diff options
Diffstat (limited to 'doc/examples/extract_mvs.c')
| -rw-r--r-- | doc/examples/extract_mvs.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/doc/examples/extract_mvs.c b/doc/examples/extract_mvs.c new file mode 100644 index 0000000000..d6fd61335e --- /dev/null +++ b/doc/examples/extract_mvs.c @@ -0,0 +1,185 @@ +/* + * Copyright (c) 2012 Stefano Sabatini + * Copyright (c) 2014 Clément Bœsch + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include <libavutil/motion_vector.h> +#include <libavformat/avformat.h> + +static AVFormatContext *fmt_ctx = NULL; +static AVCodecContext *video_dec_ctx = NULL; +static AVStream *video_stream = NULL; +static const char *src_filename = NULL; + +static int video_stream_idx = -1; +static AVFrame *frame = NULL; +static AVPacket pkt; +static int video_frame_count = 0; + +static int decode_packet(int *got_frame, int cached) +{ + int decoded = pkt.size; + + *got_frame = 0; + + if (pkt.stream_index == video_stream_idx) { + int ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt); + if (ret < 0) { + fprintf(stderr, "Error decoding video frame (%s)\n", av_err2str(ret)); + return ret; + } + + if (*got_frame) { + int i; + AVFrameSideData *sd; + + video_frame_count++; + sd = av_frame_get_side_data(frame, AV_FRAME_DATA_MOTION_VECTORS); + if (sd) { + const AVMotionVector *mvs = (const AVMotionVector *)sd->data; + for (i = 0; i < sd->size / sizeof(*mvs); i++) { + const AVMotionVector *mv = &mvs[i]; + printf("%d,%2d,%2d,%2d,%4d,%4d,%4d,%4d,0x%"PRIx64"\n", + video_frame_count, mv->source, + mv->w, mv->h, mv->src_x, mv->src_y, + mv->dst_x, mv->dst_y, mv->flags); + } + } + } + } + + return decoded; +} + +static int open_codec_context(int *stream_idx, + AVFormatContext *fmt_ctx, enum AVMediaType type) +{ + int ret; + AVStream *st; + AVCodecContext *dec_ctx = NULL; + AVCodec *dec = NULL; + AVDictionary *opts = NULL; + + ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0); + if (ret < 0) { + fprintf(stderr, "Could not find %s stream in input file '%s'\n", + av_get_media_type_string(type), src_filename); + return ret; + } else { + *stream_idx = ret; + st = fmt_ctx->streams[*stream_idx]; + + /* find decoder for the stream */ + dec_ctx = st->codec; + dec = avcodec_find_decoder(dec_ctx->codec_id); + if (!dec) { + fprintf(stderr, "Failed to find %s codec\n", + av_get_media_type_string(type)); + return AVERROR(EINVAL); + } + + /* Init the video decoder */ + av_dict_set(&opts, "flags2", "+export_mvs", 0); + if ((ret = avcodec_open2(dec_ctx, dec, &opts)) < 0) { + fprintf(stderr, "Failed to open %s codec\n", + av_get_media_type_string(type)); + return ret; + } + } + + return 0; +} + +int main(int argc, char **argv) +{ + int ret = 0, got_frame; + + if (argc != 2) { + fprintf(stderr, "Usage: %s <video>\n", argv[0]); + exit(1); + } + src_filename = argv[1]; + + av_register_all(); + + if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) { + fprintf(stderr, "Could not open source file %s\n", src_filename); + exit(1); + } + + if (avformat_find_stream_info(fmt_ctx, NULL) < 0) { + fprintf(stderr, "Could not find stream information\n"); + exit(1); + } + + if (open_codec_context(&video_stream_idx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) { + video_stream = fmt_ctx->streams[video_stream_idx]; + video_dec_ctx = video_stream->codec; + } + + av_dump_format(fmt_ctx, 0, src_filename, 0); + + if (!video_stream) { + fprintf(stderr, "Could not find video stream in the input, aborting\n"); + ret = 1; + goto end; + } + + frame = av_frame_alloc(); + if (!frame) { + fprintf(stderr, "Could not allocate frame\n"); + ret = AVERROR(ENOMEM); + goto end; + } + + printf("framenum,source,blockw,blockh,srcx,srcy,dstx,dsty,flags\n"); + + /* initialize packet, set data to NULL, let the demuxer fill it */ + av_init_packet(&pkt); + pkt.data = NULL; + pkt.size = 0; + + /* read frames from the file */ + while (av_read_frame(fmt_ctx, &pkt) >= 0) { + AVPacket orig_pkt = pkt; + do { + ret = decode_packet(&got_frame, 0); + if (ret < 0) + break; + pkt.data += ret; + pkt.size -= ret; + } while (pkt.size > 0); + av_free_packet(&orig_pkt); + } + + /* flush cached frames */ + pkt.data = NULL; + pkt.size = 0; + do { + decode_packet(&got_frame, 1); + } while (got_frame); + +end: + avcodec_close(video_dec_ctx); + avformat_close_input(&fmt_ctx); + av_frame_free(&frame); + return ret < 0; +} |