How to stream shorter DASH segment than source mp4's GOP?

Wowza Streaming Engine
1

Hello Wowza,

We are considering to provide VOD by DASH streaming + HTML5 player as an alternative to Smooth Streaming + Silverlight.

Currently, we have petabytes of H264/MP4 videos, those GOP length are variable, about 1 to 8 seconds.

But we would like to stream them with shorter segment, at most 2 seconds, because there is seek latency issue in DASH with long segment.

Since transcoding so many videos will take too long time, we are researching much faster or on-the-fly solution.

Is there any good on-the-fly module or faster solution, some kind of keyframe inserter, than re-encoding whole video data?

Video spec: 6Mbps, 1920x1080, 30fps (and some lower bitrates for adaptive streaming)

Any suggestions would be greatly appreciated.

Best regards,

Tomonori

2

Hi,

Wowza Streaming Engine won’t change the keyframes for “vod” files. It will simply stream them with whatever is defined in the file. You could look at creating a “pseudo-live” stream using ServerListenerStreamPublisher, which “publishes” VOD playlists as a live stream, and which then allows you to transcode the stream on the fly, including setting a different keyframe. This may not be practical for large numbers of files though. In this case then from a programmatic perspective you could look at ModuleStreamControl to dynamically create a live stream.

Paul

3

Hi,

I don’t have examples of how to load the schedule outside of Flash client but the source is available for customization. You can stream the output as MPEG-DASH. I’m not sure what you mean by “seekable”. As it’s a live stream then you can’t skip through the stream. You can apply DVR-type controls by enabling the nDVR AddOn for that Wowza application, but currently this is not available for MPEG-DASH. We do hope to provide nDVR for DASH in the future though.

Paul

4

Thank you for the answer Paul,

You could look at creating a “pseudo-live” stream using ServerListenerStreamPublisher, which “publishes” VOD playlists as a live stream, and which then allows you to transcode the stream on the fly, including setting a different keyframe. This may not be practical for large numbers of files though. In this case then from a programmatic perspective you could look at ModuleStreamControl to dynamically create a live stream.

According to the “pseudo-live” stream, we have two questions:

  1. is it possible to program this as a Wowza custom module without any client side flash?

  2. is the “pseudo-live” stream seekable with an HTML5 DASH player?

Best regards,

Tomonori

5

Thank you Paul,

You can apply DVR-type controls by enabling the nDVR AddOn for that Wowza application, but currently this is not available for MPEG-DASH. We do hope to provide nDVR for DASH in the future though.

That is what I wanted to know. I think HLS can play with videojs-contrib-hls.

Tomonori