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• FFmpeg concat images and audio what can't control framerate

  27 septembre 2016, par kensonLiang

  Good day !
  I want to concat images and audios to a video.and I found the command like that :

  ffmpeg -ss 00:00:00 -t 00:00:10 -i a.mp3 -ss 00:01:01 -t 00:00:10 -i b.mp3 -thread_queue_size 1024 -r 3 -i C:\f1\im\%08d.jpg -filter_complex "[0:a] [1:a] concat=v=0:a=1 [outa];movie=im/%08d.jpg,fps=3 [img]" -map [outa] -map [img] output.mp4

  It’s work.but whatever I set the fps and -r,the video stream will complete in 1second,and the audio will playing with the last frame of the video after the first second.
  help me,please !

• Decode video with CUDA nccuvid and ffmpeg [closed]

  25 avril 2013, par Oleksandr Kyrpa

  *strong text*I starting to implement custum video decoder that utilize cuda HW decoder to generate YUV frame for next to encode it.

  How can I fill "CUVIDPICPARAMS" struc ???
  Is it possible ?

  My algorithm are :

  For get video stream packet I'm use ffmpeg-dev libs avcodec, avformat...

  My steps :

  1) Open input file :

  avformat_open_input(&ff_formatContext,in_filename,nullptr,nullptr);

  2) Get video stream property's :

  avformat_find_stream_info(ff_formatContext,nullptr);

  3) Get video stream :

  ff_video_stream=ff_formatContext->streams[i];

  4) Get CUDA device and init it :

  cuDeviceGet(&cu_device,0);
  
  CUcontext cu_vid_ctx;

  5) Init video CUDA decoder and set create params :

  CUVIDDECODECREATEINFO *cu_decoder_info=new CUVIDDECODECREATEINFO;
  
  memset(cu_decoder_info,0,sizeof(CUVIDDECODECREATEINFO));
  
  ...
  
  cuvidCreateDecoder(cu_video_decoder,cu_decoder_info);

  6)Read frame data to AVpacket

  av_read_frame(ff_formatContext,ff_packet);

  AND NOW I NEED decode frame packet on CUDA video decoder, in theoretical are :

  cuvidDecodePicture(pDecoder,&picParams);

  BUT before I need fill CUVIDPICPARAMS

  CUVIDPICPARAMS picParams ;//=new CUVIDPICPARAMS ;
  memset(&picParams, 0, sizeof(CUVIDPICPARAMS)) ;

  HOW CAN I FILL "CUVIDPICPARAMS" struc ???
  
  
  
  typedef struct _CUVIDPICPARAMS
  
  {
  
      int PicWidthInMbs;      // Coded Frame Size
  
      int FrameHeightInMbs;   // Coded Frame Height
  
      int CurrPicIdx;         // Output index of the current picture
  
      int field_pic_flag;     // 0=frame picture, 1=field picture
  
      int bottom_field_flag;  // 0=top field, 1=bottom field (ignored if field_pic_flag=0)
  
      int second_field;       // Second field of a complementary field pair
  
      // Bitstream data
  
      unsigned int nBitstreamDataLen;        // Number of bytes in bitstream data buffer
  
      const unsigned char *pBitstreamData;   // Ptr to bitstream data for this picture (slice-layer)
  
      unsigned int nNumSlices;               // Number of slices in this picture
  
      const unsigned int *pSliceDataOffsets; // nNumSlices entries, contains offset of each slice within the bitstream data buffer
  
      int ref_pic_flag;       // This picture is a reference picture
  
      int intra_pic_flag;     // This picture is entirely intra coded
  
      unsigned int Reserved[30];             // Reserved for future use
  
      // Codec-specific data
  
      union {
  
          CUVIDMPEG2PICPARAMS mpeg2;          // Also used for MPEG-1
  
          CUVIDH264PICPARAMS h264;
  
          CUVIDVC1PICPARAMS vc1;
  
          CUVIDMPEG4PICPARAMS mpeg4;
  
          CUVIDJPEGPICPARAMS jpeg;
  
          unsigned int CodecReserved[1024];
  
      } CodecSpecific;
  
  } CUVIDPICPARAMS;
  
