Recherche avancée

Sur d’autres sites (5078)

• How to extract frames at 30 fps using FFMPEG APIs on Android ?

  11 mars 2020, par Amber Beriwal

  We are working on a project that consumes FFMPEG library for video frame extraction on Android platform.

  On Windows, we have observed :

  • Using CLI, ffmpeg is capable of extracting frames at 30 fps using command ffmpeg -i input.flv -vf fps=1 out%d.png.
  • Using Xuggler, we are able to extract frames at 30 fps.
  • Using FFMPEG APIs directly in code, we are getting frames at 30 fps.

  But when we use FFMPEG APIs directly on Android (See Hardware Details), we are getting following results :

  • 720p video (1280 x 720) - 16 fps (approx. 60 ms/frame)
  • 1080p video (1920 x 1080) - 7 fps (approx. 140 ms/frame)

  We haven’t tested Xuggler/CLI on Android yet.

  Ideally, we should be able to get the data in constant time (approx. 30 ms/frame).

  How can we get 30 fps on Android ?

  Code being used on Android :

  if (avformat_open_input(&pFormatCtx, pcVideoFile, NULL, NULL)) {
  
      iError = -1;  //Couldn't open file
  
  }
  
  
  
  if (!iError) {
  
      //Retrieve stream information
  
      if (avformat_find_stream_info(pFormatCtx, NULL) < 0)
  
          iError = -2; //Couldn't find stream information
  
  }
  
  
  
  //Find the first video stream
  
  if (!iError) {
  
  
  
      for (i = 0; i < pFormatCtx->nb_streams; i++) {
  
          if (AVMEDIA_TYPE_VIDEO
  
                  == pFormatCtx->streams[i]->codec->codec_type) {
  
              iFramesInVideo = pFormatCtx->streams[i]->nb_index_entries;
  
              duration = pFormatCtx->streams[i]->duration;
  
              begin = pFormatCtx->streams[i]->start_time;
  
              time_base = (pFormatCtx->streams[i]->time_base.num * 1.0f)
  
                      / pFormatCtx->streams[i]->time_base.den;
  
  
  
              pCodecCtx = avcodec_alloc_context3(NULL);
  
              if (!pCodecCtx) {
  
                  iError = -6;
  
                  break;
  
              }
  
  
  
              AVCodecParameters params = { 0 };
  
              iReturn = avcodec_parameters_from_context(&params,
  
                      pFormatCtx->streams[i]->codec);
  
              if (iReturn < 0) {
  
                  iError = -7;
  
                  break;
  
              }
  
  
  
              iReturn = avcodec_parameters_to_context(pCodecCtx, &params);
  
              if (iReturn < 0) {
  
                  iError = -7;
  
                  break;
  
              }
  
  
  
              //pCodecCtx = pFormatCtx->streams[i]->codec;
  
  
  
              iVideoStreamIndex = i;
  
              break;
  
          }
  
      }
  
  }
  
  
  
  if (!iError) {
  
      if (iVideoStreamIndex == -1) {
  
          iError = -3; // Didn't find a video stream
  
      }
  
  }
  
  
  
  if (!iError) {
  
      // Find the decoder for the video stream
  
      pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
  
      if (pCodec == NULL) {
  
          iError = -4;
  
      }
  
  }
  
  
  
  if (!iError) {
  
      // Open codec
  
      if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0)
  
          iError = -5;
  
  }
  
  
  
  if (!iError) {
  
      iNumBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB24, pCodecCtx->width,
  
              pCodecCtx->height, 1);
  
  
  
      // initialize SWS context for software scaling
  
      sws_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
  
              pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
  
              AV_PIX_FMT_RGB24,
  
              SWS_BILINEAR,
  
              NULL,
  
              NULL,
  
              NULL);
  
      if (!sws_ctx) {
  
          iError = -7;
  
      }
  
  }
  
  clock_gettime(CLOCK_MONOTONIC_RAW, &end);
  
  delta_us = (end.tv_sec - start.tv_sec) * 1000000
  
          + (end.tv_nsec - start.tv_nsec) / 1000;
  
  start = end;
  
  //LOGI("Starting_Frame_Extraction: %lld", delta_us);
  
  if (!iError) {
  
      while (av_read_frame(pFormatCtx, &packet) == 0) {
  
          // Is this a packet from the video stream?
  
          if (packet.stream_index == iVideoStreamIndex) {
  
              pFrame = av_frame_alloc();
  
              if (NULL == pFrame) {
  
                  iError = -8;
  
                  break;
  
