Recherche avancée

Sur d’autres sites (4894)

• I have created a commandlist but when I run ffmpeg() it says not defined. Does the ffmpeg() needs the commandlist nested or am I missing something ?

  5 septembre 2022, par jiraiya_sensei

  #/ I have ommited the first half of the code/

  


  def buildFFmpeg():
        commandlist = [
            "ffmpeg",
            "-i",
            inputdic[1],
            "-c:v",
            inputdic[4],
            "-preset",
            inputdic[3],
            "-crf",
            inputdic[2],
            "-q:v",
            inputdic[6],
            "-c:a",
            inputdic[5],
            "-b:a",
            inputdic[7],
            "output.mkv"        
            ]
    
    return commandlist
    
    def runFFmpeg(commandlist):

            print(commandlist)               

            if subprocess.run(commandlist).returncode == 0:

                    print ("FFmpeg Script Ran Successfully")

            else:
                    print ("There was an error running your FFmpeg script")
                    
                
    print('Press 1 to start to encoding or 2 to stop this process')

    start = input('Press to start: ')

    x = int(start)

    if x == 1:
        runFFmpeg(buildFFmpeg())

    else:
         exit()


  


  so with the changes of runFFmpeg() — runFFmpeg(buildFFmpeg()) in line 58 and def runFFmpeg() : — def runFFmpeg(commandlist) : in line45 the code runs successfully. But I would like to understand as to how defining the def runFFmpeg(commandlist) : and executing runFFmpeg(buildFFmpeg()) makes the code work.

  


• FFmpeg encoding to H265

  17 février 2016, par Some1Else

  I read that the new H265 is supposed to have around twice the compression efficiency of H264 and supposed files around half the size http://x265.org/hevc-h265/ All of my results trying to encode to H265 give me larger files than H264 from the same source.

  For H264 I am passing these switches to ffmpeg command line

  -c:v libx264 -preset:v veryslow -profile:v high -crf 15 -pix_fmt yuvj420p -an -y -r 30

  For H265 I am using these switches

  -c:v libx265 -preset:v veryslow -crf 15 -an -y -r 30

  In all tests using a variety of different source frames the H265 always results in a larger file size (and is also much much slower to encode).

  Any tips for H265 ? I want the H265 to look like the same quality as H264 but not result in larger files.

  Thanks.

• Add PNG image overlay to video starting with non-key frame

  8 mai 2020, par RamRick

  Alright, so I'm trying to edit a bunch of short to very long videos.
The goal is to mute a 1 minute part within each video and overlay that small part with a PNG image for the full duration.

  



  Because this all has to be done as fast as possible, I figured it would be the best idea to split every video into 3 parts, then mute and add the overlay to part #2 and put all 3 parts back together.

  



  The first problem I ran into was that part #2 and #3 always started with a 1-2 second freeze in video, while the audio was fine.

  



  I found out that this was caused by me cutting at key frames and ignoring non-key frames at the beginning.

  



  I fixed that by adding the -copyinkf parameter to also copy all non-key frames, like so :

  



  ffmpeg -i "in.mp4" \
-to 0:04:00 -c:v copy -c:a copy -copyinkf "p1.mp4" \
-ss 0:04:00 -to 0:05:00 -c:v copy -c:a copy -copyinkf "p2.mp4" \
-ss 0:05:00 -c:v copy -c:a copy -copyinkf "p3.mp4"


  



  So I went on and proceeded to mute part #2, like so :

  



  ffmpeg -i "p2.mp4" -af "volume=0" -c:v copy -copyinkf "p2_muted.mp4"


  



  All fine until this point, and IF I put the parts back together right now it would also be quick and accurate, like so :

  



  --parts.txt
file 'p1.mp4'
file 'p2_muted.mp4'
file 'p3.mp4'

ffmpeg -f concat -safe 0 -i parts.txt -c copy "out.mp4"


  



  But now comes the problem :

  



  Since I have to re-encode part #2 to overlay the PNG image, I get the 1-2 seconds freeze frame problem at the beginning again and I can't for the life of me figure out the "equivalent" of -copyinkf for re-encoding a video.

  



  Right now I'm overlaying the PNG image like so :

  



  ffmpeg -i "p2_muted.mp4" -i "../banner.png" -filter_complex "[1][0]scale2ref[i][v];[v][i]overlay" -c:a copy "p2_edited.mp4"


  



  So my question is, what would the equivalent to -copyinkf be, or in case there is a better way than mine, what would that be to achieve my task.