Video 创建视频文件的精确副本[ffmpeg]

我已经使用ffmpeg的库编写了一些代码，它对视频文件的每一帧进行解码，对其进行一些操作，最后对帧进行编码并将其多路复用到新的容器中。这一切都很有效。 我在这里试图解决的问题是如何使输出文件具有精确的流设置作为输入文件

如果我在我的文件上运行ffmpeg-I，我会得到以下结果-
1） 输入文件-

Duration: 00:00:30.95, start: 0.000000, bitrate: 1195 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv), 1280x720 [SAR 1:1 DAR 16:9], **996 kb/s**, 25 fps, 25 tbr, 25k tbn, **50 tbc (default)**
    <br>Metadata:
      creation_time   : 2015-09-30 06:33:24
      handler_name    : Mainconcept MP4 Video Media Handler
      encoder         : AVC Coding

Duration: 00:00:30.96, start: 0.000000, bitrate: 1225 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], **1032 kb/s**, 25.03 fps, 25 tbr, 25k tbn, **100 tbc (default)**<br>
    Metadata:
      handler_name    : VideoHandler

请注意，每次我运行代码时，比特率和TBC都在变化

我应该如何配置编码器，使输出文件与输入文件相同？当前用于配置编码器的代码如下所示-

    c = out_stream->codec;
    c->codec_id                = inputStream->codec->codec_id;
    c->bit_rate                = inputStream->codec->bit_rate;

    /* Resolution must be a multiple of two. */
    c->width                   = inputStream->codec->width;
    c->height                  = inputStream->codec->height;
    c->gop_size                = inputStream->codec->gop_size;

    c->time_base               = inputStream->codec->time_base;
    out_stream->time_base      = inputStream->time_base;

        av_stream_set_r_frame_rate(out_stream,av_stream_get_r_frame_rate(inputStream));
    out_stream->avg_frame_rate = inputStream->avg_frame_rate;

    c->pix_fmt                 = AV_PIX_FMT_YUV420P;
    c->sample_aspect_ratio.num = inputStream->codec->sample_aspect_ratio.num;
    c->sample_aspect_ratio.den = inputStream->codec->sample_aspect_ratio.den;
    c->ticks_per_frame         = inputStream->codec->ticks_per_frame;
    c->profile                 = inputStream->codec->profile;
    out_stream->duration       = inputStream->duration;

    c = out_stream->codec;
    c->codec_id                = inputStream->codec->codec_id;
    c->bit_rate                = inputStream->codec->bit_rate;

    /* Resolution must be a multiple of two. */
    c->width                   = inputStream->codec->width;
    c->height                  = inputStream->codec->height;
    c->gop_size                = inputStream->codec->gop_size;

    c->time_base               = inputStream->codec->time_base;
    out_stream->time_base      = inputStream->time_base;

        av_stream_set_r_frame_rate(out_stream,av_stream_get_r_frame_rate(inputStream));
    out_stream->avg_frame_rate = inputStream->avg_frame_rate;

    c->pix_fmt                 = AV_PIX_FMT_YUV420P;
    c->sample_aspect_ratio.num = inputStream->codec->sample_aspect_ratio.num;
    c->sample_aspect_ratio.den = inputStream->codec->sample_aspect_ratio.den;
    c->ticks_per_frame         = inputStream->codec->ticks_per_frame;
    c->profile                 = inputStream->codec->profile;
    out_stream->duration       = inputStream->duration;