| 1 | /* |
| 2 | * Copyright (c) 2010 Nicolas George |
| 3 | * Copyright (c) 2011 Stefano Sabatini |
| 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 | /** |
| 25 | * @file |
| 26 | * API example for decoding and filtering |
| 27 | * @example filtering_video.c |
| 28 | */ |
| 29 | |
| 30 | #define _XOPEN_SOURCE 600 /* for usleep */ |
| 31 | #include <unistd.h> |
| 32 | |
| 33 | #include <libavcodec/avcodec.h> |
| 34 | #include <libavformat/avformat.h> |
| 35 | #include <libavfilter/avfiltergraph.h> |
| 36 | #include <libavfilter/avcodec.h> |
| 37 | #include <libavfilter/buffersink.h> |
| 38 | #include <libavfilter/buffersrc.h> |
| 39 | #include <libavutil/opt.h> |
| 40 | |
| 41 | const char *filter_descr = "scale=78:24"; |
| 42 | |
| 43 | static AVFormatContext *fmt_ctx; |
| 44 | static AVCodecContext *dec_ctx; |
| 45 | AVFilterContext *buffersink_ctx; |
| 46 | AVFilterContext *buffersrc_ctx; |
| 47 | AVFilterGraph *filter_graph; |
| 48 | static int video_stream_index = -1; |
| 49 | static int64_t last_pts = AV_NOPTS_VALUE; |
| 50 | |
| 51 | static int open_input_file(const char *filename) |
| 52 | { |
| 53 | int ret; |
| 54 | AVCodec *dec; |
| 55 | |
| 56 | if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) { |
| 57 | av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n"); |
| 58 | return ret; |
| 59 | } |
| 60 | |
| 61 | if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) { |
| 62 | av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n"); |
| 63 | return ret; |
| 64 | } |
| 65 | |
| 66 | /* select the video stream */ |
| 67 | ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0); |
| 68 | if (ret < 0) { |
| 69 | av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n"); |
| 70 | return ret; |
| 71 | } |
| 72 | video_stream_index = ret; |
| 73 | dec_ctx = fmt_ctx->streams[video_stream_index]->codec; |
| 74 | av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0); |
| 75 | |
| 76 | /* init the video decoder */ |
| 77 | if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) { |
| 78 | av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n"); |
| 79 | return ret; |
| 80 | } |
| 81 | |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | static int init_filters(const char *filters_descr) |
| 86 | { |
| 87 | char args[512]; |
| 88 | int ret = 0; |
| 89 | AVFilter *buffersrc = avfilter_get_by_name("buffer"); |
| 90 | AVFilter *buffersink = avfilter_get_by_name("buffersink"); |
| 91 | AVFilterInOut *outputs = avfilter_inout_alloc(); |
| 92 | AVFilterInOut *inputs = avfilter_inout_alloc(); |
| 93 | enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE }; |
| 94 | |
| 95 | filter_graph = avfilter_graph_alloc(); |
| 96 | if (!outputs || !inputs || !filter_graph) { |
| 97 | ret = AVERROR(ENOMEM); |
| 98 | goto end; |
| 99 | } |
| 100 | |
| 101 | /* buffer video source: the decoded frames from the decoder will be inserted here. */ |
| 102 | snprintf(args, sizeof(args), |
| 103 | "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d", |
| 104 | dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt, |
| 105 | dec_ctx->time_base.num, dec_ctx->time_base.den, |
| 106 | dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den); |
| 107 | |
| 108 | ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in", |
| 109 | args, NULL, filter_graph); |
| 110 | if (ret < 0) { |
| 111 | av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n"); |
| 112 | goto end; |
| 113 | } |
| 114 | |
| 115 | /* buffer video sink: to terminate the filter chain. */ |
| 116 | ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out", |
| 117 | NULL, NULL, filter_graph); |
| 118 | if (ret < 0) { |
| 119 | av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n"); |
| 120 | goto end; |
| 121 | } |
| 122 | |
| 123 | ret = av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts, |
| 124 | AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN); |
| 125 | if (ret < 0) { |
| 126 | av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n"); |
| 127 | goto end; |
| 128 | } |
| 129 | |
| 130 | /* Endpoints for the filter graph. */ |
