H.264多路複用從CCTV（HW）編碼器MP4，如何獲取AVCodecContext而額外::

我想從通過CCTV相機的SDK API接收的數據包混流到mp4文件的視頻。來自中央電視臺的信息流似乎只包含h264 I和P幀（不包含B幀）。H.264多路複用從CCTV（HW）編碼器MP4，如何獲取AVCodecContext而額外::

的問題是，該文件是不是在Daum的PotPlayer可玩的，當我離開AVCodecContext ::空而額外不過，我可以在VLC播放文件。如果我餵了額外的數據（可能不正確 - 我只是從硬件編碼器接收的數據包中的第一個50個字節複製），該文件是在可玩PotPlayer，但不是在VLC。

我不知道，如何正確地準備而額外。

下面的代碼示出了複用。

void WriteVideo() 
{ 
    AVFormatContext* formatContext = nullptr; 
    AVStream* stream = nullptr; 

    int ret = 0; 

    ret = avformat_alloc_output_context2(&formatContext, nullptr, "mp4", OUTPUT_V_FILE_NAME); 
    if (ret < 0) 
    { 
     fprintf(stderr, "Error occurred when allocating output context: %d\n", ret); 
     return; 
    } 

    stream = avformat_new_stream(formatContext, nullptr); 
    if (!stream) 
    { 
     avformat_free_context(formatContext); 
     formatContext = nullptr; 
     fprintf(stderr, "Error occurred creating new stream"); 
     return; 
    } 

    stream->codec->codec_tag = 0; 

    if (formatContext->oformat->flags & AVFMT_GLOBALHEADER) 
    { 
     stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER; 
    } 


    stream->codec->codec_type = AVMEDIA_TYPE_VIDEO; 
    stream->codec->codec_id = AV_CODEC_ID_H264; 
    stream->codec->pix_fmt = AV_PIX_FMT_YUV420P; 
    stream->codec->bit_rate = 4096000; // 8192000; // 4096000; // 384000; 
    stream->codec->width = 1920; // 352 
    stream->codec->height = 1080; // 288 
    stream->codec->gop_size = 50; 

    AVRational tb; 
    tb.num = 1; 
    tb.den = 25; 
    stream->codec->time_base = tb; 
    //stream->codec->field_order = AVFieldOrder::AV_FIELD_UNKNOWN; 
    //stream->codec->color_primaries = AVColorPrimaries::AVCOL_PRI_BT470BG; 
    //stream->codec->color_trc = AVColorTransferCharacteristic::AVCOL_TRC_GAMMA22; 
    //stream->codec->colorspace = AVColorSpace::AVCOL_SPC_BT470BG; 
    //stream->codec->chroma_sample_location = AVChromaLocation::AVCHROMA_LOC_CENTER; 
    AVRational aratio; 
    aratio.num = 1; 
    aratio.den = 1; 
    stream->codec->sample_aspect_ratio = aratio; 
    // stream->codec->delay = 0; 
    // stream->codec->color_range = AVColorRange::AVCOL_RANGE_MPEG; 

    av_dump_format(formatContext, 0, formatContext->filename, 1); 

    if (!(formatContext->oformat->flags & AVFMT_NOFILE)) 
    { 
     if (avio_open(&formatContext->pb, formatContext->filename, AVIO_FLAG_WRITE) < 0) 
     { 
      avformat_free_context(formatContext); 
      formatContext = nullptr; 
      fprintf(stderr, "Error occurred when opening output file."); 
      return; 

     } 
    } 

    avformat_write_header(formatContext, nullptr); 

    int frameIdx = 0; 
    int pts = 0; 
    int dts = 0; 
    int pkt_pos = 0; 
    int size = static_cast<int>(tmpRawFrameBuffer.size()); 

    AVPacket pkt = { 0 }; 
    av_init_packet(&pkt); 

    while (frameIdx < size) 
    { 
     pkt.data = tmpRawFrameBuffer[frameIdx]; 
     pkt.size = tmpRawFrameSizes[frameIdx]; 