              }
  
  
  
              // Decode video frame
  
              avcodec_decode_video2(pCodecCtx, pFrame, &iFrameFinished,
  
                      &packet);
  
              if (iFrameFinished) {
  
                  //OUR CODE
  
              }
  
              av_frame_free(&pFrame);
  
              pFrame = NULL;
  
          }
  
          av_packet_unref(&packet);
  
      }
  
  }

• How can I convert a mp4 into an ogv with ffmpeg ? I am getting a "segmentation fault"

  8 mars 2020, par xrainbowuk

  I am trying to use ffmpeg to convert a mp4 video into an ogv and a webm. I am using a Mac and this is what I am putting into the terminal :

  ffmpeg -i "Hands-typing-(mobile-1080p-loop) copy.mp4" -codec:v libtheora -codec:a libvorbis -f ogv output.ogv

  This is what I am getting in response :

      ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  
    built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  
    libavutil      56. 31.100 / 56. 31.100
  
    libavcodec     58. 54.100 / 58. 54.100
  
    libavformat    58. 29.100 / 58. 29.100
  
    libavdevice    58.  8.100 / 58.  8.100
  
    libavfilter     7. 57.100 /  7. 57.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libswscale      5.  5.100 /  5.  5.100
  
    libswresample   3.  5.100 /  3.  5.100
  
    libpostproc    55.  5.100 / 55.  5.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Hands-typing-(mobile-1080p-loop) copy.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41
  
      creation_time   : 2020-03-04T20:14:21.000000Z
  
    Duration: 00:00:21.18, start: 0.000000, bitrate: 8201 kb/s
  
      Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 8085 kb/s, 30 fps, 30 tbr, 30k tbn, 60k tbc (default)
  
      Metadata:
  
        creation_time   : 2020-03-04T20:14:21.000000Z
  
        handler_name    : ?Mainconcept Video Media Handler
  
        encoder         : AVC Coding
  
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 125 kb/s (default)
  
      Metadata:
  
        creation_time   : 2020-03-04T20:14:21.000000Z
  
        handler_name    : #Mainconcept MP4 Sound Media Handler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> theora (libtheora))
  
    Stream #0:1 -> #0:1 (aac (native) -> vorbis (libvorbis))
  
  Press [q] to stop, [?] for help
  
  zsh: segmentation fault  ffmpeg -i "Hands-typing-(mobile-1080p-loop) copy.mp4" -codec:v libtheora   -f

  I have also tried this, which doesn’t work :

  ffmpeg -i "Hands-typing-(mobile-1080p-loop) copy.mp4" -codec:v libtheora -qscale:v 3 -codec:a libvorbis \
  
    -qscale:a 3 -f ogv output.ogv

  I am struggling to find the answer to my question. Especially as there are so many posts about "segmentation faults".

  Any help is very much appreciated.

• ffmpeg : match audio video duration post concatenation

  20 janvier 2020, par Massimo Vantaggio

  I wrote this bash to automate concatentation of videos for dash mpeg streaming infinite loop.
  Im unable to obtain same duration for audio and video, with the videos that i’m using for testing i get always 6 ms more for audio track.
  May ask help to debug it and understand how to get same duration for both audio and video track ?

  #!/bin/bash
  
  #CANCAT 0.3
  
  
  
  cd input
  
  fps=()
  
  # GET FPS OF EACH VIDEO INTO ARRAY
  
  for f in *.mp4; do
  
      _f=$(ffmpeg -i "$f" 2>&1 | sed -n "s/.*, \\(.*\\) fp.*/\\1/p")
  
      fps+=("$_f")
  
  done
  
  
  
  #GET NUMBER OF ELEMENTS IN FPS ARRAY  
  
  tLen=${#fps[@]}
  
  #CHECK FPS EQUALITY     
  
  for tLen in "${fps[@]:1}"; do
  
      if [[ $tLen != ${fps[0]} ]]; then
  
          printf "WARNING: VIDEO’S FRAME-RATE ARE NOT EQUALS, THE PROCESS CAN’T START."
  
          printf "%s\\0" "${fps[@]}" |
  
              sort -zu |
  
              xargs -0 printf " %s"
  
          printf "\\n"
  
         exit 1
  
      fi
  
  done
  
  
  
