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• Revision 256cf7ee7d : Correct ssse3 8/16-pixel wide sub-pixel filter calculation Although no mismatch

  20 novembre 2013, par Yunqing Wang

  Changed Paths :
   Modify /vp9/common/x86/vp9_subpixel_8t_ssse3.asm

  
  
  Correct ssse3 8/16-pixel wide sub-pixel filter calculation

  Although no mismatch was indicated for 8/16 wide sub-pixel filters
  in issue 661, they had similar problems that could cause mismatch
  potentially. This patch fixed calculations in HORIZx8/16
  and VERTx8/16.

  Change-Id : I169961c9d40a20340995b7d22aafc89ccf30bfca

• Play a Video from MemoryStream, Using FFMpeg

  7 juin 2014, par Delphi.Boy

  I’m having a hard time, searching how to play a video file from a TMemoryStream (or a similar buffer in memory) using FFMpeg. I’ve seen many things, including UltraStarDX, expensive FFMpeg components for Delphi and so on.

  One component called FFMpeg Vcl Player claims to play video formats from a memory stream. I downloaded the trial version and I guess it uses CircularBuffer.pas for that matter (maybe).

  Does any one know how to do this ?

  Edit :
  Now the better question is how to play an encrypted video file, using FFMpeg or similar libraries.

• Image to MPEG on Linux works, same code on Android = green video

  27 novembre 2014, par JScoobyCed

  EDIT
  I have check the execution and found that the error is not (yet) at the swscale point. My current issue is that the JPG image is not found :
  No such file or directory
  when doing the avformat_open_input(&pFormatCtx, imageFileName, NULL, NULL);
  Before you tell me I need to register anything, I can tell I already did (I updated the code below).
  I also added the Android permission to access the external storage (I don’t think it is related to Android since I can already write to the /mnt/sdcard/ where the image is also located)
  END EDIT

  I have been through several tutorials (including the few posted from SO, i.e. http://dranger.com/ffmpeg/, how to compile ffmpeg for Android...,been through dolphin-player source code). Here is what I have :
  . Compiled ffmpeg for android
  . Ran basic tutorials using NDK to create a dummy video on my android device
  . been able to generate a MPEG2 video from images on Ubuntu using a modified version of dummy video code above and a lot of Googling
  . running the new code on Android device gives a green screen video (duration 1 sec whatever the number of frames I encode)

  I saw another post about iPhone in a similar situation that mentioned the ARM processor optimization could be the culprit. I tried a few ldextra-flags (-arch armv7-a and similar) to no success.

  I include at the end the code that loads the image. Is there something different to do on Android than on linux ? Is my ffmpeg build not correct for Android video encoding ?

  void copyFrame(AVCodecContext *destContext, AVFrame* dest,
  
              AVCodecContext *srcContext, AVFrame* source) {
  
  struct SwsContext *swsContext;
  
  swsContext = sws_getContext(srcContext->width, srcContext->height, srcContext->pix_fmt,
  
                  destContext->width, destContext->height, destContext->pix_fmt,
  
                  SWS_FAST_BILINEAR, NULL, NULL, NULL);
  
  sws_scale(swsContext, source->data, source->linesize, 0, srcContext->height, dest->data, dest->linesize);
  
  sws_freeContext(swsContext);
  
  }
  
  
  
  int loadFromFile(const char* imageFileName, AVFrame* realPicture, AVCodecContext* videoContext) {
  
  AVFormatContext *pFormatCtx = NULL;
  
  avcodec_register_all();
  
  av_register_all();
  
  
  
  int ret = avformat_open_input(&pFormatCtx, imageFileName, NULL, NULL);
  
  if (ret != 0) {
  
      // ERROR hapening here
  
      // Can't open image file. Use strerror(AVERROR(ret))) for details
  
      return ERR_CANNOT_OPEN_IMAGE;
  
  }
  
  
  
  AVCodecContext *pCodecCtx;
  
  
  
  pCodecCtx = pFormatCtx->streams[0]->codec;
  
  pCodecCtx->width = W_VIDEO;
  
  pCodecCtx->height = H_VIDEO;
  
  pCodecCtx->pix_fmt = PIX_FMT_YUV420P;
  
  
  
  // Find the decoder for the video stream
  
  AVCodec *pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
  
  if (!pCodec) {
  
      // Codec not found
  
      return ERR_CODEC_NOT_FOUND;
  
  }
  
  
  
  // Open codec
  
  if (avcodec_open(pCodecCtx, pCodec) < 0) {
  
      // Could not open codec
  
      return ERR_CANNOT_OPEN_CODEC;
  
  }
  
  
  
  // 
  
  AVFrame *pFrame;
  
  
  
  pFrame = avcodec_alloc_frame();
  
  
  
  if (!pFrame) {
  
      // Can't allocate memory for AVFrame
  
      return ERR_CANNOT_ALLOC_MEM;
  
  }
  
  
  
  int frameFinished;
  
  int numBytes;
  
  
  
  // Determine required buffer size and allocate buffer
  
  numBytes = avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
  
  uint8_t *buffer = (uint8_t *) av_malloc(numBytes * sizeof (uint8_t));
  
  
  
  avpicture_fill((AVPicture *) pFrame, buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
  
  AVPacket packet;
  
  int res = 0;
  
  while (av_read_frame(pFormatCtx, &packet) >= 0) {
  
      if (packet.stream_index != 0)
  
          continue;
  
  
  
      ret = avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
      if (ret > 0) {
  
          // now, load the useful info into realPicture
  
          copyFrame(videoContext, realPicture, pCodecCtx, pFrame);
  
          // Free the packet that was allocated by av_read_frame
  
          av_free_packet(&packet);
  
          return 0;
  
      } else {
  
          // Error decoding frame. Use strerror(AVERROR(ret))) for details
  
          res = ERR_DECODE_FRAME;
  
      }
  
  }
  
  av_free(pFrame);
  
  
  
  // close codec
  
  avcodec_close(pCodecCtx);
  
  
  
  // Close the image file
  
  av_close_input_file(pFormatCtx);
  
  
  
  return res;
  
  }

  Some ./configure options :
  --extra-cflags="-O3 -fpic -DANDROID -DHAVE_SYS_UIO_H=1 -Dipv6mr_interface=ipv6mr_ifindex -fasm -Wno-psabi -fno-short-enums -fno-strict-aliasing -finline-limit=300 -mfloat-abi=softfp -mfpu=vfp -marm -march=armv7-a -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE"

  --extra-ldflags="-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib -lc -lm -ldl -llog"

  --arch=armv7-a --enable-armv5te --enable-armv6 --enable-armvfp --enable-memalign-hack