Results 1 to 9 of 9

Thread: 320x240 frame size max

  1. #1

    Default 320x240 frame size max

    Both these links advise a frame size no bigger than 320x240, is this correct that the encoder will not support anything larger than this?

    http://www.wowza.com/forums/showthre...964#post135964

    http://www.wowza.com/forums/showthre...3042#post93042

    So from a live streaming perspective the official stance from wowza is 320x240?

  2. #2
    Join Date
    Jul 2012
    Posts
    299

    Default

    Hi,

    These posts are in reference to specific best practices for a web-based Flash encoder workflow. Certianly not a general, "official" stance. Wowza is extremely robust with capability of handling very large, high bitrate streams.

    What are you working to accomplish? Do you have a particular specification that you are looking to achieve?

    -Tim

  3. #3

    Default

    Hi Tim,

    Yep, I am looking at a web based flash encoder workflow. I am publishing an H.264 RTMP stream from a flash based application using the Wowza Transcoder to transform the audio to AAC enabling playback support for HLS, etc. Currently averaging 100-200 connected users to live streams across a range of devices.

    What I am trying to determine is the Wowza gold standard for the setup above i.e. live streams from a flash web based encoder through the Wowza transcoder. This is to ultimately determine the most reliable, solid approach with the best results.

    Frame size, rate and key frame interval are the core values I am seeking to determine based on the latest version of Wowza.

  4. #4
    Join Date
    Sep 2011
    Posts
    1,933

    Default

    Hi,
    In the source stream we recommend a keyframe interval of 1-4 seconds (1 or 2 seconds is best).
    The frame rate should be between 25-30 FPS and resolution will vary depending on bitrate.

    If you open the [Wowza-Install]/transcoder/templates/transcode.xml file with a text editor you will see some pre-defined encodes (some of which are not activated).
    You can also see these encodes in the Wowza Streaming Engine Manager (WSEM) by navigating to the "Applications > [LiveAppName] > Transcoder AddOn > [TemplateName] > [Encode]"

    Please find our transcoding tutorial below for reference.
    How to set up and run Wowza Transcoder AddOn for live streaming

    You will get a good idea of how many transcodes can be achieved by a single server by looking at our Wowza Transcoder AddOn Performance Benchmark

    Regards,
    Jason
    Last edited by JasonH; 08-01-2014 at 08:13 AM.

  5. #5

    Default

    Thank you Jason,

    Just to close this matter, can you please confirm that if publishing using a flash encoder, Wowza advises 320x240 as a maximum frame size?

    If this is the case it gives me a clearer indication into what transcoding options are available, I want to avoid degrading quality by scaling content up using the transcoder (which removes most available options it would appear based on framesize adjustment).
    Last edited by newtriks; 08-04-2014 at 05:55 AM.

  6. #6
    Join Date
    Sep 2011
    Posts
    1,933

    Default

    Quote Originally Posted by newtriks View Post
    Thank you Jason,

    Just to close this matter, can you please confirm that if publishing using a flash encoder, Wowza advises 320x240 as a maximum frame size?

    If this is the case it gives me a clearer indication into what transcoding options are available, I want to avoid degrading quality by scaling content up using the transcoder (which removes most available options it would appear based on framesize adjustment).
    Hi,
    Wowza does NOT recommend a maximum frame size of 320x240, the resolution should vary depending on bitrate of the stream.
    Try publishing a stream at 1.3 Mbps which is 1280x720 and you will see this plays fine if the viewing client has the sufficient bandwidth to play the stream.

    We do not recommend scaling up using the transcoder, you should only create lower bitrate/resolution streams using the Wowza Transcoder AddOn.
    The source stream should be the highest bitrate/resolution stream.

    Regards,
    Jason

  7. #7

    Default

    Wowza does NOT recommend a maximum frame size of 320x240, the resolution should vary depending on bitrate of the stream.
    Try publishing a stream at 1.3 Mbps which is 1280x720 and you will see this plays fine if the viewing client has the sufficient bandwidth to play the stream.
    Thank you so much for confirming this Jason and I am sorry I pushed for confirmation here. I needed to make 100% sure that previous posts from Wowza support (salvadore & rrlanham) that stated a specific frame size of 320x240 as a maximum for web based application publishing of streams, was indeed incorrect.

    I will ignore these previous posts now and happily use larger frame sizes in our web based flash application safe in the knowledge that the Wowza encoder will easily support them (based on bandwidth).

    Cheers,

    Simon

  8. #8
    Join Date
    Jun 2012
    Posts
    722

    Default

    Hi,

    The encoding process is using lots of HW resources, especially CPU. In this particular case, I think the issue is the encoding capacity of the web based Flash encoder, rather that the Wowza capacity to ingest a certain video size.

    If you try to encode a large frame size with a high bitrate using the Flash web based encoder, you might see that the web client does not have enough HW resources available to deliver the desired output. The statement of using a maximum frame size of 320x240 for the web based Flash encoder, that Wowza support "salvadore" and "rrlanham" were mentioning, was a result of several tests performed using the web based Flash encoder (also used in the VideoChat flash example application). It was observed that going above that video size would cause the encoder to struggle in order to keep up with the desired output.

    Of course, you can do your own tests and establish the best encoding settings for your Flash web based encoder.

    You can also use a software encoder and make a comparison test in order to best observe Wowza behavior, when using similar settings. (eg. 1280x720 @1.3Mbps)

    Zoran

  9. #9

    Default

    Quote Originally Posted by zoran_u View Post
    Hi,

    The encoding process is using lots of HW resources, especially CPU. In this particular case, I think the issue is the encoding capacity of the web based Flash encoder, rather that the Wowza capacity to ingest a certain video size.

    If you try to encode a large frame size with a high bitrate using the Flash web based encoder, you might see that the web client does not have enough HW resources available to deliver the desired output. The statement of using a maximum frame size of 320x240 for the web based Flash encoder, that Wowza support "salvadore" and "rrlanham" were mentioning, was a result of several tests performed using the web based Flash encoder (also used in the VideoChat flash example application). It was observed that going above that video size would cause the encoder to struggle in order to keep up with the desired output.

    Zoran
    Fantastic, thank you for clarifying all of that for me. It was the statement made on the post here that I based my original question on as it stated the wowza encoder itself was limited: QUOTE:
    I would shy away from anything larger than frame size 320x240. The encoder built-in to Wowza is limited.
    Cheers

Similar Threads

  1. changing aspect ratio, GOP size and frame rate
    By manojprasath in forum AddOn: Transcoder
    Replies: 3
    Last Post: 07-08-2013, 06:35 AM
  2. Replies: 30
    Last Post: 08-02-2012, 05:11 AM
  3. Simulate frame-by-frame (for HLS players that don't support it natively)
    By swhiteman in forum Video On Demand Streaming Discussion
    Replies: 2
    Last Post: 12-01-2011, 10:26 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •