Recherche avancée

Sur d’autres sites (13838)

• How to get the highest resolution, dividable by 2 that contains the video without black borders after rotation ?

  22 avril 2016, par Vitalis Hommel

  I rotate a video. Then my goal is to get the biggest resolution, dividable by 2 that contains the video without black borders.

  

  to

  

  My approach.

  ffmpeg -ss 6 -i "t.MP4" -ss 0 -t 5 -vf "rotate='8*PI/180:ow=hypot(iw,ih):oh=ow', scale='1920:1920', crop='1920:1080:0:420'" -c:v libx264 -crf 28 -acodec copy "t2.MP4"

  But that does not meet the criteria. Which command do I need ?

• Advice about older android, VideoView and resolutions

  20 avril 2016, par Diogo Garcia

  I’ve been testing webm and mp4 for videoView and looking around for quite some time and right now the best way for me to play a video in a older android(2.3.3+) is using mp4 AVC-Baseline using the code

  "ffmpeg.exe" -i "intro.mp4" -codec:v libx264 -profile:v baseline
  -preset slow -b:v 500k -maxrate 500k -bufsize 1000k -vf scale=432:320 -codec:a aac -strict experimental -b:a 96k -f mp4 "intro_result.mp4"

  By far this is the best solution for my android 2.3.3 device... But this resolution is very low when using it in a bigger device for example it gets blurry, so I tried to increase the resolution but it crashes the video when I try to run in my android 2.3.3 device.

  Does anyone has any idea how to be able to view this video no matter the resolution of the device ?

  I was thinking about keep a high quality video inside the app and then check if the device has a low resolution and somehow try to resize the hiquality video before injecting it inside the VideoView. But I don’t even know if it is possible...

• Encode video with FFmpeg fps have been wrong

  7 novembre 2016, par Burak Hamuryen

  I’m trying to encod a video with FFmpeg but i have a problem about fps.
  So i build the sample code as follows

  AVCodec *codec;
  
  AVCodecContext *c = NULL;
  
  int i, ret, x, y, got_output;
  
  FILE *f;
  
  AVFrame *frame;
  
  AVPacket pkt;
  
  uint8_t endcode[] = { 0, 0, 1, 0xb7 };
  
  
  
  printf("Encode video file %s\n", filename);
  
  
  
  /* find the mpeg1 video encoder */
  
  codec = avcodec_find_encoder((AVCodecID)codec_id);
  
  if (!codec) {
  
      fprintf(stderr, "Codec not found\n");
  
      exit(1);
  
  }
  
  
  
  c = avcodec_alloc_context3(codec);
  
  if (!c) {
  
      fprintf(stderr, "Could not allocate video codec context\n");
  
      exit(1);
  
  }
  
  
  
  /* put sample parameters */
  
  c->bit_rate = 400000;
  
  /* resolution must be a multiple of two */
  
  c->width = 352;
  
  c->height = 288;
  
  /* frames per second */
  
  c->time_base.num = 1;
  
  c->time_base.den = 5; //changed
  
  
  
  /* emit one intra frame every ten frames
  
  * check frame pict_type before passing frame
  
  * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
  
  * then gop_size is ignored and the output of encoder
  
  * will always be I frame irrespective to gop_size
  
  */
  
  c->gop_size = 10;
  
  c->max_b_frames = 1;
  
  c->pix_fmt = AV_PIX_FMT_YUV420P;
  
  
  
  if (codec_id == AV_CODEC_ID_H264)
  
      av_opt_set(c->priv_data, "preset", "slow", 0);
  
  
  
  /* open it */
  
  if (avcodec_open2(c, codec, NULL) < 0) {
  
      fprintf(stderr, "Could not open codec\n");
  
      exit(1);
  
  }
  
  
  
  f = fopen(filename, "wb");
  
  if (!f) {
  
      fprintf(stderr, "Could not open %s\n", filename);
  
      exit(1);
  
  }
  
  
  
  frame = av_frame_alloc();
  
  if (!frame) {
  
      fprintf(stderr, "Could not allocate video frame\n");
  
      exit(1);
  
  }
  
  frame->format = c->pix_fmt;
  
  frame->width = c->width;
  
  frame->height = c->height;
  
  
  
  /* the image can be allocated by any means and av_image_alloc() is
  
  * just the most convenient way if av_malloc() is to be used */
  
  ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height,
  
      c->pix_fmt, 32);
  
  if (ret < 0) {
  
      fprintf(stderr, "Could not allocate raw picture buffer\n");
  
      exit(1);
  
  }
  
  
  
