Recherche avancée

Sur d’autres sites (8190)

• HTML5 video duration varies across browsers when the start time is negative

  31 août 2017, par luis

  I’m working on a web video editor and the duration for videos with negative start time varies across browsers. Here’s the ffmpeg output :

  ffmpeg -i filename.mp4
  
  
  
  ffmpeg version 3.3.2 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 8.1.0 (clang-802.0.42)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  
    libavutil      55. 58.100 / 55. 58.100
  
    libavcodec     57. 89.100 / 57. 89.100
  
    libavformat    57. 71.100 / 57. 71.100
  
    libavdevice    57.  6.100 / 57.  6.100
  
    libavfilter     6. 82.100 /  6. 82.100
  
    libavresample   3.  5.  0 /  3.  5.  0
  
    libswscale      4.  6.100 /  4.  6.100
  
    libswresample   2.  7.100 /  2.  7.100
  
    libpostproc    54.  5.100 / 54.  5.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/filipebrandao/Downloads/mars1.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 1
  
      compatible_brands: mp41mp42isom
  
      creation_time   : 2017-08-24T19:43:26.000000Z
  
    Duration: 00:00:03.25, start: -0.001610, bitrate: 2037 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x534 [SAR 1:1 DAR 640:267], 1075 kb/s, 23.91 fps, 23.98 tbr, 90k tbn, 47.95 tbc (default)
  
      Metadata:
  
        creation_time   : 2017-08-24T19:43:26.000000Z
  
        handler_name    : Core Media Video
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 126 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-08-24T19:43:26.000000Z
  
        handler_name    : Core Media Audio
  
  At least one output file must be specified 

  The important bit from above is the negative start time :

  Duration: 00:00:03.25, start: -0.001610, bitrate: 2037 kb/s

  When I play this video in Chrome and Firefox, both browsers report a duration of 5.72 secs. When I use Safari, the browser reports a duration of 3.24 sec.

  Do you know of a way of having consistent duration and start time values across browsers ?

• ffmpeg : Could not find codec parameters for stream 1 (Video : vp8, yuv420p) : unspecified size ?

  17 août 2024, par Thomas Carlton

  I have an RTP stream coming from Kurento Media Server.

  


  I would like to record this stream to a file using ffmpeg. I'm running the command

  


  ffmpeg -protocol_whitelist file,crypto,udp,rtp -i a.sdp -c:v libx264 -analyzeduration 100M -probesize 100M -y output.mp4


  


  The SDP File is :

  


  v=0
o=- 3831930560 3831930560 IN IP4 127.0.0.1
s=Kurento Media Server
c=IN IP4 127.0.0.1
t=0 0
m=audio 20000 RTP/AVPF 96 0 97
a=setup:actpass
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=rtpmap:96 opus/48000/2
a=rtpmap:97 AMR/8000
a=rtcp:13001
a=sendrecv
a=mid:audio0
a=ssrc:2843019226 cname:user7547104516@host-14132be
m=video 20002 RTP/AVPF 102 103
a=setup:actpass
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=rtpmap:102 VP8/90000
a=rtpmap:103 H264/90000
a=fmtp:103 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f
a=rtcp:56917
a=sendrecv
a=mid:video0
a=rtcp-fb:102 nack
a=rtcp-fb:102 nack pli
a=rtcp-fb:102 goog-remb
a=rtcp-fb:102 ccm fir
a=rtcp-fb:103 nack
a=rtcp-fb:103 nack pli
a=rtcp-fb:103 ccm fir
a=ssrc:1320996934 cname:user7547104516@host-14132be


  


  ffmpeg starts recording however it records only audio. No video recorded and I'm having the error :

  


  


  Could not find codec parameters for stream 1 (Video : vp8, yuv420p) : unspecified size

  


  


  How can I solve that ?

  


  

  


• Installing OpenCV 3.1.0 with CMake on Windows 7, opencv_ffmpeg.dll invalid hash

  21 novembre 2016, par Troppsi

  I’m trying to install OpenCV 3.1.0 with MSVC2015 compiler using CMake. I get an error saying that the file hash is different from the expected hash. I have no access to internet on the PC this needs to be installed on. I tired to install it successfully on a PC with internet to see if I could copy those files to the PC without internet. But that didn’t work as CMake deletes the files, and tries to do it it’s own way. I also tried this solution, but it didn’t work.

  Here is the error message :

  CMake Warning at cmake/OpenCVUtils.cmake:872 (message):
  
    Download: Local copy of opencv_ffmpeg.dll has invalid MD5 hash:
  
    d41d8cd98f00b204e9800998ecf8427e (expected:
  
    89c783eee1c47bfc733f08334ec2e31c)
  
  Call Stack (most recent call first):
  
    3rdparty/ffmpeg/ffmpeg.cmake:10 (ocv_download)
  
    cmake/OpenCVFindLibsVideo.cmake:206 (include)
  
    CMakeLists.txt:536 (include)
  
  
  
  Downloading opencv_ffmpeg.dll...
  
  CMake Error at cmake/OpenCVUtils.cmake:895 (file):
  
    file DOWNLOAD HASH mismatch
  
  
  
      for file: [C:/OpenCV/opencv/sources/3rdparty/ffmpeg/downloads/89c783eee1c47bfc733f08334ec2e31c/opencv_ffmpeg.dll]
  
        expected hash: [89c783eee1c47bfc733f08334ec2e31c]
  
          actual hash: [d41d8cd98f00b204e9800998ecf8427e]
  
               status: [6;"Couldn't resolve host name"]
  
  
  
  Call Stack (most recent call first):
  
    3rdparty/ffmpeg/ffmpeg.cmake:10 (ocv_download)
  
    cmake/OpenCVFindLibsVideo.cmake:206 (include)
  
    CMakeLists.txt:536 (include)
  
  
  
  
  
  CMake Error at cmake/OpenCVUtils.cmake:899 (message):
  
    Failed to download opencv_ffmpeg.dll.  Status=6;"Couldn't resolve host
  
    name"
  
  Call Stack (most recent call first):
  
    3rdparty/ffmpeg/ffmpeg.cmake:10 (ocv_download)
  
    cmake/OpenCVFindLibsVideo.cmake:206 (include)
  
    CMakeLists.txt:536 (include)

  I would like to be able to install this without internet, but it proves very diffucult. Does anyone have any solutions to this ?

  Thanks in advance.