Twitch.tv has decided recently, in a twitch news update this morning, that they're gonna change the Broadcast Requirements for everybody starting September 1st. These Requirements are...
"Video Requirements
- Codec: H.264
- Mode: Strict CBR
- Keyframe Interval: 2 seconds
Audio Requirements
- Codec: AAC-LC or MP3, Stereo or Mono
- Maximum bit rate: 160 kbps (AAC), 128 kbps (MP3)
- Sampling frequency: any (AAC), 44.1 KHz (MP3)
These configurations are already supported and are active by default in the latest versions of our most popular broadcast software options.
To help you determine whether your stream settings are compatible, we’ve added a new ingest feedback feature on your Broadcast Dashboard."
Twitch.tv also have requirements for Partners and Non-Partners.
"For Partners:
Optimal (All video requirements are met)
- Viewers will have access to the highest quality stream (a non-transcoded passthrough of your broadcast)
- Your broadcast will be available on mobile and consoles
Minimal (Just enough video requirements are met)
- Viewers will only see your resolution options (no direct passthrough to viewer)
- Your broadcast will be available on mobile and consoles
Incompatible (Important settings are not met)
- Your stream will continue to be available on the website until August 31st. Starting September 1st, your ingest will be rejected.
âFor Non-Partners:
Optimal (All video requirements are met)
- Viewers will have access to the highest quality stream (a non-transcoded passthrough of your broadcast)
- Your broadcast will be available on mobile and consoles
Minimal (Just enough video requirements are met)
- Viewers will have access to a non-transcoded passthrough of your broadcast
- Your broadcast will NOT be available on mobile and consoles
Incompatible (Important settings are not met)
- Your stream will continue to be available on the website until August 31st. Starting September 1st, your ingest will be rejected."
They are requiring the H264 Codec only...
â"Video codec must be set to h.264 (it is currently "{codec}")
- Set your video codec to h.264 (AVC)
- If you see this, you’re probably running a very strange RTMP encoder. Try to adjust the codec in the settings.
- See if you’re able to adjust the codec in the settings.
- All the software displayed on http://twitch.tv/broadcast can provide h.264 encoding.
Audio codec must be set to MP3 or AAC (it is currently "{codec}")
- Only MP3 and AAC are supported in HLS.
- Be careful as some of the more exotic hardware encoders come with audio codecs that may not play nice with our transcoding and demuxing tools.
- The software we list on http://twitch.tv/broadcast fully supports MP3 or AAC."
And they're also forcing Keyframe Interval settings required and CBR (Constant BitRate) ONLY!
"Max keyframe interval is currently at {current} seconds. Please set it to {target} seconds.
- Means the gaps between their keyframes are too large. In the case of XSplit, there is a setting called max keyframe interval that you can adjust. In the case of OBS, you need to add a parameter to the advanced options: -keyint=X where X is their framerate * 2
- With more exotic encoders, such as the elemental, you can change the GOP size to create the 2 second keyframe interval state needed (depending on the framerate)
The broadcast is not set to constant bitrate (CBR). [Current average: {avg} kbps, current max: {max} kbps]
- This means the bitrate we see is fluctuating too much. On average you are transmitting at {avg}, but peaking at {max}, and the difference is large. Enable CBR in your broadcast software accordingly."
So far they have a tutorial setup on the article for those who are on XSplit to setup their settings with the settings required. Yet to have one on OBS (Open Broadcaster Software)
While these are probably great settings and Twitch.tv is thinking in the best interest of themselves... New Users or Users who are newish to Twitch.tv will probably struggle with the settings, not realizing the settings they're running will probably be rejected by the ingest servers. This will probably cause Twitch.tv to lose users to other sites rather than help them. I personally don't find this move to be a really bad move for myself in general since I can follow these settings without a problem, being a Broadcasting Veteran. New Users, or users who struggle with their settings already, on the other hand are probably going to struggle with the CBR and Keyframe Interval changes.
I really do like VBR myself. the fluctuations really don't bother me but what alot of casters favor CBR which is their choice. More power to you. What alot of casters don't understand is... if you use CBR and you're sitting with a still image... and you start to move, your bitrate will kick up 2 or 3 times higher than what VBR would ever do for a couple seconds. CBR might actually make it worse for Twitch.tv on the fact that CBR is going to constantly use a high bitrate rather than sit at a low bitrate then spike high on movement. I really can't think of anything else to say other than I think this is going to hurt Twitch more than help them. Their servers are going to be relieved... by either the CBR change or most likely by viewers leaving Twitch for other streaming websites.
