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• Encoding video only FLV

  25 mars 2012, par NadavRub

  I am trying to generate a video only FLV file, I am using :

  1. libx264 + ffmpeg
  2. 30 fps ( fixed )
  3. playback is done using VLC 2.0.1 and flowplayer

  When playing the FLV the frame-rate seems 1 frame per sec, following is the way I cfg ffmpeg :

  AVOutputFormat* fmtOutput = av_oformat_next(0);
  
  while((0 != fmtOutput) && (0 != strcmp(fmtOutput->name, "flv")))
  
      fmtOutput = av_oformat_next(fmtOutput);
  
  m_pFmtCtxOutput          = avformat_alloc_context();
  
  m_pFmtCtxOutput->oformat = fmtOutput;
  
  
  
  AVStream* pOutVideoStream= av_new_stream(m_pFmtCtxOutput, pInVideoStream->id);
  
  AVCodec*  videoEncoder   = avcodec_find_encoder(CODEC_ID_H264);
  
  
  
  pOutVideoStream->codec->width    = 640;
  
  pOutVideoStream->codec->height   = 480;
  
  pOutVideoStream->codec->level    = 30;
  
  pOutVideoStream->codec->pix_fmt  = PIX_FMT_YUV420P;
  
  pOutVideoStream->codec->bit_rate = 3000000;
  
  
  
  pOutVideoStream->cur_dts         = 0;
  
  pOutVideoStream->first_dts       = 0;
  
  pOutVideoStream->index           = 0;
  
  pOutVideoStream->avg_frame_rate  = (AVRational){ 30, 1 };
  
  pOutVideoStream->time_base       =
  
  pOutVideoStream->codec->time_base= (AVRational){ 1, 30000 };
  
  pOutVideoStream->codec->gop_size = 30;
  
  %% Some specific libx264 settings %%
  
  m_dVideoStep                     = 1000;// packet dts/pts is incremented by this amount each frame
  
  
  
  pOutVideoStream->codec->flags   |= CODEC_FLAG_GLOBAL_HEADER;
  
  avcodec_open(pOutVideoStream->codec, videoEncoder);

  The resulting file seems OK, with the exception of the playback frame-rate.
  having in mind that :

  1. pOutVideoStream->avg_frame_rate = (AVRational) 30, 1  ;
  2. pOutVideoStream->time_base = (AVRational) 1, 30000  ;
  3. pOutVideoStream->codec->time_base= (AVRational) 1, 30000  ;
  4. For each frame I increment the dts/pts by 1000

  What am I doing wrong here ? why the file is playing choppy ( 1 fps ) ?

  Any help will be appreciated.

  Nadav at Sophin

• Revision ccef8842d2 : Allow full coeff probability model and cost update This commit moves the simpli

  13 août 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_speed_features.c

  
  
  Allow full coeff probability model and cost update

  This commit moves the simplified coefficient probability model
  and costing update to speed 4, and turns on chessboard pattern
  mode search for sub 720p sequences. The overall coding performance
  of speed 3 is improved :
  derf 0.889%
  stdhd 1.744%

  The speed 3 runtime for test sequences are improved :
  bus cif at 1000 kbps 9823 ms -> 9642 ms
  pedestrian 1080p 2000 kbps 189559 ms -> 183284 ms

  Change-Id : Iecbc7496a68f31fd49fb09f8dfd97c028d675a5d

• Cropping Square Video using FFmpeg

  27 juin 2014, par zoruc

  Updated

  So I am trying to decode a mp4 file, crop the video into a square, and then re encode it back out to another mp4 file. This is my current code but there are a few issues with it.

  One is that the video doesn’t keep its rotation after the video has been re encoded

  Second is that the frames get outputted in a very fast video file that is not the same length as the original

  Third is that there is no sound

  Lastly and most importantly is do I need AVFilter to do the frame cropping or can it just be done per frame as a resize of the frame and then encoded back out.

  const char *inputPath = "test.mp4";
  
  const char *outPath = "cropped.mp4";
  
  const char *outFileType = "mp4";
  
  
  
  static AVFrame *oframe = NULL; 
  
  static AVFilterGraph *filterGraph = NULL;  
  
  static AVFilterContext *crop_ctx = NULL;
  
  static AVFilterContext *buffersink_ctx = NULL;
  
  static AVFilterContext *buffer_ctx = NULL;
  
  
  
  int err;
  
  
  
  int crop_video(int width, int height) {
  
  
  
  av_register_all();
  
  avcodec_register_all();
  
  avfilter_register_all();
  
  
  
  AVFormatContext *inCtx = NULL;
  
  
  
  // open input file
  
  err = avformat_open_input(&inCtx, inputPath, NULL, NULL);
  
  if (err < 0) {
  
      printf("error at open input in\n");
  
      return err;
  
  }
  
  
  
  // get input file stream info
  
  err = avformat_find_stream_info(inCtx, NULL);
  
  if (err < 0) {
  
      printf("error at find stream info\n");
  
      return err;
  
