Add mp3_plugin, support rtsp with mp3 (#4048)

增加mp3_plugin, 解决rtmp推流转rtsp无法播放问题
ref: https://datatracker.ietf.org/doc/html/rfc2250#section-3.5

ext-codec/MP3.cpp

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT-like license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "MP3.h"
+#include "MP3Rtp.h"
+#include "Extension/Factory.h"
+#include "Extension/CommonRtp.h"
+#include "Extension/CommonRtmp.h"
+
+using namespace std;
+using namespace toolkit;
+
+namespace mediakit {
+
+Sdp::Ptr MP3Track::getSdp(uint8_t payload_type) const {
+    return std::make_shared<DefaultSdp>(payload_type, *this);
+}
+
+Track::Ptr MP3Track::clone() const {
+    return std::make_shared<MP3Track>(*this);
+}
+
+namespace {
+
+CodecId getCodec() {
+    return CodecMP3;
+}
+
+Track::Ptr getTrackByCodecId(int sample_rate, int channels, int sample_bit) {
+    return std::make_shared<MP3Track>(sample_rate, channels);
+}
+
+Track::Ptr getTrackBySdp(const SdpTrack::Ptr &track) {
+    return std::make_shared<MP3Track>(track->_samplerate, track->_channel);
+}
+
+RtpCodec::Ptr getRtpEncoderByCodecId(uint8_t pt) {
+    return std::make_shared<MP3RtpEncoder>();
+}
+
+RtpCodec::Ptr getRtpDecoderByCodecId() {
+    return std::make_shared<MP3RtpDecoder>();
+}
+
+RtmpCodec::Ptr getRtmpEncoderByTrack(const Track::Ptr &track) {
+    return std::make_shared<CommonRtmpEncoder>(track);
+}
+
+RtmpCodec::Ptr getRtmpDecoderByTrack(const Track::Ptr &track) {
+    return std::make_shared<CommonRtmpDecoder>(track);
+}
+
+Frame::Ptr getFrameFromPtr(const char *data, size_t bytes, uint64_t dts, uint64_t pts) {
+    return std::make_shared<FrameFromPtr>(CodecMP3, (char *)data, bytes, dts, pts);
+}
+
+} // namespace
+
+CodecPlugin mp3_plugin = { getCodec,
+                           getTrackByCodecId,
+                           getTrackBySdp,
+                           getRtpEncoderByCodecId,
+                           getRtpDecoderByCodecId,
+                           getRtmpEncoderByTrack,
+                           getRtmpDecoderByTrack,
+                           getFrameFromPtr };
+
+}//namespace mediakit
+
+

ext-codec/MP3.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT-like license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef ZLMEDIAKIT_MP3_H
+#define ZLMEDIAKIT_MP3_H
+
+#include "Extension/Frame.h"
+#include "Extension/Track.h"
+
+namespace mediakit {
+
+/**
+ * MP3音频通道
+ */
+class MP3Track : public AudioTrackImp{
+public:
+    using Ptr = std::shared_ptr<MP3Track>;
+    MP3Track(int sample_rate, int channels) : AudioTrackImp(CodecMP3,sample_rate,channels,16){}
+
+private:
+    Sdp::Ptr getSdp(uint8_t payload_type) const override;
+    Track::Ptr clone() const override;
+};
+
+}//namespace mediakit
+#endif //ZLMEDIAKIT_MP3_H

