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• Rotate video adding black bars with ffmpeg

  13 février 2016, par MrMoog

  I have a lot of mp4 full hd videos made with a smartphone that looks rotated 90°.

  These files have proper rotation metadata and they plays correctly on VLC or other desktop mediaplayers, but I want to display them on my dvd player that does not handles mp4 metadata.

  So I tried to transpose with ffmpeg but I obtain 1080x1920 files, resolution obviously not recognized by tv/dvd-player.

  How can I transpose, resize and add black side (left/right) bars of the correct dimensions to get "correct" 1920x1080 videos ?

• FFMPEG converted file for jwplayer shows black [migrated]

  24 octobre 2013, par Karolis Narkevičius

  im new to ffmpeg, and I'm trying to convert it to mp4 to play on jwplayer, the video converts, the sound is good, but all i can see is black color, maybie anyone knows the answer to this problem ?

  ffmpeg -y -i Bear.wmv -vcodec libx264 -b:v 1000k -bufsize 1000k -preset:v ultrafast -movflags +faststart -crf 0 -vf scale=800:400 -ab 128k -vsync 2 -strict -2 outas.mp4

  my ffmpeg code
  my ffmpeg version 2.0.1

• H265 codec changes from hvc1 to hev1

  30 mai 2018, par ppcat

  I try to copy mp4 file with hevc video.
  Source file have hvc1 codec.

  Stream #0:0(und): Video: hevc (Main) (hvc1 / 0x31637668)

  After copying the codec gets the value of hev1

  Stream #0:0(und): Video: hevc (Main) (hev1 / 0x31766568)

  How can i get hvc1 ?
  I found that ffmpeg can do it with "-tag:v hvc1"
  (https://stackoverflow.com/questions/32152090/encode-h265-to-hvc1-codec)
  And how to set tag in c++ code (FFMpeg copy streams without transcode)
  But it does not effect

  My code :

  AVOutputFormat *ofmt = NULL;
  
  AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
  
  AVPacket pkt;
  
  const char *in_filename, *out_filename;
  
  int ret, i;
  
  int stream_index = 0;
  
  int *stream_mapping = NULL;
  
  int stream_mapping_size = 0;
  
  
  
  if (argc < 3) {
  
      printf("usage: %s input output\n"
  
          "API example program to remux a media file with libavformat and libavcodec.\n"
  
          "The output format is guessed according to the file extension.\n"
  
          "\n", argv[0]);
  
      return 1;
  
  }
  
  
  
  in_filename = argv[1];
  
  out_filename = argv[2];
  
  
  
  av_register_all();
  
  
  
  if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
  
      fprintf(stderr, "Could not open input file '%s'", in_filename);
  
      goto end;
  
  }
  
  
  
  if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
  
      fprintf(stderr, "Failed to retrieve input stream information");
  
      goto end;
  
  }
  
  
  
  av_dump_format(ifmt_ctx, 0, in_filename, 0);
  
  
  
  avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
  
  if (!ofmt_ctx) {
  
      fprintf(stderr, "Could not create output context\n");
  
      ret = AVERROR_UNKNOWN;
  
      goto end;
  
  }
  
  
  
  stream_mapping_size = ifmt_ctx->nb_streams;
  
  stream_mapping = (int*)av_mallocz_array(stream_mapping_size, sizeof(*stream_mapping));
  
  if (!stream_mapping) {
  
      ret = AVERROR(ENOMEM);
  
      goto end;
  
  }
  
  
  
  ofmt = ofmt_ctx->oformat;
  
  
  
  for (i = 0; i < (int)ifmt_ctx->nb_streams; i++) {
  
      AVStream *out_stream;
  
      AVStream *in_stream = ifmt_ctx->streams[i];
  
      AVCodecParameters *in_codecpar = in_stream->codecpar;
  
      AVCodec *decoder = avcodec_find_decoder(in_stream->codecpar->codec_id);
  
      AVCodec *encoder = avcodec_find_encoder(in_stream->codecpar->codec_id);
  
  
  
      if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO &&
  
          in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
  
          in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
  
          stream_mapping[i] = -1;
  
          continue;
  
      }
  
  
  
      stream_mapping[i] = stream_index++;
  
