Recherche avancée

Sur d’autres sites (13679)

• libavcodec/vaapi_decode : fix the problem that init_pool_size nb_surface

  11 janvier 2022, par Wenbin Chen

  libavcodec/vaapi_decode : fix the problem that init_pool_size < nb_surface
  For vaapi if the init_pool_size is not zero, the pool size is fixed.
  
  This means max surfaces is init_pool_size, but when mapping vaapi
  
  frame to qsv frame, the init_pool_size < nb_surface. The cause is that
  
  vaapi_decode_make_config() config the init_pool_size and it is called
  
  twice. The first time is to init frame_context and the second time is to
  
  init codec. On the second time the init_pool_size is changed to original
  
  value so the init_pool_size is lower than the reall size because
  
  pool_size used to initialize frame_context need to plus thread_count and
  
  3 (guarantee 4 base work surfaces). Now add code to make sure
  
  init_pool_size is only set once. Now the following commandline works :
  ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 \
  
   hwaccel_output_format vaapi -i input.264 \
  
   vf "hwmap=derive_device=qsv,format=qsv" \
  
   c:v h264_qsv output.264
  Signed-off-by : Wenbin Chen <wenbin.chen@intel.com>
  

  • [DH] libavcodec/vaapi_decode.c

• how to multi thread with ffmpeg ?

  10 juillet 2018, par priojeet priyom

  I am trying to split, convert and merge an audio. I used writingMinds FFmpeg build for Android. But it is taking to much time for long duration audios.

  To speed it up I tried using the "thread -4" command on a phone having 8 cores but it didn’t improve the performance.

  So then I split the audio into 4 parts (to use 4 threads) and then called FFmpeg.execute() inside separate threads for multithreading. But FFmpeg library processes the files sequentially. Is it possible for ffmpeg to parallelly process these 4 parts in 4 threads ? If so how ?

  UPDATE
  see alex cohn’s answer.
  In this case, it was also because of the calling method of FFmpegExecuteAsyncTask as execute method of Asynctask class only allows one instance to run at a time in modern APIs.
  a workaround was using this checks.

  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { // Android 3.0 to
  
                      // Android 4.3
  
                      // Parallel AsyncTasks are not possible unless using executeOnExecutor
  
                      ffmpegExecuteAsyncTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
  
                  } else { // Below Android 3.0
  
                      // Parallel AsyncTasks are possible, with fixed thread-pool size
  
                      ffmpegExecuteAsyncTask.execute();
  
                  }

• avcodec/h264 : fix stride calculation in slice_table for multi-slice field video deblo...

  24 décembre 2024, par Lingyi Kong

  avcodec/h264 : fix stride calculation in slice_table for multi-slice field video deblocking
  fix for https://trac.ffmpeg.org/ticket/11360
  
  A new fate test case is added to validate the fix, the smaple file is located at https://trac.ffmpeg.org/attachment/ticket/11360/slice2_field_aurora4.264.
  Signed-off-by : Lingyi Kong <konglingyi@visionular.com>
  

  • [DH] libavcodec/h264_mb.c
  • [DH] tests/fate/h264.mak
  • [DH] tests/ref/fate/h264-conformance-slice2_field_aurora4