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/*
* Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*
*/
#include "modules/video_coding/codecs/h264/include/h264.h"
#include <memory>
#include <optional>
#include <string>
#include "absl/container/inlined_vector.h"
#include "api/video_codecs/sdp_video_format.h"
#include "media/base/media_constants.h"
#include "rtc_base/trace_event.h"
#if defined(WEBRTC_USE_H264)
#include "modules/video_coding/codecs/h264/h264_decoder_impl.h"
#include "modules/video_coding/codecs/h264/h264_encoder_impl.h"
#endif
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
namespace webrtc {
namespace {
#if defined(WEBRTC_USE_H264)
bool g_rtc_use_h264 = true;
#endif
// If H.264 OpenH264/FFmpeg codec is supported.
bool IsH264CodecSupported() {
#if defined(WEBRTC_USE_H264)
return g_rtc_use_h264;
#else
return false;
#endif
}
constexpr ScalabilityMode kSupportedScalabilityModes[] = {
ScalabilityMode::kL1T1, ScalabilityMode::kL1T2, ScalabilityMode::kL1T3};
} // namespace
SdpVideoFormat CreateH264Format(H264Profile profile,
H264Level level,
const std::string& packetization_mode,
bool add_scalability_modes) {
const std::optional<std::string> profile_string =
H264ProfileLevelIdToString(H264ProfileLevelId(profile, level));
RTC_CHECK(profile_string);
absl::InlinedVector<ScalabilityMode, kScalabilityModeCount> scalability_modes;
if (add_scalability_modes) {
for (const auto scalability_mode : kSupportedScalabilityModes) {
scalability_modes.push_back(scalability_mode);
}
}
return SdpVideoFormat(kH264CodecName,
{{kH264FmtpProfileLevelId, *profile_string},
{kH264FmtpLevelAsymmetryAllowed, "1"},
{kH264FmtpPacketizationMode, packetization_mode}},
scalability_modes);
}
void DisableRtcUseH264() {
#if defined(WEBRTC_USE_H264)
g_rtc_use_h264 = false;
#endif
}
std::vector<SdpVideoFormat> SupportedH264Codecs(bool add_scalability_modes) {
TRACE_EVENT0("webrtc", __func__);
if (!IsH264CodecSupported())
return std::vector<SdpVideoFormat>();
// We only support encoding Constrained Baseline Profile (CBP), but the
// decoder supports more profiles. We can list all profiles here that are
// supported by the decoder and that are also supersets of CBP, i.e. the
// decoder for that profile is required to be able to decode CBP. This means
// we can encode and send CBP even though we negotiated a potentially
// higher profile. See the H264 spec for more information.
//
// We support both packetization modes 0 (mandatory) and 1 (optional,
// preferred).
return {CreateH264Format(H264Profile::kProfileBaseline, H264Level::kLevel3_1,
"1", add_scalability_modes),
CreateH264Format(H264Profile::kProfileBaseline, H264Level::kLevel3_1,
"0", add_scalability_modes),
CreateH264Format(H264Profile::kProfileConstrainedBaseline,
H264Level::kLevel3_1, "1", add_scalability_modes),
CreateH264Format(H264Profile::kProfileConstrainedBaseline,
H264Level::kLevel3_1, "0", add_scalability_modes),
CreateH264Format(H264Profile::kProfileMain, H264Level::kLevel3_1, "1",
add_scalability_modes),
CreateH264Format(H264Profile::kProfileMain, H264Level::kLevel3_1, "0",
add_scalability_modes)};
}
std::vector<SdpVideoFormat> SupportedH264DecoderCodecs() {
TRACE_EVENT0("webrtc", __func__);
if (!IsH264CodecSupported())
return std::vector<SdpVideoFormat>();
std::vector<SdpVideoFormat> supportedCodecs = SupportedH264Codecs();
// OpenH264 doesn't yet support High Predictive 4:4:4 encoding but it does
// support decoding.
supportedCodecs.push_back(CreateH264Format(
H264Profile::kProfilePredictiveHigh444, H264Level::kLevel3_1, "1"));
supportedCodecs.push_back(CreateH264Format(
H264Profile::kProfilePredictiveHigh444, H264Level::kLevel3_1, "0"));
return supportedCodecs;
}
H264EncoderSettings H264EncoderSettings::Parse(const SdpVideoFormat& format) {
if (auto it = format.parameters.find(kH264FmtpPacketizationMode);
it != format.parameters.end()) {
if (it->second == "0") {
return {.packetization_mode = H264PacketizationMode::SingleNalUnit};
} else if (it->second == "1") {
return {.packetization_mode = H264PacketizationMode::NonInterleaved};
}
}
return {};
}
absl_nonnull std::unique_ptr<VideoEncoder> CreateH264Encoder(
[[maybe_unused]] const Environment& env,
[[maybe_unused]] H264EncoderSettings settings) {
#if defined(WEBRTC_USE_H264)
RTC_CHECK(g_rtc_use_h264);
RTC_LOG(LS_INFO) << "Creating H264EncoderImpl.";
return std::make_unique<H264EncoderImpl>(env, settings);
#else
RTC_CHECK_NOTREACHED();
#endif
}
bool H264Encoder::IsSupported() {
return IsH264CodecSupported();
}
bool H264Encoder::SupportsScalabilityMode(ScalabilityMode scalability_mode) {
for (const auto& entry : kSupportedScalabilityModes) {
if (entry == scalability_mode) {
return true;
}
}
return false;
}
std::unique_ptr<H264Decoder> H264Decoder::Create() {
RTC_DCHECK(H264Decoder::IsSupported());
#if defined(WEBRTC_USE_H264)
RTC_CHECK(g_rtc_use_h264);
RTC_LOG(LS_INFO) << "Creating H264DecoderImpl.";
return std::make_unique<H264DecoderImpl>();
#else
RTC_DCHECK_NOTREACHED();
return nullptr;
#endif
}
bool H264Decoder::IsSupported() {
return IsH264CodecSupported();
}
} // namespace webrtc
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