Recherche avancée

Sur d’autres sites (4716)

• Can I record a video without using UIImagePickerController ?

  24 mai 2016, par SUKIYAKI

  Can I record a video without using UIImagePickerController ?
  Of course without needing to jailbreak or anything else that would cause the App Store to reject the app.

  I think there is a way to access video device not using UIImagePickerController because these camera applications can record video and work on iPhone 2G/3G which utilizes ffmpeg :

  • iVideoCamera
  • iVidCam

  I pick this code up by googling.

  AVFormatParameters formatParams;
  
  AVInputFormat *iformat;
  
  
  
  formatParams.device = "/dev/video0";
  
  formatParams.channel = 0;
  
  formatParams.standard = "ntsc";
  
  formatParams.width = 640;
  
  formatParams.height = 480;
  
  formatParams.frame_rate = 29;
  
  formatParams.frame_rate_base = 1;
  
  filename = "";
  
  iformat = av_find_input_format("video4linux");
  
  
  
  av_open_input_file(&ffmpegFormatContext,
  
                   filename, iformat, 0, &formatParams);

  This code tell me how to open camera device, but I don’t know device path of iPhone.

  How do iVideoCamera and iVidCam record video ?

• FFMPEG .mov to .mp4 convertion failure

  25 mai 2016, par Pasha Rumkin

  I’m converting .mov and .mp4 to .mp4 with FFMPEG to play them on iOS and Android devices. Mp4 from Android is converting properly and playing on both devices iPhone and Android. But iPhone’s .mov result is strange. It’s playing on iPhone and Android 4. But when I’m trying to open this video with Photo app (Android 5, 6) it outputs unsupported video message.

  FFMPEG command :

  ffmpeg -i app/data/storage/68/fa/39/68fa392b-df25-4622-93ab-cf9bf1253f63 \
  
         -y -b:a 128k -ac 2 -acodec libfdk_aac -b:v 300k -vcodec libx264 \
  
         -filter:v scale=w=320:h=trunc(ow/a/2)*2 -vprofile baseline \
  
         -movflags faststart -f mp4 \
  
         app/data/storage/68/fa/39/68fa392b-df25-4622-93ab-cf9bf1253f63.mp4

  ffprobe with output file :

  ffprobe version N-80026-g936751b Copyright (c) 2007-2016 the FFmpeg developers
  
    built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)
  
    configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --mandir=/usr/share/man --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-libopencore-amrnb --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb --enable-libpulse --enable-libfreetype --enable-gnutls --enable-libx264 --enable-libx265 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr --enable-libxvid --enable-libvidstab
  
    libavutil      55. 24.100 / 55. 24.100
  
    libavcodec     57. 42.100 / 57. 42.100
  
    libavformat    57. 36.100 / 57. 36.100
  
    libavdevice    57.  0.101 / 57.  0.101
  
    libavfilter     6. 45.100 /  6. 45.100
  
    libavresample   3.  0.  0 /  3.  0.  0
  
    libswscale      4.  1.100 /  4.  1.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '68fa392b-df25-4622-93ab-cf9bf1253f63.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.36.100
  
    Duration: 00:00:00.65, start: 0.000000, bitrate: 297 kb/s
  
      Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 320x568, 178 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 129 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

• Texai Remote Presence System Using VP8 Video

  19 novembre 2010, par noreply@blogger.com (John Luther)

  Guest blogger Josh Tyler is a member of the Texai team at Willow Garage.

  Willow Garage is busy building the next version of its Texai remote presence platform with VP8, the video codec used in WebM.

  In short, Texai is a two-way videoconferencing app on a tele-operated robotic platform (for more details, see the piece about Texai in the New York Times). Video and audio quality are critical to providing the best user experience on Texai. We’ve evaluated several video codecs and found VP8’s image quality, low latency and tolerance to packet loss far better than anything else we tested.

  The video below shows VP8 running on one of our systems.

  (If you have a WebM-enabled browser and are enrolled in the YouTube HTML5 beta the video will play in WebM HTML5, otherwise it will play in Flash Player.)

  We’re also looking for help ! If you’re interested in helping us create an incredible, high-fidelity user experience, either by joining our team, partnering on development, or by being added to our early customer interest list, please email us at texai-info@willowgarage.com.