FFmpeg
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 FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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  if (ts == AV_NOPTS_VALUE) {
50  strcpy(buffer, " NOPTS ");
51  return;
52  }
53  ts= av_rescale_q(ts, base, (AVRational){1, 1000000});
54  snprintf(buffer, 60, "%c%"PRId64".%06"PRId64"", ts<0 ? '-' : ' ', FFABS(ts)/1000000, FFABS(ts)%1000000);
55 }
56 
57 int main(int argc, char **argv)
58 {
59  const char *filename;
61  int i, ret, stream_id;
62  int j;
63  int64_t timestamp;
65  int64_t seekfirst = AV_NOPTS_VALUE;
66  int firstback=0;
67  int frame_count = 1;
68  int duration = 4;
69 
70  for(i=2; i<argc; i+=2){
71  if (!strcmp(argv[i], "-seekforw")){
72  seekfirst = atoi(argv[i+1]);
73  } else if(!strcmp(argv[i], "-seekback")){
74  seekfirst = atoi(argv[i+1]);
75  firstback = 1;
76  } else if(!strcmp(argv[i], "-frames")){
77  frame_count = atoi(argv[i+1]);
78  } else if(!strcmp(argv[i], "-duration")){
79  duration = atoi(argv[i+1]);
80  } else if(!strcmp(argv[i], "-fastseek")) {
81  if (atoi(argv[i+1])) {
83  }
84  } else if(argv[i][0] == '-' && argv[i+1]) {
85  av_dict_set(&format_opts, argv[i] + 1, argv[i+1], 0);
86  } else {
87  argc = 1;
88  }
89  }
90 
91  av_dict_set(&format_opts, "channels", "1", 0);
92  av_dict_set(&format_opts, "sample_rate", "22050", 0);
93 
94  if (argc < 2) {
95  printf("usage: %s input_file\n"
96  "\n", argv[0]);
97  return 1;
98  }
99 
100  filename = argv[1];
101 
102  ret = avformat_open_input(&ic, filename, NULL, &format_opts);
104  if (ret < 0) {
105  fprintf(stderr, "cannot open %s\n", filename);
106  return 1;
107  }
108 
110  if (ret < 0) {
111  fprintf(stderr, "%s: could not find codec parameters\n", filename);
112  return 1;
113  }
114 
115  if(seekfirst != AV_NOPTS_VALUE){
116  if(firstback) avformat_seek_file(ic, -1, INT64_MIN, seekfirst, seekfirst, 0);
117  else avformat_seek_file(ic, -1, seekfirst, seekfirst, INT64_MAX, 0);
118  }
119  for(i=0; ; i++){
120  AVPacket pkt = { 0 };
121  AVStream *av_uninit(st);
122  char ts_buf[60];
123 
124  if(ret>=0){
125  for(j=0; j<frame_count; j++) {
126  ret= av_read_frame(ic, &pkt);
127  if(ret>=0){
128  char dts_buf[60];
129  st= ic->streams[pkt.stream_index];
130  ts_str(dts_buf, pkt.dts, st->time_base);
131  ts_str(ts_buf, pkt.pts, st->time_base);
132  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);
134  } else
135  printf("ret:%s", ret_str(ret)); // necessary to avoid trailing whitespace
136  printf("\n");
137  }
138  }
139 
140  if(i>25) break;
141 
142  stream_id= (i>>1)%(ic->nb_streams+1) - 1;
143  timestamp= (i*19362894167LL) % (duration*AV_TIME_BASE) - AV_TIME_BASE;
144  if(stream_id>=0){
145  st= ic->streams[stream_id];
146  timestamp= av_rescale_q(timestamp, AV_TIME_BASE_Q, st->time_base);
147  }
148  //FIXME fully test the new seek API
149  if(i&1) ret = avformat_seek_file(ic, stream_id, INT64_MIN, timestamp, timestamp, 0);
150  else ret = avformat_seek_file(ic, stream_id, timestamp, timestamp, INT64_MAX, 0);
151  ts_str(ts_buf, timestamp, stream_id < 0 ? AV_TIME_BASE_Q : st->time_base);
152  printf("ret:%-10s st:%2d flags:%d ts:%s\n", ret_str(ret), stream_id, i&1, ts_buf);
153  }
154 
156 
157  return 0;
158 }
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:634
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
AV_TIME_BASE_Q
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:260
ret_str
static const char * ret_str(int v)
Definition: seek.c:34
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1299
format_opts
AVDictionary * format_opts
Definition: cmdutils.c:70
base
uint8_t base
Definition: vp3data.h:141
mathematics.h
AVDictionary
Definition: dict.c:30
ts_str
static void ts_str(char buffer[60], int64_t ts, AVRational base)
Definition: seek.c:47
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1772
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4519
main
int main(int argc, char **argv)
Definition: seek.c:57
pkt
AVPacket * pkt
Definition: movenc.c:59
duration
int64_t duration
Definition: movenc.c:64
AVFormatContext::flags
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1362
av_rescale_q
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
AVFormatContext
Format I/O context.
Definition: avformat.h:1231
NULL
#define NULL
Definition: coverity.c:32
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1287
avformat_find_stream_info
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3650
AVPacket::size
int size
Definition: packet.h:370
avformat_alloc_context
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:211
avformat_seek_file
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:2570
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
printf
printf("static const uint8_t my_array[100] = {\n")
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:368
buffer
static char buffer[20]
Definition: seek.c:32
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
av_dict_free
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values.
Definition: dict.c:203
AVFMT_FLAG_FAST_SEEK
#define AVFMT_FLAG_FAST_SEEK
Enable fast, but inaccurate seeks for some formats.
Definition: avformat.h:1390
i
int i
Definition: input.c:407
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:362
avformat_open_input
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:547
AV_TIME_BASE
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:254
common.h
av_uninit
#define av_uninit(x)
Definition: attributes.h:154
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:873
avformat.h
AVPacket::stream_index
int stream_index
Definition: packet.h:371
AVPacket
This structure stores compressed data.
Definition: packet.h:346
av_dict_set
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:70
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:389
snprintf
#define snprintf
Definition: snprintf.h:34