fall back to payload types from lower range after exhausting [96,127]
Both flexfec and AV1 seem not to have created interop issues and falling
back to the lower range is better than skipping the codecs.
BUG=webrtc:12295
Change-Id: I58459133beae4f17b767af92a4e2c9028ab8cbe3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/217888
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@nvidia.com>
Cr-Commit-Position: refs/heads/master@{#34182}
diff --git a/media/engine/webrtc_video_engine.cc b/media/engine/webrtc_video_engine.cc
index 4ca6c8f..2ec6b48 100644
--- a/media/engine/webrtc_video_engine.cc
+++ b/media/engine/webrtc_video_engine.cc
@@ -105,10 +105,10 @@
}
}
-// This function will assign dynamic payload types (in the range [96, 127]) to
-// the input codecs, and also add ULPFEC, RED, FlexFEC, and associated RTX
-// codecs for recognized codecs (VP8, VP9, H264, and RED). It will also add
-// default feedback params to the codecs.
+// This function will assign dynamic payload types (in the range [96, 127]
+// and then [35, 63]) to the input codecs, and also add ULPFEC, RED, FlexFEC,
+// and associated RTX codecs for recognized codecs (VP8, VP9, H264, and RED).
+// It will also add default feedback params to the codecs.
// is_decoder_factory is needed to keep track of the implict assumption that any
// H264 decoder also supports constrained base line profile.
// Also, is_decoder_factory is used to decide whether FlexFEC video format
@@ -133,16 +133,6 @@
if (supported_formats.empty())
return std::vector<VideoCodec>();
- // Due to interoperability issues with old Chrome/WebRTC versions only use
- // the lower range for new codecs.
- static const int kFirstDynamicPayloadTypeLowerRange = 35;
- static const int kLastDynamicPayloadTypeLowerRange = 63;
-
- static const int kFirstDynamicPayloadTypeUpperRange = 96;
- static const int kLastDynamicPayloadTypeUpperRange = 127;
- int payload_type_upper = kFirstDynamicPayloadTypeUpperRange;
- int payload_type_lower = kFirstDynamicPayloadTypeLowerRange;
-
supported_formats.push_back(webrtc::SdpVideoFormat(kRedCodecName));
supported_formats.push_back(webrtc::SdpVideoFormat(kUlpfecCodecName));
@@ -162,60 +152,65 @@
supported_formats.push_back(flexfec_format);
}
+ // Due to interoperability issues with old Chrome/WebRTC versions that
+ // ignore the [35, 63] range prefer the lower range for new codecs.
+ static const int kFirstDynamicPayloadTypeLowerRange = 35;
+ static const int kLastDynamicPayloadTypeLowerRange = 63;
+
+ static const int kFirstDynamicPayloadTypeUpperRange = 96;
+ static const int kLastDynamicPayloadTypeUpperRange = 127;
+ int payload_type_upper = kFirstDynamicPayloadTypeUpperRange;
+ int payload_type_lower = kFirstDynamicPayloadTypeLowerRange;
+
std::vector<VideoCodec> output_codecs;
for (const webrtc::SdpVideoFormat& format : supported_formats) {
VideoCodec codec(format);
bool isCodecValidForLowerRange =
absl::EqualsIgnoreCase(codec.name, kFlexfecCodecName) ||
absl::EqualsIgnoreCase(codec.name, kAv1CodecName);
- if (!isCodecValidForLowerRange) {
- codec.id = payload_type_upper++;
- } else {
+ bool isFecCodec = absl::EqualsIgnoreCase(codec.name, kUlpfecCodecName) ||
+ absl::EqualsIgnoreCase(codec.name, kFlexfecCodecName);
+
+ // Check if we ran out of payload types.
+ if (payload_type_lower > kLastDynamicPayloadTypeLowerRange) {
+ // TODO(https://bugs.chromium.org/p/webrtc/issues/detail?id=12248):
+ // return an error.
+ RTC_LOG(LS_ERROR) << "Out of dynamic payload types [35,63] after "
+ "fallback from [96, 127], skipping the rest.";
+ RTC_DCHECK_EQ(payload_type_upper, kLastDynamicPayloadTypeUpperRange);
+ break;
+ }
+
+ // Lower range gets used for "new" codecs or when running out of payload
+ // types in the upper range.
+ if (isCodecValidForLowerRange ||
+ payload_type_upper >= kLastDynamicPayloadTypeUpperRange) {
codec.id = payload_type_lower++;
+ } else {
+ codec.id = payload_type_upper++;
}
AddDefaultFeedbackParams(&codec, trials);
output_codecs.push_back(codec);
- if (payload_type_upper > kLastDynamicPayloadTypeUpperRange) {
- RTC_LOG(LS_ERROR)
- << "Out of dynamic payload types [96,127], skipping the rest.";
- // TODO(https://bugs.chromium.org/p/webrtc/issues/detail?id=12194):
- // continue in lower range.
- break;
- }
- if (payload_type_lower > kLastDynamicPayloadTypeLowerRange) {
- // TODO(https://bugs.chromium.org/p/webrtc/issues/detail?id=12248):
- // return an error.
- RTC_LOG(LS_ERROR)
- << "Out of dynamic payload types [35,63], skipping the rest.";
- break;
- }
-
// Add associated RTX codec for non-FEC codecs.
- if (!absl::EqualsIgnoreCase(codec.name, kUlpfecCodecName) &&
- !absl::EqualsIgnoreCase(codec.name, kFlexfecCodecName)) {
- if (!isCodecValidForLowerRange) {
- output_codecs.push_back(
- VideoCodec::CreateRtxCodec(payload_type_upper++, codec.id));
- } else {
- output_codecs.push_back(
- VideoCodec::CreateRtxCodec(payload_type_lower++, codec.id));
- }
-
- if (payload_type_upper > kLastDynamicPayloadTypeUpperRange) {
- RTC_LOG(LS_ERROR)
- << "Out of dynamic payload types [96,127], skipping rtx.";
- // TODO(https://bugs.chromium.org/p/webrtc/issues/detail?id=12194):
- // continue in lower range.
- break;
- }
+ if (!isFecCodec) {
+ // Check if we ran out of payload types.
if (payload_type_lower > kLastDynamicPayloadTypeLowerRange) {
// TODO(https://bugs.chromium.org/p/webrtc/issues/detail?id=12248):
// return an error.
- RTC_LOG(LS_ERROR)
- << "Out of dynamic payload types [35,63], skipping rtx.";
+ RTC_LOG(LS_ERROR) << "Out of dynamic payload types [35,63] after "
+ "fallback from [96, 127], skipping the rest.";
+ RTC_DCHECK_EQ(payload_type_upper, kLastDynamicPayloadTypeUpperRange);
break;
}
+ if (isCodecValidForLowerRange ||
+ payload_type_upper >= kLastDynamicPayloadTypeUpperRange) {
+ output_codecs.push_back(
+ VideoCodec::CreateRtxCodec(payload_type_lower++, codec.id));
+ } else {
+ output_codecs.push_back(
+ VideoCodec::CreateRtxCodec(payload_type_upper++, codec.id));
+ }
}
}
return output_codecs;
