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• dca : add emms_c after usage of AV_COPY128

  2 février 2016, par Hendrik Leppkes

  dca : add emms_c after usage of AV_COPY128
  Similar to AV_ZERO128, AV_COPY128 can use MMX instructions in x86
  

  • [DH] libavcodec/dca_core.c

• FFMPEG - Audio going out of sync when using Tempo And setPTS

  5 février 2016, par loveforfire33

  Very new to ffmpeg and have been trying all day to get this working. I am trying to slow down a video and its audio at the same time (mp4). I have tried doing the audio and video separately with a very similar version of the code below but still get the same effect.

  The audio slowly goes out of sync with the video after roughly 30 seconds(audio goes faster). Any advice would be appreciated.

  -i "INPUT" -filter_complex "[0:v]setpts=1.1*PTS[v] ;[0:a]atempo=0.9[a]" -map "[v]"" -map "[a]" "OUTPUT"

  Thanks in advance

• ffmpeg error on decode

  25 octobre 2013, par ademar111190

  I'm developing an android app with the libav and I'm trying decode a 3gp with code below :

  #define simbiLog(...) __android_log_print(ANDROID_LOG_DEBUG, "simbiose", __VA_ARGS__)

  ...

  AVCodec *codec;
  
  AVCodecContext *c = NULL;
  
  int len;
  
  FILE *infile, *outfile;
  
  uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
  
  AVPacket avpkt;
  
  AVFrame *decoded_frame = NULL;
  
  
  
  simbiLog("inbuf size: %d", sizeof(inbuf) / sizeof(inbuf[0]));
  
  
  
  av_register_all();
  
  av_init_packet(&avpkt);
  
  
  
  codec = avcodec_find_decoder(AV_CODEC_ID_AMR_NB);
  
  if (!codec) {
  
      simbiLog("codec not found");
  
      return ERROR;
  
  }
  
  
  
  c = avcodec_alloc_context3(codec);
  
  if (!c) {
  
      simbiLog("Could not allocate audio codec context");
  
      return ERROR;
  
  }
  
  
  
  int open = avcodec_open2(c, codec, NULL);
  
  if (open < 0) {
  
      simbiLog("could not open codec %d", open);
  
      return ERROR;
  
  }
  
  
  
  infile = fopen(inputPath, "rb");
  
  if (!infile) {
  
      simbiLog("could not open %s", inputPath);
  
      return ERROR;
  
  }
  
  
  
  outfile = fopen(outputPath, "wb");
  
  if (!outfile) {
  
      simbiLog("could not open %s", outputPath);
  
      return ERROR;
  
  }
  
  
  
  avpkt.data = inbuf;
  
  avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, infile);
  
  int iterations = 0;
  
  
  
  while (avpkt.size > 0) {
  
      simbiLog("iteration %d", (++iterations));
  
      simbiLog("avpkt.size %d avpkt.data %X", avpkt.size, avpkt.data);
  
      int got_frame = 0;
  
  
  
      if (!decoded_frame) {
  
          if (!(decoded_frame = avcodec_alloc_frame())) {
  
              simbiLog("out of memory");
  
              return ERROR;
  
          }
  
      } else {
  
          avcodec_get_frame_defaults(decoded_frame);
  
      }
  
  
  
      //below the error, but it isn't occur on first time, only in 4th loop interation
  
      len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt); 
  
      if (len < 0) {
  
          simbiLog("Error while decoding error %d frame %d duration %d", len, got_frame, avpkt.duration);
  
          return ERROR;
  
      } else {
  
          simbiLog("Decoding length %d frame %d duration %d", len, got_frame, avpkt.duration);
  
      }
  
  
  
      if (got_frame) {
  
          int data_size = av_samples_get_buffer_size(NULL, c->channels, decoded_frame->nb_samples, c->sample_fmt, 1);
  
          size_t* fwrite_size = fwrite(decoded_frame->data[0], 1, data_size, outfile);
  
          simbiLog("fwrite returned %d", fwrite_size);
  
