Recherche avancée

Sur d’autres sites (11110)

• HTML5 - ffmpeg encoded x264 video fails to play in Chrome/IE

  11 août 2014, par Saren Arterius

  I have totally no idea why http://jiro.wtako.net/video/39 does work in all browsers while http://jiro.wtako.net/video/40 only works in Firefox.

  1 is encoded by MediaCoder (x264 + Nero encoder) and 2 is encoded by Arch Linux ffmpeg.

  ffmpeg version : ffmpeg 1:2.3.1-1

  x264 version : libx264 1:142.20140311-6

  It seems that video size, frame rate, profile, level, bitrate does not affect whether the video can be played, because I have tried all these parameters, none of these works :

  $ ffmpeg -i in.avi -c:v libx264 -crf 25 -pix_fmt yuv420p -preset veryslow -vf scale=640:360 -c:a aac -strict -2 -b:a 192k out.mp4
  
  
  
  $ ffmpeg -i in.avi -c:v libx264 -crf 25 -pix_fmt yuv420p -preset veryslow -vf scale=640:360 -c:a aac -strict -2 -b:a 128k out.mp4
  
  
  
  $ ffmpeg -i in.avi -c:v libx264 -crf 28 -pix_fmt yuv420p -preset veryslow -c:a aac -strict -2 -b:a 192k out.mp4
  
  
  
  $ ffmpeg -i in.avi -c:v libx264 -b:v 2000k -pix_fmt yuv420p -preset veryslow -c:a aac -strict -2 -b:a 192k out.mp4
  
  
  
  $ ffmpeg -i in.avi -c:v libx264 -crf 28 -pix_fmt yuv420p -level:v 3.2 -preset veryslow -c:a aac -strict -2 -b:a 192k out.mp4
  
  
  
  $ ffmpeg -i in.avi -c:v libx264 -crf 28 -pix_fmt yuv420p -profile:v baseline -preset veryslow -c:a aac -strict -2 -b:a 192k out.mp4

  Here is the media info of the video that does work in all browsers.

  Format                                   : MPEG-4
  
  Format profile                           : Base Media
  
  Codec ID                                 : isom
  
  File size                                : 12.5 MiB
  
  Duration                                 : 1mn 52s
  
  Overall bit rate mode                    : Variable
  
  Overall bit rate                         : 932 Kbps
  
  Encoded date                             : UTC 2014-05-01 13:14:37
  
  Tagged date                              : UTC 2014-05-01 13:14:37
  
  
  
  Video
  
  ID                                       : 1
  
  Format                                   : AVC
  
  Format/Info                              : Advanced Video Codec
  
  Format profile                           : High@L3.1
  
  Format settings, CABAC                   : Yes
  
  Format settings, ReFrames                : 15 frames
  
  Codec ID                                 : avc1
  
  Codec ID/Info                            : Advanced Video Coding
  
  Duration                                 : 1mn 52s
  
  Bit rate                                 : 768 Kbps
  
  Maximum bit rate                         : 1 307 Kbps
  
  Width                                    : 640 pixels
  
  Height                                   : 360 pixels
  
  Display aspect ratio                     : 16:9
  
  Frame rate mode                          : Constant
  
  Frame rate                               : 60.000 fps
  
  Color space                              : YUV
  
  Chroma subsampling                       : 4:2:0
  
  Bit depth                                : 8 bits
  
  Scan type                                : Progressive
  
  Bits/(Pixel*Frame)                       : 0.056
  
  Stream size                              : 10.7 MiB (86%)
  
  Writing library                          : x264 core 128 r2216 198a7ea
  
  Encoding settings                        : cabac=1 / ref=16 / deblock=1:0:0 / analyse=0x3:0x133 / me=tesa / subme=11 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=9 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=16 / b_pyramid=1 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=abr / mbtree=1 / bitrate=768 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
  
  Encoded date                             : UTC 2014-05-01 13:14:37
  
  Tagged date                              : UTC 2014-05-01 13:14:37
  
  
  
  Audio
  
  ID                                       : 2
  
  Format                                   : AAC
  
  Format/Info                              : Advanced Audio Codec
  
  Format profile                           : LC
  
  Codec ID                                 : 40
  
  Duration                                 : 1mn 52s
  
  Bit rate mode                            : Variable
  
  Bit rate                                 : 124 Kbps
  
  Maximum bit rate                         : 133 Kbps
  
  Channel(s)                               : 2 channels
  
  Channel positions                        : Front: L R
  
  Sampling rate                            : 48.0 KHz
  
  Compression mode                         : Lossy
  
  Stream size                              : 1.66 MiB (13%)
  
  Encoded date                             : UTC 2014-05-01 13:14:37
  
  Tagged date                              : UTC 2014-05-01 13:14:37

  Here is the media info of the video that does work only in Firefox.

