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 
24 #include <libavutil/motion_vector.h>
25 #include <libavcodec/avcodec.h>
26 #include <libavformat/avformat.h>
27 
28 static AVFormatContext *fmt_ctx = NULL;
29 static AVCodecContext *video_dec_ctx = NULL;
30 static AVStream *video_stream = NULL;
31 static const char *src_filename = NULL;
32 
33 static int video_stream_idx = -1;
34 static AVFrame *frame = NULL;
35 static int video_frame_count = 0;
36 
decode_packet(const AVPacket *pkt)37 static int decode_packet(const AVPacket *pkt)
38 {
39     int ret = avcodec_send_packet(video_dec_ctx, pkt);
40     if (ret < 0) {
41         fprintf(stderr, "Error while sending a packet to the decoder: %s\n", av_err2str(ret));
42         return ret;
43     }
44 
45     while (ret >= 0)  {
46         ret = avcodec_receive_frame(video_dec_ctx, frame);
47         if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
48             break;
49         } else if (ret < 0) {
50             fprintf(stderr, "Error while receiving a frame from the decoder: %s\n", av_err2str(ret));
51             return ret;
52         }
53 
54         if (ret >= 0) {
55             int i;
56             AVFrameSideData *sd;
57 
58             video_frame_count++;
59             sd = av_frame_get_side_data(frame, AV_FRAME_DATA_MOTION_VECTORS);
60             if (sd) {
61                 const AVMotionVector *mvs = (const AVMotionVector *)sd->data;
62                 for (i = 0; i < sd->size / sizeof(*mvs); i++) {
63                     const AVMotionVector *mv = &mvs[i];
64                     printf("%d,%2d,%2d,%2d,%4d,%4d,%4d,%4d,0x%"PRIx64"\n",
65                         video_frame_count, mv->source,
66                         mv->w, mv->h, mv->src_x, mv->src_y,
67                         mv->dst_x, mv->dst_y, mv->flags);
68                 }
69             }
70             av_frame_unref(frame);
71         }
72     }
73 
74     return 0;
75 }
76 
open_codec_context(AVFormatContext *fmt_ctx, enum AVMediaType type)77 static int open_codec_context(AVFormatContext *fmt_ctx, enum AVMediaType type)
78 {
79     int ret;
80     AVStream *st;
81     AVCodecContext *dec_ctx = NULL;
82     const AVCodec *dec = NULL;
83     AVDictionary *opts = NULL;
84 
85     ret = av_find_best_stream(fmt_ctx, type, -1, -1, &dec, 0);
86     if (ret < 0) {
87         fprintf(stderr, "Could not find %s stream in input file '%s'\n",
88                 av_get_media_type_string(type), src_filename);
89         return ret;
90     } else {
91         int stream_idx = ret;
92         st = fmt_ctx->streams[stream_idx];
93 
94         dec_ctx = avcodec_alloc_context3(dec);
95         if (!dec_ctx) {
96             fprintf(stderr, "Failed to allocate codec\n");
97             return AVERROR(EINVAL);
98         }
99 
100         ret = avcodec_parameters_to_context(dec_ctx, st->codecpar);
101         if (ret < 0) {
102             fprintf(stderr, "Failed to copy codec parameters to codec context\n");
103             return ret;
104         }
105 
106         /* Init the video decoder */
107         av_dict_set(&opts, "flags2", "+export_mvs", 0);
108         ret = avcodec_open2(dec_ctx, dec, &opts);
109         av_dict_free(&opts);
110         if (ret < 0) {
111             fprintf(stderr, "Failed to open %s codec\n",
112                     av_get_media_type_string(type));
113             return ret;
114         }
115 
116         video_stream_idx = stream_idx;
117         video_stream = fmt_ctx->streams[video_stream_idx];
118         video_dec_ctx = dec_ctx;
119     }
120 
121     return 0;
122 }
123 
main(int argc, char **argv)124 int main(int argc, char **argv)
125 {
126     int ret = 0;
127     AVPacket *pkt = NULL;
128 
129     if (argc != 2) {
130         fprintf(stderr, "Usage: %s <video>\n", argv[0]);
131         exit(1);
132     }
133     src_filename = argv[1];
134 
135     if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
136         fprintf(stderr, "Could not open source file %s\n", src_filename);
137         exit(1);
138     }
139 
140     if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {
141         fprintf(stderr, "Could not find stream information\n");
142         exit(1);
143     }
144 
145     open_codec_context(fmt_ctx, AVMEDIA_TYPE_VIDEO);
146 
147     av_dump_format(fmt_ctx, 0, src_filename, 0);
148 
149     if (!video_stream) {
150         fprintf(stderr, "Could not find video stream in the input, aborting\n");
151         ret = 1;
152         goto end;
153     }
154 
155     frame = av_frame_alloc();
156     if (!frame) {
157         fprintf(stderr, "Could not allocate frame\n");
158         ret = AVERROR(ENOMEM);
159         goto end;
160     }
161 
162     pkt = av_packet_alloc();
163     if (!pkt) {
164         fprintf(stderr, "Could not allocate AVPacket\n");
165         ret = AVERROR(ENOMEM);
166         goto end;
167     }
168 
169     printf("framenum,source,blockw,blockh,srcx,srcy,dstx,dsty,flags\n");
170 
171     /* read frames from the file */
172     while (av_read_frame(fmt_ctx, pkt) >= 0) {
173         if (pkt->stream_index == video_stream_idx)
174             ret = decode_packet(pkt);
175         av_packet_unref(pkt);
176         if (ret < 0)
177             break;
178     }
179 
180     /* flush cached frames */
181     decode_packet(NULL);
182 
183 end:
184     avcodec_free_context(&video_dec_ctx);
185     avformat_close_input(&fmt_ctx);
186     av_frame_free(&frame);
187     av_packet_free(&pkt);
188     return ret < 0;
189 }
190