ios ffmpeg 保存mp4

废话不说，直接上代码：

header写入成功：

-(void) init_mp4saving:(AVFormatContext*) pFormatCtx videoStreamin:(int) videoStream savenamein:(NSString *)savename {
    
    i_video_stream=pFormatCtx->streams[videoStream];
    int ret;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSCalendar *curCalendar = [NSCalendar currentCalendar];
    NSUInteger unitFlags = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
    NSDateComponents *dateComponents = [curCalendar components:unitFlags fromDate:[NSDate date]];
    movBasePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    filePath = [movBasePath stringByAppendingPathComponent:[NSString stringWithFormat:@"%ld-%ld-%ld.mp4",(long)dateComponents.hour, (long)dateComponents.minute, (long)dateComponents.second ]];
    [fileManager createFileAtPath:filePath contents:nil attributes:nil];
    const char *out_filename = [filePath UTF8String];//URL 路径
    //    av_register_all();//注册所有容器格式和CODEC
    avformat_alloc_output_context2(&outfmt_ctx, NULL, "mp4", out_filename);// 初始化一个用于输出的AVFormatContext结构体
    if (!outfmt_ctx) {
        NSLog(@ "Could not create output context\n");
    }
    outFormat = outfmt_ctx->oformat;
    AVCodec *codec = avcodec_find_decoder(AV_CODEC_ID_H264);//查找对应的解码器
    AVStream *out_stream = avformat_new_stream(outfmt_ctx, codec);//创建输出码流的AVStream
    if (!out_stream){
        NSLog(@ "Failed allocating output stream\n");
    }
    out_Cdc_ctx=out_stream->codec;
    out_Cdc_ctx->pix_fmt = i_video_stream->codec->pix_fmt;
    int FPS=30;
    out_Cdc_ctx = out_stream->codec;
    out_Cdc_ctx->extradata = i_video_stream->codec->extradata;
    out_Cdc_ctx->extradata_size = i_video_stream->codec->extradata_size;
    out_Cdc_ctx->bit_rate = 16*1000;
    out_Cdc_ctx->codec_id = i_video_stream->codec->codec_id;
    out_Cdc_ctx->codec_type = i_video_stream->codec->codec_type;
    out_Cdc_ctx->time_base.num =1;// i_video_stream->time_base.num;
    out_Cdc_ctx->time_base.den =25;// i_video_stream->time_base.den;
    out_Cdc_ctx->time_base = (AVRational){1,FPS};
    fprintf(stderr, "time_base.num = %d time_base.den = %d\n", out_Cdc_ctx->time_base.num, out_Cdc_ctx->time_base.den);
    out_Cdc_ctx->width = i_video_stream->codec->width;
    out_Cdc_ctx->height = i_video_stream->codec->height;
    out_Cdc_ctx->pix_fmt = i_video_stream->codec->pix_fmt;
    NSLog(@"mp4save width:%d height:%d pix_fmt: %d", out_Cdc_ctx->width, out_Cdc_ctx->height, out_Cdc_ctx->pix_fmt);
    out_Cdc_ctx->flags = i_video_stream->codec->flags;
    out_Cdc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;
    out_Cdc_ctx->me_range = i_video_stream->codec->me_range;
    out_Cdc_ctx->max_qdiff = i_video_stream->codec->max_qdiff;
    out_Cdc_ctx->qmin = i_video_stream->codec->qmin;
    out_Cdc_ctx->qmax = i_video_stream->codec->qmax;
    out_Cdc_ctx->qcompress = i_video_stream->codec->qcompress;
    //    ret = avcodec_copy_context(out_stream->codec, avcodec_alloc_context3(codec));//拷贝输入视频码流的AVCodecContex的数值t到输出视频的AVCodecContext。
    //    if (ret < 0)
    //    {
    //        NSLog(@ "Failed to copy context from input to output stream codec context\n");
    //    }
    //    out_stream->codec->pix_fmt = AV_PIX_FMT_YUV420P;//支持的像素格式
    //    out_stream->codec->flags = CODEC_FLAG_GLOBAL_HEADER;
    //    out_stream->codec->width = i_video_stream->codec->width;
    //    out_stream->codec->height = i_video_stream->codec->height;
    //    out_stream->time_base=i_video_stream->time_base;
    ////    out_stream->codec->time_base = (AVRational){1,FPS};
    ////    out_stream->codec->gop_size = FPS;
    //    out_stream->codec->bit_rate = 16*1000;
    //    out_stream->codec->codec_tag = 0;
    out_stream->codec->time_base = (AVRational){1,FPS};
    if (outfmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
    {
        out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
    }
    //    AVBitStreamFilterContext \*avFilter = av_bitstream_filter_init("h264_mp4toannexb");
    //    out_stream->codec->extradata_size = size;
    //    out_stream->codec->extradata = (uint8_t \*)av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
    //输出一下格式------------------
    av_dump_format(outfmt_ctx, 0, out_filename, 1);
    if (!(outFormat->flags & AVFMT_NOFILE))
    {
                ret = avio_open(&outfmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
                if (ret < 0)
                {
                    NSLog(@ "Could not open output file %@", out_filename);
                }
    }
    //    //写文件头（Write file header）
    AVDictionary* opt = NULL;
    //av_dict_set(&opt, "video_track_timescale", "25", 0);
    av_dict_set(&opt, "timescale", "25", 0);
    av_dict_set(&opt, "video_timescale", "25", 0);
    av_dict_set(&opt, "track_timescale", "25", 0);
        ret = avformat_write_header(outfmt_ctx, &opt);
        if (ret < 0)
        {
            NSLog(@ "Error occurred when opening output file\n");
        }
    //    input_video_stream = *(pFormatCtx->streams[videoStream]);
    //o_video_stream->time_base.num = 1;
    // o_video_stream->time_base.den = 25;
   }

