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• FFmpeg api iOS "Resource temporarily unavailable"

  8 octobre 2017, par Julius Naeumann

  I’ve spent hours trying to fix this :

  I’m trying to use the ffmpeg api on iOS. My Xcode project is building and I can call ffmpeg api functions. I am trying to write code that decodes a video (Without outputting anything for now), and I keep getting error -35 : "Resource temporarily unavailable".

  The input file is from the camera roll (.mov) and I’m using Mpeg-4 for decoding. All I’m currently doing is getting data from the file, parsing it and sending the parsed packets to the decoder. When I try to get frames, all I get is an error. Does anyone know what I’m doing wrong ?

  +(void)test: (NSString*)filename outfile:(NSString*)outfilename {
  
  
  
  /* register all the codecs */
  
  avcodec_register_all();
  
  
  
  AVCodec *codec;
  
  AVCodecParserContext *parser;
  
  AVCodecContext *c= NULL;
  
  int frame_count;
  
  FILE* f;
  
  AVFrame* frame;
  
  AVPacket* avpkt;
  
  avpkt = av_packet_alloc();
  
  //av_init_packet(avpkt);
  
  char buf[1024];
  
  
  
  uint8_t inbuf[INBUF_SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
  
  uint8_t *data;
  
  size_t   data_size;
  
  
  
  /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
  
  memset(inbuf + INBUF_SIZE, 0, AV_INPUT_BUFFER_PADDING_SIZE);
  
  
  
  printf("Decode video file %s to %s\n", [filename cStringUsingEncoding:NSUTF8StringEncoding], [outfilename cStringUsingEncoding:NSUTF8StringEncoding]);
  
  /* find the h264 video decoder */
  
  codec = avcodec_find_decoder(AV_CODEC_ID_MPEG4);
  
  if (!codec) {
  
      fprintf(stderr, "Codec not found\n");
  
      exit(1);
  
  }
  
  c = avcodec_alloc_context3(codec);
  
  if (!c) {
  
      fprintf(stderr, "Could not allocate video codec context\n");
  
      exit(1);
  
  }
  
  if (codec->capabilities & AV_CODEC_CAP_TRUNCATED)
  
      c->flags |= AV_CODEC_FLAG_TRUNCATED; // we do not send complete frames
  
  /* For some codecs, such as msmpeg4 and mpeg4, width and height
  
   MUST be initialized there because this information is not
  
   available in the bitstream. */
  
  /* open it */
  
  if (avcodec_open2(c, codec, NULL) < 0) {
  
      fprintf(stderr, "Could not open codec\n");
  
      exit(1);
  
  }
  
  f = fopen([filename cStringUsingEncoding:NSUTF8StringEncoding], "rb");
  
  if (!f) {
  
      fprintf(stderr, "Could not open %s\n", [filename cStringUsingEncoding:NSUTF8StringEncoding]);
  
      exit(1);
  
  }
  
  frame = av_frame_alloc();
  
  if (!frame) {
  
      fprintf(stderr, "Could not allocate video frame\n");
  
      exit(1);
  
  }
  
  frame_count = 0;
  
  
  
  parser = av_parser_init(codec->id);
  
  if (!parser) {
  
      fprintf(stderr, "parser not found\n");
  
      exit(1);
  
  }
  
  
  
  while (!feof(f)) {
  
      /* read raw data from the input file */
  
      data_size = fread(inbuf, 1, INBUF_SIZE, f);
  
      if (!data_size)
  
          break;
  
      /* use the parser to split the data into frames */
  
      data = inbuf;
  
      while (data_size > 0) {
  
          int ret = av_parser_parse2(parser, c, &avpkt->data, &avpkt->size, data, data_size, AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);
  
          if (ret < 0) {
  
              fprintf(stderr, "Error while parsing\n");
  
              exit(1);
  
          }
  
          data      += ret;
  
          data_size -= ret;
  
          if (avpkt->size){
  
              char buf[1024];
  
  
  
              ret = avcodec_send_packet(c, avpkt);
  
              if (ret < 0) {
  
  
  
                  fprintf(stderr, "Error sending a packet for decoding\n");
  
                  continue;
  
                  exit(1);
  
