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
28static AVFormatContext *fmt_ctx = NULL;
29static AVCodecContext *video_dec_ctx = NULL;
30static AVStream *video_stream = NULL;
31static const char *src_filename = NULL;
32
33static int video_stream_idx = -1;
34static AVFrame *frame = NULL;
35static int video_frame_count = 0;
36
37static 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
77static 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
124int 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
183end:
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