保存帧和尾的代码：

  bool isIDR = true;
               unsigned char c[5] ={ 0x00, 0x00, 0x00, 0x01, 0x67};
               int n=0;
               for( n =0 ;n<5;n++){
                   if(vp.data[n]!=c[n]){
                       isIDR=false;break;
                   }
               }
               if(!isIDR){
                   if(record_status==1){
//                       sprintf(savename,"/sdcard/record_%d.mp4", ++record_num);
                        savename = [NSHomeDirectory()stringByAppendingPathComponent:@"Documents/Movie2.mp4"];
                       [self init_mp4saving:pFormatCtx videoStreamin:videoStream savenamein:savename ];
                       last_pts = 0;
                       last_dts = 0;
                       finished = 0;
                       NSLog(@"record_status ok  : record_status = %d \n",record_status);
                       record_status=2;
                   }
               }
               
               if(record_status==2){
                   frame_num++;
                   NSLog(@"record_status ok  : record_status = %d \n",record_status);
                   NSLog(@"frame index %d\n", frame_num);
                   packet.flags |= AV_PKT_FLAG_KEY;
                   packet.pts += last_pts;
//                   if (pCodecCtx->coded_frame->pts != AV_NOPTS_VALUE){
//                       packet.pts= av_rescale_q(pCodecCtx->coded_frame->pts, pCodecCtx->time_base, _videoStream->time_base);
//                       NSLog(@"frame index2 %d packet->pts %d\n", frame_num,packet.pts);
//                   }
                   packet.dts += last_dts;
                   packet.stream_index = 0;
                   packet.duration=1;
                   
                   av_interleaved_write_frame(outfmt_ctx, &packet);
                   if(frame_num>200){
                       record_status=3;
                   }
               }  else if(record_status==3){
                   // avformat_close_input(&i_fmt_ctx);
                   
                   NSLog(@"av_write_trailer!!!!!!!!!!  \n" );
                   av_write_trailer(outfmt_ctx);
                   
                   NSLog(@" avcodec_close!!!!!!!!  \n" );
                   avcodec_close(outfmt_ctx->streams[0]->codec);
                   
                   av_freep(&outfmt_ctx->streams[0]->codec);
                   av_freep(&outfmt_ctx->streams[0]);
                   avio_close(outfmt_ctx->pb);
                   av_free(outfmt_ctx);
                   record_status = 0;
                   NSLog(@"record_end\n");
               }