  }
  
  
  
  // get info about video
  
  av_dump_format(inCtx, 0, inputPath, 0);
  
  
  
  // find video input stream
  
  int vs = -1;
  
  int s;
  
  for (s = 0; s < inCtx->nb_streams; ++s) {
  
      if (inCtx->streams[s] && inCtx->streams[s]->codec && inCtx->streams[s]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  
          vs = s;
  
          break;
  
      }
  
  }
  
  
  
  // check if video stream is valid
  
  if (vs == -1) {
  
      printf("error at open video stream\n");
  
      return -1;
  
  }
  
  
  
  // set output format
  
  AVOutputFormat * outFmt = av_guess_format(outFileType, NULL, NULL);
  
  if (!outFmt) {
  
      printf("error at output format\n");
  
      return -1;
  
  }
  
  
  
  // get an output context to write to
  
  AVFormatContext *outCtx = NULL;
  
  err = avformat_alloc_output_context2(&outCtx, outFmt, NULL, NULL);
  
  if (err < 0 || !outCtx) {
  
      printf("error at output context\n");
  
      return err;
  
  }
  
  
  
  // input and output stream
  
  AVStream *outStrm = avformat_new_stream(outCtx, NULL);
  
  AVStream *inStrm = inCtx->streams[vs];
  
  
  
  // add a new codec for the output stream
  
  AVCodec *codec = NULL;
  
  avcodec_get_context_defaults3(outStrm->codec, codec);
  
  
  
  outStrm->codec->thread_count = 1;
  
  
  
  outStrm->codec->coder_type = AVMEDIA_TYPE_VIDEO;
  
  
  
  if(outCtx->oformat->flags & AVFMT_GLOBALHEADER) {
  
      outStrm->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
  }
  
  
  
  outStrm->codec->sample_aspect_ratio = outStrm->sample_aspect_ratio = inStrm->sample_aspect_ratio;
  
  
  
  err = avio_open(&outCtx->pb, outPath, AVIO_FLAG_WRITE);
  
  if (err < 0) {
  
      printf("error at opening outpath\n");
  
      return err;
  
  }
  
  
  
  outStrm->disposition = inStrm->disposition;
  
  outStrm->codec->bits_per_raw_sample = inStrm->codec->bits_per_raw_sample;
  
  outStrm->codec->chroma_sample_location = inStrm->codec->chroma_sample_location;
  
  outStrm->codec->codec_id = inStrm->codec->codec_id;
  
  outStrm->codec->codec_type = inStrm->codec->codec_type;
  
  
  
  if (!outStrm->codec->codec_tag) {
  
      if (! outCtx->oformat->codec_tag
  
          || av_codec_get_id (outCtx->oformat->codec_tag, inStrm->codec->codec_tag) == outStrm->codec->codec_id
  
          || av_codec_get_tag(outCtx->oformat->codec_tag, inStrm->codec->codec_id) <= 0) {
  
          outStrm->codec->codec_tag = inStrm->codec->codec_tag;
  
      }
  
  }
  
  
  
  outStrm->codec->bit_rate = inStrm->codec->bit_rate;
  
  outStrm->codec->rc_max_rate = inStrm->codec->rc_max_rate;
  
  outStrm->codec->rc_buffer_size = inStrm->codec->rc_buffer_size;
  
  
  
  const size_t extra_size_alloc = (inStrm->codec->extradata_size > 0) ?
  
  (inStrm->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE) :
  
  0;
  
  
  
  if (extra_size_alloc) {
  
      outStrm->codec->extradata = (uint8_t*)av_mallocz(extra_size_alloc);
  
      memcpy( outStrm->codec->extradata, inStrm->codec->extradata, inStrm->codec->extradata_size);
  
  }
  
  
  
  outStrm->codec->extradata_size = inStrm->codec->extradata_size;
  
  
  
  AVRational input_time_base = inStrm->time_base;
  
  AVRational frameRate = {25, 1};
  
  if (inStrm->r_frame_rate.num && inStrm->r_frame_rate.den
  
      && (1.0 * inStrm->r_frame_rate.num / inStrm->r_frame_rate.den < 1000.0)) {
  
      frameRate.num = inStrm->r_frame_rate.num;
  
      frameRate.den = inStrm->r_frame_rate.den;
  
  }
  
  
  
  outStrm->r_frame_rate = frameRate;
  
  outStrm->codec->time_base = inStrm->codec->time_base;
  
  
  
  outStrm->codec->pix_fmt = inStrm->codec->pix_fmt;
  
  outStrm->codec->width = width;
  
  outStrm->codec->height =  height;
  
  outStrm->codec->has_b_frames =  inStrm->codec->has_b_frames;
  
  
  
  if (!outStrm->codec->sample_aspect_ratio.num) {
  
      AVRational r0 = {0, 1};
  
      outStrm->codec->sample_aspect_ratio =
  
      outStrm->sample_aspect_ratio =
  
      inStrm->sample_aspect_ratio.num ? inStrm->sample_aspect_ratio :
  
      inStrm->codec->sample_aspect_ratio.num ?
  
