libx264 -b:v 2000k -y -pix_fmt yuv420p -f mp4 animation.mp4

  Here is some console output :

  ffmpeg version 2.3 Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Aug 11 2014 21:19:46 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --enable-gpl --enable-libass --enable-libfreetype --enable-libtheora --enable-libvorbis --enable-libx264
  
    libavutil      52. 92.100 / 52. 92.100
  
    libavcodec     55. 69.100 / 55. 69.100
  
    libavformat    55. 48.100 / 55. 48.100
  
    libavdevice    55. 13.102 / 55. 13.102
  
    libavfilter     4. 11.100 /  4. 11.100
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 19.100 /  0. 19.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, gif, from 'animation.gif':
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: gif, bgra, 500x375, 100 tbr, 100 tbn, 100 tbc
  
  [libx264 @ 0x239ea00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x239ea00] profile High, level 3.1
  
  [libx264 @ 0x239ea00] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=6 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=abr mbtree=1 bitrate=2000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to 'animation.mp4':
  
    Metadata:
  
      encoder         : Lavf55.48.100
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 500x374, q=-1--1, 2000 kb/s, 100 fps, 12800 tbn, 100 tbc
  
      Metadata:
  
        encoder         : Lavc55.69.100 libx264
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (gif (native) -> h264 (libx264))
  
  Press [q] to stop, [?] for help
  
  frame=    7 fps=0.0 q=-1.0 Lsize=       7kB time=00:00:00.05 bitrate=1222.1kbits/s dup=5 drop=0    
  
  video:7kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 13.542441%
  
  [libx264 @ 0x239ea00] frame I:1     Avg QP:34.86  size:  3657
  
  [libx264 @ 0x239ea00] frame P:3     Avg QP:30.86  size:   744
  
  [libx264 @ 0x239ea00] frame B:3     Avg QP:33.33  size:    49
  
  [libx264 @ 0x239ea00] consecutive B-frames: 42.9%  0.0%  0.0% 57.1%
  
  [libx264 @ 0x239ea00] mb I  I16..4: 10.2% 78.3% 11.6%
  
  [libx264 @ 0x239ea00] mb P  I16..4:  1.2%  5.0%  0.8%  P16..4: 11.7%  3.3%  1.2%  0.0%  0.0%    skip:76.8%
  
  [libx264 @ 0x239ea00] mb B  I16..4:  0.0%  0.1%  0.0%  B16..8:  3.7%  0.0%  0.0%  direct: 0.0%  skip:96.2%  L0:23.5% L1:76.5% BI: 0.0%
  
  [libx264 @ 0x239ea00] final ratefactor: 20.31
  
  [libx264 @ 0x239ea00] 8x8 transform intra:77.0% inter:79.4%
  
  [libx264 @ 0x239ea00] coded y,uvDC,uvAC intra: 39.5% 0.0% 0.0% inter: 2.7% 0.0% 0.0%
  
  [libx264 @ 0x239ea00] i16 v,h,dc,p: 38% 27%  7% 28%
  
  [libx264 @ 0x239ea00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 35% 12% 13%  7%  6% 10%  4%  8%  5%
  
  [libx264 @ 0x239ea00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 38% 11% 14%  5%  8% 10%  5%  7%  2%
  
  [libx264 @ 0x239ea00] i8c dc,h,v,p: 100%  0%  0%  0%
  
  [libx264 @ 0x239ea00] Weighted P-Frames: Y:0.0% UV:0.0%
  
  [libx264 @ 0x239ea00] ref P L0: 99.1%  0.7%  0.3%
  
  [libx264 @ 0x239ea00] ref B L0: 85.0% 15.0%
  
  [libx264 @ 0x239ea00] ref B L1: 95.4%  4.6%
  
  [libx264 @ 0x239ea00] kb/s:689.83