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• How can i implement of video editor on ffmpeg

  13 octobre 2014, par Baek Seung Hoon

  I’m using ffmpeg least version.

  I want to make video editor on Windows or Android Application through NDK..

  Video Editor must be supported to add Text(front or end frame), add transition effects between two clips, add fade-in/out effect..

  So I found some libraries, such as ffmpeg, opencv, mlt framework, kdenlive etc but I don’t know what to choose.

  If I use ffmpeg library on the project, how can I implements this function ??

• Convert audio files to mp3 using ffmpeg

  21 janvier 2017, par Hrishikesh Choudhari

  I need to convert audio files to mp3 using ffmpeg.

  When i write the command as ffmpeg -i audio.ogg -acodec mp3 newfile.mp3, I get the error :

  FFmpeg version 0.5.2, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  
    configuration: 
  
    libavutil     49.15. 0 / 49.15. 0
  
    libavcodec    52.20. 1 / 52.20. 1
  
    libavformat   52.31. 0 / 52.31. 0
  
    libavdevice   52. 1. 0 / 52. 1. 0
  
    built on Jun 24 2010 14:56:20, gcc: 4.4.1
  
  Input #0, mp3, from 'ZHRE.mp3':
  
    Duration: 00:04:12.52, start: 0.000000, bitrate: 208 kb/s
  
      Stream #0.0: Audio: mp3, 44100 Hz, stereo, s16, 256 kb/s
  
  Output #0, mp3, to 'audio.mp3':
  
      Stream #0.0: Audio: 0x0000, 44100 Hz, stereo, s16, 64 kb/s
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Unsupported codec for output stream #0.0

  I also ran this command :

   ffmpeg -formats | grep mp3

  and got this in response :

  FFmpeg version 0.5.2, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  
    configuration: 
  
    libavutil     49.15. 0 / 49.15. 0
  
    libavcodec    52.20. 1 / 52.20. 1
  
    libavformat   52.31. 0 / 52.31. 0
  
    libavdevice   52. 1. 0 / 52. 1. 0
  
    built on Jun 24 2010 14:56:20, gcc: 4.4.1
  
   DE mp3             MPEG audio layer 3
  
   D A    mp3             MP3 (MPEG audio layer 3)
  
   D A    mp3adu          ADU (Application Data Unit) MP3 (MPEG audio layer 3)
  
   D A    mp3on4          MP3onMP4
  
   text2movsub remove_extra noise mov2textsub mp3decomp mp3comp mjpegadump imxdump h264_mp4toannexb dump_extra

  I guess that the mp3 codec isnt installed. Am I right here ? Can anyone help me out here ?

• Zlib vs. XZ on 2SF

  21 juillet 2012, par Multimedia Mike — General, psf, saltygme, xz, zlib

  I recently released my Game Music Appreciation website. It allows users to play an enormous range of video game music directly in their browsers. To do this, the site has to host the music. And since I’m a compression bore, I have to know how small I can practically make these music files. I already published the results of my effort to see if XZ could beat RAR (RAR won, but only slightly, and I still went with XZ for the project) on the corpus of Super Nintendo chiptune sets. Next is the corpus of Nintendo DS chiptunes.

  Repacking Nintendo DS 2SF
  The prevailing chiptune format for storing Nintendo DS songs is the .2sf format. This is a subtype of the Portable Sound Format (PSF). The designers had the foresight to build compression directly into the format. Much of payload data in a PSF file is compressed with zlib. Since I already incorporated Embedded XZ into the player project, I decided to try repacking the PSF payload data from zlib -> xz.

  In an effort to not corrupt standards too much, I changed the ’PSF’ file signature (seen in the first 3 bytes of a file) to ’psf’.

  Results
  There are about 900 Nintendo DS games currently represented in my website’s archive. Total size of the original PSF archive, payloads packed with zlib : 2.992 GB. Total size of the same archive with payloads packed as xz : 2.059 GB.

  Using xz vs. zlib saved me nearly a gigabyte of storage. That extra storage doesn’t really impact my hosting plan very much (I have 1/2 TB, which is why I’m so nonchalant about hosting the massive MPlayer Samples Archive). However, smaller individual files translates to a better user experience since the files are faster to download.

  Here is a pretty picture to illustrate the space savings :

  
  
  

  The blue occasionally appears to dip below the orange but the data indicates that xz is always more efficient than zlib. Here’s the raw data (comes in vanilla CSV flavor too).

  Interface Impact
  So the good news for the end user is that the songs are faster to load up front. The downside is that there can be a noticeable delay when changing tracks. Even though all songs are packaged into one file for download, and the entire file is downloaded before playback begins, each song is individually compressed. Thus, changing tracks triggers another decompression operation. I’m toying the possibility of some sort of background process that decompresses song (n+1) while playing song (n) in order to help compensate for this.

  I don’t like the idea of decompressing everything up front because A) it would take even longer to start playing ; and B) it would take a huge amount of memory.

  Corner Case
  There was at least one case in which I found zlib to be better than xz. It looks like zlib’s minimum block size is smaller than xz’s. I think I discovered xz to be unable to compress a few bytes to a block any smaller than about 60-64 bytes while zlib got it down into the teens. However, in those cases, it was more efficient to just leave the data uncompressed anyway.