void
JsepTrack::NegotiateCodecs(
const SdpMediaSection& remote,
std::vector<JsepCodecDescription*>* codecs,
std::map<std::string, std::string>* formatChanges) const
{
PtrVector<JsepCodecDescription> unnegotiatedCodecs;
std::swap(unnegotiatedCodecs.values, *codecs);
// Outer loop establishes the remote side's preference
for (const std::string& fmt : remote.GetFormats()) {
for (size_t i = 0; i < unnegotiatedCodecs.values.size(); ++i) {
JsepCodecDescription* codec = unnegotiatedCodecs.values[i];
if (!codec || !codec->mEnabled || !codec->Matches(fmt, remote)) {
continue;
}
std::string originalFormat = codec->mDefaultPt;
if(codec->Negotiate(fmt, remote)) {
codecs->push_back(codec);
unnegotiatedCodecs.values[i] = nullptr;
if (formatChanges) {
(*formatChanges)[originalFormat] = codec->mDefaultPt;
}
break;
}
}
}
// Make sure strongly preferred codecs are up front, overriding the remote
// side's preference.
std::stable_sort(codecs->begin(), codecs->end(), CompareCodec);
// TODO(bug 814227): Remove this once we're ready to put multiple codecs in an
// answer
if (!codecs->empty()) {
for (size_t i = 1; i < codecs->size(); ++i) {
delete (*codecs)[i];
(*codecs)[i] = nullptr;
}
codecs->resize(1);
}
}
void
JsepTrack::NegotiateCodecs(
const SdpMediaSection& remote,
std::vector<JsepCodecDescription*>* codecs,
std::map<std::string, std::string>* formatChanges) const
{
PtrVector<JsepCodecDescription> unnegotiatedCodecs;
std::swap(unnegotiatedCodecs.values, *codecs);
// Outer loop establishes the remote side's preference
for (const std::string& fmt : remote.GetFormats()) {
for (size_t i = 0; i < unnegotiatedCodecs.values.size(); ++i) {
JsepCodecDescription* codec = unnegotiatedCodecs.values[i];
if (!codec || !codec->mEnabled || !codec->Matches(fmt, remote)) {
continue;
}
std::string originalFormat = codec->mDefaultPt;
if(codec->Negotiate(fmt, remote)) {
codecs->push_back(codec);
unnegotiatedCodecs.values[i] = nullptr;
if (formatChanges) {
(*formatChanges)[originalFormat] = codec->mDefaultPt;
}
break;
}
}
}
// Find the (potential) red codec and ulpfec codec
JsepVideoCodecDescription* red = nullptr;
JsepVideoCodecDescription* ulpfec = nullptr;
for (auto codec : *codecs) {
if (codec->mName == "red") {
red = static_cast<JsepVideoCodecDescription*>(codec);
}
else if (codec->mName == "ulpfec") {
ulpfec = static_cast<JsepVideoCodecDescription*>(codec);
}
}
// if we have a red codec remove redundant encodings that don't exist
if (red) {
// Since we could have an externally specified redundant endcodings
// list, we shouldn't simply rebuild the redundant encodings list
// based on the current list of codecs.
std::vector<uint8_t> unnegotiatedEncodings;
std::swap(unnegotiatedEncodings, red->mRedundantEncodings);
for (auto redundantPt : unnegotiatedEncodings) {
std::string pt = std::to_string(redundantPt);
for (auto codec : *codecs) {
if (pt == codec->mDefaultPt) {
red->mRedundantEncodings.push_back(redundantPt);
break;
}
}
}
}
// Video FEC is indicated by the existence of the red and ulpfec
// codecs and not an attribute on the particular video codec (like in
// a rtcpfb attr). If we see both red and ulpfec codecs, we enable FEC
// on all the other codecs.
if (red && ulpfec) {
for (auto codec : *codecs) {
if (codec->mName != "red" && codec->mName != "ulpfec") {
JsepVideoCodecDescription* videoCodec =
static_cast<JsepVideoCodecDescription*>(codec);
videoCodec->EnableFec();
}
}
}
// Make sure strongly preferred codecs are up front, overriding the remote
// side's preference.
std::stable_sort(codecs->begin(), codecs->end(), CompareCodec);
// TODO(bug 814227): Remove this once we're ready to put multiple codecs in an
// answer. For now, remove all but the first codec unless the red codec
// exists, and then we include the others per RFC 5109, section 14.2.
if (!codecs->empty() && !red) {
for (size_t i = 1; i < codecs->size(); ++i) {
delete (*codecs)[i];
(*codecs)[i] = nullptr;
}
codecs->resize(1);
}
}