Wowza Community

Adaptive bitrate Lag & Quality Issue‏

Wowza application currently running several live streaming and transcoder is enable for 360p(1Mbps) & 240p(700Kbps) only. My encoder is set up to 1800Kbps (video bitrate).

Source stream is playing fine, but when playing transcoded streams, it’s causing lag & very poor quality. Here is an example streams http://175.126.111.78:81/i.html that lag for 360p & 240p, also video quality is very poor.

I’m using Wowza Engine Version: 4.1.2.

What I can do to resolve this issue?

Hello there and welcome to the Wowza support forum.

Can you please share your transcoder settings?

Are you using:

true

Thanks,

Salvadore

Hi,

Please can you provide an update on the situation, I’ve viewed the stream using the player provided but I’m not seeing any issues with the playback.

Looking at the page source I see that the stream name is “CHBOX_0” which does not match what the streams would be called if using the transcoding template provided.

Your transcoding template is configured to add _360p and _240p to the source stream name (default configuration) but this does not appear to be happening.

I tried using the URL for the current stream and then adding _360p and _240p to the stream name but this fails as though the streams do not exist.

If the stream for this player has been altered or you have moved on due to resolving this problem then please update this thread to confirm this.

When having issues with transcoded streams it is worth checking the wowzastreamingengine_access.log file for any SKIP messages which are generally caused by a lack of CPU/GPU on the server for the transcoding task.

Regards,

Jason

Hi,

To transcode such a high number of streams, you’re likely going to need some kind of hardware accelerated assistance. Note that NVENC and CUDA can only be used for the encodes which means the decoding of all 50-55 streams will be done by the CPU if QuickSync isn’t available. This will likely be the limitation of how many streams can be transcoded concurrently.

For more information on NVENC and CUDA cards, please see Server specifications for NVIDIA NVENC and NVIDIA CUDA acceleration

For more information on Intel Quick Sync acceleration, please see Server specifications for Intel Quick Sync acceleration

To others reading this thread, please see the Wowza Transcoder performance benchmark for a guide to how many streams the transcoder can handle based on the server hardware which was referenced above.

Regards,

Jason

Thanks for your response. Yes I’m using

true

Please take a look http://173.82.12.234/transcoder.xml at my transcoder settings.

Dear JasonH,

Thanks for your response. I’ve emailed to support and according to their response my server isn’t powerful enough to process transcoding for 20+ stream. Now transcoding is turned off, so there’s no transcoded streams.

I’ve checked transcoder performance bechmark link in wowza and wondering if i want to transcode 50-55 live stream to 360p & 240p only what should be my server specification. If it’s not much of trouble can you please enlighten me with this information. Also is there any other way for such huge workload.

Thanks.