使用FFmpeg将mp4转为ts（代码实现）

 使用ffmpeg将mp4转为ts的命令格式如下：

点击(此处)折叠或打开

1. ffmpeg -i b.mp4 -codec copy -bsf h264_mp4toannexb a.ts

如果不使用-bsf h264_mp4toannexb参数，会提示错误，错误信息如下：

点击(此处)折叠或打开

1. ffmpeg -i b.mp4 -codec copy a.ts
   
2. ffmpeg version N-65108-gf2855eb Copyright (c) 2000-2014 the FFmpeg developers
   
3.   built on Jul 31 2014 02:29:27 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
   
4.   configuration: --prefix=/usr/local --enable-gpl --enable-nonfree --enable-libfaac --enable-libfreetype --enable-libx264 --enable-libx265
   
5.   libavutil 52. 93.100 / 52. 93.100
   
6.   libavcodec 55. 71.100 / 55. 71.100
   
7.   libavformat 55. 49.100 / 55. 49.100
   
8.   libavdevice 55. 13.102 / 55. 13.102
   
9.   libavfilter 4. 11.102 / 4. 11.102
   
10.   libswscale 2. 6.100 / 2. 6.100
    
11.   libswresample 0. 19.100 / 0. 19.100
    
12.   libpostproc 52. 3.100 / 52. 3.100
    
13. Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'b.mp4':
    
14.   Metadata:
    
15.     major_brand : isom
    
16.     minor_version : 512
    
17.     compatible_brands: isomiso2avc1mp41
    
18.     title : ????????
    
19.     encoder : Lavf55.49.100
    
20.     copyright : (C) 2004 HFD2B
    
21.   Duration: 00:04:09.44, start: 0.000000, bitrate: 568 kb/s
    
22.     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 592x336, 436 kb/s, 23.98 fps, 23.98 tbr, 785647.00 tbn, 47.95 tbc (default)
    
23.     Metadata:
    
24.       handler_name : VideoHandler
    
25.     Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 127 kb/s (default)
    
26.     Metadata:
    
27.       handler_name : SoundHandler
    
28. File 'a.ts' already exists. Overwrite ? [y/N] y
    
29. [adts @ 0x2269660] Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead.
    
30. Output #0, mpegts, to 'a.ts':
    
31.   Metadata:
    
32.     major_brand : isom
    
33.     minor_version : 512
    
34.     compatible_brands: isomiso2avc1mp41
    
35.     title : ????????
    
36.     copyright : (C) 2004 HFD2B
    
37.     encoder : Lavf55.49.100
    
38.     Stream #0:0(und): Video: h264 (avc1 / 0x31637661), yuv420p, 592x336, q=2-31, 436 kb/s, 23.98 fps, 90k tbn, 23.98 tbc (default)
    
39.     Metadata:
    
40.       handler_name : VideoHandler
    
41.     Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, 127 kb/s (default)
    
42.     Metadata:
    
43.       handler_name : SoundHandler
    
44. Stream mapping:
    
45.   Stream #0:0 -> #0:0 (copy)
    
46.   Stream #0:1 -> #0:1 (copy)
    
47. Press [q] to stop, [?] for help
    
48. [mpegts @ 0x22761a0] H.264 bitstream malformed, no startcode found, use the h264_mp4toannexb bitstream filter (-bsf h264_mp4toannexb)
    
49. av_interleaved_write_frame(): Invalid argument
    
50. frame= 1 fps=0.0 q=-1.0 Lsize= 1kB time=00:00:00.04 bitrate= 216.3kbits/s
    
51. video:1kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
    
52. Conversion

从上面的提示纤细可以看到，提示了：
[mpegts @ 0x22761a0] H.264 bitstream malformed, no startcode found, use the h264_mp4toannexb bitstream filter (-bsf h264_mp4toannexb)
av_interleaved_write_frame(): Invalid argument
主要是因为使用了mp4中的h264编码，而h264有两种封装：
一种是annexb模式，传统模式，有startcode，SPS和PPS是在ES中；另一种是mp4模式，一般mp4、mkv、avi会没有 startcode，SPS和PPS以及其它信息被封装在container中，每一个frame前面是这个frame的长度，很多解码器只支持 annexb这种模式，因此需要将mp4做转换；在ffmpeg中用h264_mp4toannexb_filter可以做转换；所以需要使用-bsf h264_mp4toannexb来进行转换；

下面介绍一下代码实现：
代码实现主要分为三个步骤：

点击(此处)折叠或打开

1. 1. 初始化filterav_bitstream_filter_init
   
2. 2. 使用filter转换av_bitstream_filter_filter
   
3. 3. 关闭filter av_bitstream_filter_close

其他与正常的转封装相同

点击(此处)折叠或打开

1. #include <stdio.h>
   
2. #include <stdlib.h>
   
3. #include <libavformat/avformat.h>
   
4. #include <libavutil/avutil.h>
   
5. 
   
6. #define FORMAT "mpegts"
   
7. #define OUTPUT_FILE "./fuck.ts"
   
8. #define INPUT_FILE "./a.avi"
   
9. 
   
10. int main(int argc, char *argv[])
    
11. {
    
12.     AVPacket pkt;
    
13.     AVFormatContext *input_fmtctx = NULL;
    
14.     AVFormatContext *output_fmtctx = NULL;
    
15.     AVCodecContext *enc_ctx = NULL;
    
16.     AVCodecContext *dec_ctx = NULL;
    
17.     AVCodec *encoder = NULL;
    
18.     AVBitStreamFilterContext * vbsf = NULL;
    
19.     int ret = 0;
    
20.     int i = 0;
    
21.     int have_key = 0;
    
22.     static int first_pkt = 1;
    
23. 
    
