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Thread: Is it possible to do closed captioning in Live MEPG-DASH stream using wowza?

  1. #1
    Join Date
    Aug 2015
    Posts
    5

    Question Is it possible to do closed captioning in Live MEPG-DASH stream using wowza?

    I would like to do closed captioning for live MPEG-DASH stream and i dont see mention of wowza supporting it?

  2. #2
    Join Date
    Jun 2011
    Posts
    1,047

    Default

    Hi,
    Closed captioning is currently not supported in the Wowza Streaming Engine implementation of MPEG-DASH.
    There's no time-frame for when (if) it will be added.
    I'll let our product management team know of your interest in this.

    Daren

  3. #3
    Join Date
    Jul 2015
    Posts
    3

    Exclamation CC and multiple audio lack are the blockers for this product

    In Europe, lack of multiple language audio track support and multiple language subtitle support is blocking this product from using it for typical telco need:
    1. Take 100 channel streams from IPTV, typically multicast
    2. Create 100 channels for OTT streaming (secure, with DRM, Widevine is the best as it is free, and also native for Android)

    For example, in Europe EuroNews channel has 13 languages, BabyTV Europe has 10 languages..

    We need to take standard MPEG-TS feeds from satellite, that contain video in MPEG-2 or H.264, audio in MPEG1 or AC3 or AAC, text subtitles in EBU-TXT typically, transcode and prepare it for ABR, and deliver to OTT playback with DRM and the ability for the user to select audio language and subtitles language.
    Contrary to IPTV or DVB tuners, where all languages and subtitles are always delivered to STB and user selects on the STB audio and subtitles, it is impossible to deliver all languages in OTT scenario. Player must only get the one language that is selected and the one subtitle if it is selected.

    Hopefully this most important development will be bumped up in priorities. We are the telco, long time Wowza customer for tens of channels delivery to "second screen" devices, but new legal regulations requiring to deliver multiple languages and the DRM requirement from content owners will soon push us out of wowza to other solutions, unfortunately, as today we can deliver just one language and no subtitles. Half of users do not use/will not install app, so the practical way to deliver content where DRM is required is DASH+Widevine, plays without apps/installations in Android or Chrome on PC.

    Try to answer the typical telco need: how to serve my IPTV channels to the "second screen", i.e. PC/Phone/Tablet viewer that is not using apps (via browser), with DRM and DVR (time shift for 30 days). If I can help somehow, for example deliver input MPEG-TS stream samples from European satellites (with many languages, subtitles, etc.) just send me e-mail.

  4. #4
    Join Date
    Jun 2011
    Posts
    1,047

    Default

    Hi,
    Thanks very much for the comments. Stream samples might be useful. I'll pass your comments and offer along to our product marketing team, who may want to follow up.

    Daren

  5. #5
    Join Date
    Jul 2015
    Posts
    3

    Default

    I see there is some new hope for live subtitles support. First possibility only for American market, as CEA-608 is not used for broadcasts in Europe, but this means transcoder workflow was implemented:
    https://www.wowza.com/blog/wowza-str...cloud-rest-api
    Any chances to see support for EBU-TXT text subtitles being able to pass-through encoder and reach MPEG-DASH output? I understand DVB subtitles are issue because they are sent as graphical pictures, it is a challenge to do OCR in real time to convert them into text, but EBU-TXT come as text stream and shall be realistic to pass-through same as CEA-608. EBU-TXT subtitles are used throughout Europe for DVB-S, DVB-C and DVB-T subtitles.

    Regarding several audio languages support via MPEG-DASH+DRM output, as I understood there is no progress yet. Any news if this may appear on roadmap?

    I want to avoid a huge project to replace Wowza to competitors solution as new regulations require to support multiple languages and subtitles in 2017, and channels like CNN starting to require DRM to get the streaming license from them, so MPEG-DASH+DRM seems like the only option going forward. We have MPEG-DASH with DRM support in Wowza, but lack of a) multiple audio languages and b) live subtitles is blocking the future for this product in Europe. I see that some funny activities like sending live video from mobile phone have higher priorities in development than keeping big telco customers that have needs to provide second screen / OTT services for hundreds of TV channels with quality up to Full-HD at 50fps, with many days DVR and tens of thousands of viewers, and challenges to keep up with new regulations that require multiple languages, subtitles, and DRM support.
    Hopefully multiple languages will appear in the product not too late, to avoid replacing it.

  6. #6

    Default

    Hello,

    There is an internal feature request for MPEG-DASH with multi-language Audio support as well as Closed Captioning with MPEG-DASH, to be created as a future enhancement, and this has been forwarded to our Product Manager for consideration to be added to the core product. I will be documenting your Use-case to add more votes for these feature request. I will also create a new Feature request to notify the Product Manager about the EBU-TXT subtitles request.

