处理seek offset为负数情况 (#4742)

详见media-server的buffer实现， seek的语义和回调不一致，这边进行统一
static int mov_file_read(void* fp, void* data, uint64_t bytes)
{
    if (bytes == fread(data, 1, bytes, (FILE*)fp))
        return 0;
	return 0 != ferror((FILE*)fp) ? ferror((FILE*)fp) : -1 /*EOF*/;
}

static int mov_file_write(void* fp, const void* data, uint64_t bytes)
{
return bytes == fwrite(data, 1, bytes, (FILE*)fp) ? 0 :
ferror((FILE*)fp);
}

static int mov_file_seek(void* fp, int64_t offset)
{
	return fseek64((FILE*)fp, offset, offset >= 0 ? SEEK_SET : SEEK_END);
}

static int64_t mov_file_tell(void* fp)
{
	return ftell64((FILE*)fp);
}

README.md

@@ -233,6 +233,7 @@ bash build_docker_images.sh
    - [BXC_SipServer](https://github.com/any12345com/BXC_SipServer) c++实现的国标GB28181流媒体信令服务器
    - [gosip](https://github.com/panjjo/gosip) golang实现的GB28181服务器
    - [FreeEhome](https://github.com/tsingeye/FreeEhome) golang实现的海康ehome服务器
+   - [泉视视频监控系统](https://github.com/2929004360/ruoyi-qs-nvr) 支持onvif、海康isup、大华sdk、jt808等协议接入视频管理系统
   
  - 播放器
    - [h265web.js](https://github.com/numberwolf/h265web.js) 基于wasm支持H265的播放器，支持本项目多种专属协议

src/Common/MediaSource.cpp

@@ -66,6 +66,11 @@ ProtocolOption::ProtocolOption() {
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
+struct MediaSourceNull : public MediaSource {
+    MediaSourceNull() : MediaSource("schema", MediaTuple{"vhost", "app", "stream", ""}) {};
+    int readerCount() override { return 0; }
+};
+
 MediaSource &MediaSource::NullMediaSource() {
     static std::shared_ptr<MediaSource> s_null = std::make_shared<MediaSourceNull>();
     return *s_null;
@@ -272,7 +277,7 @@ bool MediaSource::setupRecord(Recorder::type type, bool start, const string &cus
         WarnL << "未设置MediaSource的事件监听者，setupRecord失败:" << getUrl();
         return false;
     }
-    return listener->getMuxer(const_cast<MediaSource &>(*this))->setupRecord(type, start, custom_path, max_second);
+    return listener->getMuxer(const_cast<MediaSource &>(*this))->setupRecord(*this, type, start, custom_path, max_second);
 }
 
 bool MediaSource::isRecording(Recorder::type type){

src/Common/MediaSource.h

@@ -573,11 +573,5 @@ private:
     toolkit::ObjectStatistic<MediaSource> _statistic;
 };
 
-struct MediaSourceNull : public MediaSource {
-    MediaSourceNull(const MediaTuple &tuple = { "vhost", "app", "stream", "" })
-        : MediaSource("schema", tuple) { };
-    int readerCount() override { return 0; }
-};
-
 } /* namespace mediakit */
 #endif //ZLMEDIAKIT_MEDIASOURCE_H

src/Common/MultiMediaSourceMuxer.cpp

@@ -206,7 +206,6 @@ void MultiMediaSourceMuxer::forEachRtpSender(const std::function<void(const std:
 }
 #endif // ENABLE_RTPPROXY
 MultiMediaSourceMuxer::MultiMediaSourceMuxer(const MediaTuple& tuple, float dur_sec, const ProtocolOption &option): _tuple(tuple) {
-    _null_src = std::make_shared<MediaSourceNull>(tuple);
     if (!option.stream_replace.empty()) {
         // 支持在on_publish hook中替换stream_id  [AUTO-TRANSLATED:375eb2ff]
         // Support replacing stream_id in on_publish hook
@@ -314,13 +313,13 @@ int MultiMediaSourceMuxer::totalReaderCount(MediaSource &sender) {
 
 // 此函数可能跨线程调用  [AUTO-TRANSLATED:e8c5f74d]
 // This function may be called across threads
-bool MultiMediaSourceMuxer::setupRecord(Recorder::type type, bool start, const string &custom_path, size_t max_second) {
+bool MultiMediaSourceMuxer::setupRecord(MediaSource &sender, Recorder::type type, bool start, const string &custom_path, size_t max_second) {
     CHECK(getOwnerPoller(MediaSource::NullMediaSource())->isCurrentThread(), "Can only call setupRecord in it's owner poller");
     onceToken token(nullptr, [&]() {
         if (_option.mp4_as_player && type == Recorder::type_mp4) {
             // 开启关闭mp4录制，触发观看人数变化相关事件  [AUTO-TRANSLATED:b63a8deb]
             // Turn on/off mp4 recording, trigger events related to changes in the number of viewers
-            onReaderChanged(*_null_src, totalReaderCount());
+            onReaderChanged(sender, totalReaderCount());
         }
     });
     switch (type) {

src/Common/MultiMediaSourceMuxer.h

@@ -133,7 +133,7 @@ public:
      
