DashCast

DashCast is an application which allows users to:

1. transcode a live/non-live stream in multiple qualities (eg. bitrate and resolution).

2. segment it in small chunks and packetize them for delivery via Dynamic Adaptive Streaming over HTTP (DASH) standard.

Also try the Tiny Multimedia Framework. The Dash filter is not implemented yet but it is going to be implemented soon. the example 10 now is able to capture webcam stream and display it.

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DashCast

21 thoughts on “DashCast

  1. Stas says:

    Hi

    i need some help with dashcast:
    i have connected a web camera to my computer and i have tryied create video segments on the fly with dashcast.

    i’m runnig the folloing command:
    DashCast -vf video4linux2 -vfr 30 -vres 640×480 -v /dev/video0 -af alsa -a plughw:card0,device0 -conf dashcast.conf -live

    and i’m getting the following error:
    Options:
    video source: /dev/video0
    video format: video4linux2
    video framerate: 30
    video resolution: 640×480
    audio source: plughw:card0,device0
    audio format: alsa
    Configurations:
    id:v1.mp4 res:640×480 vbr:400000
    id:a1.mp4 abr:200000
    [video4linux2 @ 0xa0425e0] The V4L2 driver changed the video from 640×480 to 352×288
    [video4linux2 @ 0xa0425e0] Cannot find a proper format for codec_id 0, pix_fmt -1.
    Cannot open file /dev/video0
    Cannot open input video.

    what should i do ?

    my video drive is
    ls /dev/video*
    /dev/video0

    and audio
    arecord -l
    **** List of CAPTURE Hardware Devices ****
    card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog]
    Subdevices: 1/2
    Subdevice #0: subdevice #0
    Subdevice #1: subdevice #1

    hope you can help me
    Thanks
    Stas

  2. Stas says:

    We installed the latest svn 1 week ago.
    Could you be more specific about where to specify -v4l2f mjpeg? In dashcast, it is not a command, and i dont know where i can specfiy it.

    Also, we tried -a plughw:0,0 , we still get an error about the -V4L2F Driver.

    yacov@temp:~$ DashCast -vf video4linux2 -vfr 30 -vres 640×480 -v /dev/video0 -af alsa -a plughw:0,0 -conf dashcast.conf -live
    Options:
    video source: /dev/video0
    video format: video4linux2
    video framerate: 30
    video resolution: 640×480
    audio source: plughw:0,0
    audio format: alsa
    Configurations:
    id:v1.mp4 res:640×480 vbr:400000
    id:a1.mp4 abr:200000
    [video4linux2 @ 0x83f85e0] The V4L2 driver changed the video from 640×480 to 352×288
    [video4linux2 @ 0x83f85e0] Cannot find a proper format for codec_id 0, pix_fmt -1.
    Cannot open file /dev/video0
    Cannot open input video.

    Thanks.

  3. I added the option -v4l2f recently. That’s probably why you don’t have it. So if you update and install now you’ll have it.

    The problem seems to be from ffmpeg. Try to capture video using ffmpeg and see if you have the same problem:
    avconv -f video4linux2 -i /dev/video0 out.mp4

    PS: There is also a low chance that the problem is with your usb port, if you are using usb webcam. Could you check with different port or usb 3.0 if you have one?

  4. Stas says:

    hi arashafiei

    i have tried to reintall gpac
    and then tried to run the following command:
    avconv -f video4linux2 -i /dev/video0 out.mp4

    and i’ve got the following result:

    yacov@temp:~$ avconv -f video4linux2 -i /dev/video0 out.mp4
    avconv version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers
    built on Apr 2 2013 17:00:59 with gcc 4.6.3
    [video4linux2 @ 0x9c8d280] Cannot find a proper format for codec_id 0, pix_fmt -1.
    /dev/video0: Input/output error

    what should i do ?

    and yes i do have an usb webcam i have also tried a different usb port and i still got an error.
    what type of camera should i use (maybe i can arrange something)?

    thanks
    Stas

  5. @Chia-Liang-Ke

    Since DashCast is using libavdevice and libavformat for media acquisition, it supports all kinds of inputs which are supported by these libraries.

    I have not tested DashCast with IP camera yet. But I know that ffmpeg supports, so there should not be a problem.

  6. Chia-Liang-Ke says:

    Hello, I didnt see base url in dashcast mpd file. Does it work? or i have to wirte something in the mpd?

  7. it would be great add reading from stdin. I have h264 stream and I just want pack it into MPEG DASH. So there should be also no transcoding option. Just get h264 stream and pack it. Is that possible?

  8. wangcl says:

    Hi arashafiei,
    how can I read the mpd file generated by DashCast,
    the MP4Client seems not work with that…..

    wangcl

  9. Tércio says:

    To create the sgments and the mpd file i used this:
    DashCast -av teste.mp4 -seg-dur 1000 -frag-dur 200 -mpd teste.mpd.
    I gess that I’m typing the wrong command;
    Should I use a diferent command?

  10. David Lou says:

    I am new to the DashCast. I want to use DashCast to stream live video from a webcam. After installation with the instructions from https://gpac.wp.mines-telecom.fr/dashcast/ on a Ubuntu 14.04 64-bit linux machine, I tried with the first example

    DashCast -vf video4linux2 -v4l2f mjpeg -vfr 30 -vres 1280×720 -v /dev/video0 -conf dashcast.conf -live

    But it failed with the following message:
    [libx264@0x7f52380000920] AVFrame.format is not set
    [libx264@0x7f52380000920] AVFrame.width or height is not set
    [libx264@0x7f52380000920] AVFrame.format is not set
    [libx264@0x7f52380000920] AVFrame.width or height is not set
    …….

    I have tried to tune some parameters, e.g. codec from mjpeg to yuyv422, resolution from 1280×720 to 960×540, etc. Neither works around. Can you help me there? Is there more online documentation about DashCast?

    Many thanks in advance
    David

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