  #AUDIO ENCODING
  
  for f in *.mp4; 
  
  do
  
  NAME=$(echo "$f" | cut -d'.' -f1) 
  
  ffmpeg -y -i "$f" -c copy -video_track_timescale 90k -c:a aac -b:a 384k -ar 44100 -ac 2 -shortest -af aresample=async=1 ../buffer/${NAME}_buffer.mp4
  
  done
  
  #-af aresample=async=1000
  
  #-filter_complex " [1:0] apad "
  
  
  
  cd ..
  
  cd buffer
  
  times=()
  
  for f in *.mp4; 
  
  do 
  
  echo "file '$f'" >> list.txt;
  
  
  
  # GET DURATION OF EACH VIDEO
  
  _t=$(ffprobe -i "$f" -show_entries format=duration -v quiet -of csv="p=0")
  
  times+=("$_t")
  
  done
  
  
  
  #SUM ALL DURATIONS
  
  TOTALDURATION=$( echo "${times[@]}" | sed 's/ /+/g' | bc )
  
  DURROUND=$(echo "$TOTALDURATION" | cut -d'.' -f1)
  
  TOTDELTA="$((DURROUND%2))"
  
  TOTDUR="$(($DURROUND-$TOTDELTA))"
  
  
  
  #GET FPS
  
  FPS="$(ffmpeg -i ${f[0]} 2>&1 | sed -n "s/.*, \(.*\) fp.*/\1/p")"
  
  #ROUND FPS
  
  FPSC=$( echo "($FPS+0.5)/1" | bc )
  
  #GET GOP
  
  GOP="$((FPSC*2))"
  
  
  
  #ENCODING MASTER TRACK
  
  ffmpeg -f concat -safe 0 -y -i list.txt -loop 1 -i ../logo/logo.png -c:a copy -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -r $FPSC -b:v 4800k -maxrate 9600k -bufsize 19200k -profile:v main -crf 22 -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-10:10,scale=1920:1080,setsar=1" -t $TOTDUR 1080set.mp4 
  
  
  
  #EXTRACTING AUDIO FROM MASTER VIDEO TRACK
  
  ffmpeg -y -i 1080set.mp4 -c copy -vn ../output/output_audio.mp4
  
  
  
  #REMOVE AUDIO FROM MASTER VIDEO TRACK
  
  ffmpeg -y -i 1080set.mp4 -c copy -an ../output/output_1080.mp4
  
  
  
  #CLEAN BUFFER
  
  rm *.mp4
  
  rm *.txt
  
  
  
  cd .. 
  
  cd output
  
  
  
  #ENCODE 720p
  
  ffmpeg -y -i output_1080.mp4 -an -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -s 1280x720 -r $FPSC -b:v 2400k -maxrate 4800k -bufsize 9600k -profile:v main -crf 22 output_720.mp4
  
  
  
  #ENCODE 360p
  
  ffmpeg -y -i output_1080.mp4 -an -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -s 640x360 -r $FPSC -b:v 800k -maxrate 1600k -bufsize 3200k -profile:v main -crf 22 output_360.mp4
  
  
  
  #VALIDATOR
  
  echo 1080p ENCODING
  
  echo GOP:   $GOP 
  
  echo VIDEO FORMAT CONTAINER DURATION:   
  
  ffprobe -v error -show_entries format=duration \
  
    -of default=noprint_wrappers=1:nokey=1 output_1080.mp4
  
  echo VIDEO STREAM DURATION:
  
  ffprobe -v error -select_streams v:0 -show_entries stream=duration \
  
    -of default=noprint_wrappers=1:nokey=1 output_1080.mp4
  
  echo AUDIO FORMAT CONTAINER DURATION:   
  
  ffprobe -v error -show_entries format=duration \
  
    -of default=noprint_wrappers=1:nokey=1 output_audio.mp4
  
  
  
  echo ______________________________________________________________
  
  
  
  echo 720p ENCODING
  
  echo GOP:   $GOP 
  
  echo VIDEO FORMAT CONTAINER DURATION:   
  
  ffprobe -v error -show_entries format=duration \
  
    -of default=noprint_wrappers=1:nokey=1 output_720.mp4
  
  echo VIDEO STREAM DURATION:
  
  ffprobe -v error -select_streams v:0 -show_entries stream=duration \
  
    -of default=noprint_wrappers=1:nokey=1 output_720.mp4
  
  echo DONE
  
  exit 1

  Here the script with my videos for test and relative folders :
  https://gofile.io/?c=WPAC0Q