| 131 | outputs->name = av_strdup("in"); |
| 132 | outputs->filter_ctx = buffersrc_ctx; |
| 133 | outputs->pad_idx = 0; |
| 134 | outputs->next = NULL; |
| 135 | |
| 136 | inputs->name = av_strdup("out"); |
| 137 | inputs->filter_ctx = buffersink_ctx; |
| 138 | inputs->pad_idx = 0; |
| 139 | inputs->next = NULL; |
| 140 | |
| 141 | if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr, |
| 142 | &inputs, &outputs, NULL)) < 0) |
| 143 | goto end; |
| 144 | |
| 145 | if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0) |
| 146 | goto end; |
| 147 | |
| 148 | end: |
| 149 | avfilter_inout_free(&inputs); |
| 150 | avfilter_inout_free(&outputs); |
| 151 | |
| 152 | return ret; |
| 153 | } |
| 154 | |
| 155 | static void display_frame(const AVFrame *frame, AVRational time_base) |
| 156 | { |
| 157 | int x, y; |
| 158 | uint8_t *p0, *p; |
| 159 | int64_t delay; |
| 160 | |
| 161 | if (frame->pts != AV_NOPTS_VALUE) { |
| 162 | if (last_pts != AV_NOPTS_VALUE) { |
| 163 | /* sleep roughly the right amount of time; |
| 164 | * usleep is in microseconds, just like AV_TIME_BASE. */ |
| 165 | delay = av_rescale_q(frame->pts - last_pts, |
| 166 | time_base, AV_TIME_BASE_Q); |
| 167 | if (delay > 0 && delay < 1000000) |
| 168 | usleep(delay); |
| 169 | } |
| 170 | last_pts = frame->pts; |
| 171 | } |
| 172 | |
| 173 | /* Trivial ASCII grayscale display. */ |
| 174 | p0 = frame->data[0]; |
| 175 | puts("\033c"); |
| 176 | for (y = 0; y < frame->height; y++) { |
| 177 | p = p0; |
| 178 | for (x = 0; x < frame->width; x++) |
| 179 | putchar(" .-+#"[*(p++) / 52]); |
| 180 | putchar('\n'); |
| 181 | p0 += frame->linesize[0]; |
| 182 | } |
| 183 | fflush(stdout); |
| 184 | } |
| 185 | |
| 186 | int main(int argc, char **argv) |
| 187 | { |
| 188 | int ret; |
| 189 | AVPacket packet; |
| 190 | AVFrame *frame = av_frame_alloc(); |
| 191 | AVFrame *filt_frame = av_frame_alloc(); |
| 192 | int got_frame; |
| 193 | |
| 194 | if (!frame || !filt_frame) { |
| 195 | perror("Could not allocate frame"); |
| 196 | exit(1); |
| 197 | } |
| 198 | if (argc != 2) { |
| 199 | fprintf(stderr, "Usage: %s file\n", argv[0]); |
| 200 | exit(1); |
| 201 | } |
| 202 | |
| 203 | av_register_all(); |
| 204 | avfilter_register_all(); |
| 205 | |
| 206 | if ((ret = open_input_file(argv[1])) < 0) |
| 207 | goto end; |
| 208 | if ((ret = init_filters(filter_descr)) < 0) |
| 209 | goto end; |
| 210 | |
| 211 | /* read all packets */ |
| 212 | while (1) { |
| 213 | if ((ret = av_read_frame(fmt_ctx, &packet)) < 0) |
| 214 | break; |
| 215 | |
| 216 | if (packet.stream_index == video_stream_index) { |
| 217 | got_frame = 0; |
| 218 | ret = avcodec_decode_video2(dec_ctx, frame, &got_frame, &packet); |
| 219 | if (ret < 0) { |
| 220 | av_log(NULL, AV_LOG_ERROR, "Error decoding video\n"); |
| 221 | break; |
| 222 | } |
| 223 | |
| 224 | if (got_frame) { |
| 225 | frame->pts = av_frame_get_best_effort_timestamp(frame); |
| 226 | |
| 227 | /* push the decoded frame into the filtergraph */ |
| 228 | if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) { |
| 229 | av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n"); |
| 230 | break; |
| 231 | } |
| 232 | |
| 233 | /* pull filtered frames from the filtergraph */ |
| 234 | while (1) { |
| 235 | ret = av_buffersink_get_frame(buffersink_ctx, filt_frame); |
| 236 | if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) |
| 237 | break; |
| 238 | if (ret < 0) |
| 239 | goto end; |
| 240 | display_frame(filt_frame, buffersink_ctx->inputs[0]->time_base); |
| 241 | av_frame_unref(filt_frame); |
| 242 | } |
| 243 | av_frame_unref(frame); |
| 244 | } |
| 245 | } |
| 246 | av_free_packet(&packet); |
| 247 | } |
| 248 | end: |
| 249 | avfilter_graph_free(&filter_graph); |
| 250 | avcodec_close(dec_ctx); |
| 251 | avformat_close_input(&fmt_ctx); |
| 252 | av_frame_free(&frame); |
| 253 | av_frame_free(&filt_frame); |
| 254 | |
| 255 | if (ret < 0 && ret != AVERROR_EOF) { |
| 256 | fprintf(stderr, "Error occurred: %s\n", av_err2str(ret)); |
| 257 | exit(1); |
| 258 | } |
| 259 | |
| 260 | exit(0); |
| 261 | } |