Recherche avancée

Sur d’autres sites (7911)

• Why there is no AVFrame->data[2] data when decode h264 by ffmpeg use "h264_cuvid"

  27 juillet 2017, par Wu NL

  env : ubuntu 16.04 64 bit ; ffmpeg 3.3.2 build whih cuda cuvid libnpp...
  use ffmpeg cmd : ffmpeg -vsync 0 -c:v h264_cuvid -i test.264 -f rawvideo test.yuv works fine, the generated yuv file is ok.
  BUT When I decode this 264 file by my code use ’h264_cuvid’ decoder, something problem happens, this is my code :

  #include 
  
  
  
  #define __STDC_CONSTANT_MACROS
  
  
  
  #ifdef _WIN32
  
  //Windows
  
  extern "C"
  
  {
  
  #include "libavcodec/avcodec.h"
  
  };
  
  #else
  
  //Linux...
  
  #ifdef __cplusplus
  
  extern "C"
  
  {
  
  #endif
  
  #include <libavcodec></libavcodec>avcodec.h>
  
  #ifdef __cplusplus
  
  };
  
  #endif
  
  #endif
  
  
  
  
  
  //test different codec
  
  #define TEST_H264  1
  
  #define TEST_HEVC  0
  
  
  
  int main(int argc, char* argv[])
  
  {
  
      AVCodec *pCodec;
  
      AVCodecContext *pCodecCtx= NULL;
  
      AVCodecParserContext *pCodecParserCtx=NULL;
  
  
  
      FILE *fp_in;
  
      FILE *fp_out;
  
      AVFrame *pFrame;
  
  
  
      const int in_buffer_size=4096;
  
      unsigned char in_buffer[in_buffer_size + FF_INPUT_BUFFER_PADDING_SIZE]= {0};
  
      unsigned char *cur_ptr;
  
      int cur_size;
  
      AVPacket packet;
  
      int ret, got_picture;
  
  
  
  
  
  #if TEST_HEVC
  
      enum AVCodecID codec_id=AV_CODEC_ID_HEVC;
  
      char filepath_in[]="bigbuckbunny_480x272.hevc";
  
  #elif TEST_H264
  
      AVCodecID codec_id=AV_CODEC_ID_H264;
  
      char filepath_in[]="2_60_265to264.264";
  
  #else
  
      AVCodecID codec_id=AV_CODEC_ID_MPEG2VIDEO;
  
      char filepath_in[]="bigbuckbunny_480x272.m2v";
  
  #endif
  
  
  
      char filepath_out[]="mainSend.yuv";
  
      int first_time=1;
  
  
  
  
  
      //av_log_set_level(AV_LOG_DEBUG);
  
  
  
      avcodec_register_all();
  
  
  
  //    pCodec = avcodec_find_decoder(codec_id);
  
      pCodec = avcodec_find_decoder_by_name("h264_cuvid");
  
      if (!pCodec)
  
      {
  
          printf("Codec not found\n");
  
          return -1;
  
      }
  
      pCodecCtx = avcodec_alloc_context3(pCodec);
  
      if (!pCodecCtx)
  
      {
  
          printf("Could not allocate video codec context\n");
  
          return -1;
  
      }
  
  
  
      pCodecParserCtx=av_parser_init(pCodec->id);
  
      if (!pCodecParserCtx)
  
      {
  
          printf("Could not allocate video parser context\n");
  
          return -1;
  
      }
  
  
  
      if (avcodec_open2(pCodecCtx, pCodec, NULL) &lt; 0)
  
      {
  
          printf("Could not open codec\n");
  
          return -1;
  
      }
  
      //Input File
  
      fp_in = fopen(filepath_in, "rb");
  
      if (!fp_in)
  
      {
  
          printf("Could not open input stream\n");
  
          return -1;
  
      }
  
      //Output File
  
      fp_out = fopen(filepath_out, "wb");
  
      if (!fp_out)
  
      {
  
          printf("Could not open output YUV file\n");
  
          return -1;
  
      }
  
  
  
      pFrame = av_frame_alloc();
  
      av_init_packet(&amp;packet);
  
  
  
      while (1)
  
      {
  
  
  
          cur_size = fread(in_buffer, 1, in_buffer_size, fp_in);
  
          if (cur_size == 0)
  
              break;
  
          cur_ptr=in_buffer;
  
  
  
          while (cur_size>0)
  
          {
  
  
  
              int len = av_parser_parse2(
  
                            pCodecParserCtx, pCodecCtx,
  
                            &amp;packet.data, &amp;packet.size,
  
                            cur_ptr, cur_size,
  
                            AV_NOPTS_VALUE, AV_NOPTS_VALUE, AV_NOPTS_VALUE);
  
  
  
              cur_ptr += len;
  
              cur_size -= len;
  
  
  
              if(packet.size==0)
  
                  continue;
  
  
  
              //Some Info from AVCodecParserContext
  
              printf("[Packet]Size:%6d\t",packet.size);
  
              switch(pCodecParserCtx->pict_type)
  
              {
  
              case AV_PICTURE_TYPE_I:
  
                  printf("Type:I\tNumber:%4d\n",pCodecParserCtx->output_picture_number);
  
                  break;
  
              case AV_PICTURE_TYPE_P:
  
                  printf("Type:P\t");
  
                  break;
  
              case AV_PICTURE_TYPE_B:
  
                  printf("Type:B\t");
  
                  break;
  
              default:
  
                  printf("Type:Other\t");
  
                  break;
  
              }
  
              printf("Number:%4d\n",pCodecParserCtx->output_picture_number);
  
              AVFrame* myFrame = av_frame_alloc();
  
              ret = avcodec_decode_video2(pCodecCtx, myFrame, &amp;got_picture, &amp;packet);
  
              if (ret &lt; 0)
  
