| Capsnego patterns |
| ----------------- |
| |
| |
| |
| |
| src negotiation recovery |
| ------------------------ |
| |
| common pipelines like |
| |
| filesrc -> mad -> osssink |
| |
| perform negotiation strictly left to right. At some point during |
| iterate, mad will know the caps of the media stream and will need |
| to inform osssink of this before pushing out a buffer. |
| mad only has one set of fixed caps. |
| |
| 1) try_set_caps |
| |
| mad does a try_set_caps with the caps if all goes well, osssink |
| accepts and negotiation succeeds. |
| |
| if the try_set_caps function fails, the application should have |
| a change to recover. |
| |
| - mad therefore calls gst_pad_caps_error_try_recover, this will |
| emit a signal on the pad that the app can catch. One of the |
| signal arguments will contain a list of possible caps. |
| |
| - the app can use the allowed caps to find another element that |
| is compatible with the caps and the peer element caps. |
| |
| - the app will connect the new element with mad, negotiation |
| will happen again, the link will fail or succeed, if it fails, |
| thr app knows because the link function returns FALSE. |
| |
| - if the link succeeds, pad caps are set and the try_recover |
| function returns TRUE, mad then knows the issue was resolved |
| and can continue. It will have received the final caps in its |
| srclink function. |
| |
| - if no signal handler is connected to the caps_nego_failure signal |
| the issue will remain unresolved and a big debug warning is |
| printed on the console to debug the issue. mad will get a |
| return value of FALSE and may stop. |
| |
| |