  /* encode 5 second of video */
  
  for (i = 0; i < 25; i++) {
  
      av_init_packet(&pkt);
  
      pkt.data = NULL;    // packet data will be allocated by the encoder
  
      pkt.size = 0;
  
  
  
      fflush(stdout);
  
      /* prepare a dummy image */
  
      /* Y */
  
      for (y = 0; y < c->height; y++) {
  
          for (x = 0; x < c->width; x++) {
  
              frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
  
          }
  
      }
  
  
  
      /* Cb and Cr */
  
      for (y = 0; y < c->height / 2; y++) {
  
          for (x = 0; x < c->width / 2; x++) {
  
              frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2;
  
              frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;
  
          }
  
      }
  
  
  
      frame->pts = i;
  
  
  
      /* encode the image */
  
      ret = avcodec_encode_video2(c, &pkt, frame, &got_output);
  
      if (ret < 0) {
  
          fprintf(stderr, "Error encoding frame\n");
  
          exit(1);
  
      }
  
  
  
      if (got_output) {
  
          printf("Write frame %3d (size=%5d)\n", i, pkt.size);
  
          fwrite(pkt.data, 1, pkt.size, f);
  
          av_free_packet(&pkt);
  
      }
  
  }
  
  
  
  /* get the delayed frames */
  
  for (got_output = 1; got_output; i++) {
  
      fflush(stdout);
  
  
  
      ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);
  
      if (ret < 0) {
  
          fprintf(stderr, "Error encoding frame\n");
  
          exit(1);
  
      }
  
  
  
      if (got_output) {
  
          printf("Write frame %3d (size=%5d)\n", i, pkt.size);
  
          fwrite(pkt.data, 1, pkt.size, f);
  
          av_free_packet(&pkt);
  
      }
  
  }
  
  
  
  /* add sequence end code to have a real mpeg file */
  
  fwrite(endcode, 1, sizeof(endcode), f);
  
  fclose(f);
  
  
  
  avcodec_close(c);
  
  av_free(c);
  
  av_freep(&frame->data[0]);
  
  av_frame_free(&frame);
  
  printf("\n");

  and I changed the following parts from the original

  c->time_base.num = 1;
  
  c->time_base.den = 5;

  after these changes, i expect a video to be composed of 5 seconds and 5 fps.
  But when i play the output video file, the video ends in 1 2 seconds.
  The ffprob output of output video is as follows.

  Edit :
  ffprobe output added as a text

  ffprobe version 2.0.1 Copyright (c) 2007-2013 the FFmpeg developers
  
    built on Sep 26 2013 02:00:03 with gcc 4.8.1 (GCC)
  
    configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  
    libavutil      52. 38.100 / 52. 38.100
  
    libavcodec     55. 18.102 / 55. 18.102
  
    libavformat    55. 12.100 / 55. 12.100
  
    libavdevice    55.  3.100 / 55.  3.100
  
    libavfilter     3. 79.101 /  3. 79.101
  
    libswscale      2.  3.100 /  2.  3.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, h264, from 'C:\Users\bhamuryen\Desktop\Dev\Test\ffmpeg_test\ffmpeg_test\test.h264':
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: h264 (High), yuv420p, 352x288, 5 fps, 5 tbr, 1200k tbn, 10 tbc
  
  [STREAM]
  
  index=0
  
  codec_name=h264
  
  codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  profile=High
  
  codec_type=video
  
  codec_time_base=1/10
  
  codec_tag_string=[0][0][0][0]
  
  codec_tag=0x0000
  
  width=352
  
  height=288
  
  has_b_frames=1
  
  sample_aspect_ratio=0:1
  
  display_aspect_ratio=0:1
  
  pix_fmt=yuv420p
  
  level=13
  
  timecode=N/A
  
  id=N/A
  
  r_frame_rate=10/2
  
  avg_frame_rate=5/1
  
  time_base=1/1200000
  
  start_pts=N/A
  
  start_time=N/A
  
  duration_ts=N/A
  
  duration=N/A
  
  bit_rate=N/A
  
  nb_frames=N/A
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=0
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0

  The output video file played with VLC and VLC statistic is as follows.

  

  As shown, i setted fps 5 but vlc read it like 10 fps also ffprobe say to us

  Stream #0:0 : Video : h264 (High), yuv420p, 352x288, 5 fps, 5 tbr, 1200k tbn, 10 tbc

  and

  codec_time_base=1/10

  i think the important thing is codec_time_base=1/10 and 10 tbc.
  What is wrong in this code ? i don’t know exactly the reason for the problem.
  How can i create a video(5 fps -10 fps or custom fps) and play correctly the created video ?

  Thanks for your help.