     // debug purphose start 
     FILE* f; 
     char filename[MAX_PATH]; 
     sprintf_s(filename, MAX_PATH, OUTPUT_PACKET_FILE_PATTERN_NAME, frameIdx); 
     auto err = fopen_s(&f, filename, "wb"); 
     if (err != 0) 
     { 
      fprintf(stderr, "Could not open %s\n", OUTPUT_V_FILE_NAME); 
      exit(1); 
     } 

     fflush(stdout); 
     fwrite(pkt.data, 1, pkt.size, f); 
     fclose(f); 
     // debug purphose end 

     if (tmpRawFrameTypes[frameIdx] == VIDEO_I_FRAME) 
     { 
      pkt.flags |= AV_PKT_FLAG_KEY; 
      stream->codec->extradata_size = 50; 
      stream->codec->extradata = (uint8_t*)av_malloc(stream->codec->extradata_size); 
      memcpy(stream->codec->extradata, pkt.data, stream->codec->extradata_size); 
     } 
     pkt.pts = pts++; 
     pkt.dts = dts++; 
     /* rescale output packet timestamp values from codec to stream timebase */ 
     // av_packet_rescale_ts(&pkt, stream->codec->time_base, stream->time_base); 
     pkt.pts = av_rescale_q(pkt.pts, stream->codec->time_base, stream->time_base); 
     pkt.dts = av_rescale_q(pkt.dts, stream->codec->time_base, stream->time_base); 
     pkt.duration = 512; // should be calculated (derived from FPS 25, and 12800) 
     pkt.pos = -1; 
     pkt.stream_index = stream->index; 

     auto ret = av_write_frame(formatContext, &pkt); 
     if (ret < 0) 
     { 
      fprintf(stderr, "Error while writing video frame: %d\n", ret); 
      break; 
     } 
     av_packet_unref(&pkt); 
     ++frameIdx; 
    } 

    if (formatContext) 
    { 
     av_write_trailer(formatContext); 
     if (!(formatContext->oformat->flags & AVFMT_NOFILE)) avio_close(formatContext->pb); // close the output file 
     avformat_free_context(formatContext); 
     formatContext = nullptr; 
    } 
}

看來，從攝像頭（在tmpRawFrameBuffer矢量緩存）的數據包包含一些頭，但我不能夠分析他們，我不明白標題的含義。

I幀分組的第一字節看起來像轉儲波紋管：

00 00 01 FC 02 19 F0 87 A0 23 73 41 B6 C0 01 00 
00 00 00 01 67 4D 00 2A 95 A8 1E 00 89 F9 61 00 
00 03 00 01 00 00 03 00 32 84 00 00 00 01 68 EE 
3C 80 00 00 00 01 06 E5 01 19 80 00 00 00 01 65 
B8 00 00 08 C7 B0 23 FF F7 80 EE FE 63 B6 FB F5 
...

第一P幀的第一字節：

00 00 01 FD E5 24 00 00 00 00 00 01 61 E0 22 27 
FF D6 B0 D7 A4 2B 71 6B 19 C5 87 CA BB 8B BF 60 
14 59 B4 00 CC BC 0F C0 9E FD 84 B5 FB C4 83 DB 
5A 8B 80 FC EC D6 33 6D DE 10 96 6F 31 41 86 5C 
D4 22 F9 33 48 5B CE 77 38 17 0C D6 DD C7 6C E8 
...

下一個P幀的第一字節：

00 00 01 FD 5E 2F 00 00 00 00 00 01 61 E0 42 2F 
FF E7 06 DD 3C 66 26 15 94 93 7A F1 30 8A 6D B8 
AD DD 6B 0F 38 89 1D 1B 5C AC 44 6A D7 D1 21 3B 
E2 29 F8 14 BB 98 1C 06 4D B6 10 BB DB B9 CA 4F 
0B ED B1 A9 06 78 8C EC 06 6D 9F 4F 79 0C 35 5B 
...

...

開始下一個I幀：

00 00 01 FC 02 19 F0 87 A2 23 73 41 75 89 01 00 
00 00 00 01 67 4D 00 2A 95 A8 1E 00 89 F9 61 00 
00 03 00 01 00 00 03 00 32 84 00 00 00 01 68 EE 
3C 80 00 00 00 01 06 E5 01 1B 80 00 00 00 01 65 
B8 00 00 0F 07 F0 7F F6 6C 69 43 0F F0 28 DF 97 
...