  
  
      out_stream = avformat_new_stream(ofmt_ctx, NULL);
  
      if (!out_stream) {
  
          fprintf(stderr, "Failed allocating output stream\n");
  
          ret = AVERROR_UNKNOWN;
  
          goto end;
  
      }
  
  
  
      ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
  
      if (ret < 0) {
  
          fprintf(stderr, "Failed to copy codec parameters\n");
  
          goto end;
  
      }
  
  
  
      unsigned int tag = 0;
  
      // for ffmpeg new api 3.x
  
      AVCodecParameters *parameters = out_stream->codecpar;
  
      if (av_codec_get_tag2(ofmt_ctx->oformat->codec_tag, encoder->id, &tag) == 0) {
  
          av_log(NULL, AV_LOG_ERROR, "could not find codec tag for codec id %d, default to 0.\n", encoder->id);
  
      }
  
      parameters->codec_tag = tag;
  
      out_stream->codec = avcodec_alloc_context3(encoder);
  
      // more setting for stream->codec
  
      avcodec_parameters_to_context(out_stream->codec, parameters);
  
  }
  
  av_dump_format(ofmt_ctx, 0, out_filename, 1);
  
  
  
  if (!(ofmt->flags & AVFMT_NOFILE)) {
  
      ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
  
      if (ret < 0) {
  
          fprintf(stderr, "Could not open output file '%s'", out_filename);
  
          goto end;
  
      }
  
  }
  
  
  
  ret = avformat_write_header(ofmt_ctx, NULL);
  
  if (ret < 0) {
  
      fprintf(stderr, "Error occurred when opening output file\n");
  
      goto end;
  
  }
  
  
  
  while (1) {
  
      AVStream *in_stream, *out_stream;
  
  
  
      ret = av_read_frame(ifmt_ctx, &pkt);
  
      if (ret < 0)
  
          break;
  
  
  
      in_stream = ifmt_ctx->streams[pkt.stream_index];
  
      if (pkt.stream_index >= stream_mapping_size ||
  
          stream_mapping[pkt.stream_index] < 0) {
  
          av_packet_unref(&pkt);
  
          continue;
  
      }
  
  
  
      pkt.stream_index = stream_mapping[pkt.stream_index];
  
      out_stream = ofmt_ctx->streams[pkt.stream_index];
  
      log_packet(ifmt_ctx, &pkt, "in");
  
  
  
      /* copy packet */
  
      pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
  
      pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
  
      pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
  
      pkt.pos = -1;
  
      log_packet(ofmt_ctx, &pkt, "out");
  
  
  
      ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
  
      if (ret < 0) {
  
          fprintf(stderr, "Error muxing packet\n");
  
          break;
  
      }
  
      av_packet_unref(&pkt);
  
  }
  
  
  
  av_write_trailer(ofmt_ctx);

  end :

  avformat_close_input(&ifmt_ctx);
  
  
  
  /* close output */
  
  if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
  
      avio_closep(&ofmt_ctx->pb);
  
  avformat_free_context(ofmt_ctx);
  
  
  
  av_freep(&stream_mapping);
  
  
  
  if (ret < 0 && ret != AVERROR_EOF) {
  
      fprintf(stderr, "Error occurred: %s\n", av_errTOstr(ret).c_str());
  
      return 1;
  
  }

  After changes :

      out_stream = avformat_new_stream(ofmt_ctx, NULL);
  
      ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
  
  
  
      AVCodecParameters *parameters = out_stream->codecpar;
  
      unsigned int tag = 0;
  
      av_codec_get_tag2(ofmt_ctx->oformat->codec_tag, encoder->id, &tag) == 0);
  
      parameters->codec_tag = tag;
  
  
  
      out_stream->codec = avcodec_alloc_context3(encoder);
  
      avcodec_parameters_to_context(out_stream->codec, parameters);
  
  
  
      if (in_codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
  
          parameters->codec_tag = MKTAG('h', 'v', 'c', '1');
  
      }
  
  }
  
  
  
  av_dump_format(ofmt_ctx, 0, out_filename, 1);
  
  ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
  
  
  
  ret = avformat_write_header(ofmt_ctx, NULL);
  
  if (ret < 0) {
  
      fprintf(stderr, "Error write header: %s\n", av_errTOstr(ret). c_str());
  
      goto end;
  
  }