              }
  
  
  
              while (ret >= 0) {
  
                  ret = avcodec_receive_frame(c, frame);
  
                  if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF){
  
                      char e [1024];
  
                      av_strerror(ret, e, 1024);
  
                      fprintf(stderr, "Fail: %s !\n", e);
  
  // ~~~~~~~~ This is where my program exits ~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
                      return;
  
                  }
  
                  else if (ret < 0) {
  
                      fprintf(stderr, "Error during decoding\n");
  
                      exit(1);
  
                  }
  
              }
  
  
  
  
  
          }
  
      }
  
  }
  
  /* some codecs, such as MPEG, transmit the I and P frame with a
  
   latency of one frame. You must do the following to have a
  
   chance to get the last frame of the video */
  
  
  
  fclose(f);
  
  avcodec_close(c);
  
  av_free(c);
  
  av_frame_free(&frame);
  
  printf("\n");

  }

• How to avoid the "text relocation" error by ffmpeg library on Android x86

  16 octobre 2017, par Tank2005

  My environment is Qt 5.9 for Android on Windows 10 64bit. NDK is r10e and SDK Level is 16(Those sdks are recommended version by Qt development team).

  I built a ffmpeg 3.4 source code as .so files on Ubuntu 16.04.3 LTS. Those library has no error on ARM architecture Android. But, on x86 Emulator, "Text realocations" alart is shown like this.

  

  I rewrite configure with "disable-asm, disable-yasm" referd from this site’s old posts.

  This hereby removed some errors. But only one library has a problem.
  

  I also tried the method of deleting "strtod.o", But it seems no effect. My current build configure is that. Does anyone know a better way ?

  #!/bin/bash
  
  NDK=/home/my/data/ndk
  
  SYSROOT=$NDK/platforms/android-14/arch-x86/
  
  TOOLCHAIN=$NDK/linux-x86-48
  
  CPU=x86
  
  PREFIX=$(pwd)/android/x86
  
  PATH=$TOOLCHAIN/bin:$PATH
  
  
  
  function build_one
  
  {
  
  ./configure \
  
      --cc="$TOOLCHAIN/bin/i686-linux-android-gcc-4.8" \
  
      --enable-cross-compile \
  
      --target-os=linux \
  
      --arch=x86 \
  
      --prefix=$PREFIX \
  
      --enable-shared \
  
      --disable-static \
  
      --disable-avdevice \
  
      --disable-doc \
  
      --disable-encoders \
  
      --disable-decoders \
  
      --enable-decoder=h264 \
  
      --enable-decoder=aac \
  
      --disable-protocols \
  
      --disable-demuxers \
  
      --disable-muxers \
  
      --disable-filters \
  
      --disable-network \
  
      --disable-ffplay \
  
      --disable-ffmpeg \
  
      --disable-ffprobe \
  
      --disable-ffserver \
  
      --enable-parsers \
  
      --cross-prefix=i686-linux-android- \
  
      --enable-cross-compile \
  
      --target-os=linux \
  
      --arch=x86 \
  
      --disable-doc \
  
      --sysroot=$SYSROOT \
  
      --disable-x86asm -disable-yasm --enable-pic \
  
      --extra-cflags="-std=c99 -O3 -Wall -fpic -pipe -DANDROID -DNDEBUG -march=atom -msse3 -ffast-math -mfpmath=sse" \
  
      --extra-ldflags='-lm -lz -Wl,--no-undefined -Wl,-z,noexecstack' \
  
      $ADDITIONAL_CONFIGURE_FLAG
  
  make clean
  
  rm -f $(pwd)/compat/strtod.o
  
  rm -f $(pwd)/compat/strtod.d
  
  make 
  
  make install
  
  }
  
  build_one

• Detect if "faststart" has been applied to video

  26 juin 2024, par Will Ashworth

  When running "qt-faststart" on an MP4, you're essentially taking the meta data from the back and placing it at the front of the file. In my case, so Flash can properly start playing the video before it's fully done loading.

  



  I have a large number of videos that I'm running through a shell script to encode overnight. When I upload, however, I won't necessarily know in my final folder of videos (on the server) have "qt-faststart" run on it.

  



  My goal is to find the straggler videos and run qt-faststart on them manually, but I'll need a way to compile a list. Is there any way to check for this meta data information with PHP or something ? Wondering how I can tell if a video has already had qt-faststart run on it or not.