  Format                                   : MPEG-4
  
  Format profile                           : Base Media
  
  Codec ID                                 : isom
  
  File size                                : 57.4 MiB
  
  Duration                                 : 2mn 48s
  
  Overall bit rate mode                    : Variable
  
  Overall bit rate                         : 2 856 Kbps
  
  Writing application                      : Lavf55.33.100
  
  
  
  Video
  
  ID                                       : 1
  
  Format                                   : AVC
  
  Format/Info                              : Advanced Video Codec
  
  Format profile                           : High@L5.0
  
  Format settings, CABAC                   : Yes
  
  Format settings, ReFrames                : 16 frames
  
  Codec ID                                 : avc1
  
  Codec ID/Info                            : Advanced Video Coding
  
  Duration                                 : 2mn 48s
  
  Bit rate                                 : 2 655 Kbps
  
  Width                                    : 1 280 pixels
  
  Height                                   : 720 pixels
  
  Display aspect ratio                     : 16:9
  
  Frame rate mode                          : Constant
  
  Frame rate                               : 60.000 fps
  
  Color space                              : YUV
  
  Chroma subsampling                       : 4:2:0
  
  Bit depth                                : 8 bits
  
  Scan type                                : Progressive
  
  Bits/(Pixel*Frame)                       : 0.048
  
  Stream size                              : 53.3 MiB (93%)
  
  Writing library                          : x264 core 142 r2397M b7a50c1
  
  Encoding settings                        : cabac=1 / ref=16 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=8 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=25.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
  
  
  
  Audio
  
  ID                                       : 2
  
  Format                                   : AAC
  
  Format/Info                              : Advanced Audio Codec
  
  Format profile                           : LC
  
  Codec ID                                 : 40
  
  Duration                                 : 2mn 48s
  
  Duration_LastFrame                       : -19ms
  
  Bit rate mode                            : Variable
  
  Bit rate                                 : 192 Kbps
  
  Channel(s)                               : 2 channels
  
  Channel positions                        : Front: L R
  
  Sampling rate                            : 48.0 KHz
  
  Compression mode                         : Lossy
  
  Stream size                              : 3.79 MiB (7%)

• Revision 8db245b6a1 : Add an adaptive denoising mode. On key frame, will always start with normal den

  7 août 2014, par Marco Paniconi

  Changed Paths :
   Modify /examples/vpx_temporal_svc_encoder.c

  
   Modify /vp8/common/onyx.h

  
   Modify /vp8/encoder/denoising.c

  
   Modify /vp8/encoder/denoising.h

  
   Modify /vp8/encoder/onyx_if.c

  
  
  Add an adaptive denoising mode.

  On key frame, will always start with normal denoising mode,
  but based on a computed noise metric (normalized mse on source diff)
  may switch to aggressive mode (and back down again).

  Change-Id : I20330b2dcf3056287be37223302b2cab5fc103eb

• Video Conferencing in HTML5 : WebRTC via Web Sockets

  14 juin 2012, par silvia

  A bit over a week ago I gave a presentation at Web Directions Code 2012 in Melbourne. Maxine and John asked me to speak about something related to HTML5 video, so I went for the new shiny : WebRTC – real-time communication in the browser.

  Presentation slides

  I only had 20 min, so I had to make it tight. I wanted to show off video conferencing without special plugins in Google Chrome in just a few lines of code, as is the promise of WebRTC. To a large extent, I achieved this. But I made some interesting discoveries along the way. Demos are in the slide deck.

  UPDATE : Opera 12 has been released with WebRTC support.

  Housekeeping : if you want to replicate what I have done, you need to install a Google Chrome Web Browser 19+. Then make sure you go to chrome ://flags and activate the MediaStream and PeerConnection experiment(s). Restart your browser and now you can experiment with this feature. Big warning up-front : it’s not production-ready, since there are still changes happening to the spec and there is no compatible implementation by another browser yet.

  Here is a brief summary of the steps involved to set up video conferencing in your browser :

  1. Set up a video element each for the local and the remote video stream.
  2. Grab the local camera and stream it to the first video element.
  3. (*) Establish a connection to another person running the same Web page.
  4. Send the local camera stream on that peer connection.
  5. Accept the remote camera stream into the second video element.

  Now, the most difficult part of all of this – believe it or not – is the signalling part that is required to build the peer connection (marked with (*)). Initially I wanted to run completely without a server and just enter the remote’s IP address to establish the connection. This is, however, not a functionality that the PeerConnection object provides [might this be something to add to the spec ?].

  So, you need a server known to both parties that can provide for the handshake to set up the connection. All the examples that I have seen, such as https://apprtc.appspot.com/, use a channel management server on Google’s appengine. I wanted it all working with HTML5 technology, so I decided to use a Web Socket server instead.

  I implemented my Web Socket server using node.js (code of websocket server). The video conferencing demo is in the slide deck in an iframe – you can also use the stand-alone html page. Works like a treat.

  While it is still using Google’s STUN server to get through NAT, the messaging for setting up the connection is running completely through the Web Socket server. The messages that get exchanged are plain SDP message packets with a session ID. There are OFFER, ANSWER, and OK packets exchanged for each streaming direction. You can see some of it in the below image :

  

  I’m not running a public WebSocket server, so you won’t be able to see this part of the presentation working. But the local loopback video should work.

  At the conference, it all went without a hitch (while the wireless played along). I believe you have to host the WebSocket server on the same machine as the Web page, otherwise it won’t work for security reasons.

  A whole new world of opportunities lies out there when we get the ability to set up video conferencing on every Web page – scary and exciting at the same time !