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package fmtp
import (
"encoding/hex"
)
func profileLevelIDMatches(a, b string) bool {
aa, err := hex.DecodeString(a)
if err != nil || len(aa) < 2 {
return false
}
bb, err := hex.DecodeString(b)
if err != nil || len(bb) < 2 {
return false
}
return aa[0] == bb[0] && aa[1] == bb[1]
}
type h264FMTP struct {
parameters map[string]string
}
func (h *h264FMTP) MimeType() string {
return "video/h264"
}
// Match returns true if h and b are compatible fmtp descriptions
// Based on RFC6184 Section 8.2.2:
// The parameters identifying a media format configuration for H.264
// are profile-level-id and packetization-mode. These media format
// configuration parameters (except for the level part of profile-
// level-id) MUST be used symmetrically; that is, the answerer MUST
// either maintain all configuration parameters or remove the media
// format (payload type) completely if one or more of the parameter
// values are not supported.
// Informative note: The requirement for symmetric use does not
// apply for the level part of profile-level-id and does not apply
// for the other stream properties and capability parameters.
func (h *h264FMTP) Match(b FMTP) bool {
c, ok := b.(*h264FMTP)
if !ok {
return false
}
// test packetization-mode
hpmode, hok := h.parameters["packetization-mode"]
if !hok {
return false
}
cpmode, cok := c.parameters["packetization-mode"]
if !cok {
return false
}
if hpmode != cpmode {
return false
}
// test profile-level-id
hplid, hok := h.parameters["profile-level-id"]
if !hok {
return false
}
cplid, cok := c.parameters["profile-level-id"]
if !cok {
return false
}
if !profileLevelIDMatches(hplid, cplid) {
return false
}
return true
}
func (h *h264FMTP) Parameter(key string) (string, bool) {
v, ok := h.parameters[key]
return v, ok
}
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