Libav
seek.c
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1 /*
2  * Copyright (c) 2003 Fabrice Bellard
3  * Copyright (c) 2007 Michael Niedermayer
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <stdint.h>
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <string.h>
26 
27 #include "libavutil/common.h"
28 #include "libavutil/mathematics.h"
29 
30 #include "libavformat/avformat.h"
31 
32 static char buffer[20];
33 
34 static const char *ret_str(int v)
35 {
36  switch (v) {
37  case AVERROR_EOF: return "-EOF";
38  case AVERROR(EIO): return "-EIO";
39  case AVERROR(ENOMEM): return "-ENOMEM";
40  case AVERROR(EINVAL): return "-EINVAL";
41  default:
42  snprintf(buffer, sizeof(buffer), "%2d", v);
43  return buffer;
44  }
45 }
46 
47 static void ts_str(char buffer[60], int64_t ts, AVRational base)
48 {
49  double tsval;
50  if (ts == AV_NOPTS_VALUE) {
51  strcpy(buffer, " NOPTS ");
52  return;
53  }
54  tsval = ts * av_q2d(base);
55  snprintf(buffer, 60, "%9f", tsval);
56 }
57 
58 int main(int argc, char **argv)
59 {
60  const char *filename;
61  AVFormatContext *ic = NULL;
62  int i, ret, stream_id;
63  int64_t timestamp;
65 
66  av_dict_set(&format_opts, "channels", "1", 0);
67  av_dict_set(&format_opts, "sample_rate", "22050", 0);
68 
69  /* initialize libavcodec, and register all codecs and formats */
71 
72  if (argc != 2) {
73  printf("usage: %s input_file\n"
74  "\n", argv[0]);
75  return 1;
76  }
77 
78  filename = argv[1];
79 
80  ret = avformat_open_input(&ic, filename, NULL, &format_opts);
81  av_dict_free(&format_opts);
82  if (ret < 0) {
83  fprintf(stderr, "cannot open %s\n", filename);
84  return 1;
85  }
86 
88  if (ret < 0) {
89  fprintf(stderr, "%s: could not find codec parameters\n", filename);
90  return 1;
91  }
92 
93  for(i=0; ; i++){
94  AVPacket pkt = { 0 };
95  AVStream *av_uninit(st);
96  char ts_buf[60];
97 
98  if(ret>=0){
99  ret= av_read_frame(ic, &pkt);
100  if(ret>=0){
101  char dts_buf[60];
102  st= ic->streams[pkt.stream_index];
103  ts_str(dts_buf, pkt.dts, st->time_base);
104  ts_str(ts_buf, pkt.pts, st->time_base);
105  printf("ret:%-10s st:%2d flags:%d dts:%s pts:%s pos:%7" PRId64 " size:%6d", ret_str(ret), pkt.stream_index, pkt.flags, dts_buf, ts_buf, pkt.pos, pkt.size);
106  av_packet_unref(&pkt);
107  } else
108  printf("ret:%s", ret_str(ret)); // necessary to avoid trailing whitespace
109  printf("\n");
110  }
111 
112  if(i>25) break;
113 
114  stream_id= (i>>1)%(ic->nb_streams+1) - 1;
115  timestamp= (i*19362894167LL) % (4*AV_TIME_BASE) - AV_TIME_BASE;
116  if(stream_id>=0){
117  st= ic->streams[stream_id];
118  timestamp= av_rescale_q(timestamp, AV_TIME_BASE_Q, st->time_base);
119  }
120  //FIXME fully test the new seek API
121  if(i&1) ret = avformat_seek_file(ic, stream_id, INT64_MIN, timestamp, timestamp, 0);
122  else ret = avformat_seek_file(ic, stream_id, timestamp, timestamp, INT64_MAX, 0);
123  ts_str(ts_buf, timestamp, stream_id < 0 ? AV_TIME_BASE_Q : st->time_base);
124  printf("ret:%-10s st:%2d flags:%d ts:%s\n", ret_str(ret), stream_id, i&1, ts_buf);
125  }
126 
128 
129  return 0;
130 }
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1366
int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:284
int size
Definition: avcodec.h:1347
Format I/O context.
Definition: avformat.h:940
static char buffer[20]
Definition: seek.c:32
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1008
static double av_q2d(AVRational a)
Convert rational to double.
Definition: rational.h:69
#define AVERROR_EOF
End of file.
Definition: error.h:51
AVDictionary * format_opts
Definition: cmdutils.c:59
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:99
#define AVERROR(e)
Definition: error.h:43
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values. ...
Definition: dict.c:175
static void ts_str(char buffer[60], int64_t ts, AVRational base)
Definition: seek.c:47
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1352
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:996
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:241
Stream structure.
Definition: avformat.h:705
NULL
Definition: eval.c:55
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:247
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:347
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:68
rational number numerator/denominator
Definition: rational.h:43
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1021
int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: utils.c:1575
Main libavformat public API header.
common internal and external API header
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:2092
static const char * ret_str(int v)
Definition: seek.c:34
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:2626
int main(int argc, char **argv)
Definition: seek.c:58
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1345
#define av_uninit(x)
Definition: attributes.h:109
int stream_index
Definition: avcodec.h:1348
This structure stores compressed data.
Definition: avcodec.h:1323
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
Definition: allformats.c:44
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1339
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:235