ZLMediaKit/src/Extension/Frame.cpp

/*
 * 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 "Frame.h"
#include "Common/Parser.h"
#include "Common/Stamp.h"
#include "Common/MediaSource.h"

#if defined(ENABLE_MP4)
#include "mov-format.h"
#endif

#if defined(ENABLE_HLS) || defined(ENABLE_RTPPROXY)
#include "mpeg-proto.h"
#endif

using namespace std;
using namespace toolkit;

namespace toolkit {
    StatisticImp(mediakit::Frame);
    StatisticImp(mediakit::FrameImp);
}

namespace mediakit{

Frame::Ptr Frame::getCacheAbleFrame(const Frame::Ptr &frame){
    if(frame->cacheAble()){
        return frame;
    }
    return std::make_shared<FrameCacheAble>(frame);
}

FrameStamp::FrameStamp(Frame::Ptr frame) {
    setIndex(frame->getIndex());
    _frame = std::move(frame);
}

FrameStamp::FrameStamp(Frame::Ptr frame, Stamp &stamp, int modify_stamp)
    : FrameStamp(std::move(frame)) {
    // kModifyStampSystem时采用系统时间戳，kModifyStampRelative采用相对时间戳  [AUTO-TRANSLATED:54dd5685]
    // When using kModifyStampSystem, the system timestamp is used, and when using kModifyStampRelative, the relative timestamp is used.
    stamp.revise(_frame->dts(), _frame->pts(), _dts, _pts, modify_stamp == ProtocolOption::kModifyStampSystem);
}

void FrameStamp::setStamp(int64_t dts, int64_t pts) {
    _dts = dts;
    _pts = pts;
}


TrackType getTrackType(CodecId codecId) {
    switch (codecId) {
#define XX(name, type, value, str, mpeg_id, mp4_id) case name : return type;
        CODEC_MAP(XX)
#undef XX
        default : return TrackInvalid;
    }
}

#if defined(ENABLE_MP4)
int getMovIdByCodec(CodecId codecId) {
    switch (codecId) {
#define XX(name, type, value, str, mpeg_id, mp4_id) case name : return mp4_id;
        CODEC_MAP(XX)
#undef XX
        default : return MOV_OBJECT_NONE;
    }
}

CodecId getCodecByMovId(int object_id) {
    if (object_id == MOV_OBJECT_NONE) {
        return CodecInvalid;
    }

#define XX(name, type, value, str, mpeg_id, mp4_id) { mp4_id, name },
    static map<int, CodecId> s_map = { CODEC_MAP(XX) };
#undef XX
    auto it = s_map.find(object_id);
    if (it == s_map.end()) {
        WarnL << "Unsupported mov: " << object_id;
        return CodecInvalid;
    }
    return it->second;
}
#endif

#if defined(ENABLE_HLS) || defined(ENABLE_RTPPROXY)
int getMpegIdByCodec(CodecId codec) {
    switch (codec) {
#define XX(name, type, value, str, mpeg_id, mp4_id) case name : return mpeg_id;
        CODEC_MAP(XX)
#undef XX
        default : return PSI_STREAM_RESERVED;
    }
}

CodecId getCodecByMpegId(int mpeg_id) {
    if (mpeg_id == PSI_STREAM_RESERVED || mpeg_id == 0xBD) {
        // 海康的 PS 流中会有0xBD 的包  [AUTO-TRANSLATED:32a250cb]
        // Hikvision's PS stream will have 0xBD packets.
        return CodecInvalid;
    }

#define XX(name, type, value, str, mpeg_id, mp4_id) { mpeg_id, name },
    static map<int, CodecId> s_map = { CODEC_MAP(XX) };
#undef XX
    auto it = s_map.find(mpeg_id);
    if (it == s_map.end()) {
        WarnL << "Unsupported mpeg: " << mpeg_id;
        return CodecInvalid;
    }
    return it->second;
}

#endif

const char *getCodecName(CodecId codec) {
    switch (codec) {
#define XX(name, type, value, str, mpeg_id, mp4_id) case name : return str;
        CODEC_MAP(XX)
#undef XX
        default : return "invalid";
    }
}

