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• avcodec/hap : add "compressor" option to Hap encoder to disable secondary compression

  8 novembre 2016, par Tom Butterworth

  avcodec/hap : add "compressor" option to Hap encoder to disable secondary compression
  The secondary compression in Hap is optional, this change exposes that option to
  
  the user as some use-cases favour higher bitrate files to reduce workload
  
  decoding.
  
  Adds "none" or "snappy" as options for "compressor". Selecting "none" disregards
  
  "chunks" option : chunking is only of benefit decompressing Snappy.
  Reviewed-by : Martin Vignali <martin.vignali@gmail.com>
  
  Signed-off-by : Tom Butterworth <bangnoise@gmail.com>
  

  • [DH] libavcodec/hap.h
  • [DH] libavcodec/hapenc.c

• Direct Show Video capture performance

  23 mai 2019, par Barry Andrews

  I originally started out looking for an example of how I can use FFMPEG in c++ builder to create an application to record from usb capture device and playback video because of apparrent poor performance

  I tried Mitov components, Datastead, FFMPEGVCL and winsoft camera which use directshow but their capture performance seemed poor.

  I need to capture 1920x1080 at up to 60fps into a compressed format and play this back later at both normal speed and slow speed.

  What I found was that DirectShow itself has a number of limitations which can be improved by adding things like FFMPEG, but ultimately PC hardware, in particular the HDD and processor limit capture capability.

  1920x1080 60fps is basically the upper end for DirectShow so you need to have best performing hardware in order to achieve this sort of performance @Spektre kindly gave me examples of DirectShow using the API direct which were good for comparison with the purchased components.

  Using this and comparing to the components I found that MITOV has a major issue with regards the larger video sizes and frame rates. Using this 1920x108 30fps and 60fps can be previewed but they have a massive delay between video feed and preview (5 or 6 seconds). The other components performed similar to the API direct method with only minor variations in performance. None were able to capture and record 1920x108 60fps with any sort of compression filter without large frame drops and very jerky preview.

• Using ffmpeg create an android playable music slide show

  22 avril 2014, par user2637966

  I am now creating a music slide mp4 video and going to play it in android device with ffmpeg.

  I used the following command to accomplish this mission.

  The first one is to inputting a batch of jpg files and convert it to a mp4 file.

  1.)C:/xampp/htdocs/bin/ffmpeg -y -r 1/5 -i C:/xampp/htdocs/bin/%03d.jpg -c:v libx264 -profile:v baseline -level 3.0 -r 30 -pix_fmt yuv420p C:/xampp/htdocs/bin/out.mp4

  The second one is to putting the audio to the previous created video.

  2.)C:/xampp/htdocs/bin/ffmpeg -i C:/xampp/htdocs/bin/out.mp4 -i C:/xampp/htdocs/upload/1.mp3 -y -map 0 -map 1 -codec copy -shortest C:/xampp/htdocs/bin/haha.mp4"

  Both of the command are correct and created the mp4 file. However only out.mp4 can be played in android deivce while haha.mp4 cannot.

  So it seems the audio track violate the android mp4 requirement. What should the second command be so that i can play the mp4 file in android device.