有誰知道，如何正確填寫extradata？我只是做了第一個50字節的副本，但看起來，這是不正確的。（澳大利亞）（SPS）（PPS）（I-Slice）（PPS）（P-Slice）（PPS）（P-Slice）...（澳大利亞）（SPS）（PPS）可能的標題是（澳大利亞）（I-快訊）（https://stackoverflow.com/a/20686267/1699328），但是，我不知道，如何爲

stream->codec->extradata

我試圖得到一些啓示在這個崗位H.264 muxed to MP4 using libavformat not playing back提取數據，但我無法弄清楚什麼是spsFrameLen，ppsFrameLen和spsFrame的值。

合併器（第一和最後一個字節的MP4文件的）結果：

00 00 00 20 66 74 79 70 69 73 6F 6D 00 00 02 00 
69 73 6F 6D 69 73 6F 32 61 76 63 31 6D 70 34 31 
00 00 00 08 66 72 65 65 00 26 2E 6D 6D 64 61 74 
00 00 00 0D FC 02 19 F0 87 A0 23 73 41 B6 C0 01 
00 00 00 00 16 67 4D 00 2A 95 A8 1E 00 89 F9 61 
00 00 03 00 01 00 00 03 00 32 84 00 00 00 04 68 
EE 3C 80 00 00 00 05 06 E5 01 19 80 00 01 C0 87 
65 B8 00 00 08 C7 B0 23 FF F7 80 EE FE 63 B6 FB 
F5 97 A8 6B 48 39 61 99 FD 99 27 41 F2 78 54 EE 
D1 38 8E E8 18 DD 05 E4 BA F4 EB 69 CF 91 5C 34 
... 
... 
... 
95 B8 D8 D4 C3 AF A1 BA AC 28 F0 D4 D4 7C 48 9A 
0C A6 8C 4C 98 00 00 05 1E 6D 6F 6F 76 00 00 00 
6C 6D 76 68 64 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 03 E8 00 00 13 B0 00 01 00 00 01 00 00 
00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 40 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 02 00 00 04 48 74 72 61 
6B 00 00 00 5C 74 6B 68 64 00 00 00 03 00 00 00 
00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 13 
B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 40 00 00 00 07 80 00 00 04 38 00 00 00 00 00 
24 65 64 74 73 00 00 00 1C 65 6C 73 74 00 00 00 
00 00 00 00 01 00 00 13 B0 00 00 00 00 00 01 00 
00 00 00 03 C0 6D 64 69 61 00 00 00 20 6D 64 68 
64 00 00 00 00 00 00 00 00 00 00 00 00 00 00 32 
00 00 00 FC 00 55 C4 00 00 00 00 00 2D 68 64 6C 
72 00 00 00 00 00 00 00 00 76 69 64 65 00 00 00 
00 00 00 00 00 00 00 00 00 56 69 64 65 6F 48 61 
6E 64 6C 65 72 00 00 00 03 6B 6D 69 6E 66 00 00 
00 14 76 6D 68 64 00 00 00 01 00 00 00 00 00 00 
00 00 00 00 00 24 64 69 6E 66 00 00 00 1C 64 72 
65 66 00 00 00 00 00 00 00 01 00 00 00 0C 75 72 
6C 20 00 00 00 01 00 00 03 2B 73 74 62 6C 00 00 
00 93 73 74 73 64 00 00 00 00 00 00 00 01 00 00 
00 83 61 76 63 31 00 00 00 00 00 00 00 01 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 07 80 
04 38 00 48 00 00 00 48 00 00 00 00 00 00 00 01 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 18 FF FF 00 00 00 2D 61 76 63 43 01 4D 00 2A 
FF E1 00 16 67 4D 00 2A 95 A8 1E 00 89 F9 61 00 
00 03 00 01 00 00 03 00 32 84 01 00 04 68 EE 3C 
80 00 00 00 18 73 74 74 73 00 00 00 00 00 00 00 
01 00 00 00 7E 00 00 02 00 00 00 00 1C 73 74 73 
73 00 00 00 00 00 00 00 03 00 00 00 01 00 00 00 
33 00 00 00 65 00 00 00 34 73 74 73 63 00 00 00 
00 00 00 00 03 00 00 00 01 00 00 00 3B 00 00 00 
01 00 00 00 02 00 00 00 37 00 00 00 01 00 00 00 
03 00 00 00 0C 00 00 00 01 00 00 02 0C 73 74 73 
7A 00 00 00 00 00 00 00 00 00 00 00 7E 00 01 C0 
C7 00 00 24 EE 00 00 2F 67 00 00 1D 83 00 00 2E 
8F 00 00 30 B6 00 00 2F 44 00 00 2F 50 00 00 34 
6B 00 00 30 BE 00 00 31 0C 00 00 31 E7 00 00 30 
EA 00 00 31 4E 00 00 31 A8 00 00 32 21 00 00 31 
E6 00 00 31 B5 00 00 31 14 00 00 31 AF 00 00 31 
9D 00 00 33 60 00 00 32 11 00 00 32 4C 00 00 31 
F0 00 00 32 91 00 00 43 43 00 00 44 29 00 00 44 
EC 00 00 44 20 00 00 44 86 00 00 45 AD 00 00 47 
47 00 00 46 9F 00 00 46 D9 00 00 47 BE 00 00 48 
CD 00 00 3E 50 00 00 40 98 00 00 41 0E 00 00 40 
43 00 00 41 07 00 00 41 BB 00 00 41 FF 00 00 30 
5E 00 00 33 C7 00 00 34 B7 00 00 33 F1 00 00 33 
0D 00 00 32 DB 00 01 89 86 00 00 3B E1 00 00 3C 
55 00 00 3C 64 00 00 3C B7 00 00 3C FD 00 00 3E 
54 00 00 3E C5 00 00 3E 1C 00 00 3E 94 00 00 3E 
44 00 00 3E D7 00 00 3F CC 00 00 3E D6 00 00 40 
00 00 00 40 4D 00 00 40 04 00 00 3F A9 00 00 40 
82 00 00 41 0F 00 00 41 64 00 00 41 E5 00 00 42 
1E 00 00 42 2C 00 00 42 80 00 00 42 4D 00 00 43 
9F 00 00 43 DA 00 00 44 45 00 00 44 21 00 00 44 
B7 00 00 45 22 00 00 45 E3 00 00 45 BF 00 00 46 
18 00 00 47 4B 00 00 45 05 00 00 47 34 00 00 46 
60 00 00 46 97 00 00 46 66 00 00 46 29 00 00 46 
38 00 00 47 1D 00 00 47 42 00 00 47 18 00 00 47 
13 00 00 46 52 00 00 47 48 00 00 46 F8 00 01 BE 
E3 00 00 3F 56 00 00 3B 32 00 00 38 F8 00 00 37 
56 00 00 36 2D 00 00 35 DA 00 00 34 6B 00 00 3E 
BE 00 00 3E B5 00 00 3F 33 00 00 3F AC 00 00 3F 
38 00 00 42 32 00 01 1B DC 00 01 80 50 00 01 14 
06 00 00 C2 BB 00 00 96 12 00 00 6D EC 00 00 54 
E6 00 00 3A AC 00 00 32 00 00 00 2F 0A 00 00 2D 
F1 00 00 1B 7F 00 00 00 1C 73 74 63 6F 00 00 00 
00 00 00 00 03 00 00 00 30 00 0F DD AB 00 1F 7D 
9E 00 00 00 62 75 64 74 61 00 00 00 5A 6D 65 74 
61 00 00 00 00 00 00 00 21 68 64 6C 72 00 00 00 
00 00 00 00 00 6D 64 69 72 61 70 70 6C 00 00 00 
00 00 00 00 00 00 00 00 00 2D 69 6C 73 74 00 00 
00 25 A9 74 6F 6F 00 00 00 1D 64 61 74 61 00 00 
00 01 00 00 00 00 4C 61 76 66 35 37 2E 32 33 2E 
31 30 30