  
  
  typedef struct _CUVIDH264PICPARAMS
  
  {
  
      // SPS
  
      int log2_max_frame_num_minus4;
  
      int pic_order_cnt_type;
  
      int log2_max_pic_order_cnt_lsb_minus4;
  
      int delta_pic_order_always_zero_flag;
  
      int frame_mbs_only_flag;
  
      int direct_8x8_inference_flag;
  
      int num_ref_frames;             // NOTE: shall meet level 4.1 restrictions
  
      unsigned char residual_colour_transform_flag;
  
      unsigned char bit_depth_luma_minus8;    // Must be 0 (only 8-bit supported)
  
      unsigned char bit_depth_chroma_minus8;  // Must be 0 (only 8-bit supported)
  
      unsigned char qpprime_y_zero_transform_bypass_flag;
  
      // PPS
  
      int entropy_coding_mode_flag;
  
      int pic_order_present_flag;
  
      int num_ref_idx_l0_active_minus1;
  
      int num_ref_idx_l1_active_minus1;
  
      int weighted_pred_flag;
  
      int weighted_bipred_idc;
  
      int pic_init_qp_minus26;
  
      int deblocking_filter_control_present_flag;
  
      int redundant_pic_cnt_present_flag;
  
      int transform_8x8_mode_flag;
  
      int MbaffFrameFlag;
  
      int constrained_intra_pred_flag;
  
      int chroma_qp_index_offset;
  
      int second_chroma_qp_index_offset;
  
      int ref_pic_flag;
  
      int frame_num;
  
      int CurrFieldOrderCnt[2];
  
      // DPB
  
      CUVIDH264DPBENTRY dpb[16];          // List of reference frames within the DPB
  
      // Quantization Matrices (raster-order)
  
      unsigned char WeightScale4x4[6][16];
  
      unsigned char WeightScale8x8[2][64];
  
      // FMO/ASO
  
      unsigned char fmo_aso_enable;
  
      unsigned char num_slice_groups_minus1;
  
      unsigned char slice_group_map_type;
  
      signed char pic_init_qs_minus26;
  
      unsigned int slice_group_change_rate_minus1;
  
      union
  
      {
  
          unsigned long long slice_group_map_addr;
  
          const unsigned char *pMb2SliceGroupMap;
  
      } fmo;
  
      unsigned int  Reserved[12];
  
      // SVC/MVC
  
      union
  
      {
  
          CUVIDH264MVCEXT mvcext;
  
          CUVIDH264SVCEXT svcext;
  
      };
  
  } CUVIDH264PICPARAMS;

  How can I fill "CUVIDPICPARAMS" struc ???
  Is it possible ?

• VLC snytax to transcode & stream to stdout ?

  4 octobre 2016, par Will Tower

  Goal : I am trying to use VLC as a local server to expand the video capabilities of an app created with Adobe AIR, Flex and Actionscript. I am using VLC to stream to stdoutand reading that output from within my app.

  VLC Streaming capabilities
  VLC Flash Video

  Status : I am able to launch VLC as a background process and control it through its remote control interface (more detail). I can load, transcode and stream a local video file. The example app below is a barebones testbed demonstrating this.

  Issue : I am getting data in to my app but it is not rendering as video. I don’t know if it is a problem with my VLC commands or with writing to/reading from stdout. This technique of reading from stdout in AIR works (with ffmpeg for example).

  One of the various transcoding commands I have tried :

  -I rc  // remote control interface  
  
  -vvv   // verbose debuging  
  
  --sout  // transcode, stream to stdout 
  
  "#transcode{vcodec=FLV1}:std{access=file,mux=ffmpeg{mux=flv},dst=-}"

  This results in data coming into to my app but for some reason it is not rendering as video when using appendBytes with the NetStream instance.

  If instead I write the data to an .flv file, a valid file is created – so the broken part seems to be writing it to stdout. One thing I have noticed : I am not getting metadata through the stdout`method. If I play the file created with the command below, I do see metadata.

  Hoping someone sees where I am going wrong here.

  ---

  // writing to a file
  
  var output:File = File.desktopDirectory.resolvePath("stream.flv");
  
  var outputPath:String = output.nativePath;
  
  "#transcode{vcodec=FLV1}:std{access=file,mux=ffmpeg{mux=flv},dst=" + outputPath + "}");

  ---

  Note : In order to get this to work in AIR, you need to define the app profile as "extendedDesktop"

  ---

    <?xml version="1.0" encoding="utf-8"?>