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• vulkan_hevc : handle non-contiguous SPS/PPS/VPS ids

  30 septembre 2023, par Benjamin Cheng

  vulkan_hevc : handle non-contiguous SPS/PPS/VPS ids
  Some clips (i.e. SLIST_B_Sony_9) will use PPS 0 and 8, before PPS 1-7.
  
  vulkan_hevc expects sps,pps,vps_list to be filled in order, which
  
  causes PPS 8 to not be added to the Vulkan session params when it is
  
  being used by a picture.
  This removes the expectation that these lists are filled in order. The
  
  indicies into vps_list are saved since there are multiple usages of it.
  This also fixes a bug with some clips (i.e. PPS_A_qualcomm_7) which use
  
  all 64 available PPS slots, causing the old loop to think there are more
  
  than 64 PPS-es.
  

  • [DH] libavcodec/vulkan_hevc.c

• How to increase video encoding speed in ffmpeg ?

  16 octobre 2017, par Ashutosh Tiwari

  I am recording video clips and then joining all the clips in a final video.
  Everything goes fine but the joining process takes too long.

  Tried to using some ffmpeg filters from here :
  https://trac.ffmpeg.org/wiki/Encode/H.264

  And here is my ffmpeg command that I am using to increase the speed (which seems to be wrong) :

  command = new String[]{"-y",
  
                  "-f",
  
                  "concat",
  
                  "-safe",
  
                  "0",
  
                  "-i",
  
                  "/storage/emulated/0/DCIM/my_file.txt",
  
                  "-c:v",
  
                  "-preset",
  
                  "fast",
  
                  "-crf",
  
                  "22",
  
                  "copy",
  
                  "-flags",
  
                  "+global_header",
  
                  "/storage/emulated/0/DCIM/SampleApp/" + videoOutputPath
  
          };

  Please help ! Thanks much.

• FFMPEG with moviepy

  5 novembre 2023, par Shenhav Mor

  I'm working on something that concatenate videos and adds some titles on through moviepy.

  


  As I saw on the web and on my on pc moviepy works on the CPU and takes a lot of time to save(render) a movie. Is there a way to improve the speed by running the writing of moviepy on GPU ? Like using FFmpeg or something like this ?

  


  I didn't find an answer to that on the web, so I hope that some of you can help me.
I tried using thread=4 and thread=16 but they are still very very slow and didn't change much.

  


  My CPU is very strong (i7 10700k), but still, rendering on moviepy takes me for a compilation with a total of 8 minutes 40 seconds, which is a lot.

  


  Any ideas ?Thanks !
the code doesnt realy matter but :

  


  def Edit_Clips(self):

    clips = []

    time=0.0
    for i,filename in enumerate(os.listdir(self.path)):
        if filename.endswith(".mp4"):
            tempVideo=VideoFileClip(self.path + "\\" + filename)

            txt = TextClip(txt=self.arrNames[i], font='Amiri-regular',
                           color='white', fontsize=70)
            txt_col = txt.on_color(size=(tempVideo.w + txt.w, txt.h - 10),
                                   color=(0, 0, 0), pos=(6, 'center'), col_opacity=0.6)

            w, h = moviesize = tempVideo.size
            txt_mov = txt_col.set_pos(lambda t: (max(w / 30, int(w - 0.5 * w * t)),
                                                 max(5 * h / 6, int(100 * t))))

            sub=txt_mov.subclip(time,time+4)
            time = time + tempVideo.duration

            final=CompositeVideoClip([tempVideo,sub])

            clips.append(final)

    video = concatenate_videoclips(clips, method='compose')
    print("after")
    video.write_videofile(self.targetPath+"\\"+'test.mp4',threads=16,audio_fps=44100,codec = 'libx264')