#define XX(name, type, value, str, mpeg_id, mp4_id) {str, name},
static map<string, CodecId, StrCaseCompare> codec_map = { CODEC_MAP(XX) };
#undef XX

CodecId getCodecId(const string &str){
    auto it = codec_map.find(str);
    return it == codec_map.end() ? CodecInvalid : it->second;
}

static map<string, TrackType, StrCaseCompare> track_str_map = {
        {"video",       TrackVideo},
        {"audio",       TrackAudio},
        {"application", TrackApplication}
};

TrackType getTrackType(const string &str) {
    auto it = track_str_map.find(str);
    return it == track_str_map.end() ? TrackInvalid : it->second;
}

const char* getTrackString(TrackType type){
    switch (type) {
        case TrackVideo : return "video";
        case TrackAudio : return "audio";
        case TrackApplication : return "application";
        default: return "invalid";
    }
}

const char *CodecInfo::getCodecName() const {
    return mediakit::getCodecName(getCodecId());
}

TrackType CodecInfo::getTrackType() const {
    return mediakit::getTrackType(getCodecId());
}

std::string CodecInfo::getTrackTypeStr() const {
    return getTrackString(getTrackType());
}

static size_t constexpr kMaxFrameCacheSize = 100;

bool FrameMerger::willFlush(const Frame::Ptr &frame) const{
    if (_frame_cache.empty()) {
        // 缓存为空  [AUTO-TRANSLATED:b9505a19]
        // Cache is empty.
        return false;
    }
    if (!frame) {
        return true;
    }
    switch (_type) {
        case none : {
            // frame不是完整的帧，我们合并为一帧  [AUTO-TRANSLATED:00e9f200]
            // The frame is not a complete frame, we merge it into one frame.
            bool new_frame = false;
            switch (frame->getCodecId()) {
                case CodecH264:
                case CodecH265: {
                    // 如果是新的一帧，前面的缓存需要输出  [AUTO-TRANSLATED:b4deff81]
                    // If it is a new frame, the previous cache needs to be output.
                    new_frame = frame->prefixSize();
                    break;
                }
                default: break;
            }
            // 遇到新帧、或时间戳变化或缓存太多，防止内存溢出，则flush输出  [AUTO-TRANSLATED:0292964a]
            // When encountering a new frame, or a timestamp change, or too much cache, flush the output to prevent memory overflow.
            return new_frame || _frame_cache.back()->dts() != frame->dts() || _frame_cache.size() > kMaxFrameCacheSize;
        }

        case mp4_nal_size:
        case h264_prefix: {
            if (!_have_decode_able_frame) {
                // 缓存中没有有效的能解码的帧，所以这次不flush  [AUTO-TRANSLATED:5d860722]
                // There are no valid frames that can be decoded in the cache, so no flush this time.
                return _frame_cache.size() > kMaxFrameCacheSize;
            }
            if (_frame_cache.back()->dts() != frame->dts() || frame->decodeAble() || frame->configFrame()) {
                // 时间戳变化了,或新的一帧，或遇到config帧，立即flush  [AUTO-TRANSLATED:8c2523b1]
                // When the timestamp changes, or a new frame, or a config frame is encountered, flush immediately.
                return true;
            }
            return _frame_cache.size() > kMaxFrameCacheSize;
        }
        default: /*不可达*/ assert(0); return true;
    }
}

