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extract_mvs.c
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1 /*
2  * Copyright (c) 2012 Stefano Sabatini
3  * Copyright (c) 2014 Clément Bœsch
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a copy
6  * of this software and associated documentation files (the "Software"), to deal
7  * in the Software without restriction, including without limitation the rights
8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9  * copies of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21  * THE SOFTWARE.
22  */
23 
25 #include <libavformat/avformat.h>
26 
27 static AVFormatContext *fmt_ctx = NULL;
29 static AVStream *video_stream = NULL;
30 static const char *src_filename = NULL;
31 
32 static int video_stream_idx = -1;
33 static AVFrame *frame = NULL;
34 static AVPacket pkt;
35 static int video_frame_count = 0;
36 
37 static int decode_packet(int *got_frame, int cached)
38 {
39  int decoded = pkt.size;
40 
41  *got_frame = 0;
42 
43  if (pkt.stream_index == video_stream_idx) {
44  int ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt);
45  if (ret < 0) {
46  fprintf(stderr, "Error decoding video frame (%s)\n", av_err2str(ret));
47  return ret;
48  }
49 
50  if (*got_frame) {
51  int i;
52  AVFrameSideData *sd;
53 
56  if (sd) {
57  const AVMotionVector *mvs = (const AVMotionVector *)sd->data;
58  for (i = 0; i < sd->size / sizeof(*mvs); i++) {
59  const AVMotionVector *mv = &mvs[i];
60  printf("%d,%2d,%2d,%2d,%4d,%4d,%4d,%4d,0x%"PRIx64"\n",
62  mv->w, mv->h, mv->src_x, mv->src_y,
63  mv->dst_x, mv->dst_y, mv->flags);
64  }
65  }
66  }
67  }
68 
69  return decoded;
70 }
71 
72 static int open_codec_context(int *stream_idx,
73  AVFormatContext *fmt_ctx, enum AVMediaType type)
74 {
75  int ret;
76  AVStream *st;
77  AVCodecContext *dec_ctx = NULL;
78  AVCodec *dec = NULL;
79  AVDictionary *opts = NULL;
80 
81  ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
82  if (ret < 0) {
83  fprintf(stderr, "Could not find %s stream in input file '%s'\n",
85  return ret;
86  } else {
87  *stream_idx = ret;
88  st = fmt_ctx->streams[*stream_idx];
89 
90  /* find decoder for the stream */
91  dec_ctx = st->codec;
92  dec = avcodec_find_decoder(dec_ctx->codec_id);
93  if (!dec) {
94  fprintf(stderr, "Failed to find %s codec\n",
96  return AVERROR(EINVAL);
97  }
98 
99  /* Init the video decoder */
100  av_dict_set(&opts, "flags2", "+export_mvs", 0);
101  if ((ret = avcodec_open2(dec_ctx, dec, &opts)) < 0) {
102  fprintf(stderr, "Failed to open %s codec\n",
104  return ret;
105  }
106  }
107 
108  return 0;
109 }
110 
111 int main(int argc, char **argv)
112 {
113  int ret = 0, got_frame;
114 
115  if (argc != 2) {
116  fprintf(stderr, "Usage: %s <video>\n", argv[0]);
117  exit(1);
118  }
119  src_filename = argv[1];
120 
121  av_register_all();
122 
123  if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
124  fprintf(stderr, "Could not open source file %s\n", src_filename);
125  exit(1);
126  }
127 
128  if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {
129  fprintf(stderr, "Could not find stream information\n");
130  exit(1);
131  }
132 
134  video_stream = fmt_ctx->streams[video_stream_idx];
135  video_dec_ctx = video_stream->codec;
136  }
137 
138  av_dump_format(fmt_ctx, 0, src_filename, 0);
139 
140  if (!video_stream) {
141  fprintf(stderr, "Could not find video stream in the input, aborting\n");
142  ret = 1;
143  goto end;
144  }
145 
146  frame = av_frame_alloc();
147  if (!frame) {
148  fprintf(stderr, "Could not allocate frame\n");
149  ret = AVERROR(ENOMEM);
150  goto end;
151  }
152 
153  printf("framenum,source,blockw,blockh,srcx,srcy,dstx,dsty,flags\n");
154 
155  /* initialize packet, set data to NULL, let the demuxer fill it */
156  av_init_packet(&pkt);
157  pkt.data = NULL;
158  pkt.size = 0;
159 
160  /* read frames from the file */
161  while (av_read_frame(fmt_ctx, &pkt) >= 0) {
162  AVPacket orig_pkt = pkt;
163  do {
164  ret = decode_packet(&got_frame, 0);
165  if (ret < 0)
166  break;
167  pkt.data += ret;
168  pkt.size -= ret;
169  } while (pkt.size > 0);
170  av_free_packet(&orig_pkt);
171  }
172 
173  /* flush cached frames */
174  pkt.data = NULL;
175  pkt.size = 0;
176  do {
177  decode_packet(&got_frame, 1);
178  } while (got_frame);
179 
180 end:
181  avcodec_close(video_dec_ctx);
182  avformat_close_input(&fmt_ctx);
183  av_frame_free(&frame);
184  return ret < 0;
185 }