      }
  
      avpkt.size -= len;
  
      avpkt.data += len;
  
      if (avpkt.size < AUDIO_REFILL_THRESH) {
  
          memmove(inbuf, avpkt.data, avpkt.size);
  
          avpkt.data = inbuf;
  
          len = fread(avpkt.data + avpkt.size, 1, AUDIO_INBUF_SIZE - avpkt.size, infile);
  
          if (len > 0)
  
              avpkt.size += len;
  
          simbiLog("fread returned %d", len);
  
      }
  
  }
  
  
  
  fclose(outfile);
  
  fclose(infile);
  
  
  
  avcodec_close(c);
  
  av_free(c);
  
  av_free(decoded_frame);

  but I'm getting the follow log and error :

  inbuf size: 20488
  
  iteration 1
  
  avpkt.size 3305 avpkt.data BEEED40C
  
  Decoding length 13 frame 1 duration 0
  
  fwrite returned 640
  
  fread returned 0
  
  iteration 2
  
  avpkt.size 3292 avpkt.data BEEED40C
  
  Decoding length 13 frame 1 duration 0
  
  fwrite returned 640
  
  fread returned 0
  
  iteration 3
  
  avpkt.size 3279 avpkt.data BEEED40C
  
  Decoding length 14 frame 1 duration 0
  
  fwrite returned 640
  
  fread returned 0
  
  iteration 4
  
  avpkt.size 3265 avpkt.data BEEED40C
  
  Error while decoding error -1052488119 frame 0 duration 0

  the audio file I'm trying decode :

  $ avprobe blue.3gp 
  
  avprobe version 0.8.6-6:0.8.6-1ubuntu2, Copyright (c) 2007-2013 the Libav developers
  
    built on Mar 30 2013 22:23:21 with gcc 4.7.2
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'blue.3gp':
  
    Metadata:
  
      major_brand     : 3gp4
  
      minor_version   : 0
  
      compatible_brands: isom3gp4
  
      creation_time   : 2013-09-19 18:53:38
  
    Duration: 00:00:01.52, start: 0.000000, bitrate: 17 kb/s
  
      Stream #0.0(eng): Audio: amrnb, 8000 Hz, 1 channels, flt, 12 kb/s
  
      Metadata:
  
        creation_time   : 2013-09-19 18:53:38

  thanks a lot !

  ---

  EDITED

  I read on ffmper documentation about the method avcodec_decode_audio4 the follow :

  @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE larger than the actual read bytes because some optimized bitstream readers read 32 or 64 bits at once and could read over the end.
  
  @note You might have to align the input buffer. The alignment requirements depend on the CPU and the decoder.

  and I see here a solution using posix_memalign, to android i founded a similar method called memalign, so i did the change :

  removed :

  uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];

  inserted :

  int inbufSize = sizeof(uint8_t) * (AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
  
  uint8_t *inbuf = memalign(FF_INPUT_BUFFER_PADDING_SIZE, inbufSize);
  
  simbiLog("inbuf size: %d", inbufSize);
  
  for (; inbufSize >= 0; inbufSize--)
  
      simbiLog("inbuf position: %d index: %p", inbufSize, &inbuf[inbufSize]);

  I'm getting the correct memory sequence position, but the error not changed.

  A piece of outpout :

  inbuf position: 37 index: 0x4e43d745
  
  inbuf position: 36 index: 0x4e43d744
  
  inbuf position: 35 index: 0x4e43d743
  
  inbuf position: 34 index: 0x4e43d742
  
  inbuf position: 33 index: 0x4e43d741
  
  inbuf position: 32 index: 0x4e43d740
  
  inbuf position: 31 index: 0x4e43d73f
  
  inbuf position: 30 index: 0x4e43d73e
  
  inbuf position: 29 index: 0x4e43d73d
  
  inbuf position: 28 index: 0x4e43d73c
  
  inbuf position: 27 index: 0x4e43d73b
  
  inbuf position: 26 index: 0x4e43d73a
  
  inbuf position: 25 index: 0x4e43d739
  
  inbuf position: 24 index: 0x4e43d738
  
  inbuf position: 23 index: 0x4e43d737
  
  inbuf position: 22 index: 0x4e43d736
  
  inbuf position: 21 index: 0x4e43d735
  
  inbuf position: 20 index: 0x4e43d734
  
  inbuf position: 19 index: 0x4e43d733