1 /*
2  * Copyright (c) 2013 Stefano Sabatini
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to deal
6  * in the Software without restriction, including without limitation the rights
7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8  * copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20  * THE SOFTWARE.
21  */
22 
23 /**
24  * @file
25  * libavformat/libavcodec demuxing and muxing API example.
26  *
27  * Remux streams from one container format to another.
28  * @example remuxing.c
29  */
30 
31 #include <libavutil/timestamp.h>
32 #include <libavformat/avformat.h>
33 
log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)34 static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
35 {
36     AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;
37 
38     printf("%s: pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
39            tag,
40            av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
41            av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
42            av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
43            pkt->stream_index);
44 }
45 
main(int argc, char **argv)46 int main(int argc, char **argv)
47 {
48     const AVOutputFormat *ofmt = NULL;
49     AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
50     AVPacket *pkt = NULL;
51     const char *in_filename, *out_filename;
52     int ret, i;
53     int stream_index = 0;
54     int *stream_mapping = NULL;
55     int stream_mapping_size = 0;
56 
57     if (argc < 3) {
58         printf("usage: %s input output\n"
59                "API example program to remux a media file with libavformat and libavcodec.\n"
60                "The output format is guessed according to the file extension.\n"
61                "\n", argv[0]);
62         return 1;
63     }
64 
65     in_filename  = argv[1];
66     out_filename = argv[2];
67 
68     pkt = av_packet_alloc();
69     if (!pkt) {
70         fprintf(stderr, "Could not allocate AVPacket\n");
71         return 1;
72     }
73 
74     if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
75         fprintf(stderr, "Could not open input file '%s'", in_filename);
76         goto end;
77     }
78 
79     if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
80         fprintf(stderr, "Failed to retrieve input stream information");
81         goto end;
82     }
83 
84     av_dump_format(ifmt_ctx, 0, in_filename, 0);
85 
86     avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
87     if (!ofmt_ctx) {
88         fprintf(stderr, "Could not create output context\n");
89         ret = AVERROR_UNKNOWN;
90         goto end;
91     }
92 
93     stream_mapping_size = ifmt_ctx->nb_streams;
94     stream_mapping = av_calloc(stream_mapping_size, sizeof(*stream_mapping));
95     if (!stream_mapping) {
96         ret = AVERROR(ENOMEM);
97         goto end;
98     }
99 
100     ofmt = ofmt_ctx->oformat;
101 
102     for (i = 0; i < ifmt_ctx->nb_streams; i++) {
103         AVStream *out_stream;
104         AVStream *in_stream = ifmt_ctx->streams[i];
105         AVCodecParameters *in_codecpar = in_stream->codecpar;
106 
107         if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO &&
108             in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
109             in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
110             stream_mapping[i] = -1;
111             continue;
112         }
113 
114         stream_mapping[i] = stream_index++;
115 
116         out_stream = avformat_new_stream(ofmt_ctx, NULL);
117         if (!out_stream) {
118             fprintf(stderr, "Failed allocating output stream\n");
119             ret = AVERROR_UNKNOWN;
120             goto end;
121         }
122 
123         ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
124         if (ret < 0) {
125             fprintf(stderr, "Failed to copy codec parameters\n");
126             goto end;
127         }
128         out_stream->codecpar->codec_tag = 0;
129     }
130     av_dump_format(ofmt_ctx, 0, out_filename, 1);
131 
132     if (!(ofmt->flags & AVFMT_NOFILE)) {
133         ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
134         if (ret < 0) {
135             fprintf(stderr, "Could not open output file '%s'", out_filename);
136             goto end;
137         }
138     }
139 
140     ret = avformat_write_header(ofmt_ctx, NULL);
141     if (ret < 0) {
142         fprintf(stderr, "Error occurred when opening output file\n");
143         goto end;
144     }
145 
146     while (1) {
147         AVStream *in_stream, *out_stream;
148 
149         ret = av_read_frame(ifmt_ctx, pkt);
150         if (ret < 0)
151             break;
152 
153         in_stream  = ifmt_ctx->streams[pkt->stream_index];
154         if (pkt->stream_index >= stream_mapping_size ||
155             stream_mapping[pkt->stream_index] < 0) {
156             av_packet_unref(pkt);
157             continue;
158         }
159 
160         pkt->stream_index = stream_mapping[pkt->stream_index];
161         out_stream = ofmt_ctx->streams[pkt->stream_index];
162         log_packet(ifmt_ctx, pkt, "in");
163 
164         /* copy packet */
165         av_packet_rescale_ts(pkt, in_stream->time_base, out_stream->time_base);
166         pkt->pos = -1;
167         log_packet(ofmt_ctx, pkt, "out");
168 
169         ret = av_interleaved_write_frame(ofmt_ctx, pkt);
170         /* pkt is now blank (av_interleaved_write_frame() takes ownership of
171          * its contents and resets pkt), so that no unreferencing is necessary.
172          * This would be different if one used av_write_frame(). */
173         if (ret < 0) {
174             fprintf(stderr, "Error muxing packet\n");
175             break;
176         }
177     }
178 
179     av_write_trailer(ofmt_ctx);
180 end:
181     av_packet_free(&pkt);
182 
183     avformat_close_input(&ifmt_ctx);
184 
185     /* close output */
186     if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
187         avio_closep(&ofmt_ctx->pb);
188     avformat_free_context(ofmt_ctx);
189 
190     av_freep(&stream_mapping);
191 
192     if (ret < 0 && ret != AVERROR_EOF) {
193         fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
194         return 1;
195     }
196 
197     return 0;
198 }
199