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• Add support for playing Audible AAXC (.aaxc) files [PATCH v4]

  1er janvier 2000, par Vesselin Bontchev

  Add support for playing Audible AAXC (.aaxc) files [PATCH v4]
  The AAXC container format is the same as the (already supported) Audible
  
  AAX format but it uses a different encryption scheme.
  Note : audible_key and audible_iv values are variable (per file) and are
  
  externally fed.
  It is possible to extend https://github.com/mkb79/Audible to derive the
  
  audible_key and audible_key values.
  Relevant code :
  def decrypt_voucher(deviceSerialNumber, customerId, deviceType, asin, voucher) :
  
      buf = (deviceType + deviceSerialNumber + customerId + asin).encode("ascii")
  
      digest = hashlib.sha256(buf).digest()
  
      key = digest[0:16]
  
      iv = digest[16 :]
      # decrypt "voucher" using AES in CBC mode with no padding
  
      cipher = AES.new(key, AES.MODE_CBC, iv)
  
      plaintext = cipher.decrypt(voucher).rstrip(b"\x00")  # improve this !
  
      return json.loads(plaintext)
  The decrypted "voucher" has the required audible_key and audible_iv
  
  values.
  Update (Nov-2020) : This patch has now been tested by multiple folks -
  
  details at the following URL :
  https://github.com/mkb79/Audible/issues/3
  Signed-off-by : Vesselin Bontchev <vesselin.bontchev@yandex.com>
  

  • [DH] libavformat/isom.h
  • [DH] libavformat/mov.c

• Android ffmpeg Command not executing

  22 juin 2020, par MoTahir

  I am using this FFMPEG library,

  


  first I am playing the video inside my videoView to make sure that the video path is correct

  


  videoView.setVideoURI(Uri.parse(getExternalFilesDir(null)?.absolutePath + "videoToBeEdit"))


  


  then I am calling the code written below to crop the video then put it inside the videoView again just to see the result

  


  val ff = FFmpeg.getInstance(this@EditVideoActivity)
if (ff.isSupported){

  val inFile = File(getExternalFilesDir(null)?.absolutePath ,"videoToBeEdit")
  val outFile = File(getExternalFilesDir(null)?.absolutePath , "result")

  val command = arrayOf("ffmpeg","-i", inFile.absolutePath , "-filter:v", "crop=100:100:0:0", outFile.absolutePath)

  ff.execute(command, object : ExecuteBinaryResponseHandler() {
    override fun onSuccess(message: String?) {
      super.onSuccess(message)
      videoView.setVideoURI(Uri.parse(getExternalFilesDir(null)?.absolutePath + "videoToBeEdit"))
    }

    override fun onProgress(message: String?) {
      super.onProgress(message)
    }

    override fun onFailure(message: String?) {
      super.onFailure(message)
      Log.e("error", "failed")
    }

    override fun onStart() {
      super.onStart()
      Log.e("start", "started the process")
    }

    override fun onFinish() {
      super.onFinish()
      Log.e("finish", "done")
    }
  })
}


  


  but my code above goes from start to error then finish, it doesn't show any error messages and that's making it really hard to know what's actually wrong :( I tried to write my command in different ways following those tutorials tutorial1 tutorial2 link
please help, thank you in advance...

  


• Ffmpeg inaccurate cutting with ts and m3u8 files despite resamping audio filter

  31 juillet 2020, par Lemon Sky

  I need to accurately seek and cut a video. Some online sources say put -ss in front or after the source. The result is the same for me. In the examples below, the start time is accurate but the duration is not accurate.

  


  ffmpeg -y -ss 00:00:05 -t 00:00:05 -i output.ts 5s.wav
ffprobe 5s.wav

Duration: 00:00:04.74

ffmpeg -y -i output.ts -ss 00:00:05 -t 00:00:05 5s.wav
ffprobe 5s.wav

Duration: 00:00:04.74


  


  Sometimes the starting point is not accurate but the duration is. This is clearly audible by cutting the ts file and cutting an uncompressed wav file, and listening to both.

  


  ffmpeg -y -i output.ts -ss 00:00:15 -t 00:00:05 5s.wav

ffmpeg -y -i output.wav -ss 00:00:15 -t 00:00:05 5s-reference.wav


  


  What fixes the starting time is if I use an m3u8 file that contains the byte offset for every keyframe AND I put the -ss option in front of the source file (if I put it after the source, the start time is inaccurate but the duration is accurate) :

  


  ffmpeg -y -ss 00:00:15 -t 00:00:05 -i output.m3u8 5s.wav


  


  This fixes the start time but the duration is at the location that I would get had I used no m3u8 file (duration is just 4.47s).

  


  It seems different timestamps are involved, and sometimes one or the other gets used.

  


  The ts file was generated by capturing a UDP stream and storing it with ffmpeg and -codec:v copy.

  


  Is ffmpeg broken, or the ts file ? How do I work around this issue or fix the ts file ? What I realize is that the video starts later than the audio, probably because the video does not start with a keyframe. Can I get ffmpeg to start the -codec:v copy after the first keyframe ? What I also notice is that using ffprobe reports "start : 1.400000". Can I force it to start at 0 ?

  


  Any hints would be appreciated.

  


  I tried both ffmpeg 4.3.1 and ffmpeg git-2020-07-24-21442a8.

  


  The output.* files were generated as follows. The statement "af aresample=async=1" should fill missing audio according to Duration of source video and subtracted audio are different. Adding this statement makes no difference in terms of accuracy or duration. The question is not a duplicate.

  


  ffmpeg -i udp://example:port ^
-af aresample=async=1 ^
-codec:v copy ^
-codec:a aac -ac 2 -ar 44100 -b:a 160k ^
-hls_time 4 -hls_flags single_file -hls_list_size 0 -hls_segment_filename output.ts -hls_segment_type mpegts output.m3u8 ^
-codec:a pcm_s16le -bitexact -ar 11025 -ac 1 output.wav