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• VLC - Could someone assist me into improving latency in streaming to web based app ?

  19 janvier 2017, par zyeek

  I have been looking for solutions in which I can stream an IP camera’s stream to HTML 5. Currently as is it doesn’t support RTSP so easily.

  I am trying to be able to view the camera’s stream as live as possible. I was hoping someone could help me achieve that. I have been playing with it to get something workable, but at the moment I get a 5s delay stream. It is smooth, but wish to get it hopefully within <1-2s delay if possible.

  My current setup goes from taking my IP camera’s stream in RTSP and converting it to a webm and streaming it to a url, which then I plan on using that to put else where in a web app.

  ---

  What I would like to achieve

  Use a protocol that has low latency with audio was well. Webm was used as test, but I can’t seem to get other commands to get the proper stream to be going.

  I would like to use DASH, but from reading FFMPEG currently doesn’t support it. I was thinking maybe RTMP would be good enough for now, being both low latency and HTTP 5 compatible. I am just unable to figure out how to get FFMPEG to transcode the RTSP to RTMP.

  ---

  SETUP :

  I am using ffserver and ffmpeg. Overall scope : trying to pull IP camera stream and put it on a web app.

  Framework I am use is Meteor JS. So, I am trying to few plugins or outside complex setups as I want to be able to deploy this Meteor app on mobile devices as well. So, I want to stay within the boundaries of what HTML 5 can support.

  My current ffserver setup is ffserver.conf (this was taking from bunch of different place :

  HTTPPort 8090                      # Port to bind the server to
  
  HTTPBindAddress 0.0.0.0
  
  MaxHTTPConnections 2000
  
  MaxClients 1000
  
  MaxBandwidth 10000             # Maximum bandwidth per client
  
                                 # set this high enough to exceed stream bitrate
  
  CustomLog -
  
  
  
  <feed>
  
       File /tmp/feed.ffm
  
       FileMaxSize 100K
  
       ACL allow 127.0.0.1
  
  </feed>
  
  
  
  
  
  <stream>
  
       Format webm
  
       Feed feed.ffm
  
       NoAudio
  
       VideoCodec libvpx
  
       VideoFrameRate 24
  
       VideoBitRate 1024
  
       VideoSize 480x270
  
       VideoBufferSize 1024
  
       AVOptionVideo flags +global_header
  
       StartSendOnKey
  
  </stream>
  
  
  
  <stream>            # Server status URL
  
     Format status
  
     # Only allow local people to get the status
  
     ACL allow localhost
  
  </stream>
  
  
  
  <redirect>    # Just an URL redirect for index
  
     # Redirect index.html to the appropriate site
  
     URL url/
  
  </redirect>

  Works normally :

  ffserver version 3.2.2 Copyright (c) 2000-2016 the FFmpeg developers
  
    built with Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.1.2/include/openjpeg-2.1 --enable-nonfree --enable-vda
  
    libavutil      55. 34.100 / 55. 34.100
  
    libavcodec     57. 64.101 / 57. 64.101
  
    libavformat    57. 56.100 / 57. 56.100
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libavresample   3.  1.  0 /  3.  1.  0
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  /etc/ffserver.conf:27: Setting default value for video bit rate tolerance = 256000. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:27: Setting default value for video rate control equation = tex^qComp. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:27: Setting default value for video max rate = 2048000. Use NoDefaults to disable it.
  
  Wed Jan 18 17:04:30 2017 FFserver started.

  Now I give life to the feed with ffmpeg. Command I use :

  ffmpeg -vsync 2 -i rtsp://admin:password@192.168.2.165:88/videoMain -map 0 http://localhost:8090/feed.ffm

  which gives the result :

  ffmpeg version 3.2.2 Copyright (c) 2000-2016 the FFmpeg developers
  
    built with Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.1.2/include/openjpeg-2.1 --enable-nonfree --enable-vda
  
    libavutil      55. 34.100 / 55. 34.100
  
    libavcodec     57. 64.101 / 57. 64.101
  
    libavformat    57. 56.100 / 57. 56.100
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libavresample   3.  1.  0 /  3.  1.  0
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  Guessed Channel Layout for Input Stream #0.1 : mono
  
  Input #0, rtsp, from 'rtsp://admin:password@192.168.2.165:88/videoMain':
  
    Metadata:
  
      title           : IP Camera Video
  
      comment         : videoMain
  
    Duration: N/A, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: h264 (Main), yuv420p(progressive), 1280x720, 90k tbr, 90k tbn, 180k tbc
  