非常感謝任何建議。

來源

2016-05-25 Dom

首先，有一些數據是不是視頻流的一部分。你需要弄清楚如何去除這個問題。一切都可以在這裏得到解答：Possible Locations for Sequence/Picture Parameter Set(s) for H.264 Stream

來源

2016-05-25 22:51:44 szatmary

謝謝，我在寫這個問題之前經歷了幾次你的帖子，但它對我而言仍然不是那麼清楚...... 請問你能更具體些什麼數據不是流的一部分？我認爲這可以跳過： '00 00 01 FC 02 19 F0 87 A0 23 73 41 B6 C0 01 00 00 00 00 01 67 4D 00 2A 95 A8 1E 00 89 F9 61 00 00 03 00 01 00 00 03 00 32 84 00 00 00 01 68 EE 3C 80 00 00 00 01 06 E5 01 19 80' （第一個I-幀），然而，這個部分也有一些起始碼... 刪除它們不成問題。提前致謝！ – Dom

您需要用眼睛解析數據。閱讀數據包並查看數據。你看到一個開始，接下來會發生什麼？這是一項逆向工程工作。 00 00 00 01 67 - >這是一個SPS，你可以通過一眼就知道。 00 00 01 FC - > type 28，那就是undefined。現在尋找一個模式。你可以放棄未知類型的NALU嗎？也許。 – szatmary

H.264多路複用從CCTV（HW）編碼器MP4，如何獲取AVCodecContext而額外::

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