iOS中实现音视频合并的完整代码

// 合并音频文件（支持 .mp3/.m4a 等格式）
- (void)mergeaudiofiles:(nsarray<nsurl *> *)audiourls completion:(void (^)(nsurl *outputurl, nserror *error))completion {
    // 1. 创建 avmutablecomposition 对象
    avmutablecomposition *composition = [avmutablecomposition composition];
    
    // 2. 添加音频轨道
    avmutablecompositiontrack *audiotrack = [composition addmutabletrackwithmediatype:avmediatypeaudio preferredtrackid:kcmpersistenttrackid_invalid];
    
    // 3. 插入每个音频文件到轨道中
    cmtime currenttime = kcmtimezero;
    for (nsurl *url in audiourls) {
        avurlasset *asset = [avurlasset urlassetwithurl:url options:nil];
        avassettrack *assettrack = [[asset trackswithmediatype:avmediatypeaudio] firstobject];
        [audiotrack inserttimerange:cmtimerangemake(kcmtimezero, asset.duration)
                         oftrack:assettrack
                          attime:currenttime
                           error:nil];
        currenttime = cmtimeadd(currenttime, asset.duration);
    }
    
    // 4. 导出合并后的音频
    avassetexportsession *exportsession = [[avassetexportsession alloc] initwithasset:composition presetname:avassetexportpresetapplem4a];
    nsstring *outputpath = [nstemporarydirectory() stringbyappendingpathcomponent:@"mergedaudio.m4a"];
    exportsession.outputurl = [nsurl fileurlwithpath:outputpath];
    exportsession.outputfiletype = avfiletypeapplem4a;
    
    [exportsession exportasynchronouslywithcompletionhandler:^{
        if (exportsession.status == avassetexportsessionstatuscompleted) {
            nslog(@"音频合并成功: %@", outputpath);
            if (completion) completion([nsurl fileurlwithpath:outputpath], nil);
        } else {
            nserror *error = exportsession.error;
            nslog(@"音频合并失败: %@", error.localizeddescription);
            if (completion) completion(nil, error);
        }
    }];
}

// 示例：合并两个音频文件
nsarray<nsurl *> *audiourls = @[
    [nsurl fileurlwithpath:[[nsbundle mainbundle] pathforresource:@"audio1" oftype:@"mp3"]],
    [nsurl fileurlwithpath:[[nsbundle mainbundle] pathforresource:@"audio2" oftype:@"mp3"]]
];

[self mergeaudiofiles:audiourls completion:^(nsurl *outputurl, nserror *error) {
    if (outputurl) {
        nslog(@"合并后的音频路径: %@", outputurl.path);
    }
}];

// 合并视频文件（支持 .mp4 等格式）
- (void)mergevideofiles:(nsarray<nsurl *> *)videourls completion:(void (^)(nsurl *outputurl, nserror *error))completion {
    // 1. 创建 avmutablecomposition 对象
    avmutablecomposition *composition = [avmutablecomposition composition];
    
    // 2. 添加视频轨道和音频轨道
    avmutablecompositiontrack *videotrack = [composition addmutabletrackwithmediatype:avmediatypevideo preferredtrackid:kcmpersistenttrackid_invalid];
    avmutablecompositiontrack *audiotrack = [composition addmutabletrackwithmediatype:avmediatypeaudio preferredtrackid:kcmpersistenttrackid_invalid];
    
    // 3. 插入每个视频文件到轨道中
    cmtime currenttime = kcmtimezero;
    for (nsurl *url in videourls) {
        avurlasset *asset = [avurlasset urlassetwithurl:url options:nil];
        avassettrack *videoassettrack = [[asset trackswithmediatype:avmediatypevideo] firstobject];
        avassettrack *audioassettrack = [[asset trackswithmediatype:avmediatypeaudio] firstobject];
        
        [videotrack inserttimerange:cmtimerangemake(kcmtimezero, asset.duration)
                         oftrack:videoassettrack
                          attime:currenttime
                           error:nil];
        [audiotrack inserttimerange:cmtimerangemake(kcmtimezero, asset.duration)
                         oftrack:audioassettrack
                          attime:currenttime
                           error:nil];
        currenttime = cmtimeadd(currenttime, asset.duration);
    }
    