      * [AUTO-TRANSLATED:cb1fd8a9]
      */
-    bool setupRecord(Recorder::type type, bool start, const std::string &custom_path, size_t max_second);
+    bool setupRecord(MediaSource &sender, Recorder::type type, bool start, const std::string &custom_path, size_t max_second);
 
     /**
      * 开始录制mp4
@@ -266,7 +266,6 @@ private:
     toolkit::EventPoller::Ptr _poller;
     RingType::Ptr _ring;
     MediaSinkInterface::Ptr _delegate;
-    MediaSourceNull::Ptr _null_src;
     // 对象个数统计  [AUTO-TRANSLATED:3b43e8c2]
     // Object count statistics
     toolkit::ObjectStatistic<MultiMediaSourceMuxer> _statistic;

src/Record/MP4.cpp

@@ -35,7 +35,7 @@ static struct mov_buffer_t s_io = {
         },
         [](void *ctx) {
             MP4FileIO *thiz = (MP4FileIO *) ctx;
-            return (int64_t)thiz->onTell();
+            return thiz->onTell();
         }
 };
 
@@ -128,11 +128,11 @@ int MP4FileDisk::onWrite(const void *data, size_t bytes) {
     return bytes == fwrite(data, 1, bytes, _file.get()) ? 0 : ferror(_file.get());
 }
 
-int MP4FileDisk::onSeek(uint64_t offset) {
-    return fseek64(_file.get(), offset, SEEK_SET);
+int MP4FileDisk::onSeek(int64_t offset) {
+    return fseek64(_file.get(), offset, offset >= 0 ? SEEK_SET : SEEK_END);
 }
 
-uint64_t MP4FileDisk::onTell() {
+int64_t MP4FileDisk::onTell() {
     return ftell64(_file.get());
 }
 
@@ -149,15 +149,23 @@ size_t MP4FileMemory::fileSize() const{
     return _memory.size();
 }
 
-uint64_t MP4FileMemory::onTell(){
+int64_t MP4FileMemory::onTell(){
     return _offset;
 }
 
-int MP4FileMemory::onSeek(uint64_t offset){
+int MP4FileMemory::onSeek(int64_t offset){
+    if (offset < 0) {
+        offset += _memory.size();
+        if (offset < 0) {
+            return -1;
+        }
+        _offset = offset;
+    } else {
         if (offset > _memory.size()) {
             return -1;
         }
         _offset = offset;
+    }
     return 0;
 }
 
@@ -167,7 +175,7 @@ int MP4FileMemory::onRead(void *data, size_t bytes){
         return -1;
     }
     bytes = MIN(bytes, _memory.size() - _offset);
-    memcpy(data, _memory.data(), bytes);
+    memcpy(data, _memory.data() + _offset, bytes);
     _offset += bytes;
     return 0;
 }

src/Record/MP4.h

@@ -66,7 +66,7 @@ public:
      
      * [AUTO-TRANSLATED:f8a5b290]
      */
-    virtual uint64_t onTell() = 0;
+    virtual int64_t onTell() = 0;
 
     /**
      * seek至文件某处
@@ -78,7 +78,7 @@ public:
      
      * [AUTO-TRANSLATED:936089eb]
      */
-    virtual int onSeek(uint64_t offset) = 0;
+    virtual int onSeek(int64_t offset) = 0;
 
     /**
      * 从文件读取一定数据
@@ -136,8 +136,8 @@ public:
     void closeFile();
 
 protected:
-    uint64_t onTell() override;
-    int onSeek(uint64_t offset) override;
+    int64_t onTell() override;
+    int onSeek(int64_t offset) override;
     int onRead(void *data, size_t bytes) override;
     int onWrite(const void *data, size_t bytes) override;
 
@@ -167,13 +167,13 @@ public:
     std::string getAndClearMemory();
 
 protected:
-    uint64_t onTell() override;
-    int onSeek(uint64_t offset) override;
+    int64_t onTell() override;
+    int onSeek(int64_t offset) override;
     int onRead(void *data, size_t bytes) override;
     int onWrite(const void *data, size_t bytes) override;
 
 private:
-    uint64_t _offset = 0;
+    int64_t _offset = 0;
     std::string _memory;
 };