      Stream #0:1: Audio: pcm_mulaw, 8000 Hz, mono, s16, 64 kb/s
  
  [libvpx @ 0x7fd58184a600] v1.6.0
  
  Output #0, ffm, to 'http://localhost:8090/feed.ffm':
  
    Metadata:
  
      title           : IP Camera Video
  
      comment         : videoMain
  
      creation_time   : now
  
      encoder         : Lavf57.56.100
  
      Stream #0:0: Video: vp8 (libvpx), yuv420p, 480x270, q=-1--1, 1024 kb/s, 90k fps, 1000k tbn, 24 tbc
  
      Metadata:
  
        encoder         : Lavc57.64.101 libvpx
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/0 buffer size: 8388608 vbv_delay: -1
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> vp8 (libvpx))
  
  Press [q] to stop, [?] for help
  
  [rtsp @ 0x7fd581000000] max delay reached. need to consume packet
  
  [rtsp @ 0x7fd581000000] RTP: missed 5 packets
  
  [h264 @ 0x7fd5818ae800] Increasing reorder buffer to 1
  
  frame=  139 fps= 18 q=0.0 Lsize=     440kB time=00:00:09.25 bitrate= 389.7kbits/s speed=1.19x    
  
  video:429kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.663893%

• opus : add a native Opus encoder

  11 février 2017, par Rostislav Pehlivanov

  opus : add a native Opus encoder
  This marks the first time anyone has written an Opus encoder without
  
  using any libopus code. The aim of the encoder is to prove how far
  
  the format can go by writing the craziest encoder for it.
  Right now the encoder’s basic, it only supports CBR encoding, however
  
  internally every single feature the CELT layer has is implemented
  
  (except the pitch pre-filter which needs to work well with the rest of
  
  whatever gets implemented). Psychoacoustic and rate control systems are
  
  under development.
  The encoder takes in frames of 120 samples and depending on the value of
  
  opus_delay the plan is to use the extra buffered frames as lookahead.
  
  Right now the encoder will pick the nearest largest legal frame size and
  
  won’t use the lookahead, but that’ll change once there’s a
  
  psychoacoustic system.
  Even though its a pretty basic encoder its already outperforming
  
  any other native encoder FFmpeg has by a huge amount.
  The PVQ search algorithm is faster and more accurate than libopus’s
  
  algorithm so the encoder’s performance is close to that of libopus
  
  at zero complexity (libopus has more SIMD).
  
  The algorithm might be ported to libopus or other codecs using PVQ in
  
  the future.
  The encoder still has a few minor bugs, like desyncs at ultra low
  
  bitrates (below 9kbps with 20ms frames).
  Signed-off-by : Rostislav Pehlivanov <atomnuker@gmail.com>
  

  • [DH] configure
  • [DH] libavcodec/Makefile
  • [DH] libavcodec/allcodecs.c
  • [DH] libavcodec/opus_celt.h
  • [DH] libavcodec/opus_pvq.c
  • [DH] libavcodec/opus_pvq.h
  • [DH] libavcodec/opusenc.c

• How to convert VP8 track with different frame resolution to h264

  13 septembre 2016, par Nikita

  I have a .webm file with VP8 track, recorded from WebRTC stream by external service (TokBox Archiving). The stream is adaptive, so each frame in track could have different resolution. Most players (in webkit browsers) use video resolution from track description (which is always 640x480) and scale frames to this resolution. Firefox and VLC player uses real frame resolution, changing video resolution respectively.

  I want to achieve 2 goals :

  1. play this video in Internet Explorer 9+ without additional plugin installation.
  2. change frames resolution to one fixed resolution, so the video will look identically in different browsers.

  So, my plan is :

  • extract frames from source webm file to images with real frame resolution (e.g. PNG or BMP) (how could I do that ?)
  • find max width and max height of images
  • add black padding to images, so smaller frames will be in the center of a new frame (of size MAX_WIDHTxMAX_HEIGHT)
  • combine images to h264 track using ffmpeg

  Is all correct ? How can I achieve this ? Can this algorithm be optimized some way ?

  I tried ffmpeg to extract images, but it does not parse real frame resolution, using resolution from track header.
  I think some libwebm functions can help me (to parse frame headers and extract images). Maybe someone has some code snippets to do this ?

  Example .webm (download source, do not play google-converted version) : https://drive.google.com/file/d/0BwFZRvYNn9CKcndhMzlVa0psX00/view?usp=sharing

  Official description of adaptive stream from TokBox support : https://support.tokbox.com/hc/en-us/community/posts/206241666-Archived-video-resolution-is-supposed-to-be-720x1280-but-reports-as-640x480