ffmpeg转码之TS转PS

Remux：无损的取出HD-DVD和BluRay-DVD里面的视频和音频数据，重新封装到另一种容器。

根据ffmpeg的sample例子remuxing写了一个ts转ps的例子。

写了一个ts转ps的demo。ts数据从文件中读取。

ffmpeg怎么从从内存中获取看这篇博文http://blog.youkuaiyun.com/rootusers/article/details/42551935

然后将ts流转换为ps流，存储在内存中。

下面是代码：

1. <pre name="code" class="cpp">extern "C"
2. {
3. #include "libavformat/avformat.h"
4. }
5. FILE *file = NULL;
6. int write_packet(void *opaque, uint8_t *buf, int buf_size)
7. {
8. //printf("write data\n");
9. if (file)
10. fwrite(buf, buf_size, 1, file);//可以写文件，也可以通过协议发出去
11. return 0;
12. }
14. int main(int argc, char **argv)
15. {
16. fopen_s(&file, "output.dat", "ab+");//输出ps数据到文件
17. if (file == NULL)
18. printf("open output file failed\n");
20. AVIOContext* pb = NULL;
21. AVOutputFormat *ofmt = (AVOutputFormat*)av_mallocz(sizeof(AVOutputFormat));//输出格式
23. AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
24. AVPacket pkt;
25. const char *in_filename, *out_filename;
26. int ret, i;
29. in_filename = "nihao.ts";//源文件
31. av_register_all();
33. if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
34. fprintf(stderr, "Could not open input file '%s'", in_filename);
35. goto end;
36. }
38. if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
39. fprintf(stderr, "Failed to retrieve input stream information");
40. goto end;
41. }
42. av_dump_format(ifmt_ctx, 0, in_filename, 0);
44. uint8_t* buf = (uint8_t*)av_mallocz(sizeof(uint8_t)* 32768);
45. pb = avio_alloc_context(buf, 32768, 0, NULL, NULL, write_packet, NULL);//
47. avformat_alloc_output_context2(&ofmt_ctx, NULL, "dvd", NULL/*out_filename*/);//设置输出视频的格式为Mpegs-ps，在ffmpeg定义为dvd
48. if (!ofmt_ctx) {
49. fprintf(stderr, "Could not create output context\n");
50. ret = AVERROR_UNKNOWN;
51. goto end;
52. }
53. ofmt_ctx->pb = pb;//这个是关键，指定ps输出的方式
54. //ofmt_ctx->flags = AVFMT_FLAG_CUSTOM_IO;
55. //dvd
56. printf("output format:%s[%s]\n", ofmt_ctx->oformat->name, ofmt_ctx->oformat->long_name);
57. ofmt = ofmt_ctx->oformat;
58. //输出环境上下文的初始化
59. for (i = 0; i < ifmt_ctx->nb_streams; i++) {
60. AVStream *in_stream = ifmt_ctx->streams[i];
61. //Add a new stream to a media file
62. AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
63. if (!out_stream) {
64. fprintf(stderr, "Failed allocating output stream\n");
65. ret = AVERROR_UNKNOWN;
66. goto end;
67. }
69. ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
70. if (ret < 0) {
71. fprintf(stderr, "Failed to copy context from input to output stream codec context\n");
72. goto end;
73. }
74. out_stream->codec->codec_tag = 0;
75. if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
76. out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
77. }
78. av_dump_format(ofmt_ctx, 0, NULL, 1);
80. ret = avformat_write_header(ofmt_ctx, NULL);
81. if (ret < 0) {
82. fprintf(stderr, "Error occurred when opening output file\n");
83. goto end;
84. }
85. //实现REMUXING
86. while (1) {
87. AVStream *in_stream, *out_stream;
89. ret = av_read_frame(ifmt_ctx, &pkt);
90. if (ret < 0)
91. break;
93. in_stream = ifmt_ctx->streams[pkt.stream_index];
94. out_stream = ofmt_ctx->streams[pkt.stream_index];
96. pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
97. pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
98. pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
99. pkt.pos = -1;
101. ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
102. if (ret < 0) {
103. fprintf(stderr, "Error muxing packet\n");
104. break;
105. }
106. av_free_packet(&pkt);
107. }
109. av_write_trailer(ofmt_ctx);
110. end:
112. avformat_close_input(&ifmt_ctx);
114. /* close output */
115. if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
116. avio_close(ofmt_ctx->pb);
117. avformat_free_context(ofmt_ctx);
119. if (ret < 0 && ret != AVERROR_EOF) {
120. return 1;
121. }
123. return 0;
124. }