24.     av_register_all();
    
25. 
    
26.     if (avformat_open_input(&input_fmtctx, INPUT_FILE, NULL, NULL) < 0) {
    
27.         av_log(NULL, AV_LOG_ERROR, "Cannot open the file %s\n", "./a.mp4");
    
28.         return -ENOENT;
    
29.     }
    
30. 
    
31.     if (avformat_find_stream_info(input_fmtctx,0) < 0) {
    
32.         av_log(NULL, AV_LOG_ERROR, "bbs.chinaffmpeg.com 孙悟空 Failed to retrieve input stream information\n");
    
33.         return -EINVAL;
    
34.     }
    
35. 
    
36.     av_dump_format(input_fmtctx, NULL, INPUT_FILE, 0);
    
37. 
    
38.     if (avformat_alloc_output_context2(&output_fmtctx, NULL, FORMAT, OUTPUT_FILE) < 0) {
    
39.         av_log(NULL, AV_LOG_ERROR, "Cannot open the file %s bbs.chinaffmpeg.com 孙悟空\n", OUTPUT_FILE);
    
40.         return -ENOENT;
    
41.     }
    
42. 
    
43.     /* Process transcode parameters */
    
44.     for (i = 0; i < input_fmtctx->nb_streams; i++) {
    
45.         AVStream *out_stream = NULL;
    
46.         AVStream *in_stream = NULL;
    
47. 
    
48.         in_stream = input_fmtctx->streams[i];
    
49.         out_stream = avformat_new_stream(output_fmtctx, in_stream->codec->codec);
    
50.         if (out_stream < 0) {
    
51.             av_log(NULL, AV_LOG_ERROR, "bbs.chinaffmpeg.com 孙悟空 Alloc new Stream error\n");
    
52.             return -EINVAL;
    
53.         }
    
54. 
    
55.         avcodec_copy_context(output_fmtctx->streams[i]->codec, input_fmtctx->streams[i]->codec);
    
56. 
    
57.         out_stream->codec->codec_tag = 0;
    
58.         if (output_fmtctx->oformat->flags & AVFMT_GLOBALHEADER) {
    
59.             out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
    
60.         }
    
61.     }
    
62. 
    
63.     vbsf = av_bitstream_filter_init("h264_mp4toannexb");
    
64. 
    
65. 
    
66.     av_dump_format(output_fmtctx, NULL, OUTPUT_FILE, 1);
    
67. 
    
68.     if (avio_open2(&output_fmtctx->pb, OUTPUT_FILE, AVIO_FLAG_WRITE, &output_fmtctx->interrupt_callback, NULL) < 0) {
    
69.         av_log(NULL, AV_LOG_ERROR, "cannot open the output file '%s' bbs.chinaffmpeg.com 孙悟空\n", "./fuck.m3u8");
    
70.         return -ENOENT;
    
71.     }
    
72. 
    
73.     av_opt_set(output_fmtctx->priv_data, "hls_time", "10");
    
74. 
    
75.     if ((ret = avformat_write_header(output_fmtctx, NULL)) < 0) {
    
76.         av_log(NULL, AV_LOG_ERROR, "bbs.chinaffmpeg.com 孙悟空 Cannot write the header for the file '%s' ret = %d\n", "fuck.ts", ret);
    
77.         return -ENOENT;
    
78.     }
    
79. 
    
80.     while (1) {
    
81.         AVStream *in_stream = NULL;
    
82.         AVStream *out_stream = NULL;
    
83. 
    
84.         ret = av_read_frame(input_fmtctx, &pkt);
    
85.         if (ret < 0) {
    
86.             av_log(NULL, AV_LOG_ERROR, "read frame error %d bbs.chinaffmpeg.com 孙悟空\n", ret);
    
87.             break;
    
88.         }
    
89. 
    
90.         if (pkt.pts == AV_NOPTS_VALUE && first_pkt) {
    
91.             pkt.pts = pkt.dts;
    
92.             first_pkt = 0;
    
93.         }
    
94. 
    
95.         in_stream = input_fmtctx->streams[pkt.stream_index];
    
96.         out_stream = output_fmtctx->streams[pkt.stream_index];
    
97. 
    
98.         pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
    
99.         pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
    
100.         pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
     
101.         pkt.pos = -1;
     
102. 
     
103.         if (pkt.stream_index == 0) {
     
104. 
     
105.                 AVPacket fpkt = pkt;
     
106.                 int a = av_bitstream_filter_filter(vbsf,
     
107.                             out_stream->codec, NULL, &fpkt.data, &fpkt.size,
     
108.                                                pkt.data, pkt.size, pkt.flags & AV_PKT_FLAG_KEY);
     
109.                 pkt.data = fpkt.data;
     
110.                 pkt.size = fpkt.size;
     
111. 
     
112.         }
     
113. 
     
114.         ret = av_write_frame(output_fmtctx, &pkt);
     
115.         if (ret < 0) {
     
116.             av_log(NULL, AV_LOG_ERROR, "bbs.chinaffmpeg.com 孙悟空 Muxing Error\n");
     
117.             break;
     
118.         }
     
119. 
     
120.         av_free_packet(&pkt);
     
121.     }
     
122. 
     
123.     av_write_trailer(output_fmtctx);
     
124.     avformat_close_input(&input_fmtctx);
     
125.     avio_close(output_fmtctx->pb);
     
126.     avformat_free_context(output_fmtctx);
     
127.     av_bitstream_filter_close(vbsf);
     
128.     vbsf = NULL;
     
129. 
     
130.     return 0;
     
131. }