void FrameMerger::doMerge(BufferLikeString &merged, const Frame::Ptr &frame) const{
    switch (_type) {
        case none : {
            // 此处是合并ps解析输出的流，解析出的流可能是半帧或多帧，不能简单的根据nal type过滤  [AUTO-TRANSLATED:4a231bdc]
            // Here, the PS parsing output stream is merged. The parsed stream may be half a frame or multiple frames, and cannot be simply filtered according to the nal type.
            // 此流程只用于合并ps解析输出为H264/H265，后面流程有split和忽略无效帧操作  [AUTO-TRANSLATED:2d40274e]
            // This process is only used to merge PS parsing output into H264/H265. The subsequent process has split and ignore invalid frame operations.
            merged.append(frame->data(), frame->size());
            break;
        }
        case h264_prefix: {
            if (frame->prefixSize()) {
                merged.append(frame->data(), frame->size());
            } else {
                merged.append("\x00\x00\x00\x01", 4);
                merged.append(frame->data(), frame->size());
            }
            break;
        }
        case mp4_nal_size: {
            uint32_t nalu_size = (uint32_t) (frame->size() - frame->prefixSize());
            nalu_size = htonl(nalu_size);
            merged.append((char *) &nalu_size, 4);
            merged.append(frame->data() + frame->prefixSize(), frame->size() - frame->prefixSize());
            break;
        }
        default: /*不可达*/ assert(0); break;
    }
}

static bool isNeedMerge(CodecId codec){
    switch (codec) {
        case CodecH264:
        case CodecH265: return true;
        default: return false;
    }
}

bool FrameMerger::inputFrame(const Frame::Ptr &frame, onOutput cb, BufferLikeString *buffer) {
    if (frame && !isNeedMerge(frame->getCodecId())) {
        cb(frame->dts(), frame->pts(), frame, true);
        return true;
    }
    if (willFlush(frame)) {
        Frame::Ptr back = _frame_cache.back();
        Buffer::Ptr merged_frame = back;
        bool have_key_frame = back->keyFrame();

        if (_frame_cache.size() != 1 || _type == mp4_nal_size || buffer) {
            // 在MP4模式下，一帧数据也需要在前添加nalu_size  [AUTO-TRANSLATED:4a7e5c20]
            // In MP4 mode, a frame of data also needs to add nalu_size in front.
            BufferLikeString tmp;
            BufferLikeString &merged = buffer ? *buffer : tmp;

            if (!buffer) {
                tmp.reserve(back->size() + 1024);
            }

            _frame_cache.for_each([&](const Frame::Ptr &frame) {
                doMerge(merged, frame);
                if (frame->keyFrame()) {
                    have_key_frame = true;
                }
            });
            merged_frame = std::make_shared<BufferOffset<BufferLikeString> >(buffer ? merged : std::move(merged));
        }
        cb(back->dts(), back->pts(), merged_frame, have_key_frame);
        _frame_cache.clear();
        _have_decode_able_frame = false;
    }

    if (!frame) {
        return false;
    }

    if (frame->decodeAble()) {
        _have_decode_able_frame = true;
    }
    _cb = std::move(cb);
    _frame_cache.emplace_back(Frame::getCacheAbleFrame(frame));
    return true;
}

FrameMerger::FrameMerger(int type) {
    _type = type;
}

void FrameMerger::clear() {
    _frame_cache.clear();
    _have_decode_able_frame = false;
}

void FrameMerger::flush() {
    if (_cb) {
        inputFrame(nullptr, std::move(_cb), nullptr);
    }
    clear();
}
/**
 * 写帧接口转function，辅助类
 * Write frame interface to function, auxiliary class
 
 * [AUTO-TRANSLATED:ce04a5e9]
 */
class FrameWriterInterfaceHelper : public FrameWriterInterface {
public:
    using Ptr = std::shared_ptr<FrameWriterInterfaceHelper>;
    using onWriteFrame = std::function<bool(const Frame::Ptr &frame)>;

    /**
     * inputFrame后触发onWriteFrame回调
     * Trigger onWriteFrame callback after inputFrame
     
     * [AUTO-TRANSLATED:169e5944]
     */
    FrameWriterInterfaceHelper(onWriteFrame cb) { _callback = std::move(cb); }

    /**
     * 写入帧数据
     * Write frame data
     
     
     * [AUTO-TRANSLATED:d46c6fc2]
     */
    bool inputFrame(const Frame::Ptr &frame) override { return _callback(frame); }

private:
    onWriteFrame _callback;
};

FrameWriterInterface* FrameDispatcher::addDelegate(std::function<bool(const Frame::Ptr &frame)> cb) {
    return addDelegate(std::make_shared<FrameWriterInterfaceHelper>(std::move(cb)));
}

}//namespace mediakit