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• diracdec : rewrite HQ slice decoding

  23 juin 2016, par Rostislav Pehlivanov

  diracdec : rewrite HQ slice decoding
  Now coefficients are written to a buffer and are then dequantized by the
  
  new SIMD dequantization functions. For the lower bands without enough
  
  coefficients to fill a register (and hence they overwrite) the C version
  
  of the dequantization function is used.
  The buffer is per-thread and will be realloc’d if anything changes.
  
  This prevents regressions and having to limit slice size.
  Signed-off-by : Rostislav Pehlivanov <rpehlivanov@obe.tv>
  

  • [DH] libavcodec/diracdec.c

• Can I get pictures/stills/photos from inside a container file from a CD-I disc ?

  8 décembre 2017, par user9047197

  I have ffmpeg setup.

  Is there a way to extract pictures/stills/photos (etc) from a container (file) that’s from an old CD-I game that I have.

  I don’t want to extract the audio nor video. And I don’t want frames from the videos either.

  I want the bitmaps (etc) from INSIDE that container file.

  I know my Windows 8.1 PC can’t read inside that container file - so I’m hoping there’s a way to extract all the files (I want) instead using ffmpeg.

  (IsoBuster only gives the audio and video so I know already about IsoBuster.)

  I think there are no individual headers for the pictures/stills/photos, etc.

  Here’s what ExifTool decoded the file as :

  ExifTool Version Number (10.68) 
  
  File Name (green.3t) 
  
  File Size (610 MB) 
  
  File Permissions (rw-rw-rw-) 
  
  File Type (MPEG) 
  
  File Type Extension (mpg) 
  
  MIME Type (video/mpeg) 
  
  MPEG Audio Version (1) 
  
  Audio Layer (2) 
  
  Audio Bitrate (80 kbps) 
  
  Sample Rate (44100) 
  
  Channel Mode (Single Channel) 
  
  Mode Extension (Bands 4-31)
  
  Copyright Flag (False) 
  
  Original Media (False) 
  
  Emphasis (None) 
  
  Image Width (368)
  
  Image Height (272) 
  
  Aspect Ratio (1.0695) 
  
  Frame Rate (25 fps) 
  
  Video Bitrate (1.29 Mbps) 
  
  Duration (1:02:12 approx) 
  
  Image Size (368x272) 
  
  Megapixels (0.100) 

  Thank you for reading and - help !! :D

• FFmpeg iOS -> output file is invalid

  15 juillet 2016, par Vive

  I’m using following library to convert mkv to mp4 : https://github.com/SterlingOnLoop/FFmpegWrapper.

  - (void)convertUsingFFmpegWrapper {
  
      NSString *mp4Extension = @"mp4";
  
      NSString *mkvExtension = @"mkv";
  
  
  
      NSString *videoName = @"file1";
  
  //    NSString *videoName = @"file2";
  
  
  
      NSString *mkvVideoFilePath = [[NSBundle mainBundle] pathForResource:videoName ofType:mkvExtension];
  
      NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  
      NSString *documentsDirectory = paths[0];
  
      NSString *mp4VideoFilePath = [NSString stringWithFormat:@"%@/%@.%@", documentsDirectory, videoName, mp4Extension];
  
  
  
      FFmpegWrapper *ffmpegWrapper = [[FFmpegWrapper alloc] init];
  
      NSDictionary *options = @{kFFmpegInputFormatKey: mkvExtension, kFFmpegOutputFormatKey: mp4Extension};
  
      [ffmpegWrapper convertInputPath:mkvVideoFilePath outputPath:mp4VideoFilePath options:options progressBlock:nil completionBlock:^(BOOL success, NSError *error) {
  
          if (success && !error) {
  
              // delete mp4 file
  
          } else if (error) {
  
              NSLog(@"Error during .MKV -> .MP4 conversion occured: %@", error.localizedDescription);
  
          } else {
  
              NSLog(@"Unknown error during .MKV -> .MP4 conversion occured.");
  
          }
  
      }];
  
  }

  Here are the values from LLDB about the automatically detected codec types :

  (lldb) po inputStream.codecName
  
  aac
  
  
  
  (lldb) po outputStream.codecName
  
  aac

  I should mention here, that originally the file is generated on Linux with following codecs : vaapiencode_h264 for video and faac for sound.

  The issue is that the file simply does not work. I get huge amount of logs in the console, where most important is :

  [aac @ 0x7f7f65019200] Format aac detected only with low score of 1, misdetection possible!

  Inside the library, the following function is used :

  int streamInfoValue = avformat_find_stream_info(inputFormatContext, NULL);

  And exactly this line does the whole mess with the logs. Obviously, without this line I receive an error with invalid argument.

  When that line is turned on, the .mp4 file is generated. It lasts > 5 minutes, while input file is 11 seconds long. It cannot be played using VLC on my mac (seems to be broken). I get following errors (I’m pasting few of them, full track can be found here, it’s too long to quote it here) :

  [aac @ 0x7ff07c00b000] More than one AAC RDB per ADTS frame is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.
  
  [aac @ 0x7ff07c00b000] channel element 0.0 is not allocated
  
  [aac @ 0x7ff07c00b000] Sample rate index in program config element does not match the sample rate index configured by the container.
  
  [aac @ 0x7ff07c00b000] Inconsistent channel configuration.
  
  [aac @ 0x7ff07c00b000] get_buffer() failed
  
  [aac @ 0x7ff07c00b000] channel element 3.10 is not allocated
  
  [aac @ 0x7ff07c00b000] Reserved bit set.
  
  [aac @ 0x7ff07c00b000] invalid band type
  
  [aac @ 0x7ff07c00b000] Number of scalefactor bands in group (50) exceeds limit (41).
  
  [aac @ 0x7ff07c00b000] Reserved bit set.
  
  [aac @ 0x7ff07c00b000] Number of bands (7) exceeds limit (4).
  
  [aac @ 0x7ff07c00b000] Reserved bit set.
  
  [aac @ 0x7ff07c00b000] Dependent coupling is not supported together with LTP

  Any idea how to simply convert mkv to mp4 ? I don’t have any idea why the errors occurs. I’d claim that the file is not aac, but the linux uses this encoding, so it should be valid.