Wowza Community

Change display aspect ratio without changing width and height


We are streaming with Adobe Flash Media Live Encoder into our wowza server a PAL video with 720x756 pixels anamorphic (16:9).

We configured the transrate.xml file like this:




We get an output stream from wowza media server like this:


ID : 1 (0x1)

Complete name : media.ts

Format : MPEG-TS

File size : 2.67 MiB

Duration : 9s 960ms

Overall bit rate mode : Variable

Overall bit rate : 2 239 Kbps


ID : 256 (0x100)

Menu ID : 1 (0x1)

Format : AVC

Format/Info : Advanced Video Codec

Format profile : Main@L3.1

Format settings, CABAC : Yes

Format settings, ReFrames : 3 frames

Codec ID : 27

Duration : 10s 0ms

Bit rate mode : Variable

Maximum bit rate : 1 980 Kbps

Width : 720 pixels

Height : 576 pixels

Display aspect ratio : 5:4

Frame rate : 25.000 fps

Standard : NTSC

Color space : YUV

Chroma subsampling : 4:2:0

Bit depth : 8 bits

Scan type : Progressive


ID : 257 (0x101)

Menu ID : 1 (0x1)

Format : AAC

Format/Info : Advanced Audio Codec

Format version : Version 4

Format profile : LC

Muxing mode : ADTS

Codec ID : 15

Duration : 9s 891ms

Bit rate mode : Variable

Minimum bit rate : 85.1 Kbps

Maximum bit rate : 139 Kbps

Channel(s) : 2 channels

Channel positions : Front: L R

Sampling rate : 44.1 KHz

Compression mode : Lossy

Delay relative to video : 19ms

We would like to get this parameters:

Width : 720 pixels

Height : 576 pixels

Display aspect ratio : 16:9 (instead of 5:4)

Frame rate : 25.000 fps

Standard : PAL (instead of NTSC)

Is there a way to obtain these results changing some parameters of the transrate.xml file?

Thanks for advance,



The Wowza Transcoder does not support anamorphic squeeze encoding. It does support decode of video with anamorphic squeeze, but not encode. So the Display aspect ratio is only a function of Width and Height

You will have to verify following this guide but you can probably set the encode to PAL by adding this Parameter to each Transcoder template /Encode /Video Parameters container:


Look for this output in the access log with the logVideoEncodingParameters Property enabled to verify your system has this feature.

INFO server comment - # long: vui parameters: 1: PAL, 2: NTSC
INFO server comment - mainconcept.video_format: 2


Thanks for the update, Moisès. Glad it’s working



Many thanks for your help.



Hi again,

Finally, we achieved everything we needed.

The output of the access log was very helpfull:

INFO 200 - # long: vui parameters: sample aspect ratio: horizontal size in arbitrary units

INFO 200 - mainconcept.sar_width: 1

INFO 200 - # long: vui parameters: sample aspect ratio: vertical size in arbitrary units

INFO 200 - mainconcept.sar_height: 1

So we modified the transrate template to also obtain 16:9 aspect ratio with a 720x576 video resolution. We configured the pixel ratio as 16:11 (for an anamorphic wide screen; 16:9 =>










So we got this:

Width : 720 pixels

Height : 576 pixels

Display aspect ratio : 16:9

Frame rate : 25.000 fps

Standard : PAL



You may also refer to this step by step guide on how to change video aspect ratio among 4:3, 16:9, 2.35:1, 1.85:1, 1:1, 21:9 etc

Just google search Step by Step Guide on How to Change Video Aspect Ratio with iDealshare VideoGo, you will find a detailed guide.

HI, I think the best and simple way is use some kind of software, don’t need the coding staffs. I usually use the HD Video Converter Factory Pro to change aspect ratio of video to solve this kind of things. Hope it will help you.