smooth streaming VBR choppy playback/ configuration

Wowza Streaming Engine
1

Hi all.

I’m setting up Wowza Streming Engine 4.0.1 to produce multiple VBR streams (subSD, SD and HD) and each stream has 3 bitrate renditions.

My source stream is an RTMP stream at 4.580 Mbits/s. I’m having some trouble trying to configure the stream in the Smooth Streaming format, the stream playback is very choppy.

These are my requirments for Smooth Streaming:

Format must be version 2.0.

Chunk duration should be 2 seconds.

Time stamp provided should be a local Timezone.

The audios ordering should follow the Mpeg2TS encoded ordering (First One).

The Smooth Streaming EOS signaling should be enabled.

Each VBR stream has it’s own requiremnts (Max bitrate 3.5Mbps, 2 seconds Closed GOP, Support for 4:3 and 16:9, CBR Yes etc…)

I’m not sure how to set the 2 second Closed GOP, all my encodes have a key frame interval of 60 seconds.

This is a sample of my transcode.xml files (SD):

<Encode>
    <Name>480p</Name>
    <Enable>true</Enable>
    <Description></Description>
    <StreamName>mp4:${SourceStreamName}_480p</StreamName>
    <Video>
        <Codec>H.264</Codec>
        <Implementation>default</Implementation>
        <GPUID>-1</GPUID>
        <Profile>main</Profile>
        <Bitrate>1900000</Bitrate>
        <KeyFrameInterval>
            <FollowSource>false</FollowSource>
            <Interval>60</Interval>
        </KeyFrameInterval>
        <FrameSize>
            <FitMode>fit-height</FitMode>
            <Width>0</Width>
            <Height>480</Height>
            <Crop>0,0,0,0</Crop>
            <SourceRectangle></SourceRectangle>
        </FrameSize>
    </Video>
    <Audio>
        <Codec>AAC</Codec>
        <Bitrate>96000</Bitrate>
    </Audio>
</Encode>

And this is the smooth streaming properties set in Application.xml:

<LiveStreamPacketizer>
    <Properties>
            <Property>
                    <Name>smoothBufferTargetDuration</Name>
                    <Value>50000</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothBufferMinFragmentCount</Name>
                    <Value>4</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothManifestTargetDuration</Name>
                    <Value>20000</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothManifestMinFragmentCount</Name>
                    <Value>4</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothRepeaterTargetDuration</Name>
                    <Value>20000</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothRepeaterMinFragmentCount</Name>
                    <Value>4</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothFragmentTargetAudioDuration</Name>
                    <Value>2000</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothPacketSortTime</Name>
                    <Value>500</Value>
                    <Type>Integer</Type>
            </Property>
            <Property>
                    <Name>smoothAlignAudioWithVideo</Name>
                    <Value>true</Value>
                    <Type>Boolean</Type>
            </Property>
    </Properties>
</LiveStreamPacketizer>

Hopefully this information gives a good description of my setup.

Thanks in advance for any help you can provide.

Regards

Colin

2

Hi Colin,

There is not an option to enable smooth 2.0. Currently Wowza Streaming Engine supports Microsoft Smooth Streaming Silverlight 3 or later. We are not able to “roll back” to an earlier codec.

The specifications for streaming delivery including smooth stream are listed here.

Regards

Andy_E