      inStrm->codec->sample_aspect_ratio : r0;
  
  }
  
  
  
  avformat_write_header(outCtx, NULL);
  
  
  
  filterGraph = avfilter_graph_alloc();
  
  if (!filterGraph) {
  
      printf("could not open filter graph");
  
      return -1;
  
  }
  
  
  
  AVFilter *crop = avfilter_get_by_name("crop");
  
  AVFilter *buffer = avfilter_get_by_name("buffer");
  
  AVFilter *buffersink = avfilter_get_by_name("buffersink");
  
  
  
  char args[512];
  
  
  
  snprintf(args, sizeof(args), "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
  
           width, height, inStrm->codec->pix_fmt,
  
           inStrm->codec->time_base.num, inStrm->codec->time_base.den,
  
           inStrm->codec->sample_aspect_ratio.num, inStrm->codec->sample_aspect_ratio.den);
  
  
  
  err = avfilter_graph_create_filter(&buffer_ctx, buffer, NULL, args, NULL, filterGraph);
  
  if (err < 0) {
  
      printf("error initializing buffer filter\n");
  
      return err;
  
  }
  
  
  
  err = avfilter_graph_create_filter(&buffersink_ctx, buffersink, NULL, NULL, NULL, filterGraph);
  
  if (err < 0) {
  
      printf("unable to create buffersink filter\n");
  
      return err;
  
  }
  
  snprintf(args, sizeof(args), "%d:%d", width, height);
  
  err = avfilter_graph_create_filter(&crop_ctx, crop, NULL, args, NULL, filterGraph);
  
  if (err < 0) {
  
      printf("error initializing crop filter\n");
  
      return err;
  
  }
  
  
  
  err = avfilter_link(buffer_ctx, 0, crop_ctx, 0);
  
  if (err < 0) {
  
      printf("error linking filters\n");
  
      return err;
  
  }
  
  
  
  err = avfilter_link(crop_ctx, 0, buffersink_ctx, 0);
  
  if (err < 0) {
  
      printf("error linking filters\n");
  
      return err;
  
  }
  
  
  
  err = avfilter_graph_config(filterGraph, NULL);
  
  if (err < 0) {
  
      printf("error configuring the filter graph\n");
  
      return err;
  
  }
  
  
  
  printf("filtergraph configured\n");
  
  
  
  for (;;) {
  
  
  
      AVPacket packet = {0};
  
      av_init_packet(&packet);
  
  
  
      err = AVERROR(EAGAIN);
  
      while (AVERROR(EAGAIN) == err)
  
          err = av_read_frame(inCtx, &packet);
  
  
  
      if (err < 0) {
  
          if (AVERROR_EOF != err && AVERROR(EIO) != err) {
  
              printf("eof error\n");
  
              return 1;
  
          } else {
  
              break;
  
          }
  
      }
  
  
  
      if (packet.stream_index == vs) {
  
  
  
          //
  
          //            AVPacket pkt_temp_;
  
          //            memset(&pkt_temp_, 0, sizeof(pkt_temp_));
  
          //            AVPacket *pkt_temp = &pkt_temp_;
  
          //
  
          //            *pkt_temp = packet;
  
          //
  
          //            int error, got_frame;
  
          //            int new_packet = 1;
  
          //
  
          //            error = avcodec_decode_video2(inStrm->codec, frame, &got_frame, pkt_temp);
  
          //            if(error < 0) {
  
          //                LOGE("error %d", error);
  
          //            }
  
          //
  
          //            // if (error >= 0) {
  
          //
  
          //            // push the video data from decoded frame into the filtergraph
  
          //            int err = av_buffersrc_write_frame(buffer_ctx, frame);
  
          //            if (err < 0) {
  
          //                LOGE("error writing frame to buffersrc");
  
          //                return -1;
  
          //            }
  
          //            // pull filtered video from the filtergraph
  
          //            for (;;) {
  
          //                int err = av_buffersink_get_frame(buffersink_ctx, oframe);
  
          //                if (err == AVERROR_EOF || err == AVERROR(EAGAIN))
  
          //                    break;
  
          //                if (err < 0) {
  
          //                    LOGE("error reading buffer from buffersink");
  
          //                    return -1;
  
          //                }
  
          //            }
  
          //
  
          //            LOGI("output frame");
  
  
  
          err = av_interleaved_write_frame(outCtx, &packet);
  
          if (err < 0) {
  
              printf("error at write frame");
  
              return -1;
  
          }
  
  
  
          //}
  
      }
  
  
  
      av_free_packet(&packet);
  
  }
  
  
  
  av_write_trailer(outCtx);
  
  if (!(outCtx->oformat->flags & AVFMT_NOFILE) && outCtx->pb)
  
      avio_close(outCtx->pb);
  
  
  
  avformat_free_context(outCtx);
  
  avformat_close_input(&inCtx);
  
  
  
  return 0;

  }