Recherche avancée

Sur d’autres sites (4888)

• avcodec/pnm : Check magic bytes directly without pnm_get()

  1er août 2019, par Michael Niedermayer

  avcodec/pnm : Check magic bytes directly without pnm_get()
  Fixes : Timeout (10sec -> 30ms) (case 15089)
  
  Fixes : 15089/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PBM_fuzzer-5767535057698816
  
  Fixes : 16001/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGM_fuzzer-5199169645445120
  
  Fixes : 16003/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGMYUV_fuzzer-5076443270217728
  Found-by : continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/pnm.c

• Eliminate slow speed factor in ffmpeg and image-magic commands

  24 octobre 2018, par Junaid Farooq

  The basic idea of these commands is to create a compare, (A compare has defined a jpeg from past and one from the present, combine such as they will slide on each other and show before after images.)

  e.g. https://media.evercam.io/v1/cameras/1lowe-scnoe/compares/lower-jreyh.gif

  All the commands are written below, doing these operations

  • Resize before after image.
  • create a Gif using both images.
  • Add a log to Gif.
  • Create an MP4 file of from GIF.
  • Create a thumbnail from mp4 file.

  the logo is :

  

  we are making animation and mp4 files using FFmpeg and ImageMagick commands such as

  ffmpeg -i before_image.jpg -s 1280x720 before_image_resize.jpg
  
  
  
  ffmpeg -i after_image.jpg -s 1280x720 after_image_resize.jpg

  The above commands are first to resize both images which are going to be used in animation.

  This command is being used for creating a gif.

  convert after_image_resize.jpg before_image_resize.jpg -write mpr:stack -delete 0--1 mpr:stack'[1]' \\( mpr:stack'[0]' -set delay 25 -crop 15x0 -reverse \\) mpr:stack'[0]' \\( mpr:stack'[1]' -set delay 27 -crop 15x0 \\) -set delay 2 -loop 0 temp.gif

  This command to add a logo to the animation.

  convert temp.gif -gravity SouthEast -geometry +15+15 null: evercam-logo.png -layers Composite compa-efxfphu.gif

  Then to create an mp4 file as

  ffmpeg -f gif -i compa-efxfphu.gif -pix_fmt yuv420p -c:v h264_nvenc -movflags +faststart -filter:v crop='floor(in_w/2)*2:floor(in_h/2)*2' compa-efxfphu.mp4

  then to create a thumbnail from this mp4.

  ffmpeg -i compa-efxfphu.mp4 -vframes 1 -vf scale=640:-1 -y thumb-compa-efxfphu.jpg

  Is there any possibility to reduce any of these steps ? This all takes a lot of time, I am merely interested in both convert commands, can we make them into one command ?

  Or do you see any chance to reduce these all 4 in one ? any input will be so thankful.

• Definitive join MP3's in ffmpeg or avconv - whats the magic line of code ?

  10 février 2016, par pperrin

  I have some MP3’s they need to be concatenated in to a single MP3.

  What is the command line I need for FFMPEG or AVCONV to do this ?

  I don’t know or care about the quality/bit-rate etc of the inputs, I have what I have and they are random.

  I have hunted far and wide and found loads of people who like to talk about pages of useless detail that makes absolutely no difference to me...

  So...

  I have been using :

  ffmpeg -i "concat:file1.mp3|file2.mp3" -b:a:320000 -acodec file3.mp3

  The output sounds fine, but the output file often shows the duration and bitrate wrong on the output... what is the magic line of code I seek ?

  I am in no hurry - and can run the files through a dozen other processes if needed, and if quality goes down I really really don’t care - I just want a fully functional MP3 at the end of it.