              {
  
                  printf("Decode Error.\n");
  
                  return ret;
  
              }
  
              if (got_picture)
  
              {
  
                  if(first_time)
  
                  {
  
                      printf("\nCodec Full Name:%s\n",pCodecCtx->codec->long_name);
  
                      printf("width:%d\nheight:%d\n\n",pCodecCtx->width,pCodecCtx->height);
  
                      first_time=0;
  
                  }
  
                  //Y, U, V
  
                  for(int i=0; iheight; i++)
  
                  {
  
                      fwrite(myFrame->data[0]+myFrag-g>linesize[0]*i,1,myFrame->width,fp_out);
  
                  }
  
                  for(int i=0; iheight/2; i++)
  
                  {
  
                      fwrite(myFrame->data[1]+myFrag-g>linesize[1]*i,1,myFrame->width/2,fp_out);
  
                  }
  
                  for(int i=0; iheight/2; i++)
  
                  {
  
                      fwrite(myFrame->data[2]+myFrag-g>linesize[2]*i,1,myFrame->width/2,fp_out);
  
                  }
  
  //                printf("pframe's width height %d %d\t key frame %d\n",myFrame->width,myFrame->height,myFrame->key_frame);
  
                  printf("Succeed to decode 1 frame!\n");
  
                  av_frame_free(&amp;myFrame);
  
              }
  
          }
  
  
  
      }
  
  
  
      fclose(fp_in);
  
      fclose(fp_out);
  
  
  
  
  
      av_parser_close(pCodecParserCtx);
  
  
  
      av_frame_free(&amp;pFrame);
  
      avcodec_close(pCodecCtx);
  
      av_free(pCodecCtx);
  
  
  
      return 0;
  
  }

  In this demo code, I call h264_cuvid by vcodec_find_decoder_by_name("h264_cuvid");
  BUT the code crash at fwrite(myFrame->data[2]+myFrag-g>linesize[2]*i,1,myFrame->width/2,fp_out);
  So after debug with codeblocks, I found that there is no data in myFrame->data[2] codeblocks watching window

  Any suggestion ? thanks !

• How to stop ffmpeg when recording the desktop to save the file to the hard disk ?

  27 juin 2022, par Eliot Shein

  I'm trying to record the desktop with the ffmpeg and save a video file to the hard disk.

  


  using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Testings
{
    internal class FFmpeg_Capture
    {
        Process process;

        public FFmpeg_Capture()
        {
            process = new Process();
        }

        public void Start(string FileName, int Framerate)
        {
            process.StartInfo.FileName = @"D:\Captured Videos\ffmpeg.exe"; // Change the directory where ffmpeg.exe is.  
            process.EnableRaisingEvents = false;
            process.StartInfo.WorkingDirectory = @"D:\Captured Videos"; // The output directory  
            process.StartInfo.Arguments = @"-f gdigrab -framerate " + Framerate +
                " -i desktop -preset ultrafast - pix_fmt yuv420p " + FileName;
            process.Start();
            process.StartInfo.UseShellExecute = false;
            process.StartInfo.CreateNoWindow = false;
            Stop();
        }

        public void Stop()
        {
            process.Close();
        }
    }
}


  


  And using it in form1 :

  


  private void btnRecord_Click(object sender, EventArgs e)
        {
            recordToggle = !recordToggle;

            if (recordToggle)
            {
                btnRecord.Text = "Stop";
                record.Start("Testing", 60);
            }
            else
            {
                btnRecord.Text = "Record";
                record.Stop();
            }
        }


  


  but the file Testing never saved to the hard disk. my guess is that

  


  process.Close();


  


  is not like ctrl+ c and ctrl + c is what stopping the ffmpeg and save the file.

  


  This is working but how to remove the black window of the ffmpeg ?

  


  

  


  using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.IO.Pipes;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Testings
{
    internal class FFmpeg_Capture
    {
        Process process;

        public FFmpeg_Capture()
        {
            process = new Process();
        }

        public void Start(string FileName, int Framerate)
        {
            process.StartInfo.FileName = @"D:\Captured Videos\ffmpeg.exe"; // Change the directory where ffmpeg.exe is.  
            process.EnableRaisingEvents = false;
            process.StartInfo.WorkingDirectory = @"D:\Captured Videos\"; // The output directory  
            process.StartInfo.Arguments = @"-y -f gdigrab -framerate " + Framerate +
                " -i desktop -preset ultrafast -pix_fmt yuv420p " + FileName;
            process.StartInfo.UseShellExecute = false;
            process.StartInfo.CreateNoWindow = false;
            process.StartInfo.RedirectStandardInput = true; //Redirect stdin
            process.Start();
        }

        public void Stop()
        {
            byte[] qKey = Encoding.GetEncoding("gbk").GetBytes("q"); //Get encoding of 'q' key
            process.StandardInput.BaseStream.Write(qKey, 0, 1); //Write 'q' key to stdin of FFmpeg sub-processs
            process.StandardInput.BaseStream.Flush(); //Flush stdin (just in case).
            process.Close();
        }
    }
}


  


• Save video from rtsp and play in exoplayer simultaneously [closed]

  25 janvier 2024, par Julian Peña Gallego

  I am trying to receive a live stream via RTSP from an IP camera in Android Kotlin, I am recording the video to a local file with ffmpegkit but I must additionally view the live stream.

  


  When I record the live stream with ffmpeg without playing the stream through exoplayer it works fine, but when both processes are running there is packet loss in the video recording or in the exoplayer.

  


  Then I tried to get exoplayer to play the video that ffmpeg was recording, but it gave me an error since the file has not been closed yet.

  


  Could you provide me with a solution ? I have found on the internet that it is possible with server sockets but they do not indicate how to do it.