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• How to download/convert multiple streams to multiple outputs with FFmpeg ?

  16 avril 2016, par Website Newbie

  Let’s say I have 20 different online stream videos (playlist.m3u8) and I want every video to output to their own .avi files. How can I do that in single file, so I don’t have to download and convert every single one separately ?

  I found a -map command online, but didn’t get straight answer to this.

  Will this be a working code ?

  ffmpeg -i 1playlist.m3u8 -vf scale=768:-1 -vcodec libx264 -crf 24 -acodec copy -map 0 1.avi \
  
  -i 2playlist.m3u8 -vf scale=768:-1 -vcodec libx264 -crf 24 -acodec copy -map 1 2.avi \
  
  -i 3playlist.m3u8 -vf scale=768:-1 -vcodec libx264 -crf 24 -acodec copy -map 2 3.avi

• 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

• How create with ffmpeg a *.mov file which could be opened in default WMP ?

  22 mai 2016, par xiaose

  How create MOV, QuickTime Movie (.mov) which could be opened in default Windows Media Player ? Actually, smth. like this : http://cdn.online-convert.com/example-file/video/mov/example.mov

  I have files MPEG-1 or MPEG-2 and want to convert it with ffmpeg to the mov. Sure, I can write smth. like this :

  ffmpeg -i in.mpg -level 3.1 -vformat mpeg4 -qscale 1 -f mov out.mov

  ...and this will be Ok. But I need resulting file which will be correct MOV but, may be, without mpeg4 in it and played in WMP without installing any additional codecs