Recherche avancée

Sur d’autres sites (9937)

• Minimum FFMPEG configure options for H264 decoding

  26 novembre 2019, par Big Guy

  I’m working on a project using an LS1021A board, which has a Cortex-A7, NEON, FPU, etc, which seems to be very similar to a Raspberry Pi 2. We are streaming in H264 via RTP (UDP) with VLC to simulate an IP Camera with the end goal of extracting the raw RGB frame data (in a C app) to be used elsewhere in the system.

  So, I’d like to compile ffmpeg and the associated libs to do only H264 decoding, using libavcodec in C code. This will be running on a custom linux OS with tight size constraints, so lib size needs to be as small as possible.

  I have the following so far after a day or so of googling :

  ./configure --disable-encoders --disable-decoders --enable-decoder=h264 --enable-small --enable-cross-compile --arch-arm --target-os=linux --cpu=cortex-a7 --disable-debug --cross-prefix=${GCC_PREFIX} --prefix=/c/Users/labuser/Desktop/build --extra-cflags='march=armv7-a -mtune=cortex-a7 -mfpu=neon-vfpv4 -mfloat-abi=hard' --enable-neon --disable-devices --disable-sdl --disable-ffprobe --disable-ffserver --disable-doc --disable-w32threads --disable-ffplay

  Since I’ll be using libavcodec directly, I’m not sure if some of these —disable switches are needed, but can anyone give any pointers on if this looks acceptable or if there are any other switches I should be using ?

  Thanks !

• Why does Android kill a process spawned by the developed application ?

  23 octobre 2013, par uprego

  I have a weird problem that I posted as a comment in Understanding Android Tight loops / Spin-On-Suspend error without any useful further comment.

  Let be here the reproduced comment :

  Is it possible for this to be happening also to android native codes, abstracting
  
   which piece of software would be causing it? It's the only reason I know ffmpeg 
  
  (static binary custom compilation, n2.0.1 tag mint as it clones) is failing to me
  
   on some devices and not in others (but fails in no device when launched over a v
  
  algrind!! that, am now supposing, traps frequently the inner program)

  The problem, briefly, is that a compiled ffmpeg n2.0.1 is running OK in emulator and a Sony device, but failing with a segmentation violation in a Samsung device. The program was ran then from valgrind in that Samsung device, with no fail.

  • I have some clues about what could be happening here. But do you know what is happening ?
  • Can this Samsung phone run this ffmpeg compilation the same good the emulator and the Sony phone do ? If not, what are the next steps (trying - when possible - to avoid the use of the NDK) ?

• ffmpeg neighbor resize giving distortion when resizing video game footage. 2x2 pixels converted to 3x3 don't hold their color and are pixelated

  12 avril 2020, par PixelFrustated

  Here is my ffmpeg code :

  



  ffmpeg -i C :\FFMPEG\bin\input.mp4 -vf "scale=-2:1080" -sws_flags neighbor -c:v libx264 -crf 0 -preset Slow -c:a copy -b:a 320k C :\FFMPEG\bin\VIDEO2_1080p.mp4

  



  I'm converting a 720p video to 1080p. The game is 2x2 pixels and when I do the conversion they should be flat 3x3 pixels but instead they come out with slight miscolors on the insides between the pixels and their color is slightly off.

  



  Can anyone help me figure out why this warped ?

  



  Pixels on the left are 2x2 and are converted to the pixels on the right.

  



  Instead of 2x2 expanding out to a 3x3 it takes a weird blend going vertical but the horizontal pixels are just fine.