    Though do note that there is no definitive timeframe as to when we will support these new features. Please do check back in periodically to our Software Updates page to see if your feature request has been deployed.

    http://www.wowza.com/forums/content....ftware-updates

    I have also subscribed to this thread so in the event that you want to check in I should be notified and will reply back to you as soon as I am able.

    Jason

  7. #7

    Default

    Hello Almantas,

    Internally we have begun researching the upcoming 2017 regulations you have mentioned and I am wondering if you can point me to any documentation or organization that I may be able to retrieve the draft regulations from?

  8. #8

    Default

    Hi there. I have tested Dash.js player with embedded captions with VOD as in ingested with the stream. That is working but the same for Live streams does not work. Any ideas ?

  9. #9

    Default

    Hello,

    Closed captioning for MPEG-DASH for live streams is still under development.
    Please do check back in periodically to our Software Updates page to see if your feature request has been deployed.

    http://www.wowza.com/forums/content....ftware-updates

    Regards,
    Jason Hatchett

  10. #10

    Default

    Hi I just updated to 4.5 to check issues with dash were fixed and the stream has embedded 608 captions which is possibly causing bugs. I get this

    ERROR server comment - MPEGDashRepeaterHolder.deserialize : java.lang.NegativeArraySizeException|at com.wowza.wms.amf.AMFPacket.deserializePacket(AMFPacket.java:612)|at com.wowza.wms.httpstreamer.mpegdashstreaming.livestreampacketizer.MPEGDashRepeaterHolder.deserialize (MPEGDashRepeaterHolder.java:220)|at com.wowza.wms.httpstreamer.mpegdashstreaming.liverepeater.MPEGDashStreamerLiveRepeaterReceiver.addVi deoData(MPEGDashStreamerLiveRepeaterReceiver.java:203)|at com.wowza.wms.stream.live.MediaStreamLiveAbstract.addVideoData(MediaStreamLiveAbstract.java:74)|at com.wowza.wms.netconnection.NetConnectionProcessData.processNextRequest(NetConnectionProcessData.jav a:493)|
    ERROR server comment - MPEGDashRepeaterHolder.deserialize : java.lang.ArrayIndexOutOfBoundsException|at java.lang.System.arraycopy(Native Method)|at com.wowza.wms.amf.AMFPacket.deserializePacket(AMFPacket.java:613)|at com.wowza.wms.httpstreamer.mpegdashstreaming.livestreampacketizer.MPEGDashRepeaterHolder.deserialize (MPEGDashRepeaterHolder.java:220)|at com.wowza.wms.httpstreamer.mpegdashstreaming.liverepeater.MPEGDashStreamerLiveRepeaterReceiver.addVi deoData(MPEGDashStreamerLiveRepeaterReceiver.java:203)|at com.wowza.wms.stream.live.MediaStreamLiveAbstract.addVideoData(MediaStreamLiveAbstract.java:74)|
    ERROR server comment - MPEGDashRepeaterHolder.deserialize : java.lang.NegativeArraySizeException|at com.wowza.wms.amf.AMFPacket.deserializePacket(AMFPacket.java:612)|at com.wowza.wms.httpstreamer.mpegdashstreaming.livestreampacketizer.MPEGDashRepeaterHolder.deserialize (MPEGDashRepeaterHolder.java:220)|at com.wowza.wms.httpstreamer.mpegdashstreaming.liverepeater.MPEGDashStreamerLiveRepeaterReceiver.addVi deoData(MPEGDashStreamerLiveRepeaterReceiver.java:203)|at com.wowza.wms.stream.live.MediaStreamLiveAbstract.addVideoData(MediaStreamLiveAbstract.java:74)|at com.wowza.wms.netconnection.NetConnectionProcessData.processNextRequest(NetConnectionProcessData.jav a:493)|
    ERROR server comment - MPEGDashRepeaterHolder.deserialize : java.lang.NegativeArraySizeException|at com.wowza.wms.amf.AMFPacket.deserializePacket(AMFPacket.java:612)|at com.wowza.wms.httpstreamer.mpegdashstreaming.livestreampacketizer.MPEGDashRepeaterHolder.deserialize (MPEGDashRepeaterHolder.java:220)|at com.wowza.wms.httpstreamer.mpegdashstreaming.liverepeater.MPEGDashStreamerLiveRepeaterReceiver.addVi deoData(MPEGDashStreamerLiveRepeaterReceiver.java:203)|at com.wowza.wms.stream.live.MediaStreamLiveAbstract.addVideoData(MediaStreamLiveAbstract.java:74)|at com.wowza.wms.netconnection.NetConnectionProcessData.processNextRequest(NetConnectionProcessData.jav a:493)|

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