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
!=c
){

                       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");

               }