    // 4. 导出合并后的视频
    avassetexportsession *exportsession = [[avassetexportsession alloc] initwithasset:composition presetname:avassetexportpresethighestquality];
    nsstring *outputpath = [nstemporarydirectory() stringbyappendingpathcomponent:@"mergedvideo.mp4"];
    exportsession.outputurl = [nsurl fileurlwithpath:outputpath];
    exportsession.outputfiletype = avfiletypempeg4;
    
    [exportsession exportasynchronouslywithcompletionhandler:^{
        if (exportsession.status == avassetexportsessionstatuscompleted) {
            nslog(@"视频合并成功: %@", outputpath);
            if (completion) completion([nsurl fileurlwithpath:outputpath], nil);
        } else {
            nserror *error = exportsession.error;
            nslog(@"视频合并失败: %@", error.localizeddescription);
            if (completion) completion(nil, error);
        }
    }];
}

// 示例：合并两个视频文件
nsarray<nsurl *> *videourls = @[
    [nsurl fileurlwithpath:[[nsbundle mainbundle] pathforresource:@"video1" oftype:@"mp4"]],
    [nsurl fileurlwithpath:[[nsbundle mainbundle] pathforresource:@"video2" oftype:@"mp4"]]
];

[self mergevideofiles:videourls completion:^(nsurl *outputurl, nserror *error) {
    if (outputurl) {
        nslog(@"合并后的视频路径: %@", outputurl.path);
    }
}];

// 合并音频与视频
- (void)mergeaudio:(nsurl *)audiourl withvideo:(nsurl *)videourl completion:(void (^)(nsurl *outputurl, nserror *error))completion {
    // 1. 创建 avmutablecomposition 对象
    avmutablecomposition *composition = [avmutablecomposition composition];
    
    // 2. 添加视频轨道
    avmutablecompositiontrack *videotrack = [composition addmutabletrackwithmediatype:avmediatypevideo preferredtrackid:kcmpersistenttrackid_invalid];
    avurlasset *videoasset = [avurlasset urlassetwithurl:videourl options:nil];
    avassettrack *videoassettrack = [[videoasset trackswithmediatype:avmediatypevideo] firstobject];
    [videotrack inserttimerange:cmtimerangemake(kcmtimezero, videoasset.duration)
                     oftrack:videoassettrack
                      attime:kcmtimezero
                       error:nil];
    
    // 3. 添加音频轨道
    avmutablecompositiontrack *audiotrack = [composition addmutabletrackwithmediatype:avmediatypeaudio preferredtrackid:kcmpersistenttrackid_invalid];
    avurlasset *audioasset = [avurlasset urlassetwithurl:audiourl options:nil];
    avassettrack *audioassettrack = [[audioasset trackswithmediatype:avmediatypeaudio] firstobject];
    [audiotrack inserttimerange:cmtimerangemake(kcmtimezero, audioasset.duration)
                     oftrack:audioassettrack
                      attime:kcmtimezero
                       error:nil];
    
    // 4. 导出合并后的音视频
    avassetexportsession *exportsession = [[avassetexportsession alloc] initwithasset:composition presetname:avassetexportpresethighestquality];
    nsstring *outputpath = [nstemporarydirectory() stringbyappendingpathcomponent:@"mergedmedia.mp4"];
    exportsession.outputurl = [nsurl fileurlwithpath:outputpath];
    exportsession.outputfiletype = avfiletypempeg4;
    
    [exportsession exportasynchronouslywithcompletionhandler:^{
        if (exportsession.status == avassetexportsessionstatuscompleted) {
            nslog(@"音视频合并成功: %@", outputpath);
            if (completion) completion([nsurl fileurlwithpath:outputpath], nil);
        } else {
            nserror *error = exportsession.error;
            nslog(@"音视频合并失败: %@", error.localizeddescription);
            if (completion) completion(nil, error);
        }
    }];
}

// 示例：合并一个音频和一个视频文件
nsurl *audiourl = [nsurl fileurlwithpath:[[nsbundle mainbundle] pathforresource:@"backgroundmusic" oftype:@"mp3"]];
nsurl *videourl = [nsurl fileurlwithpath:[[nsbundle mainbundle] pathforresource:@"video" oftype:@"mp4"]];

[self mergeaudio:audiourl withvideo:videourl completion:^(nsurl *outputurl, nserror *error) {
    if (outputurl) {
        nslog(@"合并后的音视频路径: %@", outputurl.path);
    }
}];