ext-codec/MP3Rtp.cpp

@@ -0,0 +1,83 @@
+#include "MP3Rtp.h"
+#define MPEG12_HEADER_LEN 4
+
+namespace mediakit {
+
+//MPEG Audio-specific header
+/*
+ 0               1               2               3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+|             MBZ               |            Frag_offset        |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+    
+
+MP3RtpEncoder::MP3RtpEncoder(int sample_rate, int channels, int sample_bit) {
+    _sample_rate = sample_rate;
+    _channels = channels;
+    _sample_bit = sample_bit;
+}
+
+void MP3RtpEncoder::outputRtp(const char *data, size_t len, size_t offset, bool mark, uint64_t stamp) {
+    auto rtp = getRtpInfo().makeRtp(TrackAudio, nullptr, len + 4, mark, stamp);
+    auto payload = rtp->data() + RtpPacket::kRtpTcpHeaderSize + RtpPacket::kRtpHeaderSize;
+    payload[0] = 0;
+    payload[1] = 0;
+    payload[2] = offset >> 8;
+    payload[3] = offset ;
+    memcpy(payload + 4, data, len);
+    RtpCodec::inputRtp(std::move(rtp), false);
+}
+
+bool MP3RtpEncoder::inputFrame(const Frame::Ptr &frame) {
+    auto ptr = frame->data() + frame->prefixSize();
+    auto size = frame->size() - frame->prefixSize();
+    auto remain_size = size;
+    auto max_size = getRtpInfo().getMaxSize() - MPEG12_HEADER_LEN;
+    int  offset = 0;
+    while (remain_size > 0) {
+        if (remain_size <= max_size) {
+            outputRtp(ptr, remain_size, offset, true, frame->dts());
+            break;
+        }
+        outputRtp(ptr, max_size, offset, false, frame->dts());
+        ptr += max_size;
+        remain_size -= max_size;
+        offset += max_size;
+    }
+    return true;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////
+
+MP3RtpDecoder::MP3RtpDecoder() {
+    obtainFrame();
+}
+
+void MP3RtpDecoder::obtainFrame() {
+    _frame = FrameImp::create();
+    _frame->_codec_id = CodecMP3;
+}
+
+bool MP3RtpDecoder::inputRtp(const RtpPacket::Ptr &rtp, bool key_pos) {
+    auto payload_size = rtp->getPayloadSize();
+    if (payload_size <= MPEG12_HEADER_LEN) {
+        return false;
+    }
+    auto stamp = rtp->getStampMS();
+    auto ptr = rtp->getPayload();
+
+    _frame->_buffer.append((char *)ptr + MPEG12_HEADER_LEN, payload_size - MPEG12_HEADER_LEN);
+    flushData();
+
+    _last_dts = stamp;
+    return false;
+}
+
+void MP3RtpDecoder::flushData() {
+    RtpCodec::inputFrame(_frame);
+    obtainFrame();
+}
+
+} // namespace mediakit

ext-codec/MP3Rtp.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT-like license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef ZLMEDIAKIT_MP3RTP_H
+#define ZLMEDIAKIT_MP3RTP_H
+
+#include "Rtsp/RtpCodec.h"
+#include "Extension/Frame.h"
+#include "Extension/CommonRtp.h"
+
+namespace mediakit {
+
+class MP3RtpEncoder : public RtpCodec {
+public:
+    using Ptr = std::shared_ptr<MP3RtpEncoder>;
+
+    MP3RtpEncoder(int sample_rate = 44100, int channels = 2, int sample_bit = 16);
+
+    void outputRtp(const char *data, size_t len, size_t offset, bool mark, uint64_t stamp);
+
+    bool inputFrame(const Frame::Ptr &frame) override;
+
+private:
+    int _channels;
+    int _sample_rate;
+    int _sample_bit;
+};
+
+
+class MP3RtpDecoder : public RtpCodec {
+public:
+    using Ptr = std::shared_ptr<MP3RtpDecoder>;
+
+    MP3RtpDecoder();
+
+    bool inputRtp(const RtpPacket::Ptr &rtp, bool key_pos = false) override;
+
+private:
+    void obtainFrame();
+
+    void flushData();
+
+
+private:
+    uint64_t _last_dts = 0;
+    FrameImp::Ptr _frame;
+};
+
+}//namespace mediakit
+#endif //ZLMEDIAKIT_MP3RTP_H